title: Possible role of FLICE-like inhibitory protein (FLIP) in chemoresistant ovarian cancer cells in vitro.
abstract: Chemoresistance is a major therapeutic problem and the current knowledge on cellular mechanisms involved is incomplete. In the present study, we have investigated the possible involvement of Fas-associated death domain-like interleukin-1beta-converting enzyme (FLICE)-like inhibitory protein (FLIP) in ovarian cancer resistance by comparing chemosensitive (OV2008) and chemoresistant (C13*) ovarian cancer cells treated with cisplatin in vitro, and/or transfected with FLIP sense cDNA or FLIP small interfering RNA (siRNA) and determining FLIP protein content, cleavage of caspase-8 and caspase-3 and apoptosis. Cisplatin significantly decreased FLIP protein level, induced cleavage of caspase-8 and caspase-3 and apoptosis in a concentration-dependent manner in cisplatin-sensitive but not -resistant cells. While overexpression of FLIP-attenuated cisplatin-induced cleavage of caspase-8 and caspase-3 and apoptosis in chemosensitive cells, downregulation of FLIP in chemoresistant cells by siRNA increased apoptosis induced by cisplatin. These results suggest that FLIP plays a significant role in the regulation of apoptosis in human ovarian cancer cells and their sensitivity to cisplatin. This cell survival factor may be an important determinant in chemoresistance in ovarian cancer and may serve as a molecular target for the development of novel therapy for chemoresistant ovarian cancer.
authors.affiliation: Reproductive Biology Unit and Division of Gynecologic Oncology, Departments of Obstetrics and Gynaecology, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Abedini
authors.forename: Qing
authors.initials: Q
authors.lastname: Qiu
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Yan
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Tsang
mesh_terms: D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000633:toxicity; D018076:DNA, Complementary; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000503:physiopathology*; D034741:RNA, Small Interfering; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection
chemical_list: D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C505407:CASP3 protein, human; C505530:CASP8 protein, human; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases; D002945:Cisplatin