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<record><TEI><teiHeader><fileDesc><titleStmt><title xml:lang="en">C<sub>2</sub>-Ceramide-Induced Rb-Dominant Senescence-Like Phenotype Leads to Human Breast Cancer MCF-7 Escape from <italic>p</italic>53-Dependent Cell Death</title><author><name sortKey="Chang, Wen Tsan" sort="Chang, Wen Tsan" uniqKey="Chang W" first="Wen-Tsan" last="Chang">Wen-Tsan Chang</name><affiliation><nlm:aff id="af1-ijms-20-04292">Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af2-ijms-20-04292">Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Wu, Chang Yi" sort="Wu, Chang Yi" uniqKey="Wu C" first="Chang-Yi" last="Wu">Chang-Yi Wu</name><affiliation><nlm:aff id="af3-ijms-20-04292">Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Lin, Yin Chieh" sort="Lin, Yin Chieh" uniqKey="Lin Y" first="Yin-Chieh" last="Lin">Yin-Chieh Lin</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Wu, Min Tsui" sort="Wu, Min Tsui" uniqKey="Wu M" first="Min-Tsui" last="Wu">Min-Tsui Wu</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Su, Kai Li" sort="Su, Kai Li" uniqKey="Su K" first="Kai-Li" last="Su">Kai-Li Su</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Yuan, Shyng Shiou" sort="Yuan, Shyng Shiou" uniqKey="Yuan S" first="Shyng-Shiou" last="Yuan">Shyng-Shiou Yuan</name><affiliation><nlm:aff id="af5-ijms-20-04292">Translational Research Center, Cancer Center, Department of Medical Research, Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Wang, Hui Min David" sort="Wang, Hui Min David" uniqKey="Wang H" first="Hui-Min David" last="Wang">Hui-Min David Wang</name><affiliation><nlm:aff id="af6-ijms-20-04292">Graduate Institute of Biomedical Engineering, National Chung Hsing University, Taichung 402, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Fong, Yao" sort="Fong, Yao" uniqKey="Fong Y" first="Yao" last="Fong">Yao Fong</name><affiliation><nlm:aff id="af7-ijms-20-04292">Chest Surgery, Chi-Mei Medical Center, Yung Kang City, Tainan 901, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Lin, Yi Hsiung" sort="Lin, Yi Hsiung" uniqKey="Lin Y" first="Yi-Hsiung" last="Lin">Yi-Hsiung Lin</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af8-ijms-20-04292">Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af9-ijms-20-04292">Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Chiu, Chien Chih" sort="Chiu, Chien Chih" uniqKey="Chiu C" first="Chien-Chih" last="Chiu">Chien-Chih Chiu</name><affiliation><nlm:aff id="af3-ijms-20-04292">Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af9-ijms-20-04292">Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af10-ijms-20-04292">Center for Stem Cell Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af11-ijms-20-04292">Translational Research Center and Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">PMC</idno><idno type="pmid">31480728</idno><idno type="pmc">6747432</idno><idno type="url">http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6747432</idno><idno type="RBID">PMC:6747432</idno><idno type="doi">10.3390/ijms20174292</idno><date when="2019">2019</date><idno type="wicri:Area/Pmc/Corpus">000610</idno><idno type="wicri:explorRef" wicri:stream="Pmc" wicri:step="Corpus" wicri:corpus="PMC">000610</idno></publicationStmt><sourceDesc><biblStruct><analytic><title xml:lang="en" level="a" type="main">C<sub>2</sub>-Ceramide-Induced Rb-Dominant Senescence-Like Phenotype Leads to Human Breast Cancer MCF-7 Escape from <italic>p</italic>53-Dependent Cell Death</title><author><name sortKey="Chang, Wen Tsan" sort="Chang, Wen Tsan" uniqKey="Chang W" first="Wen-Tsan" last="Chang">Wen-Tsan Chang</name><affiliation><nlm:aff id="af1-ijms-20-04292">Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af2-ijms-20-04292">Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Wu, Chang Yi" sort="Wu, Chang Yi" uniqKey="Wu C" first="Chang-Yi" last="Wu">Chang-Yi Wu</name><affiliation><nlm:aff id="af3-ijms-20-04292">Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Lin, Yin Chieh" sort="Lin, Yin Chieh" uniqKey="Lin Y" first="Yin-Chieh" last="Lin">Yin-Chieh Lin</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Wu, Min Tsui" sort="Wu, Min Tsui" uniqKey="Wu M" first="Min-Tsui" last="Wu">Min-Tsui Wu</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Su, Kai Li" sort="Su, Kai Li" uniqKey="Su K" first="Kai-Li" last="Su">Kai-Li Su</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Yuan, Shyng Shiou" sort="Yuan, Shyng Shiou" uniqKey="Yuan S" first="Shyng-Shiou" last="Yuan">Shyng-Shiou Yuan</name><affiliation><nlm:aff id="af5-ijms-20-04292">Translational Research Center, Cancer Center, Department of Medical Research, Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Wang, Hui Min David" sort="Wang, Hui Min David" uniqKey="Wang H" first="Hui-Min David" last="Wang">Hui-Min David Wang</name><affiliation><nlm:aff id="af6-ijms-20-04292">Graduate Institute of Biomedical Engineering, National Chung Hsing University, Taichung 402, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Fong, Yao" sort="Fong, Yao" uniqKey="Fong Y" first="Yao" last="Fong">Yao Fong</name><affiliation><nlm:aff id="af7-ijms-20-04292">Chest Surgery, Chi-Mei Medical Center, Yung Kang City, Tainan 901, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Lin, Yi Hsiung" sort="Lin, Yi Hsiung" uniqKey="Lin Y" first="Yi-Hsiung" last="Lin">Yi-Hsiung Lin</name><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af8-ijms-20-04292">Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af9-ijms-20-04292">Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author><author><name sortKey="Chiu, Chien Chih" sort="Chiu, Chien Chih" uniqKey="Chiu C" first="Chien-Chih" last="Chiu">Chien-Chih Chiu</name><affiliation><nlm:aff id="af3-ijms-20-04292">Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af4-ijms-20-04292">Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af9-ijms-20-04292">Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af10-ijms-20-04292">Center for Stem Cell Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan</nlm:aff></affiliation><affiliation><nlm:aff id="af11-ijms-20-04292">Translational Research Center and Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan</nlm:aff></affiliation></author></analytic><series><title level="j">International Journal of Molecular Sciences</title><idno type="eISSN">1422-0067</idno><imprint><date when="2019">2019</date></imprint></series></biblStruct></sourceDesc></fileDesc><profileDesc><textClass></textClass></profileDesc></teiHeader><front><div type="abstract" xml:lang="en"><p>Ceramide is a sphingolipid which regulates a variety of signaling pathways in eukaryotic cells. Exogenous ceramide has been shown to induce cellular apoptosis. In this study, we observed that exogenous ceramide induced two distinct morphologies of cell fate following C<sub>2</sub>-ceramide treatment between the two breast cancer cell lines MCF-7 (wild type <italic>p</italic>53) and MDA-MB-231 (mutant <italic>p</italic>53) cells. The growth assessment showed that C<sub>2</sub>-ceramide caused significant growth inhibition and apoptosis in MDA-MB-231 cells through down-regulating the expression of mutant <italic>p</italic>53 whereas up-regulating the expression of pro-apoptotic Bad, and the proteolytic activation of caspase-3. However, senescence-associated (SA)-β-galactosidase (β-gal) was regulated in MCF-7 cells after C<sub>2</sub>-ceramide treatment. The results of proliferation and apoptosis assays showed that MCF-7 cells were more resistant to C<sub>2</sub>-ceramide treatment compared to MDA-MB-231 cells. Furthermore, C<sub>2</sub>-ceramide treatment induced a time-responsive increase in Rb protein, a key regulator of senescence accompanied with the upregulation of both mRNA level and protein level of SA-genes PAI-1 and TGaseII in MCF-7 but not in MDA-MB-231 cells, suggesting that some cancer cells escape apoptosis through modulating senescence-like phenotype. The results of our present study depicted the mechanism of C<sub>2</sub>-ceramide-resistant breast cancer cells, which might benefit the strategic development of ceramide-based chemotherapeutics against cancer in the future.</p></div></front><back><div1 type="bibliography"><listBibl><biblStruct><analytic><author><name sortKey="Akram, M" uniqKey="Akram M">M. Akram</name></author><author><name sortKey="Iqbal, M" uniqKey="Iqbal M">M. Iqbal</name></author><author><name sortKey="Daniyal, M" uniqKey="Daniyal M">M. Daniyal</name></author><author><name sortKey="Khan, A U" uniqKey="Khan A">A.U. Khan</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Hayflick, L" uniqKey="Hayflick L">L. Hayflick</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Gewirtz, D A" uniqKey="Gewirtz D">D.A. Gewirtz</name></author><author><name sortKey="Holt, S E" uniqKey="Holt S">S.E. Holt</name></author><author><name sortKey="Elmore, L W" uniqKey="Elmore L">L.W. Elmore</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Mathon, N F" uniqKey="Mathon N">N.F. Mathon</name></author><author><name sortKey="Lloyd, A C" uniqKey="Lloyd A">A.C. Lloyd</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Choudhury, A R" uniqKey="Choudhury A">A.R. Choudhury</name></author><author><name sortKey="Ju, Z" uniqKey="Ju Z">Z. Ju</name></author><author><name sortKey="Djojosubroto, M W" uniqKey="Djojosubroto M">M.W. Djojosubroto</name></author><author><name sortKey="Schienke, A" uniqKey="Schienke A">A. Schienke</name></author><author><name sortKey="Lechel, A" uniqKey="Lechel A">A. Lechel</name></author><author><name sortKey="Schaetzlein, S" uniqKey="Schaetzlein S">S. Schaetzlein</name></author><author><name sortKey="Jiang, H" uniqKey="Jiang H">H. Jiang</name></author><author><name sortKey="Stepczynska, A" uniqKey="Stepczynska A">A. Stepczynska</name></author><author><name sortKey="Wang, C" uniqKey="Wang C">C. Wang</name></author><author><name sortKey="Buer, J" uniqKey="Buer J">J. Buer</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="D Dda Di Fagagna, F" uniqKey="D Dda Di Fagagna F">F. D’Adda di Fagagna</name></author><author><name sortKey="Reaper, P M" uniqKey="Reaper P">P.M. Reaper</name></author><author><name sortKey="Clay Farrace, L" uniqKey="Clay Farrace L">L. Clay-Farrace</name></author><author><name sortKey="Fiegler, H" uniqKey="Fiegler H">H. Fiegler</name></author><author><name sortKey="Carr, P" uniqKey="Carr P">P. Carr</name></author><author><name sortKey="Von Zglinicki, T" uniqKey="Von Zglinicki T">T. Von Zglinicki</name></author><author><name sortKey="Saretzki, G" uniqKey="Saretzki G">G. Saretzki</name></author><author><name sortKey="Carter, N P" uniqKey="Carter N">N.P. Carter</name></author><author><name sortKey="Jackson, S P" uniqKey="Jackson S">S.P. Jackson</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Campisi, J" uniqKey="Campisi J">J. Campisi</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Serrano, M" uniqKey="Serrano M">M. Serrano</name></author><author><name sortKey="Lin, A W" uniqKey="Lin A">A.W. Lin</name></author><author><name sortKey="Mccurrach, M E" uniqKey="Mccurrach M">M.E. McCurrach</name></author><author><name sortKey="Beach, D" uniqKey="Beach D">D. Beach</name></author><author><name sortKey="Lowe, S W" uniqKey="Lowe S">S.W. Lowe</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Braig, M" uniqKey="Braig M">M. Braig</name></author><author><name sortKey="Lee, S" uniqKey="Lee S">S. Lee</name></author><author><name sortKey="Loddenkemper, C" uniqKey="Loddenkemper C">C. Loddenkemper</name></author><author><name sortKey="Rudolph, C" uniqKey="Rudolph C">C. Rudolph</name></author><author><name sortKey="Peters, A H" uniqKey="Peters A">A.H. Peters</name></author><author><name sortKey="Schlegelberger, B" uniqKey="Schlegelberger B">B. Schlegelberger</name></author><author><name sortKey="Stein, H" uniqKey="Stein H">H. Stein</name></author><author><name sortKey="Dorken, B" uniqKey="Dorken B">B. Dorken</name></author><author><name sortKey="Jenuwein, T" uniqKey="Jenuwein T">T. Jenuwein</name></author><author><name sortKey="Schmitt, C A" uniqKey="Schmitt C">C.A. Schmitt</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Zhuang, D" uniqKey="Zhuang D">D. Zhuang</name></author><author><name sortKey="Mannava, S" uniqKey="Mannava S">S. Mannava</name></author><author><name sortKey="Grachtchouk, V" uniqKey="Grachtchouk V">V. Grachtchouk</name></author><author><name sortKey="Tang, W H" uniqKey="Tang W">W.H. Tang</name></author><author><name sortKey="Patil, S" uniqKey="Patil S">S. Patil</name></author><author><name sortKey="Wawrzyniak, J A" uniqKey="Wawrzyniak J">J.A. Wawrzyniak</name></author><author><name sortKey="Berman, A E" uniqKey="Berman A">A.E. Berman</name></author><author><name sortKey="Giordano, T J" uniqKey="Giordano T">T.J. Giordano</name></author><author><name sortKey="Prochownik, E V" uniqKey="Prochownik E">E.V. Prochownik</name></author><author><name sortKey="Soengas, M S" uniqKey="Soengas M">M.S. Soengas</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Bartkova, J" uniqKey="Bartkova J">J. Bartkova</name></author><author><name sortKey="Rezaei, N" uniqKey="Rezaei N">N. Rezaei</name></author><author><name sortKey="Liontos, M" uniqKey="Liontos M">M. Liontos</name></author><author><name sortKey="Karakaidos, P" uniqKey="Karakaidos P">P. Karakaidos</name></author><author><name sortKey="Kletsas, D" uniqKey="Kletsas D">D. Kletsas</name></author><author><name sortKey="Issaeva, N" uniqKey="Issaeva N">N. Issaeva</name></author><author><name sortKey="Vassiliou, L V" uniqKey="Vassiliou L">L.V. Vassiliou</name></author><author><name sortKey="Kolettas, E" uniqKey="Kolettas E">E. Kolettas</name></author><author><name sortKey="Niforou, K" uniqKey="Niforou K">K. Niforou</name></author><author><name sortKey="Zoumpourlis, V C" uniqKey="Zoumpourlis V">V.C. Zoumpourlis</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Al Hajj, M" uniqKey="Al Hajj M">M. Al-Hajj</name></author><author><name sortKey="Wicha, M S" uniqKey="Wicha M">M.S. Wicha</name></author><author><name sortKey="Benito Hernandez, A" uniqKey="Benito Hernandez A">A. Benito-Hernandez</name></author><author><name sortKey="Morrison, S J" uniqKey="Morrison S">S.J. Morrison</name></author><author><name sortKey="Clarke, M F" uniqKey="Clarke M">M.F. Clarke</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Goodell, M A" uniqKey="Goodell M">M.A. Goodell</name></author><author><name sortKey="Mckinney Freeman, S" uniqKey="Mckinney Freeman S">S. McKinney-Freeman</name></author><author><name sortKey="Camargo, F D" uniqKey="Camargo F">F.D. Camargo</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Ho, M M" uniqKey="Ho M">M.M. Ho</name></author><author><name sortKey="Ng, A V" uniqKey="Ng A">A.V. Ng</name></author><author><name sortKey="Lam, S" uniqKey="Lam S">S. Lam</name></author><author><name sortKey="Hung, J Y" uniqKey="Hung J">J.Y. Hung</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Sionov, R V" uniqKey="Sionov R">R.V. Sionov</name></author><author><name sortKey="Haupt, Y" uniqKey="Haupt Y">Y. Haupt</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Lacroix, M" uniqKey="Lacroix M">M. Lacroix</name></author><author><name sortKey="Toillon, R A" uniqKey="Toillon R">R.A. Toillon</name></author><author><name sortKey="Leclercq, G" uniqKey="Leclercq G">G. Leclercq</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Prives, C" uniqKey="Prives C">C. Prives</name></author><author><name sortKey="Hall, P A" uniqKey="Hall P">P.A. Hall</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="He, C" uniqKey="He C">C. He</name></author><author><name sortKey="Li, L" uniqKey="Li L">L. Li</name></author><author><name sortKey="Guan, X" uniqKey="Guan X">X. Guan</name></author><author><name sortKey="Xiong, L" uniqKey="Xiong L">L. Xiong</name></author><author><name sortKey="Miao, X" uniqKey="Miao X">X. Miao</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Hientz, K" uniqKey="Hientz K">K. Hientz</name></author><author><name sortKey="Mohr, A" uniqKey="Mohr A">A. Mohr</name></author><author><name sortKey="Bhakta Guha, D" uniqKey="Bhakta Guha D">D. Bhakta-Guha</name></author><author><name sortKey="Efferth, T" uniqKey="Efferth T">T. Efferth</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Knappskog, S" uniqKey="Knappskog S">S. Knappskog</name></author><author><name sortKey="Lonning, P E" uniqKey="Lonning