title: Inhibition of mTOR enhances chemosensitivity in hepatocellular carcinoma.
abstract: The present study investigated the effect of mammalian target of rapamycin (mTOR) inhibition on HCC cells in vitro and in vivo, either alone or in combination with cytotoxic agents. In vitro, HCC cell lines were exposed to RAD001, an mTOR inhibitor, either alone or in combination with cisplatin. Alone, RAD001 suppressed cell proliferation in all cell lines tested, but did not induce apoptosis. RAD001 in combination with cisplatin induced a significant increase in the number of apoptotic cells, downregulated the expression of pro-survival molecules, Bcl-2, survivin and cyclinD1, and increased the cleavage of PARP, compared to RAD001 or cisplatin alone. Transfection of p53 into the Hep3B cell line increased the sensitivity of tumor cells to cisplatin. The suppression of HCC tumor growth in vivo was enhanced by RAD001 combined with cisplatin, accompanied by a significant increase in the number of apoptotic cells in tumor tissues. This study demonstrates that inhibition of mTOR suppresses tumor growth and sensitizes tumor cells to chemocytotoxic agents.
authors.affiliation: Center for Cancer Research, Department of Surgery, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Pokfulam, Hong Kong, China.
authors.forename: Ka Ho
authors.initials: KH
authors.lastname: Tam
authors.forename: Zhen Fan
authors.initials: ZF
authors.lastname: Yang
authors.forename: Chi Keung
authors.initials: CK
authors.lastname: Lau
authors.forename: Chi Tat
authors.initials: CT
authors.lastname: Lam
authors.forename: Roberta W C
authors.initials: RW
authors.lastname: Pang
authors.forename: Ronnie T P
authors.initials: RT
authors.lastname: Poon
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D019938:Cyclin D1 / Q000096:biosynthesis; D019008:Drug Resistance, Neoplasm; D016158:Genes, p53; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009368:Neoplasm Transplantation; D011494:Protein Kinases / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D000077022:Survivin; D058570:TOR Serine-Threonine Kinases
chemical_list: D000970:Antineoplastic Agents; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D000077022:Survivin; D019938:Cyclin D1; D011494:Protein Kinases; C546842:MTOR protein, human; C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases; D002945:Cisplatin