前列腺癌冷冻消融对小鼠机体抗肿瘤免疫反应的影响

目的 探讨前列腺癌冷冻消融后对机体抗肿瘤免疫反应的影响.方法 复制前列腺癌皮下移植瘤.将动物模型随机分为:对照组(A组)、手术切除组(B组)、冷冻消融组(C组).分别于治疗前、治疗后7、14、21 d取外周血、引流淋巴结、脾脏.ELISA法检测外周血干扰素(IFN)γ、白细胞介素(IL)4浓度,以IFN-γ/IL-4计算Th1/Th2比值;分离引流淋巴结、脾脏淋巴细胞,ELISPOT试验检测CD4+Th肿瘤特异性IFN-γ的分泌情况,LDH释放试验检测CD8+CTL肿瘤杀伤活性.观察各组动物肿瘤转移情况.结果 治疗后7 d,A、B、C组外周血Th1/Th2比值分别为:4.97±0.31,10.07±0.62,13.71±0.57(P<0.05).引流淋巴结每10～6个CD4+Th肿瘤特异性IFN-γ~+细胞数分别为22.3±1.0、24.0±1.2、243.4±46.2(P<0.05),引流淋巴结CD8+CTL特异杀伤活性分别为:(14.6±1.1)%、(15.2±0.8)%、(62.6±2.3)%(P<0.05).但各观察时间点A、B、C组脾脏Th细胞IFN-γ分泌及CTL细胞杀伤活性均无明显变化.术后28 d A、B、C淋巴结转移率分别为100%、80%、40%,肺转移率均为100%.结论 冷冻消融治疗前列腺癌可诱导机体Th1抗肿瘤免疫优势,并诱导引流淋巴结T细胞肿瘤特异性免疫反应,但存在一定局限性,尚需更深入研究.

Experimental study of anti-tumor immunologic response induced by cryoablation for prostate cancer

Objective To assess the anti-tumor immune response of cryoablation for prostate cancer. Methods Mouse model of prostate cancer was established. And the tumor-bearing mice were divided into three groups: control group ( Group A) , surgery group (Group B) and cryoablation group (Group C) . Blood samples were withdrawn before and at Days 7, 14, 21 post-treatment IFN-γ and IL-4 were analyzed by enzyme-linked immunosorbent assay (ELISA). Thl/Th2 ratio was estimated from the IFN-γ/IL-4 ratio. Lymphocytes of draining lymph node ( DLN) and spleen were isolated. And the post therapeutical number of tumor-specific IFN-γ~+ CD4 + Th cells was measured by the method of enzyme link immunal spot (ELISPOT). And tumor-specific cytolytic activity of CD8 + cytotoxic T lymphocyte (CTL) was measured by LDH assay. The rate of metastasis was assessed. Results At Day 7 post-treatment in Groups A, B and C, Thl/Th2 ratio was 4. 97 ± 0. 31, 10.07 ± 0. 62 and 13.71 ± 0. 57 respectively ( P < 0. 05); the number of IFN-γ~+ cells every 10~6 CD4 +Th cells in DLN 22. 3 ± 1. 0, 24.0 ± 1. 2 and 243.4 ± 46. 2 respectively; cytolytic activity of cytotoxic T lymphocyte against prostate cancer cells (14. 6 ± 1. 1) % , (15. 2 ± 0. 8) % and (62. 6 ± 2. 3) % respectively (P < 0. 05). But for T cells derived from spleen, there were no difference in IFN-γ~+ CD4 + Th cells or cytolytic activity of CTL among the groups. At Day 28 post treatment, the rate of DLN metastasis was 100% , 80% and 40% respectively. And the rates of lung metastasis were all 100%. Conclusion Cryoablation for prostate cancer can induce the Th1 advantage of anti-tumor immunity and generate the tumor-specific immune response in DLN. But the response remains limited. Further studies are warranted.