rAd-p53 enhances the sensitivity of human gastric cancer cells to chemotherapy

AIM:To investigate potential antitumor effects of rAd-p53 by determining if it enhanced sensitivity of gastric cancer cells to chemotherapy.METHODS:Three gastric cancer cell lines with distinct levels of differentiation were treated with various doses of rAd-p53 alone,oxaliplatin(OXA) alone,or a combination of both.Cell growth was assessed with an 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide assay and the expression levels of p53,Bax and Bcl-2 were determined by immunohistochemistry.The presence of apoptosis and the expression of caspase-3 were determined using flow cytometry.RESULTS:Treatment with rAd-p53 or OXA alone inhibited gastric cancer cell growth in a time-and dosedependent manner;moreover,significant synergistic effects were observed when these treatments were combined.Immunohistochemical analysis demonstrated that treatment with rAd-p53 alone,OXA alone or combined treatment led to decreased Bcl-2 expression and increased Bax expression in gastric cancer cells.Furthermore,flow cytometry showed that rAd-p53 alone,OXA alone or combination treatment induced apoptosis of gastric cancer cells,which was accompanied by increased expression of caspase-3.CONCLUSION:rAd-p53 enhances the sensitivity of gastric cancer cells to chemotherapy by promoting apoptosis.Thus,our results suggest that p53 gene therapy combined with chemotherapy represents a novel avenue for gastric cancer treatment.