Abstract: To investigate the expression of the CD70 gene in hepatocellular carcinoma and its role in the immune escape of hepatocellular carcinoma. MethodsCD70 expression was determined by RTPCR. The eukaryotic expression vector（CD70pcDNA3）was constructed and transiently transfected into the HepG2 cell line. After coculturing HepG2 with Jurkat, the effects of CD70 on inhibiting lymphocyte proliferation were assessed by the Cell counting kit 8(CCK8). Results① CD70 gene presented in BEL7402 and SMMC7721 but not in HepG2. CD70 was positive in 3 cases of hepatocellular carcinoma while it was negative in 2 cases of liver tissues adjacent to cancer tissues. ② The eukaryotic expression vector (CD70pcDNA3) was successfully constructed and transiently transfected into the HepG2 cell line. The HepG2 cell line transfected with the CD70 gene can significantly inhibit the proliferation of PHAactivated Jurkat cells. The proliferation inhibition rate of Jurkat cells cocultured with HepG2 cells transfected by the CD70 gene was 65.03%, which was significantly higher than that of Jurkat cells and Jurka cells cocultured with HepG2 cells (38.01% and 30.15%). ConclusionThe CD70 gene is expressed in hepatocellular carcinoma and can inhibit the proliferation of lymphocytes. The CD70 gene may play an important role in the immune escape of hepatoma cells.

Key words: Hepatocellular carcinoma, CD70, Immune escape