RAD51AP1 as an immune-related prognostic biomarker and therapeutic response predictor in hepatocellular carcinoma

Abstract

Abstract RAD51 associated protein 1 (RAD51AP1) has been showed that regulated cell proliferation and cancer progression. However, the immune infiltrating correlation and therapeutics guidance of RAD51AP1 in hepatocellular carcinoma (HCC) still need further investigation. In this study, differential expression, clinicopathologic correlation, prognostic value, and function enrichment analysis of RAD51AP1 were performed in TCGA, GSE14520, GSE76427 and ICGC datasets and were validated using Guangxi cohort. We explored the predictive value of RAD51AP1 to therapeutics response comprehensively and probed the correlation between RAD51AP1 and HCC immunoinfiltration by CIBERSORT and ssGSEA. RAD51AP1 with a high diagnostic accuracy was significantly overexpressed in HCC tissues. The shorter survival time and poorer clinical features were showed when RAD51AP1 upregulated. A nomogram featuring RAD51AP1 and clinicopathologic factors was established to predict OS of HCCs. RAD51AP1 might be engaged in the carcinogenic and celluar cycle processes. In CIBERSORT analysis, higher T cells follicular helper but lower T cells CD4 + memory resting infiltrations were exhibited when RAD51AP1 upregulated. T demonstrated that High-RAD51AP1 expression subgroup had higher macrophages, Th2 and Treg cells infiltration, but lower type Ⅱ IFN response function in ssGSEA analysis, exhibited the upregulated immune-related checkpoint expression levels, lower IPS and TIDE scores, suggesting a better immunotherapy response, and may be more susceptible to Bexarotene, Doxorubicin, Gemcitabine and Tipifarnib. Taken together, RAD51AP1 mediating the immunosuppressive microenvironment is a potential diagnostic and prognostic biomarker and could be underlying HCC treatment strategy.