Antitumor effects of vaccine consisting of dendritic cells pulsed with tumor RNA from gastric cancer

AIM: To investigate the immunotherapeutic potential of vaccine consisting of dendritic cells (DCs) pulsed with total RNA from MFC gastric cancer cells. METHODS: DCs were prepared from the spleens of strain 615 mice by magnetic cell sorting (MACS). After culture for 24 h, DCs were pulsed with total RNA from MFC gastric cancer cells. Mice of one group were immunized with tumor RNA pulsed DC (RNA/DC) at the dosage of 1x10(6) on d 14 and 7 by s c inoculation before tumor implantation. Mice of another group were immunized with unpulsed DC (UDC) at the same dosage on days as the RNA/DC group. The third group of control mice was untreated. On d 0, all the mice were challenged with s c injections of 5x10(5) MFC gastric cancer cells. After inoculation, the mice were monitored closely with respect to tumor growth. Activities of NK cells in PBL and splenocytes and CTL were tested. RESULTS: On d 21 after tumor cell inoculation, the mice of control group manifested the largest tumors with volume at a mean of 2.6323 +/- 1.1435 cm(3), followed by the UDC and RNA/DC groups with mean volumes at 0.7536 +/- 0.3659 cm(3) and 0.3688 +/- 0.6571 cm(3), respectively. The activities of NK cells in PBL and splenocytes in RNA/DC group were 66.2% and 65.4%, respectively, higher than that in the control group. The tumor specific CTL activity in RNA/DC group was 49.5%, higher than that in the control group. CONCLUSION: The tumor vaccine with DCs pulsed with total RNA from gastric cancer cells possesses the ability to stimulate tumor specific CTL activity and to establish antitumor immunity when administered in vivo.