BACKGROUND: Matrix metalloproteinases (MMPs) and its natural tissue inhibitors of metalloproteinases (TIMPs) are involved in cancer progression. This study was undertaken to determine the effects of overexpression of TIMP-1 on human hepatocellular carcinoma (HCC) cell growth, proliferation, and invasion. METHODS: Employing the efifcient AdEasyTM system, recombinant adenovirus AdTIMP-1 containing full-length cDNA of TIMP-1 was generated by homologous recombination and ampliifed in 293 cells. Then, human HCC cell line (HepG2) underwent gene transfection to overexpress TIMP-1 (so-called HepG-T cells). The mRNA and protein expressions of TIMP-1 were detected with RT-PCR and Western blotting, respectively. The ultrastructure was observed with a transmission electron microscope and the proliferation of HepG-T cells was determined by MTT assay and growth curve. The potential of in vitro invasion was measured with Millicell Chamber. RESULTS:The resulting AdTIMP-1 and HepG-T cells were generated and the expression of TIMP-1 was detected in vitro. The cell proliferation curves and MTT assay showed HepG-T cells growth, and proliferation were obviously inhibited. The invasion across Matrigel-coated iflters was signiifcantly decreased compared with controls. The suppression rate of HepG-2 cells with AdhTIMP-1 transfection was 50%, and AdhTIMP-1 transfectioninhibited by more than 91.6% of the invasion into the Matrigel-coated iflter (P