OBJECTIVETo explore the effects of overexpression of human tissue inhibitors of metalloproteinase-1 (hTIMP-1) on proliferation, invasion, metastasis, angiogenesis, and apoptosis in human hepatocellular carcinoma (HCC) cells in vitro and in vivo.

METHODSRecombinant adenoviral vector containing hTIMP-1 (AdhTIMP-1) was constructed previously. HepG2 cells were infected by AdhTIMP-1 and the changes of cell proliferation and invasion were detected in vitro. The anticancer activity of AdhTIMP-1 was evaluated in BAL B/c mice bearing HCC. Tumor volume and pulmonary metastases were observed. The mechanisms underlying the antitumor effect in vivo were investigated based on detection of microvessel density and apoptosis in tumor tissues.

RESULTSThe resultant AdhTIMP-1 was successfully constructed and the expression of hTIMP-1 was detected by Western blot and RT-PCR. AdTIMP-1 could effectively infect HepG2 cells and significantly inhibit the proliferative activity and invasive ability of the tumor cells. Compared with the controls, pre-infection of HepG2 cells by AdhTIMP-1 resulted in a significant inhibition of tumor formation by 75. 8%. A single local injection of AdhTIMP-1 into pre-established tumors significantly reduced the tumor growth rate by 45.4%, tumor-associated angiogenesis index by 47.8%, lung metastases by 70.4%, and showed a 3-fold increase of apoptotic tumor cells.

CONCLUSIONOur data indicated that AdhTIMP-1 can significantly attenuate tumor proliferation and invasion, reduce metastasis, inhibit angiogenesis, and induce apoptosis in HCC-bearing mice and may pave the way for further liver cancer gene therapy.