P">P.E. Lonning</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Zhang, S" uniqKey="Zhang S">S. Zhang</name></author><author><name sortKey="Zhou, L" uniqKey="Zhou L">L. Zhou</name></author><author><name sortKey="Hong, B" uniqKey="Hong B">B. Hong</name></author><author><name sortKey="Van Den Heuvel, A P J" uniqKey="Van Den Heuvel A">A.P.J. van den Heuvel</name></author><author><name sortKey="Prabhu, V V" uniqKey="Prabhu V">V.V. Prabhu</name></author><author><name sortKey="Warfel, N A" uniqKey="Warfel N">N.A. Warfel</name></author><author><name sortKey="Kline, C L B" uniqKey="Kline C">C.L.B. Kline</name></author><author><name sortKey="Dicker, D T" uniqKey="Dicker D">D.T. Dicker</name></author><author><name sortKey="Kopelovich, L" uniqKey="Kopelovich L">L. Kopelovich</name></author><author><name sortKey="El Deiry, W S" uniqKey="El Deiry W">W.S. El-Deiry</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Yan, W" uniqKey="Yan W">W. Yan</name></author><author><name sortKey="Zhang, Y" uniqKey="Zhang Y">Y. Zhang</name></author><author><name sortKey="Zhang, J" uniqKey="Zhang J">J. Zhang</name></author><author><name sortKey="Liu, S" uniqKey="Liu S">S. Liu</name></author><author><name sortKey="Cho, S J" uniqKey="Cho S">S.J. Cho</name></author><author><name sortKey="Chen, X" uniqKey="Chen X">X. Chen</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Gordon, R R" uniqKey="Gordon R">R.R. Gordon</name></author><author><name sortKey="Nelson, P S" uniqKey="Nelson P">P.S. Nelson</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Skolova, B" uniqKey="Skolova B">B. Skolová</name></author><author><name sortKey="Hudska, K R" uniqKey="Hudska K">K.R. Hudská</name></author><author><name sortKey="Pullmannova, P" uniqKey="Pullmannova P">P. Pullmannová</name></author><author><name sortKey="Kova Ik, A" uniqKey="Kova Ik A">A. Kováčik</name></author><author><name sortKey="Palat, K" uniqKey="Palat K">K. Palát</name></author><author><name sortKey="Roh, J" uniqKey="Roh J">J. Roh</name></author><author><name sortKey="Fleddermann, J" uniqKey="Fleddermann J">J. Fleddermann</name></author><author><name sortKey="Estrela Lopis, I" uniqKey="Estrela Lopis I">I. Estrela-Lopis</name></author><author><name sortKey="Vavrova, K" uniqKey="Vavrova K">K. Vávrová</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Goldkorn, T" uniqKey="Goldkorn T">T. Goldkorn</name></author><author><name sortKey="Chung, S" uniqKey="Chung S">S. Chung</name></author><author><name sortKey="Filosto, S" uniqKey="Filosto S">S. Filosto</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Flowers, M" uniqKey="Flowers M">M. Flowers</name></author><author><name sortKey="Fabrias, G" uniqKey="Fabrias G">G. Fabriás</name></author><author><name sortKey="Delgado, A" uniqKey="Delgado A">A. Delgado</name></author><author><name sortKey="Casas, J" uniqKey="Casas J">J. Casas</name></author><author><name sortKey="Abad, J L" uniqKey="Abad J">J.L. Abad</name></author><author><name sortKey="Cabot, M C" uniqKey="Cabot M">M.C. Cabot</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Demarchi, F" uniqKey="Demarchi F">F. Demarchi</name></author><author><name sortKey="Bertoli, C" uniqKey="Bertoli C">C. Bertoli</name></author><author><name sortKey="Greer, P" uniqKey="Greer P">P. Greer</name></author><author><name sortKey="Schneider, C" uniqKey="Schneider C">C. Schneider</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Xu, L" uniqKey="Xu L">L. Xu</name></author><author><name sortKey="Deng, X" uniqKey="Deng X">X. Deng</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Lin, I L" uniqKey="Lin I">I.L. Lin</name></author><author><name sortKey="Chou, H L" uniqKey="Chou H">H.L. Chou</name></author><author><name sortKey="Lee, J C" uniqKey="Lee J">J.C. Lee</name></author><author><name sortKey="Chen, F W" uniqKey="Chen F">F.W. Chen</name></author><author><name sortKey="Fong, Y" uniqKey="Fong Y">Y. Fong</name></author><author><name sortKey="Chang, W C" uniqKey="Chang W">W.C. Chang</name></author><author><name sortKey="Huang, H W" uniqKey="Huang H">H.W. Huang</name></author><author><name sortKey="Wu, C Y" uniqKey="Wu C">C.Y. Wu</name></author><author><name sortKey="Chang, W T" uniqKey="Chang W">W.T. Chang</name></author><author><name sortKey="Wang, H D" uniqKey="Wang H">H.D. Wang</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chang, Y C" uniqKey="Chang Y">Y.C. Chang</name></author><author><name sortKey="Fong, Y" uniqKey="Fong Y">Y. Fong</name></author><author><name sortKey="Tsai, E M" uniqKey="Tsai E">E.M. Tsai</name></author><author><name sortKey="Chang, Y G" uniqKey="Chang Y">Y.G. Chang</name></author><author><name sortKey="Chou, H L" uniqKey="Chou H">H.L. Chou</name></author><author><name sortKey="Wu, C Y" uniqKey="Wu C">C.Y. Wu</name></author><author><name sortKey="Teng, Y N" uniqKey="Teng Y">Y.N. Teng</name></author><author><name sortKey="Liu, T C" uniqKey="Liu T">T.C. Liu</name></author><author><name sortKey="Yuan, S S" uniqKey="Yuan S">S.S. Yuan</name></author><author><name sortKey="Chiu, C C" uniqKey="Chiu C">C.C. Chiu</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Jiang, C" uniqKey="Jiang C">C. Jiang</name></author><author><name sortKey="Liu, G" uniqKey="Liu G">G. Liu</name></author><author><name sortKey="Luckhardt, T" uniqKey="Luckhardt T">T. Luckhardt</name></author><author><name sortKey="Antony, V" uniqKey="Antony V">V. Antony</name></author><author><name sortKey="Zhou, Y" uniqKey="Zhou Y">Y. Zhou</name></author><author><name sortKey="Carter, A B" uniqKey="Carter A">A.B. Carter</name></author><author><name sortKey="Thannickal, V J" uniqKey="Thannickal V">V.J. Thannickal</name></author><author><name sortKey="Liu, R M" uniqKey="Liu R">R.M. Liu</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Morad, S A" uniqKey="Morad S">S.A. Morad</name></author><author><name sortKey="Messner, M C" uniqKey="Messner M">M.C. Messner</name></author><author><name sortKey="Levin, J C" uniqKey="Levin J">J.C. Levin</name></author><author><name sortKey="Abdelmageed, N" uniqKey="Abdelmageed N">N. Abdelmageed</name></author><author><name sortKey="Park, H" uniqKey="Park H">H. Park</name></author><author><name sortKey="Merrill, A H" uniqKey="Merrill A">A.H. Merrill</name></author><author><name sortKey="Cabot, M C" uniqKey="Cabot M">M.C. Cabot</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Huang, H" uniqKey="Huang H">H. Huang</name></author><author><name sortKey="Zhang, Y" uniqKey="Zhang Y">Y. Zhang</name></author><author><name sortKey="Liu, X" uniqKey="Liu X">X. Liu</name></author><author><name sortKey="Li, Z" uniqKey="Li Z">Z. Li</name></author><author><name sortKey="Xu, W" uniqKey="Xu W">W. Xu</name></author><author><name sortKey="He, S" uniqKey="He S">S. He</name></author><author><name sortKey="Huang, Y" uniqKey="Huang Y">Y. Huang</name></author><author><name sortKey="Zhang, H" uniqKey="Zhang H">H. Zhang</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Fabrias, G" uniqKey="Fabrias G">G. Fabrias</name></author><author><name sortKey="Bedia, C" uniqKey="Bedia C">C. Bedia</name></author><author><name sortKey="Casas, J" uniqKey="Casas J">J. Casas</name></author><author><name sortKey="Abad, J L" uniqKey="Abad J">J.L. Abad</name></author><author><name sortKey="Delgado, A" uniqKey="Delgado A">A. Delgado</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Kang, J H" uniqKey="Kang J">J.H. Kang</name></author><author><name sortKey="Garg, H" uniqKey="Garg H">H. Garg</name></author><author><name sortKey="Sigano, D M" uniqKey="Sigano D">D.M. Sigano</name></author><author><name sortKey="Francella, N" uniqKey="Francella N">N. Francella</name></author><author><name sortKey="Blumenthal, R" uniqKey="Blumenthal R">R. Blumenthal</name></author><author><name sortKey="Marquez, V E" uniqKey="Marquez V">V.E. Marquez</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chou, H L" uniqKey="Chou H">H.L. Chou</name></author><author><name sortKey="Lin, Y H" uniqKey="Lin Y">Y.H. Lin</name></author><author><name sortKey="Liu, W" uniqKey="Liu W">W. Liu</name></author><author><name sortKey="Wu, C Y" uniqKey="Wu C">C.Y. Wu</name></author><author><name sortKey="Li, R N" uniqKey="Li R">R.N. Li</name></author><author><name sortKey="Huang, H W" uniqKey="Huang H">H.W. Huang</name></author><author><name sortKey="Chou, C H" uniqKey="Chou C">C.H. Chou</name></author><author><name sortKey="Chiou, S J" uniqKey="Chiou S">S.J. Chiou</name></author><author><name sortKey="Chiu, C C" uniqKey="Chiu C">C.C. Chiu</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chang, T C" uniqKey="Chang T">T.C. Chang</name></author><author><name sortKey="Wentzel, E A" uniqKey="Wentzel E">E.A. Wentzel</name></author><author><name sortKey="Kent, O A" uniqKey="Kent O">O.A. Kent</name></author><author><name sortKey="Ramachandran, K" uniqKey="Ramachandran K">K. Ramachandran</name></author><author><name sortKey="Mullendore, M" uniqKey="Mullendore M">M. Mullendore</name></author><author><name sortKey="Lee, K H" uniqKey="Lee K">K.H. Lee</name></author><author><name sortKey="Feldmann, G" uniqKey="Feldmann G">G. Feldmann</name></author><author><name sortKey="Yamakuchi, M" uniqKey="Yamakuchi M">M. Yamakuchi</name></author><author><name sortKey="Ferlito, M" uniqKey="Ferlito M">M. Ferlito</name></author><author><name sortKey="Lowenstein, C J" uniqKey="Lowenstein C">C.J. Lowenstein</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="He, L" uniqKey="He L">L. He</name></author><author><name sortKey="He, X" uniqKey="He X">X. He</name></author><author><name sortKey="Lim, L P" uniqKey="Lim L">L.P. Lim</name></author><author><name sortKey="De Stanchina, E" uniqKey="De Stanchina E">E. de Stanchina</name></author><author><name sortKey="Xuan, Z" uniqKey="Xuan Z">Z. Xuan</name></author><author><name sortKey="Liang, Y" uniqKey="Liang Y">Y. Liang</name></author><author><name sortKey="Xue, W" uniqKey="Xue W">W. Xue</name></author><author><name sortKey="Zender, L" uniqKey="Zender L">L. Zender</name></author><author><name sortKey="Magnus, J" uniqKey="Magnus J">J. Magnus</name></author><author><name sortKey="Ridzon, D" uniqKey="Ridzon D">D. Ridzon</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Wang, Q" uniqKey="Wang Q">Q. Wang</name></author><author><name sortKey="Wu, P C" uniqKey="Wu P">P.C. Wu</name></author><author><name sortKey="Roberson, R S" uniqKey="Roberson R">R.S. Roberson</name></author><author><name sortKey="Luk, B V" uniqKey="Luk B">B.V. Luk</name></author><author><name sortKey="Ivanova, I" uniqKey="Ivanova I">I. Ivanova</name></author><author><name sortKey="Chu, E" uniqKey="Chu E">E. Chu</name></author><author><name sortKey="Wu, D Y" uniqKey="Wu D">D.Y. Wu</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Vaughan, D E" uniqKey="Vaughan D">D.E. Vaughan</name></author><author><name sortKey="Rai, R" uniqKey="Rai R">R. Rai</name></author><author><name sortKey="Khan, S S" uniqKey="Khan S">S.S. Khan</name></author><author><name sortKey="Eren, M" uniqKey="Eren M">M. Eren</name></author><author><name sortKey="Ghosh, A K" uniqKey="Ghosh A">A.K. Ghosh</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Eren, M" uniqKey="Eren M">M. Eren</name></author><author><name sortKey="Boe, A E" uniqKey="Boe A">A.E. Boe</name></author><author><name sortKey="Klyachko, E A" uniqKey="Klyachko E">E.A. Klyachko</name></author><author><name sortKey="Vaughan, D E" uniqKey="Vaughan D">D.E. Vaughan</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Armstrong, D M F" uniqKey="Armstrong D">D.M.F. Armstrong</name></author><author><name sortKey="Sikka, G" uniqKey="Sikka G">G. Sikka</name></author><author><name sortKey="Armstrong, A D C" uniqKey="Armstrong A">A.D.C. Armstrong</name></author><author><name sortKey="Saad, K R" uniqKey="Saad K">K.R. Saad</name></author><author><name sortKey="Freitas, W R" uniqKey="Freitas W">W.R. Freitas</name></author><author><name sortKey="Berkowitz, D E" uniqKey="Berkowitz D">D.E. Berkowitz</name></author><author><name sortKey="Fagundes, D J" uniqKey="Fagundes D">D.J. Fagundes</name></author><author><name sortKey="Santhanam, L" uniqKey="Santhanam L">L. Santhanam</name></author><author><name sortKey="Taha, M O" uniqKey="Taha M">M.O. Taha</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chakradeo, S" uniqKey="Chakradeo S">S. Chakradeo</name></author><author><name sortKey="Elmore, L W" uniqKey="Elmore L">L.W. Elmore</name></author><author><name sortKey="Gewirtz, D A" uniqKey="Gewirtz D">D.A. Gewirtz</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Sasaki, M" uniqKey="Sasaki M">M. Sasaki</name></author><author><name sortKey="Kumazaki, T" uniqKey="Kumazaki T">T. Kumazaki</name></author><author><name sortKey="Takano, H" uniqKey="Takano H">H. Takano</name></author><author><name sortKey="Nishiyama, M" uniqKey="Nishiyama M">M. Nishiyama</name></author><author><name sortKey="Mitsui, Y" uniqKey="Mitsui Y">Y. Mitsui</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Synnott, N C" uniqKey="Synnott N">N.C. Synnott</name></author><author><name sortKey="Bauer, M R" uniqKey="Bauer M">M.R. Bauer</name></author><author><name sortKey="Madden, S" uniqKey="Madden S">S. Madden</name></author><author><name sortKey="Murray, A" uniqKey="Murray A">A. Murray</name></author><author><name sortKey="Klinger, R" uniqKey="Klinger R">R. Klinger</name></author><author><name sortKey="O Onovan, N" uniqKey="O Onovan N">N. O’Donovan</name></author><author><name sortKey="O Onnor, D" uniqKey="O Onnor D">D. O’Connor</name></author><author><name sortKey="Gallagher, W M" uniqKey="Gallagher W">W.M. Gallagher</name></author><author><name sortKey="Crown, J" uniqKey="Crown J">J. Crown</name></author><author><name sortKey="Fersht, A R" uniqKey="Fersht A">A.R. Fersht</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Blaess, M" uniqKey="Blaess M">M. Blaess</name></author><author><name sortKey="Le, H P" uniqKey="Le H">H.P. Le</name></author><author><name sortKey="Claus, R A" uniqKey="Claus R">R.A. Claus</name></author><author><name sortKey="Kohl, M" uniqKey="Kohl M">M. Kohl</name></author><author><name sortKey="Deigner, H P" uniqKey="Deigner H">H.P. Deigner</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Ogretmen, B" uniqKey="Ogretmen B">B. Ogretmen</name></author><author><name sortKey="Pettus, B J" uniqKey="Pettus B">B.J. Pettus</name></author><author><name sortKey="Rossi, M J" uniqKey="Rossi M">M.J. Rossi</name></author><author><name sortKey="Wood, R" uniqKey="Wood R">R. Wood</name></author><author><name sortKey="Usta, J" uniqKey="Usta J">J. Usta</name></author><author><name sortKey="Szulc, Z" uniqKey="Szulc Z">Z. Szulc</name></author><author><name sortKey="Bielawska, A" uniqKey="Bielawska A">A. Bielawska</name></author><author><name sortKey="Obeid, L M" uniqKey="Obeid L">L.M. Obeid</name></author><author><name sortKey="Hannun, Y A" uniqKey="Hannun Y">Y.A. Hannun</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chen, J Y" uniqKey="Chen J">J.Y. Chen</name></author><author><name sortKey="Hwang, C C" uniqKey="Hwang C">C.C. Hwang</name></author><author><name sortKey="Chen, W Y" uniqKey="Chen W">W.Y. Chen</name></author><author><name sortKey="Lee, J C" uniqKey="Lee J">J.C. Lee</name></author><author><name sortKey="Fu, T F" uniqKey="Fu T">T.F. Fu</name></author><author><name sortKey="Fang, K" uniqKey="Fang K">K. Fang</name></author><author><name sortKey="Chu, Y C" uniqKey="Chu Y">Y.C. Chu</name></author><author><name sortKey="Huang, Y L" uniqKey="Huang Y">Y.L. Huang</name></author><author><name sortKey="Lin, J C" uniqKey="Lin J">J.C. Lin</name></author><author><name sortKey="Tsai, W H" uniqKey="Tsai W">W.H. Tsai</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Spyridopoulos, I" uniqKey="Spyridopoulos I">I. Spyridopoulos</name></author><author><name sortKey="Mayer, P" uniqKey="Mayer P">P. Mayer</name></author><author><name sortKey="Shook, K S" uniqKey="Shook K">K.S. Shook</name></author><author><name sortKey="Axel, D I" uniqKey="Axel D">D.I. Axel</name></author><author><name sortKey="Viebahn, R" uniqKey="Viebahn R">R. Viebahn</name></author><author><name sortKey="Karsch, K R" uniqKey="Karsch K">K.R. Karsch</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Ahn, E H" uniqKey="Ahn E">E.H. Ahn</name></author><author><name sortKey="Yang, H" uniqKey="Yang H">H. Yang</name></author><author><name sortKey="Hsieh, C Y" uniqKey="Hsieh C">C.Y. Hsieh</name></author><author><name sortKey="Sun, W" uniqKey="Sun W">W. Sun</name></author><author><name sortKey="Chang, C C" uniqKey="Chang C">C.C. Chang</name></author><author><name sortKey="Schroeder, J J" uniqKey="Schroeder J">J.J. Schroeder</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Chiu, C C" uniqKey="Chiu C">C.C. Chiu</name></author><author><name sortKey="Chou, H L" uniqKey="Chou H">H.L. Chou</name></author><author><name sortKey="Chen, B H" uniqKey="Chen B">B.H. Chen</name></author><author><name sortKey="Chang, K F" uniqKey="Chang K">K.F. Chang</name></author><author><name sortKey="Tseng, C H" uniqKey="Tseng C">C.H. Tseng</name></author><author><name sortKey="Fong, Y" uniqKey="Fong Y">Y. Fong</name></author><author><name sortKey="Fu, T F" uniqKey="Fu T">T.F. Fu</name></author><author><name sortKey="Chang, H W" uniqKey="Chang H">H.W. Chang</name></author><author><name sortKey="Wu, C Y" uniqKey="Wu C">C.Y. Wu</name></author><author><name sortKey="Tsai, E M" uniqKey="Tsai E">E.M. Tsai</name></author></analytic></biblStruct><biblStruct><analytic><author><name sortKey="Dimri, G P" uniqKey="Dimri G">G.P. Dimri</name></author><author><name sortKey="Lee, X" uniqKey="Lee X">X. Lee</name></author><author><name sortKey="Basile, G" uniqKey="Basile G">G. Basile</name></author><author><name sortKey="Acosta, M" uniqKey="Acosta M">M. Acosta</name></author><author><name sortKey="Scott, G" uniqKey="Scott G">G. Scott</name></author><author><name sortKey="Roskelley, C" uniqKey="Roskelley C">C. Roskelley</name></author><author><name sortKey="Medrano, E E" uniqKey="Medrano E">E.E. Medrano</name></author><author><name sortKey="Linskens, M" uniqKey="Linskens M">M. Linskens</name></author><author><name sortKey="Rubelj, I" uniqKey="Rubelj I">I. Rubelj</name></author><author><name sortKey="Pereira Smith, O" uniqKey="Pereira Smith O">O. Pereira-Smith</name></author></analytic></biblStruct></listBibl></div1></back></TEI><pmc article-type="research-article"><pmc-dir>properties open_access</pmc-dir>
