Expression of programmed death ligand 1 in mice with liver cancer and inhibitory effect of Biejiajian pill
LI Xin，CUI Jia-lin，ZHAO Dan
Abstract:
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 Biejia Jianwan 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 (P<0.05), while the expression of PD-L1 mRNA and protein in the BiejiaJian pill group was decreased compared to the model group (P<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.
