Targeting the PI3K/AKT/mTOR signaling pathway in prostate cancer: Molecular dysregulation, therapeutic advances, and...

Prostate cancer (PCa) is among the most common malignancies and remains a leading cause of cancer-related mortality in men worldwide. One of the main drivers is the dysregulation of the downstream signalling machinery. The PI3K, AKT, and mTOR signalling pathways play a pivotal role in cellular sustenance, growth, metabolism, and proliferation. In prostate cancer this pathway is generally altered due to the mutation or deletion of the PTEN (phosphatase and tensin homolog) gene and unnecessary activities of some components of PI3K, AKT, or mTOR. Extracellular communication of the androgen receptor (AR) with a wide array of oncogenic signatures is a primary evasion mechanism of cancer therapy and metastasis. This review focuses on the structure and function of the PI3K/AKT/mTOR pathway to better understand its role in prostate tumor biology. Furthermore, current therapeutic strategies that combinatorically target individual components of this pathway, such as allosteric and ATP-competitive AKT inhibitors, isoform-selective PI3K inhibitors, first- and second-generation mTOR inhibitors, are under consideration. The study particularly focuses on the combined use of immunotherapy (checkpoint inhibitors), chemotherapy (docetaxel), and androgen deprivation therapy (ADT), which are designed to break through the resistance-generating mechanisms and increase clinical efficacy. Overall, the findings support the need to conduct comprehensive preclinical and clinical studies on these alternative treatment regimens, and the eventual goal is to develop new treatment options for prostate cancer. The evidence of the pathway-specific therapy approach for the treatment of prostate cancer in recent clinical trials still failed to give a conclusive result. The current discussion also investigates the emerging areas of focus and perfection of combination regimens. The combination of all these developments makes it clear that the PI3K/AKT/mTOR signalling pathway is a key strategic point for developing therapeutics.