Abstract 995: Integrative genomic characterization and CRISPR-mediated gene editing studies identify IRAKs as novel therapeutic targets for inflammation-driven prostate tumorigenesis
Authors: Oseni Saheed Oluwasina , Pavlovic Mirjana , Hartmann James , Kumi-Diaka James 
Published: September 2020

A major drawback to accurate diagnosis and treatment of inflammation-driven prostate cancer (PCa) progression is our limited understanding of the molecular mechanisms underlying aberrant inflammation signaling in PCa patients. Since asymptomatic chronic inflammation is hard to diagnose, we do not have adequate knowledge of how specific genes within the inflammatory cascade drive PCa aggressiveness. Hence, an integrative genomic approach may provide us with effective prognostic and diagnostic tools to manage inflammation-driven PCa progression. The aim of this study was to characterize inflammation-associated hub genes as predictors of PCa progression and investigate the effect of aberrant signaling of interleukin-1 receptor-associated kinases (IRAKs) on prostate tumorigenesis. WES and RNA-seq datasets from a total of 726 PCa patients, stratified into subtypes: primary PCa (PPC; n=493), metastatic PCa (MPC; n=150) and the castration-resistant PCa (CRPC; n=52) and neuroendocrine PCa (NEPC; n=30) from 3 cohort studies were acquired from cBioPortal. A bioinformatics pipeline was designed to analyze the datasets. Weighted gene co-expression network analysis (WGCNA) was used to construct gene co-expression networks and identify inflammation hub genes associated with PCa progression. The top inflammation hub genes, such as ILR1, TLRs, IRAK1-4, and NF-kB were validated. IRAK1-4 hub genes were found to be differentially expressed and genetically altered in NEPC and CRPC (&gt;40%) compared to PPC and MPC (&lt;20%) patients. GISTIC and MutSigCV were used to identify somatic mutations and copy-number alterations (CNAs). IRAK1 was found to have the highest CNA in CRPC and NEPC compared to MPC and PPC patients. Interestingly, no mutation was identified in CRPC and NEPC patients. The co-occurrence of IRAK1/4 CNVs and mRNA with AR, PI3K and AURKA signaling pathways suggest a role in PCa progression. To mechanistically investigate the role of IRAK1/4 signaling on PCa progression, CRISPR-mediated knockdown of IRAK1/4 was performed in PCa cell lines (LNCaP, PC3, and NCI-H660). mRNA and protein expression analyses were performed to determine changes in the levels of AR, PI3K/AKT, and AURKA between IRAK1/4-/- and IRAK1/4+/+ cell lines. Inhibition of IRAK1/4 significantly altered AR, PI3K, and AURKA signaling, leading to a reduction in PCa viability and metastatic potential. To investigate the effect of aberrant IRAK1/4 signaling on chemoresistance induction, IRAK+/+ PCa cells were treated with either TLR agonists or IRAK1/4 inhibitors and then treated with different anticancer drugs, such as Enzalutamide, Docetaxel, and Alisertib (AURKA inhibitor) dose-dependently. IRAK1/4-/- cells were more susceptible to anticancer drug treatment compared to IRAK1+/+ cells. The combination treatments were shown to be synergistic, thereby suppressing inflammation-induced chemoresistance. In conclusion, we have identified IRAK1/4 as a potential target for treating inflammation-driven prostate cancer progression.

Citation Format: Saheed Oluwasina Oseni, Mirjana Pavlovic, James Hartmann, James Kumi-Diaka. Integrative genomic characterization and CRISPR-mediated gene editing studies identify IRAKs as novel therapeutic targets for inflammation-driven prostate tumorigenesis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 995.