Hepatitis B Virus Surface Antigen Promotes Stemness of Hepatocellular Carcinoma through Regulating MicroRNA-203a

Background and Aims:Patients with persistent positive hepatitis B surface antigen(HBsAg),even with a low HBVDNA load,have a higher risk of hepatocellular carcinoma(HCC)than those without HBV infection.Given that tumor stemness has a critical role in the occurrence and maintenance of neoplasms,this study aimed to explore whether HBsAg affects biological function and stemness of HCC by regulating microRNA,and to explore underlying mechanisms.Methods:We screened out miR-203a,the most significant down-regulated microRNA in the microarray analysis of HBsAg-positive samples and focused on that miRNA in the ensuing study.In vitro and in vivo functional experiments were performed to assess its regulatory function.The effect of miR-203a on stemness and the possible correlation with BMI1 were analyzed in this study.Results:MiR-203a was significantly down-regulated in HBsAg-positive HCC with the sharpest decrease shown in microarray analysis.The negative correlation between miR-203a and HBsAg expression was confirmed by quantitative real-time PCR after stimulation or overexpression/knockdown of HBsAg in cells.We demonstrated the function of miR-203a in inhibiting HCC cell proliferation,migration,clonogenic capacity,and tumor development in vivo.Furthermore,the overexpression of miR-203a remarkably increases the sensitivity of tumor cells to 5-FU treatment and decreases the proportion of HCC cells with stem markers.In concordance with our study,the survival analysis of both The Cancer Genome Atlas database and samples in our center indicated a worse prognosis in patients with low level of miR-203a.We also found that BMI1,a gene maintains the self-renewal capacity of stem cells,showed a significant negative correlation with miR-203a in HCC specimen(p<0.001).Similarly,opposite BMI1 changes after overexpression/knockdown of miR203a were also confirmed in vitro.Dual luciferase reporting assay suggested that miR-203a may regulate BMI1 expression by direct binding.Conclusions:HBsAg may promote the development of HCC and tumor stemness by inhibiting miR-203a,resulting in poor prognosis.miR-203a may serve as a crucial treatment target in HBsAg-positive HCC.More explicit mechanistic studies and animal experiments need to be conducted as a next step.

Clinicopathological and Prognostic Value of Programmed Cell Death 1 Expression in Hepatitis B Virus-related Hepatocellular Carcinoma:A Meta-analysis

Background and Aims:The efficacy of targeted programmed cell death 1/programmed death ligand 1(PD-1/PD-L1)monoclonal antibodies(mAbs)has been confirmed in many solid malignant tumors.The overexpression of PD-1/PD-L1 serves as a biomarker to predict prognosis and clinical progression.However,the role of PD-1 in patients with hepatitis B virus-related hepatocellular carcinoma(HBV-HCC)remains indeterminate.Given that HBV is the most important cause for HCC,this study aimed to investigate the prognostic and clinicopathological value of PD-1 in HBV-HCC via a meta-analysis.Methods:We searched PubMed,Embase,Scopus,the Cochrane Library,Web of Science and Google Scholar up to January 2021 for studies on the correlation between clinicopathology/prognosis and PD-1 in patients with HBV-HCC.The pooled hazard ratios(HRs)and 95%confidence intervals(CIs)were calculated to investigate the prognostic significance of PD-1 expression.The odds ratios(ORs)and 95%CIs were determined to explore the association between PD-1 expression and clinico-pathological features.Results:Our analysis included seven studies with 658 patients,which showed that high PD-1 expression was statistically correlated with poorer overall survival(HR=2.188,95%CI:[1.262-3.115],p<0.001)and disease-free survival(HR=2.743,95%CI:[1.980-3.506],p<0.001).PD-1 overexpression was correlated with multi-ple tumors(OR=2.268,95%CI:[1.209-4.257],p=0.011),high level of alpha fetoprotein(AFP;OR=1.495,95%CI:[1.005-2.223],p=0.047)and advanced Barcelona Clinic Liver Cancer(BCLC)stage(OR=3.738,95%CI:[2.101-6.651],p<0.001).Conclusions:Our meta-analysis revealed that the high level of PD-1 expression was associated with multiple tumors,high level of AFP and advanced BCLC stage.It significantly predicted a poor prognosis of HBV-HCC,which suggests that anti-PD-1 therapy for HBV-HCC patients is plausible.