The Molecular Basis and Clinical Consequences of Chronic Inflammation in Prostatic Diseases: Prostatitis, Benign Prostatic Hyperplasia, and Prostate Cancer

SIMPLE SUMMARY: In this review paper, we explore the role of chronic inflammation in the pathogenesis of prostatic diseases, such as chronic prostatitis, benign prostatic hyperplasia (BPH), and prostate cancer. Chronic inflammation is a significant risk factor for these diseases, but the molecular mechanisms behind it are not yet fully understood. Previous attempts to investigate, link, and target inflammatory signaling molecules in men with these conditions have been clinically ambiguous and inconclusive. As a result, we proposed a paradigm shift in which less-explored molecules in the inflammatory signaling cascade are investigated as possible therapeutic targets for prostate diseases. In addition, we comprehensively discuss how aberrant signaling of these molecules may cause prostate cancer stemness, neuroendocrine differentiation, castration resistance, metabolic reprogramming, and immunosuppression. In conclusion, we forecast that targeting the interleukin-1 receptor-associated kinases (IRAKs) signaling pathway may provide a far more effective therapeutic or prophylactic strategy for the management of chronic inflammation-driven prostatic diseases. ABSTRACT: Chronic inflammation is now recognized as one of the major risk factors and molecular hallmarks of chronic prostatitis, benign prostatic hyperplasia (BPH), and prostate tumorigenesis. However, the molecular mechanisms by which chronic inflammation signaling contributes to the pathogenesis of these prostate diseases are poorly understood. Previous efforts to therapeutically target the upstream (e.g., TLRs and IL1-Rs) and downstream (e.g., NF-κB subunits and cytokines) inflammatory signaling molecules in people with these conditions have been clinically ambiguous and unsatisfactory, hence fostering the recent paradigm shift towards unraveling and understanding the functional roles and clinical significance of the novel and relatively underexplored inflammatory molecules and pathways that could become potential therapeutic targets in managing prostatic diseases. In this review article, we exclusively discuss the causal and molecular drivers of prostatitis, BPH, and prostate tumorigenesis, as well as the potential impacts of microbiome dysbiosis and chronic inflammation in promoting prostate pathologies. We specifically focus on the importance of some of the underexplored druggable inflammatory molecules, by discussing how their aberrant signaling could promote prostate cancer (PCa) stemness, neuroendocrine differentiation, castration resistance, metabolic reprogramming, and immunosuppression. The potential contribution of the IL1R-TLR-IRAK-NF-κBs signaling molecules and NLR/inflammasomes in prostate pathologies, as well as the prospective benefits of selectively targeting the midstream molecules in the various inflammatory cascades, are also discussed. Though this review concentrates more on PCa, we envision that the information could be applied to other prostate diseases. In conclusion, we have underlined the molecular mechanisms and signaling pathways that may need to be targeted and/or further investigated to better understand the association between chronic inflammation and prostate diseases.