Epidermal growth factor receptor PROTACs as an effective strategy for cancer therapy: A review

Epidermal growth factor receptor (EGFR), a transmembrane glycoprotein that mediates cellular signaling pathways involved in cell proliferation, angiogenesis, apoptosis, and metastatic spread, is an important oncogenic drug target. Targeting the intracellular and extracellular domains of the EGFR has been authorized for a number of small-molecule TKIs and mAbs, respectively. However, their clinical application is limited by EGFR catalytic structural domain alterations, cancer heterogeneity, and persistent drug resistance. To bypass these limitations, protease-targeted chimeras (PROTACs) are emerging as an emerging and promising anti-EGFR therapy. PROTACs compensate for the limitations of traditional occupancy-driven small molecules by exploiting intracellular protein destruction processes. Recently, a mushrooming number of heterobifunctional EGFR PROTACs have been created using wild-type (WT) and mutated EGFR TKIs. PROTACs outperformed EGFR TKIs in terms of cellular inhibition, potency, toxicity profiles, and anti-drug resistance. Herein, we present a comprehensive overview of the development of PROTACs targeting EGFR for cancer therapy, while also highlighting the challenges and opportunities associated with the field.

Natural product-based PROteolysis TArgeting Chimeras (PROTACs)

Covering: upto 2022Natural products have an embedded recognition of protein surfaces. They possess this property as they are produced by biosynthetic enzymes and are substrates for one or more enzymes in the biosynthetic pathway. The inherent advantages, compared to synthetic compound libraries, is this ligand-protein binding which is, in many cases, a function of the 3-dimensional properties. Protein degradation is a recent novel therapeutic approach with several compounds now in the clinic. This review highlights the potential of PROteolysis TArgeting Chimeras (PROTACs) in the area of natural products. The approach will complement existing approaches such as the direct use of a bioactive natural product or its analogues, pharmacophore development and drug-antibody conjugates. The chemical synthesis and challenges of using natural product-based PROTACs are summarised. The review also highlights methods to detect the ternary complexes necessary for PROTAC mechanism of action.

Recent advancements in the discovery of cereblon-based protease-targeted chimeras with potential for therapeutic intervention

Protease-targeted chimeras (PROTACs) have been employed as a novel therapeutic approach, utilizing the ubiquitin-proteasome system for targeted protein degradation. PROTACs are heterobifunctional molecules consisting of an E3 ligase ligand and a small-molecule inhibitor for recruiting a protein of interest. After binding, PROTAC molecules recruit E3 ligase for ubiquitination of the protein of interest, which is followed by its proteasome-mediated degradation. PROTAC molecules have several advantages over traditional small-molecule inhibitors. A number of PROTAC molecules based on small-molecule inhibitors have been developed against various diseases, among which cereblon-based PROTAC molecules have received the greatest interest due to their promising clinical use. This article highlights the current trends in the discovery of cereblon-based PROTAC molecules along with their medicinal chemistry, clinical progression and future outlook in cancers, cardiovascular diseases and neurodegenerative disorders.

Developments of CRBN-based PROTACs as potential therapeutic agents

Protease-targeted chimeras (PROTACs) are a new technology that is receiving much attention in the treatment of diseases. The mechanism is to inhibit protein function by hijacking the ubiquitin E3 ligase for protein degradation. Heterogeneous bifunctional PROTACs contain a ligand for recruiting E3 ligase, a linker, and another ligand to bind to the target protein for degradation. A variety of small-molecule PROTACs (CRBN, VHL, IAPs, MDM2, DCAF15, DCAF16, and RNF114-based PROTACs) have been identified so far. In particular, CRBN-based PROTACs (e.g., ARV-110 and ARV-471) have received more attention for their promising therapeutic intervention. To date, CRBN-based PRTOACs have been extensively explored worldwide and have excelled not only in cancer diseases but also in cardiovascular diseases, immune diseases, neurodegenerative diseases, and viral infections. In this review, we will provide a comprehensive update on the latest research progress in CRBN-based PRTOACs area. Following the criteria, such as disease area and drug target class, we will present the degradants in alphabetical order by target. We also provide our own perspective on the future prospects and potential challenges facing PROTACs.

PROTACs technology for targeting non-oncoproteins: Advances and perspectives

Proteolysis targeting chimeras (PROTACs) have been developed to be an effective technology for targeted protein degradation. Each PROTAC contains three key components: a protein-of-interest (POI) ligand, an E3 ligase ligand, and a linker. These bifunctional molecules can hijack the intracellular inherent ubiquitin-proteasome system to degrade different POIs. With several advantages over other therapeutic strategies, PROTACs have set off a new upsurge of drug discovery in recent years. PRTOACs have been extensively explored worldwide and have excelled not only in cancer diseases but also in cardiovascular diseases, fatty liver disease, immune diseases, neurodegenerative diseases, and viral infections. In this review, we aim to summarize the rapid progress from 2010 to 2021 in PROTACs targeting various non-oncoproteins and elucidate the advantages of PROTACs technology. Finally, the potential challenges of this dynamic field are also discussed.

Discovery of A031 as effective proteolysis targeting chimera (PROTAC) androgen receptor (AR) degrader for the treatment of prostate cancer

Androgen receptor (AR) is an effective therapeutic target for the treatment of prostate cancer. We report herein the design, synthesis, and biological evaluation of highly effective proteolysis targeting chimeras (PROTAC) androgen receptor (AR) degraders, such as compound A031. It could induce the degradation of AR protein in VCaP cell lines in a time-dependent manner, achieving the IC 50 value of less than 0.25 μM. The A031 is 5 times less toxic than EZLA and works with an appropriate half-life (t 1/2) or clearance rate (Cl). Also, it has a significant inhibitory effect on tumor growth in zebrafish transplanted with human prostate cancer (VCaP). Therefore, A031 provides a further idea of developing novel drugs for prostate cancer.

Proteolysis targeting chimera (PROTAC) in drug discovery paradigm: Recent progress and future challenges

Proteolysis targeting chimera (PROTAC), hijacking protein of interest (POI) and recruiting E3 ligase for target degradation via the ubiquitin-proteasome pathway, is a novel drug discovery paradigm which has been widely used as biological tools and medicinal molecules with the potential of clinical application value. Currently, ARV-110, an orally small molecule PROTAC was designed to specifically target Androgen receptor (AR), firstly enters clinical phase I trials for the treatment of metastatic castration-resistant prostate cancer, which turns a new avenue for the development of PROTAC. We herein provide a detail summary on the latest one year progress of PROTAC target various proteins and elucidate the advantages of PROTAC technology. Finally, the potential challenges of this vibrant field are also discussed.