<front><journal-meta><journal-id journal-id-type="nlm-ta">Int J Mol Sci</journal-id><journal-id journal-id-type="iso-abbrev">Int J Mol Sci</journal-id><journal-id journal-id-type="publisher-id">ijms</journal-id><journal-title-group><journal-title>International Journal of Molecular Sciences</journal-title></journal-title-group><issn pub-type="epub">1422-0067</issn><publisher><publisher-name>MDPI</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="pmid">31480728</article-id><article-id pub-id-type="pmc">6747432</article-id><article-id pub-id-type="doi">10.3390/ijms20174292</article-id><article-id pub-id-type="publisher-id">ijms-20-04292</article-id><article-categories><subj-group subj-group-type="heading"><subject>Article</subject></subj-group></article-categories><title-group><article-title>C<sub>2</sub>-Ceramide-Induced Rb-Dominant Senescence-Like Phenotype Leads to Human Breast Cancer MCF-7 Escape from <italic>p</italic>53-Dependent Cell Death</article-title></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid" authenticated="true">https://orcid.org/0000-0001-5622-8299</contrib-id><name><surname>Chang</surname><given-names>Wen-Tsan</given-names></name><xref ref-type="aff" rid="af1-ijms-20-04292">1</xref><xref ref-type="aff" rid="af2-ijms-20-04292">2</xref></contrib><contrib contrib-type="author"><name><surname>Wu</surname><given-names>Chang-Yi</given-names></name><xref ref-type="aff" rid="af3-ijms-20-04292">3</xref><xref ref-type="aff" rid="af4-ijms-20-04292">4</xref></contrib><contrib contrib-type="author"><name><surname>Lin</surname><given-names>Yin-Chieh</given-names></name><xref ref-type="aff" rid="af4-ijms-20-04292">4</xref></contrib><contrib contrib-type="author"><name><surname>Wu</surname><given-names>Min-Tsui</given-names></name><xref ref-type="aff" rid="af4-ijms-20-04292">4</xref></contrib><contrib contrib-type="author"><name><surname>Su</surname><given-names>Kai-Li</given-names></name><xref ref-type="aff" rid="af4-ijms-20-04292">4</xref></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid" authenticated="true">https://orcid.org/0000-0002-4753-788X</contrib-id><name><surname>Yuan</surname><given-names>Shyng-Shiou</given-names></name><xref ref-type="aff" rid="af5-ijms-20-04292">5</xref></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid" authenticated="true">https://orcid.org/0000-0002-5162-9752</contrib-id><name><surname>Wang</surname><given-names>Hui-Min David</given-names></name><xref ref-type="aff" rid="af6-ijms-20-04292">6</xref></contrib><contrib contrib-type="author"><name><surname>Fong</surname><given-names>Yao</given-names></name><xref ref-type="aff" rid="af7-ijms-20-04292">7</xref></contrib><contrib contrib-type="author"><name><surname>Lin</surname><given-names>Yi-Hsiung</given-names></name><xref ref-type="aff" rid="af4-ijms-20-04292">4</xref><xref ref-type="aff" rid="af8-ijms-20-04292">8</xref><xref ref-type="aff" rid="af9-ijms-20-04292">9</xref><xref rid="c1-ijms-20-04292" ref-type="corresp">*</xref></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid" authenticated="true">https://orcid.org/0000-0001-7307-2468</contrib-id><name><surname>Chiu</surname><given-names>Chien-Chih</given-names></name><xref ref-type="aff" rid="af3-ijms-20-04292">3</xref><xref ref-type="aff" rid="af4-ijms-20-04292">4</xref><xref ref-type="aff" rid="af9-ijms-20-04292">9</xref><xref ref-type="aff" rid="af10-ijms-20-04292">10</xref><xref ref-type="aff" rid="af11-ijms-20-04292">11</xref><xref rid="c1-ijms-20-04292" ref-type="corresp">*</xref></contrib></contrib-group><aff id="af1-ijms-20-04292"><label>1</label>Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan</aff><aff id="af2-ijms-20-04292"><label>2</label>Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</aff><aff id="af3-ijms-20-04292"><label>3</label>Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan</aff><aff id="af4-ijms-20-04292"><label>4</label>Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan</aff><aff id="af5-ijms-20-04292"><label>5</label>Translational Research Center, Cancer Center, Department of Medical Research, Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan</aff><aff id="af6-ijms-20-04292"><label>6</label>Graduate Institute of Biomedical Engineering, National Chung Hsing University, Taichung 402, Taiwan</aff><aff id="af7-ijms-20-04292"><label>7</label>Chest Surgery, Chi-Mei Medical Center, Yung Kang City, Tainan 901, Taiwan</aff><aff id="af8-ijms-20-04292"><label>8</label>Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</aff><aff id="af9-ijms-20-04292"><label>9</label>Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan</aff><aff id="af10-ijms-20-04292"><label>10</label>Center for Stem Cell Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan</aff><aff id="af11-ijms-20-04292"><label>11</label>Translational Research Center and Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan</aff><author-notes><corresp id="c1-ijms-20-04292"><label>*</label>Correspondence: <email>caminolin@gmail.com</email> (Y.-H.L.); <email>cchiu@kmu.edu.tw</email> (C.-C.C.); Tel.: +886-7312-1101 (ext. 2368) (Y.-H.L. & C.-C.C.); Fax: +886-7312-5339 (Y.-H.L. & C.-C.C.)</corresp></author-notes><pub-date pub-type="epub"><day>02</day><month>9</month><year>2019</year></pub-date><pub-date pub-type="collection"><month>9</month><year>2019</year></pub-date><volume>20</volume><issue>17</issue><elocation-id>4292</elocation-id><history><date date-type="received"><day>18</day><month>7</month><year>2019</year></date><date date-type="accepted"><day>22</day><month>8</month><year>2019</year></date></history><permissions><copyright-statement>© 2019 by the authors.</copyright-statement><copyright-year>2019</copyright-year><license license-type="open-access"><license-p>Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (<ext-link ext-link-type="uri" xlink:href="http://creativecommons.org/licenses/by/4.0/">http://creativecommons.org/licenses/by/4.0/</ext-link>).</license-p></license></permissions><abstract><p>Ceramide is a sphingolipid which regulates a variety of signaling pathways in eukaryotic cells. Exogenous ceramide has been shown to induce cellular apoptosis. In this study, we observed that exogenous ceramide induced two distinct morphologies of cell fate following C<sub>2</sub>-ceramide treatment between the two breast cancer cell lines MCF-7 (wild type <italic>p</italic>53) and MDA-MB-231 (mutant <italic>p</italic>53) cells. The growth assessment showed that C<sub>2</sub>-ceramide caused significant growth inhibition and apoptosis in MDA-MB-231 cells through down-regulating the expression of mutant <italic>p</italic>53 whereas up-regulating the expression of pro-apoptotic Bad, and the proteolytic activation of caspase-3. However, senescence-associated (SA)-β-galactosidase (β-gal) was regulated in MCF-7 cells after C<sub>2</sub>-ceramide treatment. The results of proliferation and apoptosis assays showed that MCF-7 cells were more resistant to C<sub>2</sub>-ceramide treatment compared to MDA-MB-231 cells. Furthermore, C<sub>2</sub>-ceramide treatment induced a time-responsive increase in Rb protein, a key regulator of senescence accompanied with the upregulation of both mRNA level and protein level of SA-genes PAI-1 and TGaseII in MCF-7 but not in MDA-MB-231 cells, suggesting that some cancer cells escape apoptosis through modulating senescence-like phenotype. The results of our present study depicted the mechanism of C<sub>2</sub>-ceramide-resistant breast cancer cells, which might benefit the strategic development of ceramide-based chemotherapeutics against cancer in the future.</p></abstract><kwd-group><kwd>breast cancer</kwd><kwd>apoptosis</kwd><kwd>senescence-like phenotype</kwd><kwd>C<sub>2</sub>-ceramide</kwd></kwd-group></article-meta></front><body><sec sec-type="intro" id="sec1-ijms-20-04292"><title>1. Introduction</title><p>Breast cancer is the major cause of female cancer deaths worldwide, with the highest mortality and poor prognosis. It is expected to accumulate over 30% of 880,000 new cancer cases as reported by the American Cancer Society (ACS) in 2018 and it causes more than 70,000 deaths than any other cancer. To date, breast cancer remains a leading cause of public health issues for women and the most common tumor for the past two decades [<xref rid="B1-ijms-20-04292" ref-type="bibr">1</xref>].</p><p>Senescent (aging) cells lose their ability to divide because of the limited quota of divisions [<xref rid="B2-ijms-20-04292" ref-type="bibr">2</xref>]. Senescent cells exert the arrest of proliferation and acidic β-galactosidase (β-gal) activity (pH 6.0) with enlarged and flattened morphology [<xref rid="B2-ijms-20-04292" ref-type="bibr">2</xref>]. In contrast, senescence-like phenotype is a growth arrest that could be induced by stresses including hypoxic stress [<xref rid="B3-ijms-20-04292" ref-type="bibr">3</xref>], accumulation of endogenous reactive oxygen species (ROS), and some anti-tumor agents. In comparison with replicative cells, stress-induced senescence/senescent-like phenotype might occur within weeks without telomere-shortening [<xref rid="B4-ijms-20-04292" ref-type="bibr">4</xref>].</p><p>Various signaling transductions are found to be associated with cellular senescence. Direct evidence of limited telomere cell presents a DNA damage-like response and activates the signaling regarding growth arrest and senescent status [<xref rid="B5-ijms-20-04292" ref-type="bibr">5</xref>], with the up-regulation of cell cycle inhibitor <italic>p</italic>21. <italic>p</italic>21 deletion rescued the intestinal progenitor cell proliferation and improved the self-renewal capacity of hematopoietic stem cells; moreover, the signaling pathway, including ATM and ATR, resulted in down-stream H2AX phosphorylation, and Chk1 and Chk2 in <italic>p</italic>53 modification and <italic>p</italic>21/<italic>p</italic>16 activation all participate in the cell cycle-arrest effect of senescence [<xref rid="B6-ijms-20-04292" ref-type="bibr">6</xref>]. Furthermore, the oncogene-induced senescence in response to the oncogene activation or the loss of tumor suppresses regulation to protect cell integrity and restrain cell growth [<xref rid="B7-ijms-20-04292" ref-type="bibr">7</xref>]. Early evidence of over-expressed oncogene RAS resulted in cell cycle arrest with the rise of <italic>p</italic>53 and <italic>p</italic>16 activity, and other reports reveal that the RB pathway contributes to the senescence-induced tumor cell death [<xref rid="B8-ijms-20-04292" ref-type="bibr">8</xref>,<xref rid="B9-ijms-20-04292" ref-type="bibr">9</xref>]. Since then, more and more regulators are reported as being involved in senescence-initiating responses such as BRAF mutation, c-Myc suppression, ATM pathway-mediated disturbance of cdc6, and Cyclin E activation [<xref rid="B3-ijms-20-04292" ref-type="bibr">3</xref>,<xref rid="B10-ijms-20-04292" ref-type="bibr">10</xref>,<xref rid="B11-ijms-20-04292" ref-type="bibr">11</xref>].</p><p>However, another accumulated report reveals the reverse role of senescence for the rare escape of tumor cells from drug-induced cell death exhibiting unstable multiplication characteristics. Some evidence suggests that these tumor cells harbor stem cell-like phenotype with CD44<sup>+</sup>/CD24<sup>−</sup> marker features [<xref rid="B12-ijms-20-04292" ref-type="bibr">12</xref>]. Most importantly, it is found that there are side population cells showing more resistance to antitumor agent treatment due to the enrichment of drug efflux transporter protein expression and the efficient capacity of DNA repair [<xref rid="B13-ijms-20-04292" ref-type="bibr">13</xref>,<xref rid="B14-ijms-20-04292" ref-type="bibr">14</xref>]. After the drug treatment, the cell death-resistant cells are identified with an appearance of the senescent population and stem cell-marker enrichment features.</p><p><italic>p</italic>53 is a nuclear transcription factor with tumor-suppressing biological function in the cellular process, showing pro-apoptosis characteristics. Normally, <italic>p</italic>53 is activated to induce its pro-apoptosis function regarding cell cycle arrest, DNA repair, and initiation of apoptosis-related signaling [<xref rid="B15-ijms-20-04292" ref-type="bibr">15</xref>,<xref rid="B16-ijms-20-04292" ref-type="bibr">16</xref>,<xref rid="B17-ijms-20-04292" ref-type="bibr">17</xref>]. However, over 50% of human cancers exhibit the loss of <italic>p</italic>53 with genomic loci mutation, especially in solid tumors. Accumulative evidence shows that the mutant <italic>p</italic>53 acts as a dominant-negative inhibitor toward the wild-type <italic>p</italic>53 pathway in various cancers, suggesting that cancer cells harboring mutant <italic>p53</italic> exhibit chemo-resistant potential and become more malignant [<xref rid="B18-ijms-20-04292" ref-type="bibr">18</xref>,<xref rid="B19-ijms-20-04292" ref-type="bibr">19</xref>,<xref rid="B20-ijms-20-04292" ref-type="bibr">20</xref>]. </p><p>A future therapeutic target for the approach in tumors with <italic>p</italic>53 mutations appears to be an important way to improve drug treatment outcomes. For example, a small compound NSC59984 screened from National Cancer Institute (NCI; Bethesda, MD) induces the degradation of mutant <italic>p</italic>53 protein in human colon cancer cells SW480 via MDM2 and the ubiquitin-proteasome pathway [<xref rid="B21-ijms-20-04292" ref-type="bibr">21</xref>]. Another study also showed that arsenic trioxide degrades mutant <italic>p</italic>53 in HaCaT colon cancer cells, SW480 cells, and MIA PaCa-2 cells, with the authors finding that arsenic trioxide caused decreased stability of the mutant <italic>p</italic>53 protein through a proteasomal pathway in HaCaT cells [<xref rid="B22-ijms-20-04292" ref-type="bibr">22</xref>].</p><p>Chemoresistance to cancer therapeutics remains an important problem regarding treatment failure and needs to be addressed in order to reduce cancer death rate; nevertheless, a clarification of the key mechanism and biological function related to chemoresistance will always remain important for cancer therapeutics. Senescence as an alternative cellular process shows its crucial role of an important cell self-protection mechanism against internal/external pressures [<xref rid="B23-ijms-20-04292" ref-type="bibr">23</xref>] and suggests that cellular non-autonomous senescence responses may be partially involved in chemoresistance during treatment.