Integrative genomic and epigenomic analyses identified IRAK1 as a novel target for chronic inflammation-driven prostate tumorigenesis

The impacts of many inflammatory genes in prostate tumorigenesis remain understudied despite the increasing evidence that associates chronic inflammation with prostate cancer (PCa) initiation, progression, and therapy resistance. The overarching goal of this study was to identify dysregulated inflammatory genes that correlate with PCa progression and decipher their molecular mechanisms as well as clinical significance in PCa using integrative genomics, transcriptomics, and epigenomics approach. Our Weighted Gene Co-expression Analysis (WGCNA) and multivariate analysis identified 10 inflammatory genes: IRAK1, PPIL5/LRR1, HMGB3, HMGB2, TRAIP, IL1F5/IL36RN, ILF2, TRIM59, NFKBIL2/TONSL, and TRAF7 that were significantly associated with PCa progression. We explored the potentials of IRAK1 and other inflammatory genes as diagnostic and/or prognostic biomarkers by performing both KM survival and AUROC curve analyses. Our results indicate the clinical significance of these inflammatory genes in predicting the development and progression of PCa. IRAK1 was found to be overexpressed and hypomethylated in most PCa samples. A significantly high percentage of castration-resistant PCa (CRPC) and neuroendocrine PCa (NEPC) samples display copy number variations, especially amplification of the IRAK1 gene compared to the indolent prostate adenocarcinoma (PRAD) samples. Furthermore, we identified missense and frameshift mutations of IRAK1 in a few PRAD samples with potential functional implications. In conclusion, the results from this study suggest that IRAK1 dysregulation may be an important contributor to chronic prostatitis (inflammation) and PCa progression.