Involvement of proliferation of atypical hepatocytes and CDT 1 in the liver cancer of rats administered the diethylnitrosamine

Hepatoprotective effects of aspirin on diethylnitrosamine-induced hepatocellular carcinoma in rats by reducing inflammation levels and PD-L1 expression

Aspirin, as a widely used anti-inflammatory drug, has been shown to exert anti-cancer effects in a variety of cancers. PD-L1 is widely expressed in tumor cells and inhibits anti-tumor immunity. This study aims to clarify whether aspirin exerts its anti-hepatocellular carcinoma (HCC) effect by inhibiting PD-L1 expression. The rat model of HCC was established by drinking 0.01% diethylnitrosamine (DEN), and aspirin was given by gavage. The gross and blood biochemical indexes of rats were analyzed. CD4 and CD8 expression in liver tissues were investigated by immunohistochemistry. CCK8 assay was used to detect the inhibitory effect of aspirin on the proliferation of HCC cells. The regulatory effect of aspirin on PD-L1 expression was analyzed by western blot. As a result, the tumor number and liver weight ratio in the DEN + ASA group were lower than those in the DEN group (P = 0.006, P = 0.046). Compared with the DEN group, the expression of CD4 in the DEN + ASA group was significantly increased, while CD8 was decreased (all P < 0.01). Biochemical indexes showed that there were differences in all indexes between the DEN and control group (P < 0.05). The levels of DBIL, ALP, and TT in the DEN + ASA group were lower than those in the DEN group (P = 0.038, P = 0.042, P = 0.031). In the DEN group, there was an obvious fibrous capsule around the tumor, and the portal vein was dilated. The pathological changes were mild in the DEN + ASA group. Compared with the DEN group, the expression of PD-L1 in liver tissue of the DEN + ASA group was decreased (P = 0.0495). Cytological experiments further showed that aspirin could inhibit the proliferation and PD-L1 expression in Hep G2 and Hep 3B cells. In conclusion, aspirin can inhibit the proliferation of HCC cells and reduce tumor burden by reducing inflammation and targeting PD-L1.

The significance of CDT1 expression in non-cancerous and cancerous liver in cases with hepatocellular carcinoma

We previously reported that chromatin licensing and DNA replication factor 1 (CDT1) expression was associated with the extent of proliferation of atypical hepatocytes and the time to postoperative recurrence in cases of hepatocellular carcinoma (HCC). This study aimed to clarify the clinical significance or pathogenesis of CDT1 expression in both non-cancerous and cancerous liver in HCC cases, including previously published data. We investigated the association between the expression of CDT1 in non-cancerous or cancerous liver tissues and histologic findings or biochemical examination results in 62 cases. We also examined the dual localization between CDT1 and FbxW7, P57kip2, P53 and c-Myc by confocal laser scanning microscopy. CDT1 mRNA expression was significantly higher in cancerous liver than in non-cancerous liver (p<0.0001). Elevated CDT1 mRNA expression indicates a significantly degree of inflammatory cell infiltration within lobules, along with elevated serum transaminase levels, and hepatic spare decline. CDT1 mRNA was highly expressed in a group of poorly differentiated cancer cells. CDT1 co-localized with P57kip2, Fbwx7, P53 and c-Myc in the nucleus or cytoplasm of hepatocytes and cancer cells. We found that CDT1 mRNA expression could represent the degree of hepatic spare ability and the high carcinogenic state.