PIG11 is Involved in Hepatocellular Carcinogenesis and Its Over-expression Promotes Hepg2 Cell Apoptosis

PIG11 (p53-induced gene 11) is a p53 target gene and candidate tumour suppressor gene. In this study, the expression of PIG11 protein was detected in human hepatocellular carcinoma (HCC) and normal liver tissues with an immunohistochemical method. Compared with expression in human normal liver tissues, the expression of PIG11 protein was significantly down-regulated in human HCC tissues. In addition, a recombinant pLXSN-PIG11 retroviral vector was constructed and transfected into HepG2 cells (human hepatocellular carcinoma cell line) and the role of PIG11 in apoptosis was analyzed. The percentage (18.60%) of apoptotic cells transfected with pLXSN-PIG11 was higher than that in cells transfected with pLXSN only (6.03%) or the vehicle control (3.81%) (P<0.01). DNA gel electrophoresis showed a clear DNA ladder in pLXSN-PIG11-infected HepG2 cells. Our results suggested that the PIG11 gene is involved in carcinogenesis and development of hepatocarcinoma. Therefore, PIG11 is considered to be a new candidate liver tumour suppressor gene, and may play an important role in tumour suppression through promotion of cell apoptosis.