</p><p>Ceramides are sphingolipids of the cell membrane that serve as a mediator of sphingolipid metabolism and many fundamental cellular pathways [<xref rid="B24-ijms-20-04292" ref-type="bibr">24</xref>]. It has also been reported to serve as a tumor suppressor lipid against the growth of tumor cells [<xref rid="B25-ijms-20-04292" ref-type="bibr">25</xref>,<xref rid="B26-ijms-20-04292" ref-type="bibr">26</xref>,<xref rid="B27-ijms-20-04292" ref-type="bibr">27</xref>,<xref rid="B28-ijms-20-04292" ref-type="bibr">28</xref>]. For example, the effects of short carbon chain C<sub>2</sub>-ceramide on apoptosis in lung cancer cells have been studied previously [<xref rid="B27-ijms-20-04292" ref-type="bibr">27</xref>,<xref rid="B28-ijms-20-04292" ref-type="bibr">28</xref>]. Ceramide has been shown to exert strong potential for regulating cell apoptosis, cell cycle arrest, and autophagic responses [<xref rid="B29-ijms-20-04292" ref-type="bibr">29</xref>,<xref rid="B30-ijms-20-04292" ref-type="bibr">30</xref>]. Our previous studies have demonstrated the potential effects of ceramides in anticancer by regulating various cellular pathways. To investigate the effect of C<sub>2</sub>-ceramide in inducing cell senescence and its association with <italic>p</italic>53 status, two different types of breast cancer cells, harbored wild-type <italic>p</italic>53 (MCF-7) and mutant <italic>p</italic>53 (MDA-MB231), were used in this study to further clarify the cell response of apoptosis and chemoresistance toward C<sub>2</sub>-ceramide.</p></sec><sec sec-type="results" id="sec2-ijms-20-04292"><title>2. Results</title><sec id="sec2dot1-ijms-20-04292"><title>2.1. Discrepant Anti-Proliferation Effects of C<sub>2</sub>-Ceramide on Two Breast Cancer Cells</title><p>Samples from two breast cancer cell lines MCF-7 and MDA-MB-231 were treated with indicated concentrations of C<sub>2</sub>-ceramide for 24 h respectively, and the rates of cellular proliferation were determined. The results of cellular proliferation assay showed that the inhibitory effect of C<sub>2</sub>-ceramide on the proliferation of the two breast cancer cell lines is discrepant (<xref ref-type="fig" rid="ijms-20-04292-f001">Figure 1</xref>). The IC<sub>50</sub> measures of C<sub>2</sub>-ceramide in MCF-7 and MDA-MB-231 were 27.13 µM and four µM respectively. This suggests that MDA-MB-231 was more sensitive to C<sub>2</sub>-ceramide compared to MCF-7. </p></sec><sec id="sec2dot2-ijms-20-04292"><title>2.2. C<sub>2</sub>-ceramide Induced Senescence-Like Phenotype of MCF-7 Cells</title><p>Our preliminary results showed that numerous flattened and enlarged cells were observed in C<sub>2</sub>-ceramide-treated MCF-7, a hallmark of the senescence-like phenotype; accordingly, we sought to determine whether C<sub>2</sub>-ceramide could induce senescence-like phenotype in breast cancer cells. The acidic SA-β-gal staining was conducted for detecting the senescence at day six following C<sub>2</sub>-ceramide administration (<xref ref-type="fig" rid="ijms-20-04292-f002">Figure 2</xref>A). As shown in <xref ref-type="fig" rid="ijms-20-04292-f002">Figure 2</xref>A, the acidic SA-β-gal positive cells significantly increased in C<sub>2</sub>-ceramide-treated MCF-7. However, the same concentration (20 µM) of C<sub>2</sub>-ceramide induced senescence-like phenotype characteristics in MCF-7 rather than in MDA-MD-231 cells (<xref ref-type="fig" rid="ijms-20-04292-f002">Figure 2</xref>B).</p></sec><sec id="sec2dot3-ijms-20-04292"><title>2.3. C<sub>2</sub>-Ceramide Induced Apoptosis of MDA-MB-231 Cells</title><p>As shown in <xref ref-type="fig" rid="ijms-20-04292-f003">Figure 3</xref>A, the shrinkage and rounding of MDA-MB-231 cells were observed after 24 h treatments of C<sub>2</sub>-ceramide, especially at the 20 and 30 μM of C<sub>2</sub>-ceramide. Furthermore, ceramide treatments caused significant chromatin condensation, a hallmark of apoptosis in a dose-dependent manner (<xref ref-type="fig" rid="ijms-20-04292-f003">Figure 3</xref>B). The assay of fluorescence microscope-based Annexin V/Propidium Iodide staining further confirmed C<sub>2</sub>-ceramide induced apoptosis in MDA-MB-231. Besides the Annexin V positive cells, the dramatic decrease of cell number, and massive accumulation of Annexin V/PI-positive cells, a late stage of apoptosis was also observed by 50 μM of C<sub>2</sub>-ceramide treatments, indicating the susceptibility of MDA-MB-231 cells to higher concentrations (50 μM) of C<sub>2</sub>-ceramide. The results of Western blotting reveal upregulation of pro-apoptotic Bcl-2 protein Bad and the proteolytic activation of caspase-3 (cleaved caspase-3) following ceramide treatments (<xref ref-type="fig" rid="ijms-20-04292-f003">Figure 3</xref>D).</p></sec><sec id="sec2dot4-ijms-20-04292"><title>2.4. Expression Modulation of SA-Genes Was Modulated by C<sub>2</sub>-Ceramide</title><p>While senescence occurred, SA factors were activated to promote the senescence process. Thus, to further investigate the effect of C<sub>2</sub>-ceramide in inducing SA factor regulation, RT-PCR was performed to evaluate the gene expression of SA-genes. As shown in <xref ref-type="fig" rid="ijms-20-04292-f004">Figure 4</xref>, it was found that the mRNA levels of SA-genes of SM22 were not altered by C<sub>2</sub>-ceramide treatment. However, <italic>PAI-I</italic> and <italic>TGase II</italic> were upregulated 1.46-fold and 5.22-fold respectively following 20 µM C<sub>2</sub>-ceramide-treated MCF-7 for 24 h. In contrast, there was no significant alteration of SA-gene found in C<sub>2</sub>-ceramide-treated MD-MBA-231 cells. The results suggest that C<sub>2</sub>-ceramide induced a senescence-related signaling pathway in MCF-7 cells, rather than in MDA-MB-231 cells.</p></sec><sec id="sec2dot5-ijms-20-04292"><title>2.5. The Regulation of Senescence- and Pro-Apoptotic Factors in C<sub>2</sub>-Ceramide-Created Breast Cancer Cells</title><p>The regulatory effect of C<sub>2</sub>-ceramide in inducing senescence- and pro-apoptosis factors in MCF-7 and MDA-MB-231 cells was further investigated. We found that C<sub>2</sub>-ceramide induced a rapid increase of <italic>p</italic>53 5.06-fold at the early time point of 6 h and then decreased to basal expression after 24 h in MCF-7; however, C<sub>2</sub>-ceramide significantly suppressed the protein expression of mutant <italic>p</italic>53 from 12 h to 24 h after treatment in MDA-MB-231 cells (<xref ref-type="fig" rid="ijms-20-04292-f005">Figure 5</xref>A, first line), indicating that C<sub>2</sub>-ceramide induced MDA-MB-231 cell apoptosis by reducing pro-proliferating mutant <italic>p</italic>53. In contrast, compared with a slight increase of p21, C<sub>2</sub>-ceramide significantly up-regulated Rb protein expression in MCF-7 cells up to 2.47-fold in a time-dependent manner, whereas there was no obvious change compared with that in MDA-MB-231 cells (<xref ref-type="fig" rid="ijms-20-04292-f005">Figure 5</xref>A). p21 and Rb have been reported as senescence-related markers [<xref rid="B31-ijms-20-04292" ref-type="bibr">31</xref>], indicating that C<sub>2</sub>-ceramide specifically induced senescence marker p21 and Rb protein activation to promote the senescence of MCF-7 cells. To further characterize the importance of <italic>p</italic>53 in C<sub>2</sub>-ceramide-induced MCF-7 apoptosis, the <italic>p</italic>53 activator NSC59984 was used. Through single or co-treatment of NSC59984 and C<sub>2</sub>-ceramide, we found that NSC59984 significantly enhanced the cytotoxicity by increasing cell death by 40% to 60% in C<sub>2</sub>-ceramide-treated MCF-7 cells (<xref ref-type="fig" rid="ijms-20-04292-f005">Figure 5</xref>B), suggesting that the activation of wild-type <italic>p</italic>53 resensitizes MCF-7 cells toward C<sub>2</sub>-ceramide-induced death, and that the effect of <italic>p</italic>53 activation was more dominant than Rb-mediated senescence.</p></sec></sec><sec sec-type="discussion" id="sec3-ijms-20-04292"><title>3. Discussion</title><p>Our previous studies have revealed the role of C<sub>2</sub>-ceramide as a promising strategy for lung cancer therapies [<xref rid="B26-ijms-20-04292" ref-type="bibr">26</xref>,<xref rid="B32-ijms-20-04292" ref-type="bibr">32</xref>,<xref rid="B33-ijms-20-04292" ref-type="bibr">33</xref>,<xref rid="B34-ijms-20-04292" ref-type="bibr">34</xref>]. Ceramide has been validated as safe toward normal cells and for its selective cytotoxicity toward cancer cells. For example, C<sub>2</sub>-ceramide induced extremely low cytotoxicity in human dermal neonatal fibroblast (HDNF) cells with 66.5 μM of IC<sub>50</sub> (24 h) dosage [<xref rid="B35-ijms-20-04292" ref-type="bibr">35</xref>], and it was even more effective in the normal lung cell lines Beas-2B and MRC-5 cells [<xref rid="B36-ijms-20-04292" ref-type="bibr">36</xref>]. In the current study, we provided evidence regarding how C<sub>2</sub>-ceramide induced apoptotic cell death in two breast cancer cell lines. We found that C<sub>2</sub>-ceramide induced discrepant cytotoxicity in breast cancer cell lines MCF-7 and MDA-MB-231, with the IC<sub>50</sub> of 27.13 µM in MCF-7 and 4 µM in MDA-MB-231 respectively (<xref ref-type="fig" rid="ijms-20-04292-f001">Figure 1</xref>). Interestingly, C<sub>2</sub>-ceramide induced an extra effect of senescence phenotype in MCF-7 rather than MDA-MB-231 (<xref ref-type="fig" rid="ijms-20-04292-f002">Figure 2</xref>). Thus, this might be the main reason why MCF-7 was more resistant to C<sub>2</sub>-ceramide-induced cytotoxicity than MDA-MB-231. Twenty µM of C<sub>2</sub>-ceramide induced significant senescence-like phenotype in MCF-7 with the rise of acid ß-gal positive staining cells, whereas the same dose of C<sub>2</sub>-ceramide induced obvious apoptotic features of Annexin-V positive staining in MDA-MB-231 cells (<xref ref-type="fig" rid="ijms-20-04292-f003">Figure 3</xref>). Moreover, we found that MDA-MB-231 bear mutant <italic>p</italic>53 was also involved in C<sub>2</sub>-ceramide-induced apoptosis, suggesting that the reduction of mutant <italic>p</italic>53 was involved in the increased susceptibility of MDA-MB-231 to C<sub>2</sub>-ceramide treatment.</p><p>Senescence plays the role of tumor suppressor against cancer cell proliferation. Under normal conditions, the induction of senescence is reported as being part of <italic>p</italic>53-induced apoptosis and acts as a tumor suppressor-like signaling. The microRNA miR-34a is found to be one of the upstream regulators of senescence in the <italic>p</italic>53-related pathway [<xref rid="B37-ijms-20-04292" ref-type="bibr">37</xref>,<xref rid="B38-ijms-20-04292" ref-type="bibr">38</xref>]. The overexpression of miR-34a causes an increase of senescence and a reduction of cell proliferation of the human colon cancer HCT116 cell line via downregulation of E2F-related protein and cell cycle regulators; however, reports increasingly support a different role of senescence in promoting tumor cell resistance to therapeutic drug-induced cellular stress and cytotoxicity. An opposite role of senescence is reported as being an oncogenic protector that prevents the cell from cell death regulation in a cellular process. The senescent cell is found to escape from therapy drug-induced cell cycle arrest and sustained cell death by over-expressing Cdc2/Cdk1 kinase activity and prolonging cell cycle arrest. Survivin is reported to be an important regulator that is phosphorylated and cooperates with Cdc2/Cdk1 to inhibit apoptosis signaling, and the reverse results are shown to induce apoptosis [<xref rid="B39-ijms-20-04292" ref-type="bibr">39</xref>].</p><p>Besides, PAI-1 (plasminogen activator inhibitor-1) has been considered as a marker and a mediator of senescence [<xref rid="B40-ijms-20-04292" ref-type="bibr">40</xref>], and as an upstream regulator of <italic>p</italic>53 and down-stream of insulin-like growth factor binding protein-3, and the inhibition or any functional genetic mutation of PAI-1 would result in the resistance of senescence [<xref rid="B41-ijms-20-04292" ref-type="bibr">41</xref>]. Another senescence marker, Transglutaminase II (TGaseII), is also reported to be an aging-related senescent cell marker [<xref rid="B42-ijms-20-04292" ref-type="bibr">42</xref>]. TGaseII knockout mice present a markedly attenuated endothelial-dependent vasodilation (EDV) than that of wild-type mice, with regularly well-arranged elastic laminae of the tunica media [<xref rid="B42-ijms-20-04292" ref-type="bibr">42</xref>]. In this case, C<sub>2</sub>-ceramide may induce similar signaling transduction to initiate the senescence pathway by increasing the expression of SA-associated genes PAI-1 and TGaseII (<xref ref-type="fig" rid="ijms-20-04292-f004">Figure 4</xref>). Strong evidence shows that 20 µM of C<sub>2</sub>-ceramide significantly induced cell senescence in MCF-7 cells but not MDA-MB-231 cells, and this might provide cell protection against external stress and cell death, thus possibly explaining why MCF-7 appears more resistant to C<sub>2</sub>-ceramide-induced cytotoxicity.</p><p>Accumulated evidence supports the existence of at least two different signaling pathways to trigger cell senescence: the <italic>p</italic>53-dependent and Rb-dependent pathways [<xref rid="B43-ijms-20-04292" ref-type="bibr">43</xref>]. Moreover, Rb-dependent senescence appears to be potentially reversible after inactivating Rb expression [<xref rid="B43-ijms-20-04292" ref-type="bibr">43</xref>]. In our case, it showed that C<sub>2</sub>-ceramide activated wild-type <italic>p</italic>53 of MCF-7 cells rapidly at the early time point of 6 h, whereas the effect decreased from 12 to 24 h dramatically. Instead of <italic>p</italic>53, Rb protein sustained increase from 6 to 24 h in MCF-7 cells. We suggest that C<sub>2</sub>-ceramide induced a reversible Rb-dominant senescence-like phenotype (SLP) in MCF-7.</p><p>Most importantly, senescent cells are reported to be more inactive and resistant to induction of cell death, suggesting that cancer cells might escape death through modulating reversible SLP. For example, senescent cells harbored a low expression of Bcl-2, a marker of the pro-survival protein showing resistance to H<sub>2</sub>O<sub>2</sub>-induced cell death [<xref rid="B44-ijms-20-04292" ref-type="bibr">44</xref>]. It seems that the Rb-dependent reversible senescence activated by C<sub>2</sub>-ceramide might contribute to the finding as to why MCF-7 is more resistant to certain therapeutic drug treatments (<xref ref-type="fig" rid="ijms-20-04292-f006">Figure 6</xref>).</p><p>It has been reported that mutant <italic>p</italic>53 acts in a dominant-negative role in cancer progression and may provide cell protection. Although <italic>p</italic>53 plays a tumor-suppressor role against tumorigenesis, over 50% of breast cancer patients and 80% of triple-negative breast cancer (TNBC) patients bear mutant <italic>p</italic>53, demonstrating that mutant <italic>p</italic>53 plays a vital role in breast cancer progression [<xref rid="B45-ijms-20-04292" ref-type="bibr">45</xref>]. The cumulating data show that mutant <italic>p</italic>53 exhibits loss of tumor suppressor activity and gains the function of promoting cancer survival. In the current study, an opposite type of <italic>p</italic>53 was present in the two breast cancer cell lines, MCF-7 cells with wild type <italic>p</italic>53, and MDA-MB-231 cells with mutant <italic>p</italic>53. We found that C<sub>2</sub>-ceramide induced great inhibition of mutant <italic>p</italic>53 expression in MDA-MB-231 cells, and a slight increase of wild type <italic>p</italic>53 expression in MCF-7 cells. We provided further evidence regarding that when combined with <italic>p</italic>53 activator NSC59984, the cytotoxicity of C<sub>2</sub>-ceramide in MCF-7 cells was significantly enhanced, indicating that the activation of <italic>p</italic>53 and its downstream signaling and the anti-cancer effect induced by C<sub>2</sub>-ceramide were two individual actions, and so the effect of combined treatment was evident (<xref ref-type="fig" rid="ijms-20-04292-f005">Figure 5</xref>B). It also suggests that C<sub>2</sub>-ceramide could induce greater cytotoxicity in MCF-7 once the <italic>p</italic>53-related pathway was activated, and cells would no longer escape from Rb-mediated SLP to recover damage induced by C<sub>2</sub>-ceramide.