Effects of HBV-X on the malignant phenotypes of human hepatocellular carcinoma cell line SMMC-7721

Objective To study the effects of HBV-X on the malignant phenotypes of human carcinoma cell line SMMC-7721. Methods Human hepatocellular carcinoma SMMC-7721 cells were transfect-ed with plasmid pcDNA3. 1(-)-X and cells transfected with a mock plasmid served as controls. HBV-X expression was detected by using reverse transcription-polymerase chain reaction ( RT-PCR) and Western blotting, and concentrations of HBV-X, MMP-2, MMP-9 and urinase plasminogen activator (uPA) were measured by enzyme-linked immunosorbent assay (ELISA). A series of functional assays in vitro were used to monitor the changes of SMMC-7721 malignant phenotypes. Results HBV-X expression of SMMC-7721 cells was elevated after transfection. Concentrations of HBV-X, MMP-2, MMP-9 and uPA in the medium of SMMC-7721 cells after transfection were higher than those of the controls [(13.02 ± 2. 12)μg/L vs (4. 07 ±0.37)μg/L, (49.04±4.07)μg/L vs (25.15 ±5.43)μg/L, (27. 82 ±2. 25)μg/L vs (7.89± 1.27)μg/L, (10.78±3.23)μg/L vs (1.24±0.34)μg/L respectively,P<0.01]. Functional assays ire vitro indicated that SMMC-7721 cells after transfection showed higher adhensive, migrant and invasive capabilities than those of the controls [cell adhesion rate: (85.33±14.78) % vs (57.34±2.52)% ; number of outer surface cells in migrant assay: 24.3±1.9 vs 12.3±2.5; cell number in the invasive assay: 18.2± 3.2 vs 9.3±2.3 respectively.P<0.05]. Conclusion HBV-X might enhance the expression of MMP-2, MMP-9 and uPA to promote malignant phenotypes of SMMC-7721 cells. Key words: Carcinoma, hepatocellular;  HBV-X protein