A critical update on the strategies towards small molecule inhibitors targeting Serine/arginine-rich (SR) proteins and Serine/arginine-rich proteins related kinases in alternative splicing.

>90% of genes in the human body undergo alternative splicing (AS) after transcription, which enriches protein species and regulates protein levels. However, there is growing evidence that various genetic isoforms resulting from dysregulated alternative splicing are prevalent in various types of cancers. Dysregulated alternative splicing leads to cancer generation and maintenance of cancer properties such as proliferation differentiation, apoptosis inhibition, invasion metastasis, and angiogenesis. Serine/arginine-rich proteins and SR protein-associated kinases mediate splice site recognition and splice complex assembly during variable splicing. Based on the impact of dysregulated alternative splicing on disease onset and progression, the search for small molecule inhibitors targeting alternative splicing is imminent. In this review, we discuss the structure and specific biological functions of SR proteins and describe the regulation of SR protein function by SR protein related kinases meticulously, which are closely related to the occurrence and development of various types of cancers. On this basis, we summarize the reported small molecule inhibitors targeting SR proteins and SR protein related kinases from the perspective of medicinal chemistry. We mainly categorize small molecule inhibitors from four aspects, including targeting SR proteins, targeting Serine/arginine-rich protein-specific kinases (SRPKs), targeting Cdc2-like kinases (CLKs) and targeting dual-specificity tyrosine-regulated kinases (DYRKs), in terms of structure, inhibition target, specific mechanism of action, biological activity, and applicable diseases. With this review, we are expected to provide a timely summary of recent advances in alternative splicing regulated by kinases and a preliminary introduction to relevant small molecule inhibitors.

Discovery of thiohydantoin based antagonists of androgen receptor with efficient degradation for the treatment of prostate cancer.

Prostate cancer (PC) is one of the most prevalent cancers in men worldwide, and androgen receptor (AR) is a well-validated drug target for the treatment of PC. However, PC often exhibits resistance to AR antagonists over time. Thus, it is urgent to identify novel and effective drugs for PC treatment. A series of novel thiohydantoin based AR antagonists with efficient degradation against AR were designed, synthesized, and evaluated. Based on our previous SAR and further structural optimization, a tool molecule 26h was discovered with dual mechanisms including improved antagonistic activity and potent degradation (AR-fl and AR-V7). Moreover, 26h can also effectively block AR nuclear translocation and inhibit AR/AR-V7 heterodimerization, thereby inhibiting downstream gene transcription. Importantly, 26h displayed potent robust efficacy in LNCaP (TGI: 70.70%) and 22Rv1 (TGI: 78.89%) xenograft models. This provides new design strategies and advantageous potential compounds for the treatment of prostate cancer.

Overview of the development of selective androgen receptor modulators (SARMs) as pharmacological treatment for osteoporosis (1998-2021).

Osteoporosis is a common disease in which the risk of fracture increases due to decreased bone mass and qualitative skeletal changes. Selective androgen receptor modulators (SARMs) are agonists with tissue selectivity, which act as partial or weak androgen receptor (AR) agonists in androgenic tissues, but mainly as complete AR agonists in synthetic metabolic tissues. In the recent 20 years, many scaffolds of SARMs have been reported, among which several molecules are promising and are undergoing clinical trial evaluation. However, it is still a challenge to discover SARMs with high activity and reduced side effects. In this review, not only are structure of SARMs reported in the literatures systematically collected and classified but also the structure-activity relationships (SAR) are systematically summarized. Furthermore, the advances in SARMs as potential treatment for osteoporosis are also updated.