程序性死亡配体1在肝癌小鼠的表达及鳖甲煎丸的抑制作用

Expression of programmed death ligand 1 in mice with liver cancer and inhibitory effect of Biejiajian pill

目的:研究程序性死亡配体1(PD-L1)在肝癌小鼠的表达,探讨鳖甲煎丸抑制肝癌发生的作用机制。方法:健康雄性SPF级C57BL/6小鼠24只,随机分为对照组、模型组和鳖甲煎丸组,每组8只。采用高脂高糖饮食联合腹腔注射四氯化碳(CCl4)制备小鼠肝癌模型;自第6周开始,鳖甲煎丸组给予鳖甲煎丸(1.365 g/kg)灌胃,1次/d;至第24周处死小鼠,计算各组小鼠肝脏的相对质量,记录肝脏表面结节数,测定最大结节直径,取肝组织行HE染色,并分别用荧光定量PCR和Western blot检测PD-L1 mRNA和蛋白表达。结果:模型组小鼠肝脏的相对质量、表面结节数量和结节最大直径较对照组比较均增加(P<0.05);与模型组比较,鳖甲煎丸组小鼠肝脏的相对质量、表面结节数量和结节最大直径均减少(P<0.05);模型组小鼠肝组织镜下可见肝小叶结构紊乱,有增生性结节及癌结节,肝细胞脂肪变性明显,可见核深染及核分裂,伴炎症细胞浸润及点、片状坏死灶,鳖甲煎丸组的组织病理学改变较模型组减轻;模型组小鼠肝组织PD-L1 mRNA和蛋白表达较对照组升高(P<0.05),与模型组比较,鳖甲煎丸组PD-L1 mRNA和蛋白表达均降低(P<0.05)。结论:PD-L1在肝癌小鼠的肝组织中高表达,鳖甲煎丸抑制肝癌发生的作用机制包括抑制PD-L1表达、降低肝癌细胞免疫逃逸,并改善肿瘤免疫微环境。

Objective To investigate the expression of programmed death ligand 1(PD-L1)in liver cancer mice and explore the mechanism of Biejiajian pill in inhibiting the occurrence of liver cancer.Methods Male SPF C57BL/6 mice were randomly divided into control group,model group,and Biejiajian pill group,with 8 mice in each group.A mouse liver cancer model was prepared by combining a high fat and high sugar diet with intraperitoneal injection of carbon tetrachloride.The Biejiajian pill group was given Biejiajian pill(1.365 g/kg)by gavage once a day,starting from the 6th week.At the 24th week,the mice were euthanized,and the relative liver mass of each group was calculated;the number of liver surface nodules was recorded,the maximum nodule diameter was measured,and liver tissue was taken for HE staining.In addition,the PD-L1 mRNA and protein expression were detected using fluorescence quantitative PCR and Western blot,respectively.Results The relative weight of the liver,number of surface nodules,and maximum diameter of nodules in the model group were increased compared to the control group(P<0.05);Compared with the model group,the relative weight of the liver,the number of surface nodules,and the maximum diameter of nodules in the Biejiajian pill group were decreased(P<0.05);The structure of hepatic lobules were disordered,with proliferative nodules and cancerous nodules,the fatty degeneration of hepatocyte was obvious with deep staining and mitosis of nuclei,accompanied by inflammatory cell infiltration and spot and sheet necrosis in the model group;and the histopathological changes in the Biejiajian pill group were alleviated compared with the model group.The expression of PD-L1 mRNA and protein in the liver tissue of the model group was increased compared to the control group(<0.05),while the expression of PD-L1 mRNA and protein in the Biejiajian pill group was decreased compared to the model group(<0.05).Conclusion PD-L1 is highly expressed in liver cancer mice,and the mechanism of Biejiajian pill in inhibiting the occurrence of liver cancer includes inhibiting PD-L1 expression,reducing immune escape of l hepatoma cells,and improving the tumor immune microenvironment.