</p><p>The effect of exogenous C<sub>2</sub>-ceramide in the endogenous long-chain sphingolipid pathway was also investigated; accordingly, exogenous ceramide analogs was determined to have great opportunity to induce or modify the endogenous ceramide species and associated signaling while activating apoptosis-related signaling. This shows that synthetic C<sub>6</sub>-ceramide in turn activated the generation of cellular C<sub>16</sub>-ceramide concentration as well as the synthetic ceramide analogs HPL-39N and HPL-1R36N induced in tumor cells. M Blaess et al. suggest that these synthetic ceramides induce a significant effect on the expression of a gene involved in cell cycle, cell growth and cell death, which contributes to apoptosis induction [<xref rid="B46-ijms-20-04292" ref-type="bibr">46</xref>]. Moreover, evidence is shown that these exogenous ceramides would be partially incorporated into the newly synthesized long-chain ceramides via the deacylation-reacylation cycle, and then cause the regulation of growth inhibition, cell cycle arrest, and modulation of telomerase activity [<xref rid="B47-ijms-20-04292" ref-type="bibr">47</xref>]. In this case, we suggest that the exogenous C<sub>2</sub>-ceramide might act in the same way while inducing breast cancer cell apoptosis due to the phenomenon of C<sub>2</sub>-ceramide in inducing cancer cell growth inhibition, as cycle arrest has been well-proven [<xref rid="B48-ijms-20-04292" ref-type="bibr">48</xref>,<xref rid="B49-ijms-20-04292" ref-type="bibr">49</xref>].</p><p>Although C<sub>2</sub>-ceramide induced great cytotoxicity in MCF-7 and MDA-MB-231 cells with different mechanisms, there is some concern about a safety issue. Recently, it has been reported that when compared with normal breast stem cells, Type I human breast epithelial cell (HBEC), C<sub>2</sub>-ceramide induces slight cytotoxicity in Type II HBECs [<xref rid="B50-ijms-20-04292" ref-type="bibr">50</xref>], suggesting that the use of C<sub>2</sub>-ceramide needs to be optimized to reduce such cytotoxicity in normal breast cells. Our previous study provides evidence regarding the usage of C<sub>2</sub>-ceramide in combination with clinical drugs for enhanced treatment efficacy [<xref rid="B36-ijms-20-04292" ref-type="bibr">36</xref>]. Combining sub-lethal C<sub>2</sub>-ceramide and Chloroquine (CQ) greatly enhances the cytotoxicity in NSCLC cells but shows extremely low cytotoxicity in normal lung cells, suggesting that it might exhibit the same alternative use of C<sub>2</sub>-ceramide in treating breast cancer cells with less burden fornormal breast tissue or epithelial cells.</p><p>Taken together, our data support that C<sub>2</sub>-ceramide induced apoptosis in two breast cancer cell lines, including MCF-7 and MDA-MB-231 cells. C<sub>2</sub>-ceramide induced high cytotoxicity in MDA-MB-231 cells by targeting mutant <italic>p</italic>53 expression. Conversely, C<sub>2</sub>-ceramide triggered senescence-signaling transduction in MCF-7 cells and resulted in MCF-7 cells escaping from C<sub>2</sub>-ceramide-induced apoptosis. The senescence phenomenon provides a reliable explanation of why certain breast cancer cells show strong chemoresistance against therapeutic drugs during the treatment process (<xref ref-type="fig" rid="ijms-20-04292-f006">Figure 6</xref>). The current study also provided an insight showing that the alternative pharmacotherapy of C<sub>2</sub>-ceramide should be provided to patients harboring genetic mutations such as <italic>p</italic>53 mutation.</p></sec><sec id="sec4-ijms-20-04292"><title>4. Materials and Methods</title><sec id="sec4dot1-ijms-20-04292"><title>4.1. Preparation of C<sub>2</sub>-Ceramide</title><p>Short carbon-chain C<sub>2</sub>-ceramide (N-Acetyl-D -sphingosine) was purchased from Sigma (#A7191, St. Louis, MO, USA) and was dissolved in DMSO (Sigma-Aldrich, Munich, Bavaria, Germany). C<sub>2</sub>-ceramide were aliquoted and stocked at −20 °C.</p></sec><sec id="sec4dot2-ijms-20-04292"><title>4.2. Reagents</title><p>DMEM/F-12 Medium, the antibiotics streptomycin/penicillin G and fetal bovine serum (FBS) were purchased from Gibco (Gaithersburg, MD, USA). The antibodies against the following proteins Bad (#sc8044) were purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). Bax (#GTX109683) was purchased from GeneTex (Irvine, CA, USA). Caspase 3 (#IMG144A) was purchased from IMGENEX (San Diego, CA, USA). p21 (#2947P) was purchased from Cell Signaling Technology (Beverly, MA, USA). <italic>p</italic>53 (#1026-1) was purchased from Epitomics (Epitomics, Burlingame, CA, USA). β-actin (#BD612656) was purchased from BD Biosciences (Franklin Lakes, NJ, USA). Horseradish peroxidase (HRP)-conjugated secondary antibodies (#20102 for goat anti-mouse IgG, #20202 for goat anti-rabbit IgG) was purchased from Leadgene Biomedical Inc. Tainan, Taiwan. The Annexin V-fluorescein isothiocyanate (FITC) kit was purchased from Strong Biotech Co. (#AVK050, Taipei, Taiwan).</p></sec><sec id="sec4dot3-ijms-20-04292"><title>4.3. Cell Cultures</title><p>The human breast cancer cell lines MCF-7 (wild type <italic>p</italic>53) and MDA-MB-231 (mutant <italic>p</italic>53) (American Type Culture Collection, Manassas, VA, USA) were maintained in the medium DMEM and F12 supplemented (1:1 ratio) with 10% fetal bovine serum (FBS; Gibco BRL, Grand Island, NY, USA) and 0.5% streptomycin/penicillin (Mediatech, Inc., Herndon, VA, USA) at 37 °C with 5% CO<sub>2</sub>.</p></sec><sec id="sec4dot4-ijms-20-04292"><title>4.4. Cell Proliferation Assessment</title><p>The cellular proliferation was assessed using a WST-1 assay. Briefly, a total of 1 × 10<sup>3</sup>/well and culture cells in 96-well plates in a final volume of 100 µL/well medium were treated with the indicated concentrations of C<sub>2</sub>-ceramide for 24 h respectively. BPIQ, a synthetic analog of camptothecin as a positive control [<xref rid="B51-ijms-20-04292" ref-type="bibr">51</xref>], was used. Ten μL/well WST-1 reagent kit (Takara Biochem., Tokyo, Japan) was added and incubated for 30 min. The absorbance of the samples against a background control as blank was measured by a microplate reader (Multiskan Ascent 354, Thermo Fisher Scientific, Rockford, IL, USA) at 450 nm.</p></sec><sec id="sec4dot5-ijms-20-04292"><title>4.5. Apoptosis Assessment</title><p>Annexin staining was performed for detecting apoptosis [<xref rid="B36-ijms-20-04292" ref-type="bibr">36</xref>]. The cells were treated with the indicated concentrations of C<sub>2</sub>-ceramide for 24 h respectively. Afterward, the cells were stained with 10 μg/mL of Annexin V-FITC, and the cells were observed by a fluorescence microscope (TE2000-U; Nikon, Tokyo, Japan).</p></sec><sec id="sec4dot6-ijms-20-04292"><title>4.6. Senescence-Associated β-Galactosidase (SA-β-gal) Staining</title><p>The staining of SA-β-gal was used for detecting the cellular senescence [<xref rid="B52-ijms-20-04292" ref-type="bibr">52</xref>]. The protocol used in the study was according to the previously published one with minor modifications [<xref rid="B48-ijms-20-04292" ref-type="bibr">48</xref>]. In brief, cells were treated with C<sub>2</sub>-ceramide for six days. Afterward, the cells were washed twice with phosphate-buffered saline (PBS) and glutaraldehyde-fixed, then 1 mg/mL of 5-bromo-4-chloro-3-indoyl-β-galactoside was added (X-gal which was dissolved in a solvent composed of dimethylformamide, five mM potassium ferrocyanide, 150 mM NaCl, 40 mM citric acid and sodium phosphate, and 2 mM MgCl<sub>2</sub>, pH6.0) for 24 h. The cells were then washed with PBS, and the β-gal (green color) stained cells were determined. Magnification 200×.</p></sec><sec id="sec4dot7-ijms-20-04292"><title>4.7. Reverse Transcription-qPCR Assessment</title><p>1 × 10<sup>6</sup> cells were treated with C<sub>2</sub>-ceramide for 24 h. The harvested cells were lysed with RNA extraction kit EasyBlue™ (iNtRON, Seoul, Korea) according to the instructions of the manufacturer. The quantity of total RNA was measured using OD<sub>260/280 nm,</sub> and then the quality was checked using electrophoresis on a 1.0% agarose gel with 2.2 M formaldehyde. The information of primer sequences is presented in <xref rid="ijms-20-04292-t001" ref-type="table">Table 1</xref>. The primers of senescence-associated genes were designed based on the study previously published [<xref rid="B48-ijms-20-04292" ref-type="bibr">48</xref>]. The PCR products were electrophoresis-resolved and densitometric-analyzed using Gel-Pro v.4.0 software (Media Cybernetics, Silver Spring, MD, USA).</p></sec><sec id="sec4dot8-ijms-20-04292"><title>4.8. Western Blotting Assay</title><p>20 μg of protein lysates were resolved using the 10% SDS-polyacrylamide gel and then transferred to a nitrocellulose membrane. The transferred NC membranes were blocked with 5% nonfat milk. Subsequently, the membranes were reacted with primary antibodies and the corresponding secondary antibodies sequentially. The signals of specific protein were detected using a chemiluminescence detection kit (ECL™, Amersham, Piscataway, NJ, USA).</p></sec><sec id="sec4dot9-ijms-20-04292"><title>4.9. Assessment of p53 Activator</title><p>The survival rates of MCF-7 cells incubated either with C<sub>2</sub>-ceramide single treatment or <italic>p</italic>53 activator co-treatment were determined using the MTS Cell Proliferation Assay Kit (Promega, Madison, WI, USA). Briefly, 1 × 10<sup>3</sup> cells were seeded and pretreated with the indicated concentrations of <italic>p</italic>53 activator NSC59984 (Cat No. B6045 APExBIO, Houston, TX, USA) prior to the treatment of indicated concentrations of C<sub>2</sub>-ceramide (Sigma-Aldrich) for 24 h. Afterward, the MTS solution was added to the cells and further incubated for 1 h at 37 °C according to the manual of the manufacturer. Afterward, the cell viability was determined using the absorbance at 490 nm using a microreader (Biorad, Model 550, Hercules, CA USA).</p></sec><sec id="sec4dot10-ijms-20-04292"><title>4.10. Statistical Analysis</title><p>All data were presented as mean ± S.D. Differences between controls and treatment groups were analyzed by Student’s <italic>t</italic>-test.</p></sec></sec></body><back><ack><title>Acknowledgments</title><p>We would like to thank the following organizations for financial support and grants listed as above. MOST106-2320-B-037-012, MOST106-2314-B-037-053-MY3 and 107-2320-B-037-023 from the Ministry of Science and Technology, Taiwan; #NSYSU-KMU107-P002 and #NSYSU-KMU108-P021 from NSYSU-KMU; #108-CCH-KMU-002 from Changhua Christian Hospital-KMU Joint Research Project, Taiwan; and KMUH106-6R36 and KMUH107-7R33 from the Kaohsiung Medical University Hospital KMUH. We would like to thank the Center for Research Resources and Development (Kaohsiung Medical University) for supporting the flow cytometer and the confocal laser scanning microscope system.</p></ack><notes><title>Author Contributions</title><p>Y.-H.L. and C.-C.C. wrote the paper. Y.-C.L., M.-T.W., K.-L.S. and S.-S.Y. performed the experiments. Y.-H.L., Y.F. and H.-M.D.W. analyzed the data and statistics. C.-Y.W. and C.-C.C. designed the research study. All authors approved the final version.</p></notes><notes><title>Funding</title><p>The study was supported by the following grants: MOST106-2320-B-037-012, MOST106-2314-B-037-053-MY3 and MOST107-2320-B-037-023 from the Ministry of Science and Technology, Taiwan; 104CMKMU006 from ChiMei-KMU Joint Research Project; #NSYSU-KMU107-P002 and #NSYSU-KMU108-P021 from NSYSU-KMU; #108-CCH-KMU-002 from Changhua Christian Hospital-KMU Joint Research Project, Taiwan; KMUH106-6R36 and KMUH107-7R33 from the Kaohsiung Medical University Hospital KMUH.</p></notes><notes notes-type="COI-statement"><title>Conflicts of Interest</title><p>The authors declare there are no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.</p></notes><ref-list><title>References</title><ref id="B1-ijms-20-04292"><label>1.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Akram</surname><given-names>M.</given-names></name><name><surname>Iqbal</surname><given-names>M.</given-names></name><name><surname>Daniyal</surname><given-names>M.</given-names></name><name><surname>Khan</surname><given-names>A.U.</given-names></name></person-group><article-title>Awareness and current knowledge of breast cancer</article-title><source>Biol. Res.</source><year>2017</year><volume>50</volume><fpage>33</fpage><pub-id pub-id-type="doi">10.1186/s40659-017-0140-9</pub-id><pub-id pub-id-type="pmid">28969709</pub-id></element-citation></ref><ref id="B2-ijms-20-04292"><label>2.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Hayflick</surname><given-names>L.</given-names></name></person-group><article-title>The limited in vitro lifetime of human diploid cell strains</article-title><source>Exp. Cell Res.</source><year>1965</year><volume>37</volume><fpage>614</fpage><lpage>636</lpage><pub-id pub-id-type="doi">10.1016/0014-4827(65)90211-9</pub-id><pub-id pub-id-type="pmid">14315085</pub-id></element-citation></ref><ref id="B3-ijms-20-04292"><label>3.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Gewirtz</surname><given-names>D.A.</given-names></name><name><surname>Holt</surname><given-names>S.E.</given-names></name><name><surname>Elmore</surname><given-names>L.W.</given-names></name></person-group><article-title>Accelerated senescence: An emerging role in tumor cell response to chemotherapy and radiation</article-title><source>Biochem. Pharm.</source><year>2008</year><volume>76</volume><fpage>947</fpage><lpage>957</lpage><pub-id pub-id-type="doi">10.1016/j.bcp.2008.06.024</pub-id><pub-id pub-id-type="pmid">18657518</pub-id></element-citation></ref><ref id="B4-ijms-20-04292"><label>4.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Mathon</surname><given-names>N.F.</given-names></name><name><surname>Lloyd</surname><given-names>A.C.</given-names></name></person-group><article-title>Milestones in cell division: Cell senescence and cancer</article-title><source>Nat. Rev. Cancer</source><year>2001</year><volume>1</volume><fpage>203</fpage><pub-id pub-id-type="doi">10.1038/35106045</pub-id><pub-id pub-id-type="pmid">11902575</pub-id></element-citation></ref><ref id="B5-ijms-20-04292"><label>5.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Choudhury</surname><given-names>A.R.</given-names></name><name><surname>Ju</surname><given-names>Z.</given-names></name><name><surname>Djojosubroto</surname><given-names>M.W.</given-names></name><name><surname>Schienke</surname><given-names>A.</given-names></name><name><surname>Lechel</surname><given-names>A.</given-names></name><name><surname>Schaetzlein</surname><given-names>S.</given-names></name><name><surname>Jiang</surname><given-names>H.</given-names></name><name><surname>Stepczynska</surname><given-names>A.</given-names></name><name><surname>Wang</surname><given-names>C.</given-names></name><name><surname>Buer</surname><given-names>J.</given-names></name><etal></etal></person-group><article-title>Cdkn1a deletion improves stem cell function and lifespan of mice with dysfunctional telomeres without accelerating cancer formation</article-title><source>Nat. Genet.</source><year>2007</year><volume>39</volume><fpage>99</fpage><lpage>105</lpage><pub-id pub-id-type="doi">10.1038/ng1937</pub-id><pub-id pub-id-type="pmid">17143283</pub-id></element-citation></ref><ref id="B6-ijms-20-04292"><label>6.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>D’Adda di Fagagna</surname><given-names>F.</given-names></name><name><surname>Reaper</surname><given-names>P.M.</given-names></name><name><surname>Clay-Farrace</surname><given-names>L.</given-names></name><name><surname>Fiegler</surname><given-names>H.</given-names></name><name><surname>Carr</surname><given-names>P.</given-names></name><name><surname>Von Zglinicki</surname><given-names>T.</given-names></name><name><surname>Saretzki</surname><given-names>G.</given-names></name><name><surname>Carter</surname><given-names>N.P.</given-names></name><name><surname>Jackson</surname><given-names>S.P.