树突状细胞免疫治疗辅助放射治疗抑制小鼠肾癌移植瘤的生长

Inhibitory effect of intratumoral dendritic cells injection combined with radiotherapy on growth of renal carcinoma

目的：研究树突状细胞免疫治疗联合放射治疗对小鼠肾癌移植瘤的作用。方法：BALB／c小鼠右腋皮下注射2．5×10^6 Renca肾癌细胞制作移植瘤模型，分为无治疗对照组、单纯放疗组、单纯DC治疗组和DC联合放疗组4组进行治疗。皮下荷瘤的BALB／c小鼠，在第12～16天连续5d接受肿瘤局部放射治疗，6脉伏电子线，7Gy／次，并于第11、15、19和22天分别4次在肿瘤部位直接注射未负载肿瘤抗原的DC细胞（1×10^6／次），第28天处死小鼠。检测各组肿瘤生长速度和瘤体重量，ELISA检测小鼠脾细胞IL-2、IFN-γ、IL-4和IL-10分泌水平。结果：与单纯治疗组比较，DC联合放疗组小鼠的肿瘤生长明显缓慢，体积明显减小，脾细胞分泌的IL-2、IFN-γ和IL-4的能力显著提高，与其它各组比较均有非常显著性差异（P＜0．01）。结论：瘤内DC注射免疫治疗联合放疗能够有效地抑制BALB／c小鼠肾癌移植瘤生长，其效果明显好于单一方法治疗。

Objective： To study the effect of radiotherapy （RT） on dendritic cell （DC） -based immunotherapy of renal cancer in mice. Methods： Mice s. c. renal carcinoma models were established by transplanting Renca renal carcinoma cells and were divided into control group, single radiotherapy group, single DC injection group, and DC injection plus radiotherapy group. Mice in the last group received radiotherapy （7 Gy/time） on d 12-16 after inoculated with renal carci- noma cells （2.5×10^6） ; and on d 11, 15, 19 and 22, bone marrow-derived un-pulsed DCs （without tumor antigen, 106 every time） were injected into the tumors of model mice. Mice were sacrificed on day 28 and the growth rate, weight and size of tumors were measured. IL-2, IFN-γ, IL-4 and IL-10 in the splenocytes were determined by ELISA assay. Resuits： Compared with single DCs and single RT group, DCs plus RT group had an obviously decreased growth rate and tumor size, but the splenocytes had an increased secretion of IL-2, IFN-γ and IL-4 compared with other groups （P〈0. 01 ）. Conclusion： Intra-tumor DCs injection combined with radiotherapy can effectively inhibit the growth of renal carcinoma growth in BALB/c mice; its effect is better than any of the single strategy.