EZH2 Y641

These findings suggest that the Ezh2Y641F mutation may alter immune regulatory pathways, cell differentiation and apoptosis, with potential implications for disease progression. Our results highlight the critical role of mutation timing and cellular context in EZH2-driven hematopoietic disease, resulting in distinct downstream changes that shape the oncogenic impact of EZH2.

Atg7 deletion also results in increased CD8 + T cells in Ezh2Y641F melanomas and reduced myelosuppressive cell infiltration in the tumor microenvironment, particularly in Ezh2WT melanomas, suggesting a strong immune system contribution in the role of Atg7 in melanoma progression. These findings highlight the complex interplay between genetic mutations, epigenetic regulators, and autophagy in shaping tumor immunity in melanoma.

We also uncover unexpected variability in the mutational landscape of successive biopsies, pointing to frequent co-existence of different clones and cautioning against stratifying patients based on single sampling. Our results clarify how oncogenic PRC2 mutations disrupt chromatin and transcription, and the therapeutic vulnerabilities this creates.

In this study, based on the binding model of 1 (tazemetostat) with polycomb repressive complex 2 (PRC2), we designed and synthesized a series of tazemetostat analogs bearing a 1-methyl-2-benzimidazolinone moiety to improve the inhibitory activity of EZH2 wild-type (WT) and Y641 mutants and enhance metabolic stability...Additionally, N40 (T1/2 = 177.69 min) showed improved metabolic stability in human liver microsomes compared with 1 (T1/2 = 7.97 min). Our findings suggest N40 as a promising EZH2 inhibitor; further investigation remains warranted to confirm our findings and further develop N40.

The market approval of Tazemetostat (TAZVERIK) for the treatment of follicular lymphoma and epithelioid sarcoma has established "enhancer of zeste homolog 2" (EZH2) as therapeutic target in oncology...These inhibitors interact in a more entropy-driven fashion and show the most persistent effects in cellular washout and antiproliferative efficacy experiments. Our work provides mechanistic insights for the largest cohort of EZH2 inhibitors reported to date, demonstrating that-among several other binding parameters-target residence time is the best predictor of cellular efficacy.

The enhancer of zeste homolog 2 (EZH2) and its homolog EZH1 are catalytic components of polycomb repressive complex 2 (PRC2), which tri-methylate histone H3 at lysine 27 (H3K27me3) to repress transcription of their target genes. In conclusion, the present preclinical studies demonstrated that HM97662, an EZH1/2 dual inhibitor, had a promising and wide spectrum of therapeutic potential for hematological malignancies. It is urgent to assess the effectiveness of HM97662 in further clinical trials.

These cell lines serve as a preclinical tool to test novel therapeutic strategies and develop a deeper understanding of the molecular mechanisms driving lymphomagenesis, therapeutic response, and resistance in genetically defined subtypes of GC-derived B-cell lymphomas. Most importantly, this resource meets a critical need in the field for syngeneic models of lymphoma to study disease progression and precision therapy in immunocompetent mice.

Therefore, we investigated the potential of GC B cells to form iPSCs using a doxycycline-dependent mouse strain that enables the inducible expression of Yamanaka transcription factors (TF) in any given cell...We speculate that restricting plasticity to B cells under selection by T cells, limits the potential for GC B cells to acquire high levels of plasticity, hence reducing the potential for these cells to initiate lymphomas. Consistent with this notion, we found that DLBCL patients enriched for these stem cell signatures manifested inferior clinical outcomes.

Strikingly, treating EZB cells with EZH2 inhibitor tazemetostat (taz) ex vivo reprogrammed them to re-express the full spectrum of T cell engagement genes such as ICOSL, ITGB7, 4-1BBL, and OX40L and rendered them highly immunogenic...Collectively, EZH2 inhibitors yield a potent boost to CART mediated anti-lymphoma effects by enhancing CART cell functions and B cell immunogenicity, which would likely yield a significant clinical benefit for these patients where CART cells are less active. These results prompted us to initiate a clinical trial evaluating the safety and efficacy of this combination in B cell lymphomas (NCT05934838).

Another class of allosteric PRC2 inhibitor binding EED overcomes the resistance, effectively decreases H3K27me3, and blocks tumor proliferation in cells expressing EZH2 W113C. As this mutation is originally identified from lymphoma samples, our results demonstrated its activating characteristic and the deleterious consequence, provide insights on PRC2 regulation, and support the continued exploration of treatment optimization for lymphoma patients.