title: The role of Id-1 in chemosensitivity and epirubicin-induced apoptosis in bladder cancer cells.
abstract: Recurrence and progression are the major problems in the treatment of bladder cancer. Increased expression of Id-1, a basic helix-loop-helix transcription factor, has recently been shown in several types of advanced cancer. Some studies have provided evidence to suggest that Id-1 can be considered a potential therapeutic target. The objective of this study was to investigate the role of Id-1 in the chemosensitivity of bladder cancer cells, and the effect of Id-1 on chemotherapeutic drug-induced apoptosis in bladder cancer cells. We compared the different sensitivity to epirubicin in RT112 and MGH-U1 cell lines with different Id-1 expression. Then, we transfected different vectors into RT112 and MGH-U1 respectively, and generated the stable Id-1 up-regulation and down-regulation transfectants. The results of cell viability assay showed up-regulation of Id-1 in RT112 leading to increased sensitivity in response to epirubicin, and down-regulation of Id-1 increased cellular sensitivity to epirubicin. Furthermore, the analysis of apoptosis related protein revealed that up-regulation of Id-1 suppressed epirubicin-induced apoptosis and down-regulation of Id-1 leading to increased epirubicin-induced apoptosis. Wound closure assay showed up-regulation of Id-1 leading to improved migration abilities of bladder cancer cells under chemotherapy. Our results suggest that up-regulation of Id-1 in bladder cancer cells lead to increased cell viability in response to epirubicin by its improved anti-apoptotic role, and down-regulation of Id-1 increases cellular sensitivity to epirubicin by increased anticancer drug-induced apoptosis.
authors.affiliation: Department of Urology, Peking University People's Hospital, Peking University Health Science Center, Beijing 100044, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Hu
authors.forename: Hui Ying
authors.initials: HY
authors.lastname: Han
authors.forename: Yu Liang
authors.initials: YL
authors.lastname: Wang
authors.forename: Xiao Peng
authors.initials: XP
authors.lastname: Zhang
authors.forename: Chee Wai
authors.initials: CW
authors.lastname: Chua
authors.forename: Y C
authors.initials: YC
authors.lastname: Wong
authors.forename: Xiao Feng
authors.initials: XF
authors.lastname: Wang
authors.forename: Ming Tat
authors.initials: MT
authors.lastname: Ling
authors.forename: Ke Xin
authors.initials: KX
authors.lastname: Xu
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D015251:Epirubicin / Q000494:pharmacology*; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1 / Q000032:analysis / Q000502:physiology*; D014162:Transfection; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000473:pathology
chemical_list: D000903:Antibiotics, Antineoplastic; C497453:ID1 protein, human; D051798:Inhibitor of Differentiation Protein 1; D015251:Epirubicin