title: Genistein synergizes with arsenic trioxide to suppress human hepatocellular carcinoma.
abstract: Arsenic trioxide (ATO) is of limited therapeutic benefit for the treatment of solid tumors. Genistein exhibits anticancer and pro-oxidant activities, making it a potential candidate to enhance the efficacy of ATO whose cytotoxicity is oxidation-sensitive. This study sought to determine whether genistein synergizes with ATO to combat hepatocellular carcinoma (HCC). Three human HCC cell lines, namely HepG2, Hep3B, and SK-Hep-1, were incubated with ATO, genistein, or ATO + genistein. The cells were also pretreated with antioxidant agents N-acetyl-L-cysteine (NAC) or butylated hydroxyanisole (BHA). Cell viability, apoptosis, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (DeltaPsim), expression of Bcl-2, Bax, caspase-9, and -3, and release of cytochrome c into the cytosol were examined. The synergistic effect of ATO and genistein was also assessed using HepG2 xenografts subcutaneously established in BALB/c nude mice. The results show that genistein synergized with ATO to reduce viability, induce apoptosis, and diminish the DeltaPsim of cells. The combination therapy down-regulated Bcl-2 expression, up-regulated Bax expression, enhanced the activation of caspase-9 and -3, and increased the release of cytochrome c. The synergistic effect of ATO and genistein was diminished by pretreatment with NAC or BHA. Genistein increased the production of intracellular ROS, while ATO had little effect. Genistein synergized with a low dose of ATO (2.5 mg/kg) to significantly inhibit the growth of HepG2 tumors, and suppress cell proliferation and induce apoptosis in situ. There were no obvious side effects, as seen with a high dose of ATO (5 mg/kg). Combining genistein with ATO warrants investigation as a therapeutic strategy to combat HCC.
authors.affiliation: Department of General Surgery, The Hepatosplenic Surgery Center, The First Affiliated Hospital of Harbin Medical University, Harbin, China. jianghc@vip.163.com
authors.forename: Hongchi
authors.initials: H
authors.lastname: Jiang
authors.forename: Yong
authors.initials: Y
authors.lastname: Ma
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Chen
authors.forename: Shangha
authors.initials: S
authors.lastname: Pan
authors.forename: Bei
authors.initials: B
authors.lastname: Sun
authors.forename: Geoffrey W
authors.initials: GW
authors.lastname: Krissansen
authors.forename: Xueying
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000627:therapeutic use*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy*; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004357:Drug Synergism; D019833:Genistein / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D010087:Oxides / Q000627:therapeutic use*; D017382:Reactive Oxygen Species / Q000378:metabolism / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays
chemical_list: D001152:Arsenicals; D010087:Oxides; D017382:Reactive Oxygen Species; D019833:Genistein; D053453:Caspase 9; D000077237:Arsenic Trioxide