title: CITED2 silencing sensitizes cancer cells to cisplatin by inhibiting p53 trans-activation and chromatin relaxation on the ERCC1 DNA repair gene.
abstract: In this study, we show that silencing of CITED2 using small-hairpin RNA (shCITED2) induced DNA damage and reduction of ERCC1 gene expression in HEK293, HeLa and H1299 cells, even in the absence of cisplatin. In contrast, ectopic expression of ERCC1 significantly reduced intrinsic and induced DNA damage levels, and rescued the effects of CITED2 silencing on cell viability. The effects of CITED2 silencing on DNA repair and cell death were associated with p53 activity. Furthermore, CITED2 silencing caused severe elimination of the p300 protein and markers of relaxed chromatin (acetylated H3 and H4, i.e. H3K9Ac and H3K14Ac) in HEK293 cells. Chromatin immunoprecipitation assays further revealed that DNA damage induced binding of p53 along with H3K9Ac or H3K14Ac at the ERCC1 promoter, an effect which was almost entirely abrogated by silencing of CITED2 or p300. Moreover, lentivirus-based CITED2 silencing sensitized HeLa cell line-derived tumor xenografts to cisplatin in immune-deficient mice. These results demonstrate that CITED2/p300 can be recruited by p53 at the promoter of the repair gene ERCC1 in response to cisplatin-induced DNA damage. The CITED2/p300/p53/ERCC1 pathway is thus involved in the cell response to cisplatin and represents a potential target for cancer therapy.
authors.affiliation: Tumor Biology Laboratory, Department of Biochemistry and Molecular Biology, Chang Gung University, 259 Wen-Hua first Road, Gueishan, Taoyuan 333, Taiwan, Republic of China Graduate Institute of Biomedical Sciences, Chang Gung University, 259 Wen-Hua first Road, Gueishan,Taoyuan 333, Taiwan, Republic of China.
authors.forename: Yu-Chin
authors.initials: YC
authors.lastname: Liu
authors.affiliation: Tumor Biology Laboratory, Department of Biochemistry and Molecular Biology, Chang Gung University, 259 Wen-Hua first Road, Gueishan, Taoyuan 333, Taiwan, Republic of China.
authors.forename: Pu-Yuan
authors.initials: PY
authors.lastname: Chang
authors.affiliation: Tumor Biology Laboratory, Department of Biochemistry and Molecular Biology, Chang Gung University, 259 Wen-Hua first Road, Gueishan, Taoyuan 333, Taiwan, Republic of China Graduate Institute of Biomedical Sciences, Chang Gung University, 259 Wen-Hua first Road, Gueishan,Taoyuan 333, Taiwan, Republic of China cckchao@mail.cgu.edu.tw.
authors.forename: Chuck C-K
authors.initials: CC
authors.lastname: Chao
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D045744:Cell Line, Tumor; D002470:Cell Survival; D002843:Chromatin / Q000378:metabolism; D002945:Cisplatin / Q000494:pharmacology* / Q000627:therapeutic use; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D050881:E1A-Associated p300 Protein / Q000378:metabolism; D004720:Endonucleases / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D057809:HEK293 Cells; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000188:drug therapy; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; C486381:CITED2 protein, human; D002843:Chromatin; D004268:DNA-Binding Proteins; D006657:Histones; D012333:RNA, Messenger; D012097:Repressor Proteins; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; C071447:ERCC1 protein, human; D004720:Endonucleases; D002945:Cisplatin