Involvement of SEPT4_i1 in hepatocellular carcinoma: SEPT4_i1 regulates susceptibility to apoptosis in hepatocellular carcinoma cells.

SEPT4 belongs to the Septin family with multiple functions in cell division, cytoskeletal organization and other processes. This study aims to investigate the relationship between SEPT4_i1 isoform and human hepatocellular carcinoma (HCC). We showed that over-expression of SEPT4_i1 in HCC cells was able to sensitize cells to serum starvation-induced apoptosis. By contrast, knockdown of SEPT4_i1 expression in HCC cells was able to rescue cells from apoptosis induced by serum deprivation and to promote cell growth. Expressional analysis of SEPT4_i1 in tumor tissues further revealed that SEPT4_i1 was significantly down-regulated in human HCC tissues. Taken together, these data suggests a tumor suppressor role of SEPT4_i1 in HCC through regulating HCC cell apoptosis.