Identification of Two Non-Peptidergic Small Molecule Inhibitors of CBX2 Binding to K27 Trimethylated Oligonucleosomes

Bioinformatics analysis reveals that CBX2 promotes enzalutamide resistance in prostate cancer

Enzalutamide (Enz) is commonly utilized as the initial treatment strategy for advanced prostate cancer (PCa). However, a notable subset of patients may experience resistance to Enz, resulting in reduced effectiveness. Utilizing Gene Expression Omnibus (GEO) databases, we identified CBX2 as a crucial factor in mediating resistance to Enz, primarily due to its inhibitory effect on the P53 signaling pathway. Silencing of CBX2 using small interfering RNA (siRNA) led to elevated levels of P53 expression in LNCaP cells. This indicates that CBX2 may have a critical effect on PCa Enz resistance and could serve as a promising therapeutic target for individuals with Enz resistance.

Chemical inhibitors targeting histone methylation readers

Histone methylation reader domains are protein modules that recognize specific histone methylation marks, such as methylated or unmethylated lysine or arginine residues on histones. These reader proteins play crucial roles in the epigenetic regulation of gene expression, chromatin structure, and DNA damage repair. Dysregulation of these proteins has been linked to various diseases, including cancer, neurodegenerative diseases, and developmental disorders. Therefore, targeting these proteins with chemical inhibitors has emerged as an attractive approach for therapeutic intervention, and significant progress has been made in this area. In this review, we will summarize the development of inhibitors targeting histone methylation readers, including MBT domains, chromodomains, Tudor domains, PWWP domains, PHD fingers, and WD40 repeat domains. For each domain, we will briefly discuss its identification and biological/biochemical functions, and then focus on the discovery of inhibitors tailored to target this domain, summarizing the property and potential application of most inhibitors. We will also discuss the structural basis for the potency and selectivity of these inhibitors, which will aid in further lead generation and optimization. Finally, we will also address the challenges and strategies involved in the development of these inhibitors. It should facilitate the rational design and development of novel chemical scaffolds and new targeting strategies for histone methylation reader domains with the help of this body of data.

Stem Cell-Associated Signatures Help to Predict Diagnosis and Prognosis in Ovarian Serous Cystadenocarcinoma

Ovarian serous cystadenocarcinoma (OV) is a fatal gynecologic cancer with a five-year survival rate of only 46%. Resistance to platinum-based chemotherapy is a prevalent factor in OV patients, leading to increased mortality. The platinum resistance in OV is driven by transcriptome heterogeneity and tumor heterogeneity. Studies have indicated that ovarian cancer stem cells (OCSCs), which are chemoresistant and help in disease recurrence, are enriched by platinum-based chemotherapy. Stem cells have a significant influence on the OV progression and prognosis of OV patients and are key pathology mediators of OV. However, the molecular mechanisms and targets of OV have not yet been fully understood. In this study, systematic research based on the TCGA-OV dataset was conducted for the identification and construction of key stem cell-related diagnostic and prognostic models for the development of multigene markers of OV. A six-gene diagnostic and prognostic model (C19orf33, CBX2, CSMD1, INSRR, PRLR, and SLC38A4) was developed based on the differentially expressed stem cell-related gene model, which can act as a potent diagnostic biomarker and can characterize the clinicopathological properties of OV. The key genes related to stem cells were identified by screening the genes differentially expressed in OV and control samples. The mRNA-miRNA-TF molecular network for the six-gene model was constructed, and the potential biological significance of this molecular model and its impact on the infiltration of immune cells in the OV tumor microenvironment were elucidated. The differences in immune infiltration and stem cell-related biological processes were determined using gene set variation analysis (GSVA) and single-sample gene set enrichment analysis (ssGSEA) for the selection of molecular treatment options and providing a reference for elucidating the posttranscriptional regulatory mechanisms in OV.

Discovery of hit compounds for methyl-lysine reader proteins from a target class DNA-encoded library

Methyl-lysine (Kme) reader domains are prevalent in chromatin regulatory proteins which bind post-translational modification sites to recruit repressive and activating factors; therefore, these proteins play crucial roles in cellular signaling and epigenetic regulation. Proteins that contain Kme domains are implicated in various diseases, including cancer, making them attractive therapeutic targets for drug and chemical probe discovery. Herein, we report on expanding the utility of a previously reported, Kme-focused DNA-encoded library (DEL), UNCDEL003, as a screening tool for hit discovery through the specific targeting of Kme reader proteins. As an efficient method for library generation, focused DELs are designed based on structural and functional features of a specific class of proteins with the intent of novel hit discovery. To broadly assess the applicability of our library, UNCDEL003 was screened against five diverse Kme reader protein domains (53BP1 TTD, KDM7B JmjC-PHD, CDYL2 CD, CBX2 CD, and LEDGF PWWP) with varying structures and functions. From these screening efforts, we identified hit compounds which contain unique chemical scaffolds distinct from previously reported ligands. The selected hit compounds were synthesized off-DNA and confirmed using primary and secondary assays and assessed for binding selectivity. Hit compounds from these efforts can serve as starting points for additional development and optimization into chemical probes to aid in further understanding the functionality of these therapeutically relevant proteins.