Dendritic cells with CED-3 and CED-4 siRNA is effective in prolonging DC lifetime and suppresses tumor growth in gastric cancer.

Background/Aims: We investigated effects of CED-3 and CED-4-siRNA on prolonging dendritic cell life in vivo and in vitro. Methodology: The DCs were divided into three groups: pure-DC, siRNA and CED-3 and CED-4-siRNA. we performed anti-apoptosis assays for DCs with flow cytometry. The assay for cytotoxicity assay was performed in vitro by a standard chromium assay at various effector/target ratios. Percent-specific lysis was calculated. We injected three kinds of DCs from tail vein every 3 days, we calculated tumor volume control rate and tumor weight control rate with formula. Results: The DC percentages of apoptosis of CED-3 and CED-4 siRNA group were (12.09 +/- 1.14)%. Tumor-specific CTL activity showed 82.1% specific lysis for CED-3 and CED-4-siRNA DC group and 39.4% and 40.2% specific lysis for pure DC and siRNA DC group respectively. The lysis of CED-3 and CED-4-siRNA group was higher than the any other groups (p<0.05).The experiment of transplantation tumor in BALB/C mice showed that CED-3 and CED-4-siRNA DC can inhibit mice with tumors in volume and weight. Conclusions: We found that vaccination with CED-3 and CED-4-siRNA was capable of prolonging the survival of antigen-expressing DCs, and generated a strong therapeutic effect in the treatment of gastric cancer.