Genistein synergizes with arsenic trioxide to suppress human hepatocellular carcinoma

• Published in: Cancer science Vol. 101; no. 4; pp. 975 - 983
• Main Authors: Jiang, Hongchi, Ma, Yong, Chen, Xiaoning, Pan, Shangha, Sun, Bei, Krissansen, Geoffrey W., Sun, Xueying
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2010; Blackwell; John Wiley & Sons, Inc
• Subjects: Acetylcysteine; Animals; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Apoptosis; Apoptosis - drug effects; Arsenic; Arsenic trioxide; Arsenicals - therapeutic use; BAX protein; Bcl-2 protein; Biological and medical sciences; Blood; Butylated hydroxyanisole; Cancer therapies; Carcinoma, Hepatocellular - drug therapy; Caspase 9 - metabolism; Caspase-9; Cell cycle; Cell Line, Tumor; Cell proliferation; Cell Survival - drug effects; Cell viability; Cytochrome c; Cytosol; Cytotoxicity; Drug Synergism; Experiments; Flow cytometry; Gastroenterology. Liver. Pancreas. Abdomen; Genistein; Genistein - pharmacology; Genistein - therapeutic use; Hepatocellular carcinoma; Humans; Intracellular; Leukemia; Liver cancer; Liver Neoplasms - drug therapy; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Male; Medical sciences; Membrane potential; Mice; Mice, Nude; Microscopy; Original; Oxidants; Oxides - therapeutic use; Reactive oxygen species; Reactive Oxygen Species - metabolism; Reactive Oxygen Species - pharmacology; Solid tumors; Tumors; Xenograft Model Antitumor Assays; United States > US; China; Japan; Human; Tyrosine kinase inhibitor; Genistein; Hepatic disease; Hepatocellular carcinoma; Arsenic trioxide; Malignant tumor; Isoflavone derivatives; Flavonoid; Liver cancer; Polyphenol; Cancerology; Phenols; Digestive diseases; Cancer
• ISSN: 1347-9032; 1349-7006; 1349-7006
• DOI: 10.1111/j.1349-7006.2009.01464.x

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 (ΔΨm), 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 ΔΨm 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. (Cancer Sci 2010; 101: 975–983)