Discovery of novel BTK PROTACs with improved metabolic stability via linker rigidification strategy

Combinatorial Ubiquitination REal-time PROteolysis (CURE-PROs): A Modular Platform for Generating Reversible, Self-Assembling Bifunctional Targeted Degraders

Proteolysis-Targeting Chimeras (PROTACs) are bifunctional molecules that bring a target protein and an E3 ubiquitin ligase into proximity to append ubiquitin, thus directing target degradation. Although numerous PROTACs have entered clinical trials, their development remains challenging, and their large size can produce poor drug-like properties. To overcome these limitations, we have modified our Coferon platform to generate Combinatorial Ubiquitination REal-time PROteolysis (CURE-PROs). CURE-PROs are small molecule degraders designed to self-assemble through reversible bio-orthogonal linkers to form covalent heterodimers. By modifying known ligands for Cereblon, MDM2, VHL, and BRD with complementary phenylboronic acid and diol/catechol linkers, we have successfully created CURE-PROs that direct degradation of BRD4 both in vitro and in vivo. The combinatorial nature of our platform significantly reduces synthesis time and effort to identify the optimal linker length and E3 ligase partner to each target and is readily amenable to screening for new targets.

Selective and Potent PROTAC Degraders of c-Src Kinase

Using dasatinib linked to E3 ligase ligands, we identified a potent and selective dual Csk/c-Src PROTAC degrader. We then replaced dasatinib, the c-Src-directed ligand, with a conformation-selective analogue that stabilizes the αC-helix-out conformation of c-Src. Using the αC-helix-out ligand, we identified a PROTAC that is potent and selective for c-Src. We demonstrated a high degree of catalysis with our c-Src PROTACs. Using our c-Src PROTACs, we identified pharmacological advantages of c-Src degradation compared to inhibition with respect to cancer cell proliferation.

Protein kinases: The key contributors in pathogenesis and treatment of nonalcoholic fatty liver disease-derived hepatocellular carcinoma

Protein kinases (PKs), one of the largest protein families, can be further divided into different groups based on their substrate or structure and function. PKs are important signaling messengers in numerous life activities, including cell metabolism, proliferation, division, differentiation, senescence, death, and disease. Among PK-related diseases, nonalcoholic fatty liver disease (NAFLD) has been recognized as a major contributor to hepatocellular carcinoma (HCC) and liver transplantation. Unfortunately, NAFLD-derived HCC (NAFLD-HCC) has poor prognosis because it is typically accompanied by older age, multiple metabolic syndromes, obstacles in early-stage diagnosis, and limited licensed drugs for treatment. Accumulating evidence suggests that PKs are implicated in the pathogenic process of NAFLD-HCC, via aberrant metabolism, hypoxia, autophagy, hypoxia, gut microbiota dysbiosis, and/or immune cell rearrangement. The present review aims to summarize the latest research advances and emphasize the feasibility and effectiveness of therapeutic strategies that regulate the expression and activities of PKs. This might yield clinically significant effects and lead to the design of novel PK-targeting therapies. Furthermore, we discuss emerging PK-based strategies for the treatment of other malignant diseases similar to NAFLD-HCC.