title: TRIAD1 Is a Novel Transcriptional Target of p53 and Regulates Nutlin-3a-Induced Cell Death.
abstract: Nutlin-3a is a non-genotoxic, p53-activating, MDM2 inhibitor being investigated as an anticancer agent. Although Nutlin-3a selectively antagonizes the ubiquitin E3 ligase activity of MDM2, its efficacy is not entirely regulated by MDM2 levels in cancer cells. Here, we report that the cytotoxic effects of Nutlin-3a are regulated by TRIAD1 via a positive feedback loop with p53. We found that Nutlin-3a enhanced TRIAD1 transcription in a p53-dependent manner. Using in silico analysis and promoter luciferase assays, we demonstrated that p53-mediated transcription of TRIAD1 is mediated by a p53 consensus sequence in the TRIAD1 promoter region. Silencing TRIAD1 expression in wild-type p53 (p53WT) cancer cells suppressed Nutlin-3a-mediated p53 activation and p53 target gene expression. These effects were enhanced in TRIAD1-overexpressing p53WTcancer cells, but not in p53-deficient cancer cells. Furthermore, TRIAD1 knockdown significantly reduced the growth inhibitory and cytotoxic effects of Nutlin-3a in p53WTcancer cells, as demonstrated by cell viability assays, cell cycle analysis, clonogenic growth, and soft-agar colony forming assays. Together, these data indicate that TRIAD1 regulates Nutlin-3a-mediated p53 activation and the cytotoxic activity of Nutlin-3a. J. Cell. Biochem. 118: 1733-1740, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Research Institute for Molecular-Targeted Drugs, Department of Biological Engineering, Konkuk University, Seoul, 05029, Republic of Korea.
authors.forename: Junwoo
authors.initials: J
authors.lastname: Lee
authors.affiliation: Research Institute for Molecular-Targeted Drugs, Department of Biological Engineering, Konkuk University, Seoul, 05029, Republic of Korea.
authors.forename: Sungkwan
authors.initials: S
authors.lastname: An
authors.affiliation: Research Institute for Molecular-Targeted Drugs, Department of Biological Engineering, Konkuk University, Seoul, 05029, Republic of Korea.|Gene Cell Pharm Corporation, Cheongju-si, Chungcheongbuk-do 28162, Republic of Korea.
authors.forename: Yeong Min
authors.initials: YM
authors.lastname: Choi
authors.affiliation: Molecular Neurobiology Laboratory, McLean Hospital and Program in Neuroscience, Harvard Medical School, Belmont, Massachusetts, 02478.
authors.forename: Jin Hyuk
authors.initials: JH
authors.lastname: Jung
authors.affiliation: Beijing Key Laboratory of Plant Resources Research and Development, China Cosmetic Research Center, Beijing Technology and Business University, Beijing, 100048, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Beijing Key Laboratory of Plant Resources Research and Development, China Cosmetic Research Center, Beijing Technology and Business University, Beijing, 100048, P. R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Meng
authors.affiliation: Beijing Key Laboratory of Plant Resources Research and Development, China Cosmetic Research Center, Beijing Technology and Business University, Beijing, 100048, P. R. China.
authors.forename: Yinmao
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Dermatology, Konkuk University School of Medicine, Seoul, 05030, Republic of Korea.
authors.forename: Kyu Joong
authors.initials: KJ
authors.lastname: Ahn
authors.affiliation: Gene Cell Pharm Corporation, Cheongju-si, Chungcheongbuk-do 28162, Republic of Korea.
authors.forename: In-Sook
authors.initials: IS
authors.lastname: An
authors.affiliation: Research Institute for Molecular-Targeted Drugs, Department of Biological Engineering, Konkuk University, Seoul, 05029, Republic of Korea.
authors.forename: Seunghee
authors.initials: S
authors.lastname: Bae
mesh_terms: D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D007093:Imidazoles; D010879:Piperazines; D034741:RNA, Small Interfering; D016159:Tumor Suppressor Protein p53; C482205:nutlin 3; C506696:ARIH2 protein, human; D044767:Ubiquitin-Protein Ligases; D020741:rho GTP-Binding Proteins
keywords: APOPTOSIS; NUTLIN-3a; TRANSCRIPTION TARGET; TRIAD1; p53