OBJECTIVETo investigate the effects of matrine on the anti-tumor efficiency of TIM2 gene-modified murine hepatocarcinoma H22 cells.

METHODSA combined eukaryotic expression vector pIRES2-EGFP-TIM2 was constructed and transfected into H22 cells by lipofectamin. The monoclone of positive H22-TIM2 cells and negative control H22-EGFP cells transfected with pIRES2-EGFP vector were selected by G418 pressure and limited dilution method in turn and were inoculated to establish the tumor-bearing mouse model. Next, matrine was administered to the tumor-bearing mice and the inhibitory effect of matrine was determined.

RESULTSThe co-expression of EGFP protein and TIM2 gene was detected in H22 cells selected after TIM2 gene transfecion. After subcutaneous injection of H22-TIM2 cells, the rate of tumor formation (41%) was lower than that of H22 cells and H22-EGFP cells injection (92%) in mice. The tumor growth was significantly inhibited in mice vaccinated with H22-TIM2 cells. After the experiment was completed, the volume of tumors in mice of H22-TIM2 group was 31.34 +/- 9.21 mm3, smaller than those in H22-EGFP group (98.25 +/- 25.23)mm3 and H22 cells group (114.08 +/- 36.45)mm3 (P < 0.01). Matrine dramatically enhanced the anti-tumor efficiency of TIM2 gene-modified H22 cells, with the highest tumor inhibitory rate (IR) 90.6% among the H22-TIM2 group, matrine treatment group and H22-EGFP cells combined with matrine treatment group (69.2%, 67.5% and 70.8%, respectively) in the experimental mice.

CONCLUSIONThe tumorigenesity of H22 cells has been markedly impaired after modification by TIM2 gene. Matrine can enhance its inhibitory effect on tumors of H22-TIM2 cells in vivo. These data indicate importance to further study on the biological role of TIM2 gene in tumor immunity and explore the molecular mechanism of matrine in suppressing of tumor growth.