Abstract: Objective To investigate the effects of sorafenib on the activity and apoptosis of hepatoma cell lines (HepG2,MHCC97-H,QGY-7701,Bel-7404 and SKHep-1) and tyrosine kinase Janus kinase and transducer and activator of transcription (JAK-STAT) signaling pathway.Methods The effects of different concentrations of sorafenib on the inhibition and apoptosis of various cell lines were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry.The messenger RNA (mRNA) and protein expression of tyrosine kinase Janus kinase 2 (JAK2) and transducer and activator of transcription 3 (STAT3) in JAK-STAT signaling pathway were detected by quantitative real time polymerase chain reaction and western blot,respectively.Results MTT showed that the half maximal inhibitory concentrations of sorafenib for HepG2,MHCC97-H,QGY-7701,Bel-7404 and SKHep-1 cell lines were (13.17±0.09) μmol/L,(9.28±0.05) μmol/L,(11.97±0.07) μmol/L,(8.49±0.06) μmol/L and (10.54±0.03) μmol/L,respectively.When the concentration of sorafenib was 20 μmol/L and the incubation time was 72 h,the inhibitory effect was the best.Compared with the control group,sorafenib could promote the cell apoptosis,as well as reduce the mRNA and protein expression of JAK2 and STAT3 in liver cancer cell lines (P<0.01).Conclusion Sorafenib can suppress the activity of liver cancer cells,induce apoptosis of cells,and inhibit the protein expression of JAK-STAT signaling pathway in tumor cells.It is suggested that JAK-STAT signaling pathway may be the target of sorafenib,and the potential target for prevention and treatment of other tumors.

Key words: Hepatocellular carcinoma cell, Flow cytometry, MTT assay, Quantitative real time polymerase chain reaction, Western blot, Tyrosine kinase Janus kinase 2 protein, Transducer and activator of transcription 3 protein