</given-names></name></person-group><article-title>A DNA damage checkpoint response in telomere-initiated senescence</article-title><source>Nature</source><year>2003</year><volume>426</volume><fpage>194</fpage><lpage>198</lpage><pub-id pub-id-type="doi">10.1038/nature02118</pub-id><pub-id pub-id-type="pmid">14608368</pub-id></element-citation></ref><ref id="B7-ijms-20-04292"><label>7.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Campisi</surname><given-names>J.</given-names></name></person-group><article-title>Cellular senescence as a tumor-suppressor mechanism</article-title><source>Trends Cell Biol.</source><year>2001</year><volume>11</volume><fpage>S27</fpage><lpage>S31</lpage><pub-id pub-id-type="doi">10.1016/S0962-8924(01)02151-1</pub-id><pub-id pub-id-type="pmid">11684439</pub-id></element-citation></ref><ref id="B8-ijms-20-04292"><label>8.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Serrano</surname><given-names>M.</given-names></name><name><surname>Lin</surname><given-names>A.W.</given-names></name><name><surname>McCurrach</surname><given-names>M.E.</given-names></name><name><surname>Beach</surname><given-names>D.</given-names></name><name><surname>Lowe</surname><given-names>S.W.</given-names></name></person-group><article-title>Oncogenic ras provokes premature cell senescence associated with accumulation of p53 and p16INK4a</article-title><source>Cell</source><year>1997</year><volume>88</volume><fpage>593</fpage><lpage>602</lpage><pub-id pub-id-type="doi">10.1016/S0092-8674(00)81902-9</pub-id><pub-id pub-id-type="pmid">9054499</pub-id></element-citation></ref><ref id="B9-ijms-20-04292"><label>9.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Braig</surname><given-names>M.</given-names></name><name><surname>Lee</surname><given-names>S.</given-names></name><name><surname>Loddenkemper</surname><given-names>C.</given-names></name><name><surname>Rudolph</surname><given-names>C.</given-names></name><name><surname>Peters</surname><given-names>A.H.</given-names></name><name><surname>Schlegelberger</surname><given-names>B.</given-names></name><name><surname>Stein</surname><given-names>H.</given-names></name><name><surname>Dorken</surname><given-names>B.</given-names></name><name><surname>Jenuwein</surname><given-names>T.</given-names></name><name><surname>Schmitt</surname><given-names>C.A.</given-names></name></person-group><article-title>Oncogene-induced senescence as an initial barrier in lymphoma development</article-title><source>Nature</source><year>2005</year><volume>436</volume><fpage>660</fpage><lpage>665</lpage><pub-id pub-id-type="doi">10.1038/nature03841</pub-id><pub-id pub-id-type="pmid">16079837</pub-id></element-citation></ref><ref id="B10-ijms-20-04292"><label>10.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Zhuang</surname><given-names>D.</given-names></name><name><surname>Mannava</surname><given-names>S.</given-names></name><name><surname>Grachtchouk</surname><given-names>V.</given-names></name><name><surname>Tang</surname><given-names>W.H.</given-names></name><name><surname>Patil</surname><given-names>S.</given-names></name><name><surname>Wawrzyniak</surname><given-names>J.A.</given-names></name><name><surname>Berman</surname><given-names>A.E.</given-names></name><name><surname>Giordano</surname><given-names>T.J.</given-names></name><name><surname>Prochownik</surname><given-names>E.V.</given-names></name><name><surname>Soengas</surname><given-names>M.S.</given-names></name><etal></etal></person-group><article-title>C-MYC overexpression is required for continuous suppression of oncogene-induced senescence in melanoma cells</article-title><source>Oncogene</source><year>2008</year><volume>27</volume><fpage>6623</fpage><lpage>6634</lpage><pub-id pub-id-type="doi">10.1038/onc.2008.258</pub-id><pub-id pub-id-type="pmid">18679422</pub-id></element-citation></ref><ref id="B11-ijms-20-04292"><label>11.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Bartkova</surname><given-names>J.</given-names></name><name><surname>Rezaei</surname><given-names>N.</given-names></name><name><surname>Liontos</surname><given-names>M.</given-names></name><name><surname>Karakaidos</surname><given-names>P.</given-names></name><name><surname>Kletsas</surname><given-names>D.</given-names></name><name><surname>Issaeva</surname><given-names>N.</given-names></name><name><surname>Vassiliou</surname><given-names>L.V.</given-names></name><name><surname>Kolettas</surname><given-names>E.</given-names></name><name><surname>Niforou</surname><given-names>K.</given-names></name><name><surname>Zoumpourlis</surname><given-names>V.C.</given-names></name><etal></etal></person-group><article-title>Oncogene-induced senescence is part of the tumorigenesis barrier imposed by DNA damage checkpoints</article-title><source>Nature</source><year>2006</year><volume>444</volume><fpage>633</fpage><lpage>637</lpage><pub-id pub-id-type="doi">10.1038/nature05268</pub-id><pub-id pub-id-type="pmid">17136093</pub-id></element-citation></ref><ref id="B12-ijms-20-04292"><label>12.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Al-Hajj</surname><given-names>M.</given-names></name><name><surname>Wicha</surname><given-names>M.S.</given-names></name><name><surname>Benito-Hernandez</surname><given-names>A.</given-names></name><name><surname>Morrison</surname><given-names>S.J.</given-names></name><name><surname>Clarke</surname><given-names>M.F.</given-names></name></person-group><article-title>Prospective identification of tumorigenic breast cancer cells</article-title><source>Proc. Natl. Acad. Sci. USA</source><year>2003</year><volume>100</volume><fpage>3983</fpage><lpage>3988</lpage><pub-id pub-id-type="doi">10.1073/pnas.0530291100</pub-id><pub-id pub-id-type="pmid">12629218</pub-id></element-citation></ref><ref id="B13-ijms-20-04292"><label>13.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Goodell</surname><given-names>M.A.</given-names></name><name><surname>McKinney-Freeman</surname><given-names>S.</given-names></name><name><surname>Camargo</surname><given-names>F.D.</given-names></name></person-group><article-title>Isolation and characterization of side population cells</article-title><source>Methods Mol. Biol.</source><year>2005</year><volume>290</volume><fpage>343</fpage><lpage>352</lpage><pub-id pub-id-type="pmid">15361673</pub-id></element-citation></ref><ref id="B14-ijms-20-04292"><label>14.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Ho</surname><given-names>M.M.</given-names></name><name><surname>Ng</surname><given-names>A.V.</given-names></name><name><surname>Lam</surname><given-names>S.</given-names></name><name><surname>Hung</surname><given-names>J.Y.</given-names></name></person-group><article-title>Side population in human lung cancer cell lines and tumors is enriched with stem-like cancer cells</article-title><source>Cancer Res.</source><year>2007</year><volume>67</volume><fpage>4827</fpage><lpage>4833</lpage><pub-id pub-id-type="doi">10.1158/0008-5472.CAN-06-3557</pub-id><pub-id pub-id-type="pmid">17510412</pub-id></element-citation></ref><ref id="B15-ijms-20-04292"><label>15.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Sionov</surname><given-names>R.V.</given-names></name><name><surname>Haupt</surname><given-names>Y.</given-names></name></person-group><article-title>The cellular response to p53: The decision between life and death</article-title><source>Oncogene</source><year>1999</year><volume>18</volume><fpage>6145</fpage><lpage>6157</lpage><pub-id pub-id-type="doi">10.1038/sj.onc.1203130</pub-id><pub-id pub-id-type="pmid">10557106</pub-id></element-citation></ref><ref id="B16-ijms-20-04292"><label>16.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Lacroix</surname><given-names>M.</given-names></name><name><surname>Toillon</surname><given-names>R.A.</given-names></name><name><surname>Leclercq</surname><given-names>G.</given-names></name></person-group><article-title>p53 and breast cancer, an update</article-title><source>Endocr. Relat. Cancer</source><year>2006</year><volume>13</volume><fpage>293</fpage><lpage>325</lpage><pub-id pub-id-type="doi">10.1677/erc.1.01172</pub-id><pub-id pub-id-type="pmid">16728565</pub-id></element-citation></ref><ref id="B17-ijms-20-04292"><label>17.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Prives</surname><given-names>C.</given-names></name><name><surname>Hall</surname><given-names>P.A.</given-names></name></person-group><article-title>The p53 pathway</article-title><source>J. Pathol.</source><year>1999</year><volume>187</volume><fpage>112</fpage><lpage>126</lpage><pub-id pub-id-type="doi">10.1002/(SICI)1096-9896(199901)187:1<112::AID-PATH250>3.0.CO;2-3</pub-id><pub-id pub-id-type="pmid">10341712</pub-id></element-citation></ref><ref id="B18-ijms-20-04292"><label>18.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>He</surname><given-names>C.</given-names></name><name><surname>Li</surname><given-names>L.</given-names></name><name><surname>Guan</surname><given-names>X.</given-names></name><name><surname>Xiong</surname><given-names>L.</given-names></name><name><surname>Miao</surname><given-names>X.</given-names></name></person-group><article-title>Mutant p53 Gain of Function and Chemoresistance: The Role of Mutant p53 in Response to Clinical Chemotherapy</article-title><source>Chemotherapy</source><year>2017</year><volume>62</volume><fpage>43</fpage><lpage>53</lpage><pub-id pub-id-type="doi">10.1159/000446361</pub-id><pub-id pub-id-type="pmid">27322648</pub-id></element-citation></ref><ref id="B19-ijms-20-04292"><label>19.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Hientz</surname><given-names>K.</given-names></name><name><surname>Mohr</surname><given-names>A.</given-names></name><name><surname>Bhakta-Guha</surname><given-names>D.</given-names></name><name><surname>Efferth</surname><given-names>T.</given-names></name></person-group><article-title>The role of p53 in cancer drug resistance and targeted chemotherapy</article-title><source>Oncotarget</source><year>2017</year><volume>8</volume><fpage>8921</fpage><lpage>8946</lpage><pub-id pub-id-type="doi">10.18632/oncotarget.13475</pub-id><pub-id pub-id-type="pmid">27888811</pub-id></element-citation></ref><ref id="B20-ijms-20-04292"><label>20.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Knappskog</surname><given-names>S.</given-names></name><name><surname>Lonning</surname><given-names>P.E.</given-names></name></person-group><article-title>P53 and its molecular basis to chemoresistance in breast cancer</article-title><source>Expert Opin. Ther. Targets</source><year>2012</year><volume>16</volume><fpage>S23</fpage><lpage>S30</lpage><pub-id pub-id-type="doi">10.1517/14728222.2011.640322</pub-id><pub-id pub-id-type="pmid">22313396</pub-id></element-citation></ref><ref id="B21-ijms-20-04292"><label>21.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Zhang</surname><given-names>S.</given-names></name><name><surname>Zhou</surname><given-names>L.</given-names></name><name><surname>Hong</surname><given-names>B.</given-names></name><name><surname>van den Heuvel</surname><given-names>A.P.J.</given-names></name><name><surname>Prabhu</surname><given-names>V.V.</given-names></name><name><surname>Warfel</surname><given-names>N.A.</given-names></name><name><surname>Kline</surname><given-names>C.L.B.</given-names></name><name><surname>Dicker</surname><given-names>D.T.</given-names></name><name><surname>Kopelovich</surname><given-names>L.</given-names></name><name><surname>El-Deiry</surname><given-names>W.S.</given-names></name></person-group><article-title>Small-molecule NSC59984 restores p53 pathway signaling and antitumor effects against colorectal cancer via p73 activation and degradation of mutant p53</article-title><source>Cancer Res.</source><year>2015</year><volume>75</volume><fpage>3842</fpage><lpage>3852</lpage><pub-id pub-id-type="doi">10.1158/0008-5472.CAN-13-1079</pub-id><pub-id pub-id-type="pmid">26294215</pub-id></element-citation></ref><ref id="B22-ijms-20-04292"><label>22.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Yan</surname><given-names>W.</given-names></name><name><surname>Zhang</surname><given-names>Y.</given-names></name><name><surname>Zhang</surname><given-names>J.</given-names></name><name><surname>Liu</surname><given-names>S.</given-names></name><name><surname>Cho</surname><given-names>S.J.</given-names></name><name><surname>Chen</surname><given-names>X.</given-names></name></person-group><article-title>Mutant p53 protein is targeted by arsenic for degradation and plays a role in arsenic-mediated growth suppression</article-title><source>J. Biol. Chem.</source><year>2011</year><volume>286</volume><fpage>17478</fpage><lpage>17486</lpage><pub-id pub-id-type="doi">10.1074/jbc.M111.231639</pub-id><pub-id pub-id-type="pmid">21454520</pub-id></element-citation></ref><ref id="B23-ijms-20-04292"><label>23.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Gordon</surname><given-names>R.R.</given-names></name><name><surname>Nelson</surname><given-names>P.S.</given-names></name></person-group><article-title>Cellular senescence and cancer chemotherapy resistance</article-title><source>Drug Resist. Updates</source><year>2012</year><volume>15</volume><fpage>123</fpage><lpage>131</lpage><pub-id pub-id-type="doi">10.1016/j.drup.2012.01.002</pub-id><pub-id pub-id-type="pmid">22365330</pub-id></element-citation></ref><ref id="B24-ijms-20-04292"><label>24.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Skolová</surname><given-names>B.</given-names></name><name><surname>Hudská</surname><given-names>K.R.</given-names></name><name><surname>Pullmannová</surname><given-names>P.</given-names></name><name><surname>Kováčik</surname><given-names>A.</given-names></name><name><surname>Palát</surname><given-names>K.</given-names></name><name><surname>Roh</surname><given-names>J.</given-names></name><name><surname>Fleddermann</surname><given-names>J.</given-names></name><name><surname>Estrela-Lopis</surname><given-names>I.</given-names></name><name><surname>Vávrová</surname><given-names>K.</given-names></name></person-group><article-title>Different phase behavior and packing of ceramides with long (C16) and very long (C24) acyls in model membranes: Infrared spectroscopy using deuterated lipids</article-title><source>J. Phys. Chem. B</source><year>2014</year><volume>118</volume><fpage>10460</fpage><lpage>10470</lpage><pub-id pub-id-type="pmid">25122563</pub-id></element-citation></ref><ref id="B25-ijms-20-04292"><label>25.</label><element-citation publication-type="book"><person-group person-group-type="author"><name><surname>Goldkorn</surname><given-names>T.</given-names></name><name><surname>Chung</surname><given-names>S.</given-names></name><name><surname>Filosto</surname><given-names>S.</given-names></name></person-group><article-title>Lung cancer and lung injury: The dual role of ceramide</article-title><source>Sphingolipids in Disease</source><publisher-name>Springer</publisher-name><publisher-loc>Berlin/Heidelberg, Germany</publisher-loc><year>2013</year><fpage>93</fpage><lpage>113</lpage></element-citation></ref><ref id="B26-ijms-20-04292"><label>26.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Flowers</surname><given-names>M.</given-names></name><name><surname>Fabriás</surname><given-names>G.</given-names></name><name><surname>Delgado</surname><given-names>A.</given-names></name><name><surname>Casas</surname><given-names>J.</given-names></name><name><surname>Abad</surname><given-names>J.L.</given-names></name><name><surname>Cabot</surname><given-names>M.C.</given-names></name></person-group><article-title>C6-ceramide and targeted inhibition of acid ceramidase induce synergistic decreases in breast cancer cell growth</article-title><source>Breast Cancer Res. Treat.</source><year>2012</year><volume>133</volume><fpage>447</fpage><lpage>458</lpage><pub-id pub-id-type="doi">10.1007/s10549-011-1768-8</pub-id><pub-id pub-id-type="pmid">21935601</pub-id></element-citation></ref><ref id="B27-ijms-20-04292"><label>27.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Demarchi</surname><given-names>F.</given-names></name><name><surname>Bertoli</surname><given-names>C.</given-names></name><name><surname>Greer</surname><given-names>P.</given-names></name><name><surname>Schneider</surname><given-names>C.</given-names></name></person-group><article-title>Ceramide triggers an NF-κB-dependent survival pathway through calpain</article-title><source>Cell Death Differ.