The survival benefits of sorafenib treatment for patients with hepatocellular carcinoma (HCC) are limited due to drug resistance and side effects. Therefore, combinations of sorafenib with other low toxicity drugs, including arsenic trioxide (As2O3) require investigation. The present study aimed to evaluate the potency of apoptosis-induction by As2O3/sorafenib treatment in HCC cell lines, Huh7, 97H and freshly-isolated HCC cells, and also to elucidate the underlying mechanism. A total of 10 patients with HCC were enrolled in the present study. Freshly-isolated HCC cells were purified from HCC tissues collected at surgery. HCC-cell apoptosis was measured by flow cytometry using proprium iodide/Annexin-V staining. The impacts of As2O3 and/or sorafenib on Huh7, 97H and fresh-isolated HCC-cell proliferation were evaluated by Cell Counting Kit-8 assay. The expression of TNF-related apoptosis-inducing ligand (TRAIL) was determined by reverse transcription-quantitative polymerase chain reaction and western blotting. The downregulation of TRAIL protein expression was achieved using small interfering RNA. The combination of As2O3 and sorafenib had anti-proliferative and pro-apoptotic effects in the liver cancer cell line, Huh7, via increased expression of TRAIL, but not in 97H cells. TRAIL-knockdown increased the drug-resistance of Huh7 cells. Freshly-isolated HCC cells were more sensitive to the As2O3 and sorafenib combination than the single drug treatments. Overall, the combination of As2O3 and sorafenib demonstrated potent anti-tumor activity in Huh7 and freshly-isolated HCC cells via a TRAIL-dependent pathway. This may be a potential therapeutic approach for advanced HCC treatment.
Keywords: As2O3; TNF-related apoptosis-inducing ligand; apoptosis; human hepatocellular carcinoma; sorafenib.