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 1×106 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 5×105 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±1.1435cm3, followed by the UDC and RNA/DC groups with mean volumes at 0.7536±0.3659cm3 and 0.3688±0.6571cm3, 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.

目的：以肿瘤细胞与树突状细胞（dendrtic cells，Dcs）相融合使融合细胞能将肿瘤抗原递呈给T细胞，并提供T细胞激活所必需的第二信号，借此激活机体的抗肿瘤免疫。方法：通过PEG法将鼠源性胃癌细胞MFC与小鼠DC进行融合(T/DC)，融合后经50Gv电子线照射，以1×106肿瘤疫苗于小鼠皮下注射免疫2次，间隔l周后接种，后一次免疫后1周于小鼠皮下接种5×105 MFC胃癌细胞。肿瘤细胞接种3周后处死实验动物，测量肿瘤大小、外周血NK活性和脾细胞CTL活性。结果：肿瘤接种后一周对照组小鼠皮下均有肿瘤生长，而T/DC免疫组均无皮下可触及的肿瘤（10/10），10天后T/DC免疫组才有4/10只鼠皮下出现可触及的肿瘤，3周后对照组肿瘤体积明显大于T/DC免疫组。经T/DC免疫后小鼠生存期明显较对照组延长，对照组于肿瘤接种后2周开始有小鼠衰竭死亡，至肿瘤接种后3周对照组仅有3只存活，T门DC免疫组有8只鼠存活，并仍有3只无肿瘤生长。经T/DC免疫后，小鼠NK活性和肿瘤特异性CTL活性均明显提高，T/DC免疫组和对照组MFC特异性CTL活性分别为30.09%和7.12%。结论：肿瘤细胞-DC融合的肿瘤疫苗可通过加强抗原递呈激活肿瘤特异性CTL而具明显的抗肿瘤活性。

To study the effect of angiogenesis inhibitor TNP-470 on the growth and metastasis of gastric cancer in vivo. Methods: Metastatic model simulating human gastric cancer was established by orthotopic implantation of histologically intact tumor tissue into gastric wall of nude mice. TNP-470 was administrated S.C. at doses of 0mg/kg, 15mg/kg, 30mg/kg, 60mg/kg every other day for eight weeks. Ten weeks after implantation, the mice were sacrificed and the tumor size measured and the presence of metastasis recorded. The microvascular density was examined by immunohistochemical staining with anti-human factor VIII antibody. Results: Compared to the untreated controls, growth of the orthotopically implanted tumor was significantly reduced in size in the mice treated with TNP-470 with an inhibition rate of 59.9%, 77.0% and 84.9% at the dosage of 15mg/kg, 30mg/kg and 60mg/kg, respectively. Tumor metastasis to the liver and peritoneum was also significantly inhibited in a dose-dependent manner. The microvascUlar density was also decreased significantly in the treated mice. Conclusion: Angiogenesis inhibitor TNP-470 has strong inhibitory effect both on tumor growth and metastasis of human gastric cancer in nude mice.