(+)-JJ-74-138 is a novel non-competitive androgen receptor antagonist

Current and emerging approaches to noncompetitive AR inhibition

The androgen receptor (AR) has been shown to be a key determinant in the pathogenesis of castration-resistant prostate cancer (CRPC). The current standard of care therapies targets the ligand-binding domain of the receptor and can afford improvements to life expectancy often only in the order of months before resistance occurs. Emerging preclinical and clinical compounds that inhibit receptor activity via differentiated mechanisms of action which are orthogonal to current antiandrogens show promise for overcoming treatment resistance. In this review, we present an authoritative summary of molecules that noncompetitively target the AR. Emerging small molecule strategies for targeting alternative domains of the AR represent a promising area of research that shows significant potential for future therapies. The overall quality of lead candidates in the area of noncompetitive AR inhibition is discussed, and it identifies the key chemotypes and associated properties which are likely to be, or are currently, positioned to be first in human applications.

Mechanisms and targeting of proteosome-dependent androgen receptor degradation in prostate cancer

The androgen receptor (AR) remains to be a key target for the treatment of prostate cancer, including the majority of castration-resistant prostate cancer (CRPC). AR is stabilized in CRPC and the ubiquitin-proteasome system (UPS) plays a major role in AR degradation. Targeting AR for degradation provides a potential approach to overcome the resistance of CRPC to current AR antagonists, including the next generation AR signaling inhibitors. Different types of AR degraders have been developed, including the proteolysis-targeting chimeras (PROTACs), selective AR degraders (SARDs), and novel AR degraders, with several AR PROTACs currently in clinical trials. The present mini-review discusses the regulation of AR degradation by the UPS, the potential role of a novel nuclear degradation signal in AR, and different types of AR degraders.

Cathepsin K regulates the tumor growth and metastasis by IL-17/CTSK/EMT axis and mediates M2 macrophage polarization in castration-resistant prostate cancer

A common stage of advanced prostate cancer is castration-resistant prostate cancer (CRPC), greater understanding of which is required in order to address and solve the clinically difficult challenge. Cathepsin K (CTSK) is a cysteine protease that usually has a strong activity of degrading extracellular matrix and is related to osteoclast-mediated bone destruction. However, the mechanism of CTSK-regulation in CRPC is still unclear to us. The current study aimed to analyze the expression of differentially expressed genes (DEGs) in patient samples (from localized PC and CRPC). Interestingly, we found that CTSK to be significantly up-regulated in CRPC. Through further signal pathway enrichment analysis, we found that the IL-17 signaling pathway to be highly correlated with CTSK. The oncogenic functions of CTSK and IL-17 in CRPC were proven by a series of in vivo and in vitro experiments. Possible downstream molecules of CTSK were investigated, which could serve as control elements to regulate the expression of EMT, thereby facilitating the metastasis and excessive proliferation of PC cells. Expression of CTSK was related to high concentration of M2 tumor-associated macrophages (TAMs) M2 in CRPC. A CTSK-mediated feedback circuit between TAMs and CRPC tissues was indicated in the process of transfer, proving the possibility of CTSK could be use as an available therapeutic target for CRPC.