来那度胺抑制小鼠Lewis瘤作用机制的研究

Antitumor effect of lenalidomide on transplanted Lewis lung cancer in mice and its mechanism

目的通过观察来那度胺对Lewis荷瘤小鼠T淋巴细胞亚群/树突状细胞比例和程序性死亡受体1及其配体(PD1/PD-L1)通路的影响,探讨来那度胺经免疫途径治疗实体瘤的作用机制。方法细胞实验中,采用CCK8法和Hoechst 33258染色检测来那度胺对细胞凋亡的影响。动物实验中将小鼠设置为对照组、模型组、低剂量组和高剂量组4组,每组10只,对照组为正常小鼠,模型组、低剂量组、高剂量组为移植Lewis肺癌细胞的荷瘤小鼠,低剂量组采用1mg/kg来那度胺、高剂量组采用10mg/kg来那度胺灌胃,连续14d后处死小鼠,取肿瘤组织并称重。流式细胞术测定肿瘤浸润组织和外周血中T淋巴细胞亚群/树突状细胞比例。Western blot法测定PD1、PD-L1蛋白表达水平。结果来那度胺对Lewis肺癌细胞株无明显细胞毒性,但在小鼠体内可以抑制肿瘤的生长,增加肿瘤浸润组织和外周血中T淋巴细胞亚群/树突状细胞比例,且高剂量组效果优于低剂量组(均P<0.05)。来那度胺还可以降低肿瘤组织中PD1、PD-L1蛋白表达水平。结论来那度胺对Lewis肺癌细胞株无细胞毒性,抗肿瘤作用与提高体内免疫功能,减小免疫抑制有关。

Objective To investigate the effect of lenalidomide on Lewis lung cancer transplanted in mice and its mechanism. Methods Lewis lung cancer cells were treated with lenalidomide at the concentrations of 1, 5, 10, 20, 40 and 80μM for 24, 48 and 72h, and cell proliferation and apoptosis were detected with CCK8 and Hoechst 33258 staining, respectively. Forty male C57BL/6J mice were divided into four groups： control group, model group, low-dose group and high-dose group with 10 mice in each group. The Lewis lung cancer cells were inoculated in the last three groups, and 1mg/kg and 10mg/kg of lenadomide were given by gavage for 14d in low-dose group and high-dose group, respectively. The mice were sacrificed and the tumor tissues were taken and weighed. The proportion of T lymphocyte subsets/dendritic cells in tumor infiltrating tissues and peripheral blood was measured by flow cytometry. The expression level of PD1 and PD-L1 protein was determined by Western blot. Results Lenalidomide has no significant cytotoxicity in Lewis lung cancer cells, but it can inhibit the growth of tumor, increased tumor infiltrating T lymphocyte subsets/dendritic cells ratio, and the effect of high dose group was more marked than that of the low dose group（all P〈0.05）. Lenalidomide also significantly reduced the protein expression of PD1 and PD-L1 in the tumor tissues. Conclusion Lenalidomide has no cytotoxicity to Lewis lung cancer cells. The antitumor effect on Lewis tumor-bearing mice may be related to enhancing the immune function and reducing the immunosuppression.