EPAS1 Promoter Hypermethylation is a Diagnostic and Prognostic Biomarker for Non-Small Cell Lung Cancer

The importance of promoter methylation in non-small cell lung cancers (NSCLC) remains to be understood. Thus, we aimed to determine the diagnostic and prognostic value of the methylation of the endothelial PAS domain containing protein-1 (EPAS1) promoter in NSCLC. EPAS1 promoter methylation levels were quantitated by methylation-specific PCR. Further, we evaluated the expression, promoter methylation, prognostic value, and impact on immune cell infiltration of EPAS1 by analyzing the TCGA database using web-based bioinformatics tools including GEPIA, UALCAN and MethSurv. Our results demonstrated that promoter methylation of EPAS1 downregulated its expression in NSCLC tissues. Additionally, an AUC value of 0.772 indicated that the methylation of the EPAS1 promoter is a potential diagnostic marker for NSCLC. A Kaplan-Meier analysis demonstrated that high methylation levels of CpG sites in the EPAS1 promoter were indicative of poorer overall survival. Further, EPAS1 expression levels were highly correlated with the infiltration of several types of immune cells, including γδ T cells, T follicular helper cells, CD8+ T cells, and CD4+ T-cells. Collectively, our findings suggest that methylation analyses of the EPAS1 promoter could be used as a prognostic biomarker for NSCLC and that EPAS1 potentially plays an important role in immune cell infiltration in NSCLC.