</source><year>2005</year><volume>12</volume><fpage>512</fpage><pub-id pub-id-type="doi">10.1038/sj.cdd.4401592</pub-id><pub-id pub-id-type="pmid">15933726</pub-id></element-citation></ref><ref id="B28-ijms-20-04292"><label>28.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Xu</surname><given-names>L.</given-names></name><name><surname>Deng</surname><given-names>X.</given-names></name></person-group><article-title>Suppression of cancer cell migration and invasion by protein phosphatase 2A through dephosphorylation of μ-and m-calpains</article-title><source>J. Biol. Chem.</source><year>2006</year><volume>281</volume><fpage>35567</fpage><lpage>35575</lpage><pub-id pub-id-type="doi">10.1074/jbc.M607702200</pub-id><pub-id pub-id-type="pmid">16982626</pub-id></element-citation></ref><ref id="B29-ijms-20-04292"><label>29.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Lin</surname><given-names>I.L.</given-names></name><name><surname>Chou</surname><given-names>H.L.</given-names></name><name><surname>Lee</surname><given-names>J.C.</given-names></name><name><surname>Chen</surname><given-names>F.W.</given-names></name><name><surname>Fong</surname><given-names>Y.</given-names></name><name><surname>Chang</surname><given-names>W.C.</given-names></name><name><surname>Huang</surname><given-names>H.W.</given-names></name><name><surname>Wu</surname><given-names>C.Y.</given-names></name><name><surname>Chang</surname><given-names>W.T.</given-names></name><name><surname>Wang</surname><given-names>H.D.</given-names></name><etal></etal></person-group><article-title>The antiproliferative effect of C2-ceramide on lung cancer cells through apoptosis by inhibiting Akt and NFkappaB</article-title><source>Cancer Cell Int.</source><year>2014</year><volume>14</volume><fpage>1</fpage><pub-id pub-id-type="doi">10.1186/1475-2867-14-1</pub-id><pub-id pub-id-type="pmid">24393431</pub-id></element-citation></ref><ref id="B30-ijms-20-04292"><label>30.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chang</surname><given-names>Y.C.</given-names></name><name><surname>Fong</surname><given-names>Y.</given-names></name><name><surname>Tsai</surname><given-names>E.M.</given-names></name><name><surname>Chang</surname><given-names>Y.G.</given-names></name><name><surname>Chou</surname><given-names>H.L.</given-names></name><name><surname>Wu</surname><given-names>C.Y.</given-names></name><name><surname>Teng</surname><given-names>Y.N.</given-names></name><name><surname>Liu</surname><given-names>T.C.</given-names></name><name><surname>Yuan</surname><given-names>S.S.</given-names></name><name><surname>Chiu</surname><given-names>C.C.</given-names></name></person-group><article-title>Exogenous C (8)-Ceramide Induces Apoptosis by Overproduction of ROS and the Switch of Superoxide Dismutases SOD1 to SOD2 in Human Lung Cancer Cells</article-title><source>Int. J. Mol. Sci.</source><year>2018</year><volume>19</volume><elocation-id>3010</elocation-id><pub-id pub-id-type="doi">10.3390/ijms19103010</pub-id></element-citation></ref><ref id="B31-ijms-20-04292"><label>31.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Jiang</surname><given-names>C.</given-names></name><name><surname>Liu</surname><given-names>G.</given-names></name><name><surname>Luckhardt</surname><given-names>T.</given-names></name><name><surname>Antony</surname><given-names>V.</given-names></name><name><surname>Zhou</surname><given-names>Y.</given-names></name><name><surname>Carter</surname><given-names>A.B.</given-names></name><name><surname>Thannickal</surname><given-names>V.J.</given-names></name><name><surname>Liu</surname><given-names>R.M.</given-names></name></person-group><article-title>Serpine 1 induces alveolar type II cell senescence through activating p53-p21-Rb pathway in fibrotic lung disease</article-title><source>Aging Cell</source><year>2017</year><volume>16</volume><fpage>1114</fpage><lpage>1124</lpage><pub-id pub-id-type="doi">10.1111/acel.12643</pub-id><pub-id pub-id-type="pmid">28722352</pub-id></element-citation></ref><ref id="B32-ijms-20-04292"><label>32.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Morad</surname><given-names>S.A.</given-names></name><name><surname>Messner</surname><given-names>M.C.</given-names></name><name><surname>Levin</surname><given-names>J.C.</given-names></name><name><surname>Abdelmageed</surname><given-names>N.</given-names></name><name><surname>Park</surname><given-names>H.</given-names></name><name><surname>Merrill</surname><given-names>A.H.</given-names><suffix>Jr.</suffix></name><name><surname>Cabot</surname><given-names>M.C.</given-names></name></person-group><article-title>Potential role of acid ceramidase in conversion of cytostatic to cytotoxic end-point in pancreatic cancer cells</article-title><source>Cancer Chemother. Pharm.</source><year>2013</year><volume>71</volume><fpage>635</fpage><lpage>645</lpage><pub-id pub-id-type="doi">10.1007/s00280-012-2050-4</pub-id><pub-id pub-id-type="pmid">23263160</pub-id></element-citation></ref><ref id="B33-ijms-20-04292"><label>33.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Huang</surname><given-names>H.</given-names></name><name><surname>Zhang</surname><given-names>Y.</given-names></name><name><surname>Liu</surname><given-names>X.</given-names></name><name><surname>Li</surname><given-names>Z.</given-names></name><name><surname>Xu</surname><given-names>W.</given-names></name><name><surname>He</surname><given-names>S.</given-names></name><name><surname>Huang</surname><given-names>Y.</given-names></name><name><surname>Zhang</surname><given-names>H.</given-names></name></person-group><article-title>Acid sphingomyelinase contributes to evodiamine-induced apoptosis in human gastric cancer SGC-7901 cells</article-title><source>DNA Cell Biol.</source><year>2011</year><volume>30</volume><fpage>407</fpage><lpage>412</lpage><pub-id pub-id-type="doi">10.1089/dna.2010.1122</pub-id><pub-id pub-id-type="pmid">21294641</pub-id></element-citation></ref><ref id="B34-ijms-20-04292"><label>34.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Fabrias</surname><given-names>G.</given-names></name><name><surname>Bedia</surname><given-names>C.</given-names></name><name><surname>Casas</surname><given-names>J.</given-names></name><name><surname>Abad</surname><given-names>J.L.</given-names></name><name><surname>Delgado</surname><given-names>A.</given-names></name></person-group><article-title>Ceramidases in hematological malignancies: Senseless or neglected target?</article-title><source>Anti Cancer Agents Med. Chem.</source><year>2011</year><volume>11</volume><fpage>830</fpage><lpage>843</lpage><pub-id pub-id-type="doi">10.2174/187152011797655104</pub-id></element-citation></ref><ref id="B35-ijms-20-04292"><label>35.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Kang</surname><given-names>J.H.</given-names></name><name><surname>Garg</surname><given-names>H.</given-names></name><name><surname>Sigano</surname><given-names>D.M.</given-names></name><name><surname>Francella</surname><given-names>N.</given-names></name><name><surname>Blumenthal</surname><given-names>R.</given-names></name><name><surname>Marquez</surname><given-names>V.E.</given-names></name></person-group><article-title>Ceramides: Branched alkyl chains in the sphingolipid siblings of diacylglycerol improve biological potency</article-title><source>Bioorg. Med. Chem.</source><year>2009</year><volume>17</volume><fpage>1498</fpage><lpage>1505</lpage><pub-id pub-id-type="doi">10.1016/j.bmc.2009.01.005</pub-id><pub-id pub-id-type="pmid">19171486</pub-id></element-citation></ref><ref id="B36-ijms-20-04292"><label>36.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chou</surname><given-names>H.L.</given-names></name><name><surname>Lin</surname><given-names>Y.H.</given-names></name><name><surname>Liu</surname><given-names>W.</given-names></name><name><surname>Wu</surname><given-names>C.Y.</given-names></name><name><surname>Li</surname><given-names>R.N.</given-names></name><name><surname>Huang</surname><given-names>H.W.</given-names></name><name><surname>Chou</surname><given-names>C.H.</given-names></name><name><surname>Chiou</surname><given-names>S.J.</given-names></name><name><surname>Chiu</surname><given-names>C.C.</given-names></name></person-group><article-title>Combination Therapy of Chloroquine and C2-Ceramide Enhances Cytotoxicity in Lung Cancer H460 and H1299 Cells</article-title><source>Cancers</source><year>2019</year><volume>11</volume><elocation-id>370</elocation-id><pub-id pub-id-type="doi">10.3390/cancers11030370</pub-id><pub-id pub-id-type="pmid">30884764</pub-id></element-citation></ref><ref id="B37-ijms-20-04292"><label>37.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chang</surname><given-names>T.C.</given-names></name><name><surname>Wentzel</surname><given-names>E.A.</given-names></name><name><surname>Kent</surname><given-names>O.A.</given-names></name><name><surname>Ramachandran</surname><given-names>K.</given-names></name><name><surname>Mullendore</surname><given-names>M.</given-names></name><name><surname>Lee</surname><given-names>K.H.</given-names></name><name><surname>Feldmann</surname><given-names>G.</given-names></name><name><surname>Yamakuchi</surname><given-names>M.</given-names></name><name><surname>Ferlito</surname><given-names>M.</given-names></name><name><surname>Lowenstein</surname><given-names>C.J.</given-names></name><etal></etal></person-group><article-title>Transactivation of miR-34a by p53 broadly influences gene expression and promotes apoptosis</article-title><source>Mol. Cell</source><year>2007</year><volume>26</volume><fpage>745</fpage><lpage>752</lpage><pub-id pub-id-type="doi">10.1016/j.molcel.2007.05.010</pub-id><pub-id pub-id-type="pmid">17540599</pub-id></element-citation></ref><ref id="B38-ijms-20-04292"><label>38.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>He</surname><given-names>L.</given-names></name><name><surname>He</surname><given-names>X.</given-names></name><name><surname>Lim</surname><given-names>L.P.</given-names></name><name><surname>de Stanchina</surname><given-names>E.</given-names></name><name><surname>Xuan</surname><given-names>Z.</given-names></name><name><surname>Liang</surname><given-names>Y.</given-names></name><name><surname>Xue</surname><given-names>W.</given-names></name><name><surname>Zender</surname><given-names>L.</given-names></name><name><surname>Magnus</surname><given-names>J.</given-names></name><name><surname>Ridzon</surname><given-names>D.</given-names></name><etal></etal></person-group><article-title>A microRNA component of the p53 tumour suppressor network</article-title><source>Nature</source><year>2007</year><volume>447</volume><fpage>1130</fpage><lpage>1134</lpage><pub-id pub-id-type="doi">10.1038/nature05939</pub-id><pub-id pub-id-type="pmid">17554337</pub-id></element-citation></ref><ref id="B39-ijms-20-04292"><label>39.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Wang</surname><given-names>Q.</given-names></name><name><surname>Wu</surname><given-names>P.C.</given-names></name><name><surname>Roberson</surname><given-names>R.S.</given-names></name><name><surname>Luk</surname><given-names>B.V.</given-names></name><name><surname>Ivanova</surname><given-names>I.</given-names></name><name><surname>Chu</surname><given-names>E.</given-names></name><name><surname>Wu</surname><given-names>D.Y.</given-names></name></person-group><article-title>Survivin and escaping in therapy-induced cellular senescence</article-title><source>Int. J. Cancer</source><year>2011</year><volume>128</volume><fpage>1546</fpage><lpage>1558</lpage><pub-id pub-id-type="doi">10.1002/ijc.25482</pub-id><pub-id pub-id-type="pmid">20503268</pub-id></element-citation></ref><ref id="B40-ijms-20-04292"><label>40.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Vaughan</surname><given-names>D.E.</given-names></name><name><surname>Rai</surname><given-names>R.</given-names></name><name><surname>Khan</surname><given-names>S.S.</given-names></name><name><surname>Eren</surname><given-names>M.</given-names></name><name><surname>Ghosh</surname><given-names>A.K.</given-names></name></person-group><article-title>Plasminogen Activator Inhibitor-1 Is a Marker and a Mediator of Senescence</article-title><source>Arter. Thromb. Vasc. Biol.</source><year>2017</year><volume>37</volume><fpage>1446</fpage><lpage>1452</lpage><pub-id pub-id-type="doi">10.1161/ATVBAHA.117.309451</pub-id></element-citation></ref><ref id="B41-ijms-20-04292"><label>41.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Eren</surname><given-names>M.</given-names></name><name><surname>Boe</surname><given-names>A.E.</given-names></name><name><surname>Klyachko</surname><given-names>E.A.</given-names></name><name><surname>Vaughan</surname><given-names>D.E.</given-names></name></person-group><article-title>Role of plasminogen activator inhibitor-1 in senescence and aging</article-title><source>Semin. Thromb. Hemost.</source><year>2014</year><volume>40</volume><fpage>645</fpage><lpage>651</lpage><pub-id pub-id-type="doi">10.1055/s-0034-1387883</pub-id><pub-id pub-id-type="pmid">25173500</pub-id></element-citation></ref><ref id="B42-ijms-20-04292"><label>42.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Armstrong</surname><given-names>D.M.F.</given-names></name><name><surname>Sikka</surname><given-names>G.</given-names></name><name><surname>Armstrong</surname><given-names>A.D.C.</given-names></name><name><surname>Saad</surname><given-names>K.R.</given-names></name><name><surname>Freitas</surname><given-names>W.R.</given-names></name><name><surname>Berkowitz</surname><given-names>D.E.</given-names></name><name><surname>Fagundes</surname><given-names>D.J.</given-names></name><name><surname>Santhanam</surname><given-names>L.</given-names></name><name><surname>Taha</surname><given-names>M.O.</given-names></name></person-group><article-title>Knockdown of transglutaminase-2 prevents early age-induced vascular changes in mice1</article-title><source>Acta Cir. Bras.</source><year>2018</year><volume>33</volume><fpage>991</fpage><lpage>999</lpage><pub-id pub-id-type="doi">10.1590/s0102-865020180110000006</pub-id><pub-id pub-id-type="pmid">30517326</pub-id></element-citation></ref><ref id="B43-ijms-20-04292"><label>43.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chakradeo</surname><given-names>S.</given-names></name><name><surname>Elmore</surname><given-names>L.W.</given-names></name><name><surname>Gewirtz</surname><given-names>D.A.</given-names></name></person-group><article-title>Is Senescence Reversible?</article-title><source>Curr. Drug Targets</source><year>2016</year><volume>17</volume><fpage>460</fpage><lpage>466</lpage><pub-id pub-id-type="doi">10.2174/1389450116666150825113500</pub-id><pub-id pub-id-type="pmid">26302802</pub-id></element-citation></ref><ref id="B44-ijms-20-04292"><label>44.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Sasaki</surname><given-names>M.</given-names></name><name><surname>Kumazaki</surname><given-names>T.</given-names></name><name><surname>Takano</surname><given-names>H.</given-names></name><name><surname>Nishiyama</surname><given-names>M.</given-names></name><name><surname>Mitsui</surname><given-names>Y.</given-names></name></person-group><article-title>Senescent cells are resistant to death despite low Bcl-2 level</article-title><source>Mech. Ageing Dev.</source><year>2001</year><volume>122</volume><fpage>1695</fpage><lpage>1706</lpage><pub-id pub-id-type="doi">10.1016/S0047-6374(01)00281-0</pub-id><pub-id pub-id-type="pmid">11557274</pub-id></element-citation></ref><ref id="B45-ijms-20-04292"><label>45.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Synnott</surname><given-names>N.C.</given-names></name><name><surname>Bauer</surname><given-names>M.R.</given-names></name><name><surname>Madden</surname><given-names>S.</given-names></name><name><surname>Murray</surname><given-names>A.</given-names></name><name><surname>Klinger</surname><given-names>R.</given-names></name><name><surname>O’Donovan</surname><given-names>N.</given-names></name><name><surname>O’Connor</surname><given-names>D.</given-names></name><name><surname>Gallagher</surname><given-names>W.M.</given-names></name><name><surname>Crown</surname><given-names>J.