Latest ArticlesThe deubiquitinases (DUBs), as the crucial peptidohydrolases in the ubiquitin system, can reverse and strictly regulate ubiquitination and play key roles in various biological processes, including the regulation of protein stability, cell signal transduction. Ubiquitin-specific protease 28 (USP28) involves multiple cancer-related signaling pathways by enhancing the stability of various cancer-related proteins, and is closely associated with the progression of colorectal, breast cancer, lung carcinomas, and pancreatic cancer. USP28 has been considered as a promising drug target in anticancer therapy, and the development of USP28 inhibitors has made some progress. In this article, we review the structure of USP28 and its interaction with substrates, discuss the research progress of USP28 in cancers and summarize the development of USP28 inhibitors.
Protein-protein interactions (PPIs) are not only crucial for the assembly of protein complexes but also fundamental for maintaining normal biological functions. These interactions are vital for protein structure and biological functionality and play a central role in cellular signaling, metabolic pathways, and regulatory networks. The 14-3-3 protein, highly conserved and widely expressed in eukaryotes, primarily recognizes and binds to its partner proteins to participate in essential life processes such as cell cycle control, signal transduction, and energy metabolism. This review discusses the role of dysregulated PPIs between 14-3-3 proteins and their partner proteins such as estrogen receptor α (estrogen receptor α, ERα), RAF proto-oncogene serine/threonine-protein kinase (C-RAF/RAF-1), and p53 in the onset and progression of tumors, focusing on the research progress of 14-3-3/ERα, 14-3-3/C-RAF, and 14-3-3/p53 molecular glues. These molecular glues, by mimicking or enhancing the phosphorylation sites of serine on partner proteins, form covalent bonds, salt bridges, and hydrogen bonds with 14-3-3 proteins, thereby enhancing the stability of PPIs and effectively intervening in protein activity and signaling under pathological conditions. Additionally, this article explores the potential of this chemical intervention strategy in clinically suppressing tumor progression, providing a theoretical foundation and practical guidance for future research directions.
Heat shock protein 70 (Hsp70) is a class of molecular chaperones essential for maintaining protein homeostasis in cells. Hsp70s also play important roles in the pathogenesis of a variety of diseases, including cancer, neurodegenerative diseases and infectious diseases, which makes them potential targets for the treatment of these diseases. It is necessary to develop small molecule inhibitors to validate this class of important therapeutic targets. In recent years, the discovery of small molecule inhibitors for Hsp70s has made remarkable progress, and Hsp70 inhibitors with different modalities have been reported. In this paper, Hsp70 and relevant diseases are briefly introduced, and the discovery of Hsp70 small molecule inhibitors with distinct modalities are summarized, providing reference for the further discovery and development of Hsp70 small molecule inhibitors.
Heat shock protein 90 (HSP90) is a crucial molecular chaperone responsible for the activation and maturation of client proteins. Targeting HSP90 can effectively inhibit cancer cell proliferation by either competitively occupying the ATP-binding site or disrupting the protein-protein interaction sites between HSP90 and its co-chaperones. Therefore, studying the recognition and function of HSP90 binding sites is essential for molecular discovery. This study focuses on peptide P1, revealing its dual binding mechanism with HSP90. P1 is capable of simultaneously interacting with both the ATP-binding site of HSP90 and the binding interface with the co-chaperone CDC37 (cell division cycle 37). Through ATPase and Co-IP assays, we found that P1 effectively inhibits both ATP activity and the protein interaction between HSP90 and CDC37, providing a novel approach for developing new inhibitors targeting the HSP90 chaperone system.
The phenomenon of bacterial drug resistance is becoming more and more serious. Natural products, as an important resource for drug discovery, can play a role by regulating protein post-translational modifications related to bacterial infection and inflammatory responses. This provides a valuable compound library for the research and development of new antibacterial drugs. In this present research, dioscin and diosgenin were isolated and identified from Dioscorea nipponica Rhizoma, which both exhibited antibacterial activities, with stronger inhibitory on Gram-positive bacteria (G+) than Gram-negative bacteria (G-). Compared these two compounds, diosgenin showed stronger antibacterial activity than dioscin. In vivo experiments confirmed that diosgenin provided better protection against MRSA-induced sepsis in mice compared to dioscin, which could significantly improve survival rates, reduce bacterial colony counts in infected organs, alleviate pathological damage, and decrease inflammatory cytokine levels in mice. The in vivo study was approved by the Animal Ethics Committee of the PLA Air Force Military Medical University (Grant No. 20230188). Network pharmacology results also revealed that diosgenin could target inflammatory pathways, exerting dual antibacterial and anti-inflammatory activities during bacterial infection therapy.
