Abstract:
Objective:To study the effect of recombinant human adenovirus p 53injection (rAd-p 53) and Epirubicin Hy -drochloride (EPI) on human gastric cancer cells in vitro, and explore the therapeutic effect of gene therapy combined with chemotherapy on gastric cancer. Methods:The MGC- 803 human gastric adenocarcinoma cell line was treated with rAd-p 53or/and EPI or left untreated as a blank control. Cell growth, flow cytometry, Wright's staining, and cyto-immuno-chemistry were used to analyze the therapeutic efficacy of the different treatment groups. Results: After treating MGC- 803 on days 1, 2, 3 & 6, the cell inhibition rates were 34.52%, 10.53%, 58.98% and 79.17%, respectively, for rAd-p53group; 60.71%,67.29%,73.21% and 95.14%, respectively, for EPI group; and59.52%,66.17%,67.15% and 99.31%, respective-ly, for the combined group. The combined group was significantly higher than that of single agent groups (P<0.01). Based on the flow cytometry, we found that rAd-p53blocked the cell cycle at G 2/M phase ( 44.243 %) and a higher Sub-G1 peak was observed. In the combined group, the G2/M phase ( 81.734 % ) and Sub-G1 peak were significantly evident (P< 0.01). Decreased cell number, abnormal cell morphology and apoptotic cells were found under Wright's staining, and p53protein stained positively in the nucleus and cytoplasm by immunochemical analysis in rAd-p53treated group, especially in the combined treatment group. The EPI group was not different from the blank control. Conclusion:The gene therapy agent rAd-p 53has an inhibiting and apoptotic effect on MGC- 803 cells, thus it could enhance the chemotherapeutic effect of EPI on MGC-803 cells, suggesting synergism between gene therapy and chemotherapy.