Potential of antiviral drug oseltamivir for the treatment of liver cancer.

Liver cancer is a leading cause of cancer­related mortality globally. Since hepatitis virus infections have been strongly associated with the incidence of liver cancer, studies concerning the effects of antiviral drugs on liver cancer have attracted great attention in recent years. The present study investigated the effects of two anti­hepatitis virus drugs, lamivudine and ribavirin, and one anti­influenza virus drug, oseltamivir, on liver cancer cells to assess alternative methods for treating liver cancer. MTT assays, wound healing assays, Τranswell assays, flow cytometry, immunoblotting, ELISA, immunofluorescence staining and a xenograft animal model were adopted to verify the effects of lamivudine, ribavirin and oseltamivir on liver cancer cells. Treatment with ribavirin and oseltamivir for 24 and 48 h significantly decreased the viability of both Huh-7 and HepG2 cells compared with that of THLE­3 cells in a dose­dependent manner. The subsequent investigations focused on oseltamivir, considering the more serious clinical adverse effects of ribavirin than those of oseltamivir. Significantly decreased migration and invasion were observed in both Huh-7 and HepG2 cells that were treated with oseltamivir for 24 and 48 h. In addition, oseltamivir significantly increased autophagy in Huh­7 cells, as revealed by the significantly higher ratios of LC3­II/LC3­I, increased expression of Beclin­1, and decreased expression of p62, whereas no significant increases in the expression of apoptosis­related proteins, including Apaf­1, cleaved caspase­3, and cleaved PARP­1, were detected. Notably, apoptosis and autophagy were significantly increased in HepG2 cells in the presence of oseltamivir, as revealed by the significant increases in the expression of Apaf­1, cleaved caspase­3, and cleaved PARP­1, the higher ratios of LC3­II/LC3­I, the increased expression of Beclin­1, and the decreased expression of p62. Additionally, significant inhibitory effects of oseltamivir on xenografted Huh­7 cells in athymic nude mice were observed. The present study, for the first time to the best of our knowledge, reported the differential effects of oseltamivir on inducing liver cancer cell death both in vitro and in vivo and may provide an alternative approach for treating liver cancer.