</given-names></name><name><surname>Fersht</surname><given-names>A.R.</given-names></name><etal></etal></person-group><article-title>Mutant p53 as a therapeutic target for the treatment of triple-negative breast cancer: Preclinical investigation with the anti-p53 drug, PK11007</article-title><source>Cancer Lett.</source><year>2018</year><volume>414</volume><fpage>99</fpage><lpage>106</lpage><pub-id pub-id-type="doi">10.1016/j.canlet.2017.09.053</pub-id><pub-id pub-id-type="pmid">29069577</pub-id></element-citation></ref><ref id="B46-ijms-20-04292"><label>46.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Blaess</surname><given-names>M.</given-names></name><name><surname>Le</surname><given-names>H.P.</given-names></name><name><surname>Claus</surname><given-names>R.A.</given-names></name><name><surname>Kohl</surname><given-names>M.</given-names></name><name><surname>Deigner</surname><given-names>H.P.</given-names></name></person-group><article-title>Stereospecific induction of apoptosis in tumor cells via endogenous C16-ceramide and distinct transcripts</article-title><source>Cell Death Discov.</source><year>2015</year><volume>1</volume><fpage>15013</fpage><pub-id pub-id-type="doi">10.1038/cddiscovery.2015.13</pub-id><pub-id pub-id-type="pmid">27551447</pub-id></element-citation></ref><ref id="B47-ijms-20-04292"><label>47.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Ogretmen</surname><given-names>B.</given-names></name><name><surname>Pettus</surname><given-names>B.J.</given-names></name><name><surname>Rossi</surname><given-names>M.J.</given-names></name><name><surname>Wood</surname><given-names>R.</given-names></name><name><surname>Usta</surname><given-names>J.</given-names></name><name><surname>Szulc</surname><given-names>Z.</given-names></name><name><surname>Bielawska</surname><given-names>A.</given-names></name><name><surname>Obeid</surname><given-names>L.M.</given-names></name><name><surname>Hannun</surname><given-names>Y.A.</given-names></name></person-group><article-title>Biochemical mechanisms of the generation of endogenous long chain ceramide in response to exogenous short chain ceramide in the A549 human lung adenocarcinoma cell line. Role for endogenous ceramide in mediating the action of exogenous ceramide</article-title><source>J. Biol. Chem.</source><year>2002</year><volume>277</volume><fpage>12960</fpage><lpage>12969</lpage><pub-id pub-id-type="doi">10.1074/jbc.M110699200</pub-id><pub-id pub-id-type="pmid">11815611</pub-id></element-citation></ref><ref id="B48-ijms-20-04292"><label>48.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chen</surname><given-names>J.Y.</given-names></name><name><surname>Hwang</surname><given-names>C.C.</given-names></name><name><surname>Chen</surname><given-names>W.Y.</given-names></name><name><surname>Lee</surname><given-names>J.C.</given-names></name><name><surname>Fu</surname><given-names>T.F.</given-names></name><name><surname>Fang</surname><given-names>K.</given-names></name><name><surname>Chu</surname><given-names>Y.C.</given-names></name><name><surname>Huang</surname><given-names>Y.L.</given-names></name><name><surname>Lin</surname><given-names>J.C.</given-names></name><name><surname>Tsai</surname><given-names>W.H.</given-names></name><etal></etal></person-group><article-title>Additive effects of C (2)-ceramide on paclitaxel-induced premature senescence of human lung cancer cells</article-title><source>Life Sci.</source><year>2010</year><volume>87</volume><fpage>350</fpage><lpage>357</lpage><pub-id pub-id-type="doi">10.1016/j.lfs.2010.06.017</pub-id><pub-id pub-id-type="pmid">20624405</pub-id></element-citation></ref><ref id="B49-ijms-20-04292"><label>49.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Spyridopoulos</surname><given-names>I.</given-names></name><name><surname>Mayer</surname><given-names>P.</given-names></name><name><surname>Shook</surname><given-names>K.S.</given-names></name><name><surname>Axel</surname><given-names>D.I.</given-names></name><name><surname>Viebahn</surname><given-names>R.</given-names></name><name><surname>Karsch</surname><given-names>K.R.</given-names></name></person-group><article-title>Loss of cyclin A and G1-cell cycle arrest are a prerequisite of ceramide-induced toxicity in human arterial endothelial cells</article-title><source>Cardiovasc. Res.</source><year>2001</year><volume>50</volume><fpage>97</fpage><lpage>107</lpage><pub-id pub-id-type="doi">10.1016/S0008-6363(01)00196-1</pub-id><pub-id pub-id-type="pmid">11282082</pub-id></element-citation></ref><ref id="B50-ijms-20-04292"><label>50.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Ahn</surname><given-names>E.H.</given-names></name><name><surname>Yang</surname><given-names>H.</given-names></name><name><surname>Hsieh</surname><given-names>C.Y.</given-names></name><name><surname>Sun</surname><given-names>W.</given-names></name><name><surname>Chang</surname><given-names>C.C.</given-names></name><name><surname>Schroeder</surname><given-names>J.J.</given-names></name></person-group><article-title>Evaluation of chemotherapeutic and cancer-protective properties of sphingosine and C2-ceramide in a human breast stem cell derived carcinogenesis model</article-title><source>Int. J. Oncol.</source><year>2019</year><volume>54</volume><fpage>655</fpage><lpage>664</lpage><pub-id pub-id-type="doi">10.3892/ijo.2018.4641</pub-id><pub-id pub-id-type="pmid">30483770</pub-id></element-citation></ref><ref id="B51-ijms-20-04292"><label>51.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chiu</surname><given-names>C.C.</given-names></name><name><surname>Chou</surname><given-names>H.L.</given-names></name><name><surname>Chen</surname><given-names>B.H.</given-names></name><name><surname>Chang</surname><given-names>K.F.</given-names></name><name><surname>Tseng</surname><given-names>C.H.</given-names></name><name><surname>Fong</surname><given-names>Y.</given-names></name><name><surname>Fu</surname><given-names>T.F.</given-names></name><name><surname>Chang</surname><given-names>H.W.</given-names></name><name><surname>Wu</surname><given-names>C.Y.</given-names></name><name><surname>Tsai</surname><given-names>E.M.</given-names></name><etal></etal></person-group><article-title>BPIQ, a novel synthetic quinoline derivative, inhibits growth and induces mitochondrial apoptosis of lung cancer cells in vitro and in zebrafish xenograft model</article-title><source>BMC Cancer</source><year>2015</year><volume>15</volume><elocation-id>962</elocation-id><pub-id pub-id-type="doi">10.1186/s12885-015-1970-x</pub-id><pub-id pub-id-type="pmid">26672745</pub-id></element-citation></ref><ref id="B52-ijms-20-04292"><label>52.</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Dimri</surname><given-names>G.P.</given-names></name><name><surname>Lee</surname><given-names>X.</given-names></name><name><surname>Basile</surname><given-names>G.</given-names></name><name><surname>Acosta</surname><given-names>M.</given-names></name><name><surname>Scott</surname><given-names>G.</given-names></name><name><surname>Roskelley</surname><given-names>C.</given-names></name><name><surname>Medrano</surname><given-names>E.E.</given-names></name><name><surname>Linskens</surname><given-names>M.</given-names></name><name><surname>Rubelj</surname><given-names>I.</given-names></name><name><surname>Pereira-Smith</surname><given-names>O.</given-names></name></person-group><article-title>A biomarker that identifies senescent human cells in culture and in aging skin in vivo</article-title><source>Proc. Natl. Acad. Sci. USA</source><year>1995</year><volume>92</volume><fpage>9363</fpage><lpage>9367</lpage><pub-id pub-id-type="doi">10.1073/pnas.92.20.9363</pub-id><pub-id pub-id-type="pmid">7568133</pub-id></element-citation></ref></ref-list></back><floats-group><fig id="ijms-20-04292-f001" orientation="portrait" position="float"><label>Figure 1</label><caption><p>The inhibitory effect of C<sub>2</sub>-ceramide on breast cancer cells. Two breast cancer cell lines MCF-7 (<bold>A</bold>) and MDA-MB-231 (<bold>B</bold>) were treated with the indicated concentrations (from 5 to 50 μM) of C<sub>2</sub>-ceramide for 24 h respectively. The cell proliferation was determined using the PreMix WST-1 assay. Nought indicates the cells were treated with C<sub>2</sub>-ceramide-free solvent as vehicle control. Positive Control (PC): 0.5 μM 2,9-Bis [2-(pyrrolidin-1-yl) ethoxy]-6-{4-[2-(pyrrolidin-1-yl) ethoxy] phenyl}-11H-indeno [1,2-c] quinolin-11-one (BPIQ), a camptothecin analog. * <italic>p</italic> < 0.05 and ** <italic>p</italic> < 0.001 for C<sub>2</sub>-ceramide versus control respectively.</p></caption><graphic xlink:href="ijms-20-04292-g001"></graphic></fig><fig id="ijms-20-04292-f002" orientation="portrait" position="float"><label>Figure 2</label><caption><p>The detection of senescence-like phenotype using SA-β-gal staining. (<bold>A</bold>) MCF-7 cells were treated with the indicated doses of C<sub>2</sub>-ceramide for six days respectively. Afterward, the cells were glutaraldehyde-fixed and stained with the substrate X-gal (pH 6.0) for 24 h. Nought indicates the cells were treated with C<sub>2</sub>-ceramide-free solvent as vehicle control. (<bold>B</bold>) Breast cancer cells were cultured with 20 μM C<sub>2</sub>-ceramide respectively. The stained cells with green around the peri-nuclear regions were considered to be senescent cells.</p></caption><graphic xlink:href="ijms-20-04292-g002"></graphic></fig><fig id="ijms-20-04292-f003" orientation="portrait" position="float"><label>Figure 3</label><caption><p>The detection of apoptosis in C<sub>2</sub>-ceramide-treated breast cancer cells. MDA-MB-231 cells were treated with the indicated concentrations of C<sub>2</sub>-ceramide (from 5 to 50 μM) for 24 h respectively. (<bold>A</bold>) The cells were observed using phase-contrast microscopy. (<bold>B</bold>) Chromatin condensation is shown, a hallmark of apoptosis induced by ceramide treatment. The white arrows indicate the chromatin condensation-positive cells. (<bold>C</bold>) The fluorescence microscope-based apoptosis assessment using annexin-V conjugated FITC and Propodium Iodide dual staining. (<inline-graphic xlink:href="ijms-20-04292-i001.jpg"></inline-graphic> Annexin-V-positive, <inline-graphic xlink:href="ijms-20-04292-i002.jpg"></inline-graphic> propidium iodide and <inline-graphic xlink:href="ijms-20-04292-i003.jpg"></inline-graphic> indicates the late stage of apoptotic cells). (<bold>D</bold>) The protein changes of pro-apoptotic Bad and cleavage of caspase-3 indicate an index of proteolytic activation. Nought indicates the cells were treated with C<sub>2</sub>-ceramide-free solvent as a vehicle control. β-actin as an internal control. Scale bar: 100 μM * <italic>p</italic> < 0.05, ** <italic>p</italic> < 0.01.</p></caption><graphic xlink:href="ijms-20-04292-g003"></graphic></fig><fig id="ijms-20-04292-f004" orientation="portrait" position="float"><label>Figure 4</label><caption><p>C<sub>2</sub>-ceramide-modulated RNA expression of senescence-associated genes in breast cancer cells. The two breast cancer MCF-7 and MDA-MB-231 cell lines treated with 20 μM C<sub>2</sub>-ceramide for 24 h respectively. SA-genes PAI-1 and TGaseII expression levels increased in MCF-7 cells but not in MDA-MB-231 cells. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal control. All fold changes were normalized by the level of internal control.</p></caption><graphic xlink:href="ijms-20-04292-g004"></graphic></fig><fig id="ijms-20-04292-f005" orientation="portrait" position="float"><label>Figure 5</label><caption><p>C<sub>2</sub>-ceramide-induced apoptosis-related and senescence-related signaling pathway. (<bold>A</bold>) The expression changes of SA- and pro-apoptotic proteins in C<sub>2</sub>-ceramide-treated breast cancer cells. The two breast cancer cell lines were treated with 20 μM of C<sub>2</sub>-ceramide for 6, 12, and 24 h respectively. β-actin as an internal control. All fold changes were normalized by the level of internal control. (<bold>B</bold>) The investigation of <italic>p</italic>53 activator NSC59984 (1 µM) co-treated with C<sub>2</sub>-ceramide (5 and 20 µM respectively) 24 h for cell viability analysis. * <italic>p</italic> < 0.05.</p></caption><graphic xlink:href="ijms-20-04292-g005"></graphic></fig><fig id="ijms-20-04292-f006" orientation="portrait" position="float"><label>Figure 6</label><caption><p>A proposed mechanism whereby breast cancer cells escape C<sub>2</sub>-ceramide-induced apoptosis through modulating senesce-like phenotype. Exogenous C<sub>2</sub>-ceramide inhibits growth arrest and induces apoptosis in breast cancer MDA-MB-231 cells through down-regulating the expression of mutant <italic>p</italic>53 while up-regulating pro-apoptosis pathways, including the expression of Bax and Bad and the proteolytic activation of caspase-3. In contrast, C<sub>2</sub>-ceramide treatments that favor the induction of senescence-like phenotype might occur through the activation of Rb rather than the activation of <italic>p</italic>53-signaling of senescence. Rb-mediated senescence-like phenotype (SLP) might be reversible and confer more resistance of breast cancer MCF-7 cells to C<sub>2</sub>-ceramide. In contrast, the activation of wild type <italic>p</italic>53 using a <italic>p</italic>53 activator resensitizes MCF-7 cells to C<sub>2</sub>-ceramide, suggesting the critical role of wild type <italic>p</italic>53 in C<sub>2</sub>-ceramide-induced death in breast cancer cells. Therefore, the proposed model suggests that some cancer cells escape apoptosis induction through modulating senescence-like phenotype, whereas the <italic>p</italic>53 activation can overcome the chemoresistance and should be a promising strategy for treating cancer cells which favor stress-induced SLP. (↑, increase or upregulation; ↓, decrease or downregulation; T, attenuation or blockade).</p></caption><graphic xlink:href="ijms-20-04292-g006"></graphic></fig><table-wrap id="ijms-20-04292-t001" orientation="portrait" position="float"><object-id pub-id-type="pii">ijms-20-04292-t001_Table 1</object-id><label>Table 1</label><caption><p>Primer pairs used in the study.</p></caption><table frame="hsides" rules="groups"><thead><tr><th align="center" valign="middle" style="border-top:solid thin;border-bottom:solid thin" rowspan="1" colspan="1">Target Gene</th><th align="center" valign="middle" style="border-top:solid thin;border-bottom:solid thin" rowspan="1" colspan="1">Forward Primer (5′-3′)</th><th align="center" valign="middle" style="border-top:solid thin;border-bottom:solid thin" rowspan="1" colspan="1">Reverse Primer (5′-3′)</th><th align="center" valign="middle" style="border-top:solid thin;border-bottom:solid thin" rowspan="1" colspan="1">Size (bp)</th></tr></thead><tbody><tr><td align="center" valign="middle" rowspan="1" colspan="1">GAPDH</td><td align="center" valign="middle" rowspan="1" colspan="1">CGTCTTCACCATGGAGA</td><td align="center" valign="middle" rowspan="1" colspan="1">CGGCCATCACGCCCACAGTTT</td><td align="center" valign="middle" rowspan="1" colspan="1">310</td></tr><tr><td align="center" valign="middle" rowspan="1" colspan="1">PAI-1</td><td align="center" valign="middle" rowspan="1" colspan="1">GTGTTTCAGCAGGTGGCGC</td><td align="center" valign="middle" rowspan="1" colspan="1">CCGGAACAGCCTGAAGAAGTG</td><td align="center" valign="middle" rowspan="1" colspan="1">310</td></tr><tr><td align="center" valign="middle" rowspan="1" colspan="1">SM22</td><td align="center" valign="middle" rowspan="1" colspan="1">TGGCGTGATTCTGAGCAA</td><td align="center" valign="middle" rowspan="1" colspan="1">CTGCCAAGCTGCCCAAGG</td><td align="center" valign="middle" rowspan="1" colspan="1">534</td></tr><tr><td align="center" valign="middle" style="border-bottom:solid thin" rowspan="1" colspan="1">TGase II</td><td align="center" valign="middle" style="border-bottom:solid thin" rowspan="1" colspan="1">CTCGTGGAGCCAGTTATCAACAGCTAC</td><td align="center" valign="middle" style="border-bottom:solid thin" rowspan="1" colspan="1">TCTCGAAGTTCACCACCAGCTTGTG</td><td align="center" valign="middle" style="border-bottom:solid thin" rowspan="1" colspan="1">310</td></tr></tbody></table></table-wrap></floats-group></pmc></record>Pour manipuler ce document sous Unix (Dilib)
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