The anti-apoptotic members of Bcl-2 family proteins, Bcl-2 and Mcl-1, are considered therapeutic targets of various cancers. In this article, we developed four hydrophobic tag (HyT)-based protein degraders of Bcl-2/Mcl-1, based on a Bcl-2/Mcl-1 dual inhibitor S1-6, and tested their capability in Bcl-2/Mcl-1 degradation and apoptotic induction in MCF-7 cells. Interestingly, different linkers in the HyT degraders led to selective Bcl-2/Mcl-1 degradation, though the degraders S1-D1-S1-D4 maintained the pan-Bcl-2 family binding capacity. Among them, S1-D2 and S1-D4, two compounds bearing a hydrophobic linker or a PEG linker, were observed to potently and selectively induce the ubiquitination and proteasomal degradation of Bcl-2 and Mcl-1 in living cells, with a degradation rate of more than 80% or 60%, respectively. Moreover, the HyT-based degraders showed increased lethality of cancer cells compared to the parent inhibitor S1-6, demonstrating that the advantage of degraders to the occupancy-based inhibitors.
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that regulates gene expression in a range of cells, including immune and epithelial cells. AhR signaling plays important roles in the immune system in both health and disease states. Tapinarof is a first-in-class small-molecule topical therapeutic AhR modulating agent launched for the treatment of psoriasis. To improve the activity and chemical stability of Tapinarof, a series of 2-phenylchromen-4-one derivatives were designed, synthesized and evaluated as novel AhR agonists. Compounds 5a, 5c, 5e and 5f potently activated AhR with an EC50 value of 7, 9, 6 and 6 nmol·L-1, respectively, which are 10-14 fold more potent than Tapinarof. Compounds 5a and 5e exhibit comparable inhibitory effects on IFN-γ production as Tapinarof. Furthermore, compounds 5a-5f exhibited favorable photochemical stability compared to Tapinarof. The compounds may eventually serve as lead compounds for the development of new AhR agonists.
Insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) is a recognition protein for N6-methyladenosine (m6A), mediating the stability of downstream mRNA, and is a promising anti-tumor target. Based on the lead compound 1g from previous screening, this study designed and synthesized 52 IGF2BP2 small molecule inhibitors using thiazole hydrazone as the parent nucleus. Among them, 9g, 10g, 37g, 47g and 52g showed good inhibitory activities. This work represents an initial exploration in the development of small molecule inhibitors targeting IGF2BP2, using thiazolehydrazone as the core structure. It lays a foundation for subsequent related research.
As a key epigenetic regulator, histone deacetylases (HDACs) play a crucial role in cancer development. Small molecule HDAC inhibitors have been shown to inhibit tumor proliferation and induce apoptosis, attracting significant research attention. In this study, we designed and synthesized a series of novel saccharin derivatives as HDAC inhibitors. Biological experiments demonstrated that the target compound 9a exhibited superior HDACs inhibition activity to vorinostat and demonstrating promising in vitro and in vivo anti-tumor activity against triple-negative breast cancer (TNBC). All animal experiments in this study were performed in strict accordance with the protocols approved by the Ethical Committee of School of Pharmaceutical Sciences in Shandong University (Approval No. 230094). This work represents an initial exploration of developing saccharin-based HDAC inhibitors, and the active compound 9a could serve as a lead compound for further study.
The gut microbiota plays a crucial role in the development of colorectal cancer (CRC). The imbalanced gut microbiota causes damage to the body and disrupts bile acids metabolism, increases susceptibility to CRC, and affects the signaling of farnesol X receptor (FXR), thereby promoting CRC progression. Traditional Chinese medicine has unique advantages in the treatment of CRC due to its synergistic regulatory effects of multiple components, targets, and pathways. It can regulate gut microbiota, intervene in bile acids metabolism, and activate its receptor FXR to inhibit the occurrence and development of CRC. Based on this, this article discusses the main role of the gut microbiota-bile acids-FXR axis in the development of CRC, and reviews the anti CRC effects and mechanisms of traditional Chinese medicine intervention on gut microbiota-bile acids-FXR axis, in order to provide new ideas and methods for the prevention and treatment of CRC.