Abstract: Objective: To investigate the effects of Rock2 on proliferation and apoptosis of hepatocellular carcinoma Huh-7 and HepG2 cell lines. Methods: The experiment was divided into untreated group, non-targeting group, PBS group and shRock2 group. Hepatocellular carcinoma Huh-7 and HepG2 cell lines were transfected with shRock2. Reverse transcriptase polymerase chain reaction and Western blot assays were used to detect the Rock2 mRNA and protein levels, respectively. Huh-7 and HepG2 cell proliferation was measured by MTT assay. Change of cell cycle was detected by PI staining method through flow cytometry and earlier apoptosis was demonstrated by Annexin V apoptosis kit. Results: The Rock2 mRNA and protein levels both noticeably decreased in shRock2 transfected Huh-7 and HepG2 cells. After the silence of Rock2, cell proliferation was blocked in the shRock2 cells compared to the control groups (P<0.01). Knockdown of Rock2 promoted cell-cycle arrest at the G0/G1 phase. But the percentage of cells in S phase and G2/M decreased compared to the control groups（P<0.01）. The earlier apoptosis rate of shRock2 Huh-7 and HepG2 cells increased. This value was significantly higher than those of the control groups (P<0.01). Conclusion: Knockdown of Rock2 led to decreased proliferation, increased apoptosis in HCC cells and Rock2 may be a new target for HCC gene therapy.

Key words: carcinoma, hepatocellular, cell proliferation, apoptosis, liver neoplasms, protein-serine-threonine kinases, transfection, 基因沉默