Evaluation of EED Inhibitors as a Class of PRC2-Targeted Small Molecules for HIV Latency Reversal

A hallmark of human immunodeficiency type-1 (HIV) infection is the integration of the viral genome into host chromatin, resulting in a latent reservoir that persists despite antiviral therapy or immune response. Thus, key priorities toward eradication of HIV infection are to understand the mechanisms that allow HIV latency and to develop latency reversal agents (LRAs) that can facilitate the clearance of latently infected cells. The repressive H3K27me3 histone mark, catalyzed by the PRC2 complex, plays a pivotal role in transcriptional repression at the viral promoter in both cell line and primary CD4+ T cell models of latency. EZH2 inhibitors which block H3K27 methylation have been shown to act as LRAs, suggesting other PRC2 components could also be potential targets for latency reversal. EED, a core component of PRC2, ensures the propagation of H3K27me3 by allosterically activating EZH2 methyltransferase activity. Therefore, we sought to investigate if inhibition of EED would also reverse latency. Inhibitors of EED, EED226 and A-395, demonstrated latency reversal activity as single agents, and this activity was further enhanced when used in combination with other known LRAs. Loss of H3K27me3 following EED inhibition significantly increased the levels of H3K27 acetylation globally and at the HIV LTR. These results further confirm that PRC2 mediated repression plays a significant role in the maintenance of HIV latency and suggest that EED may serve as a promising new target for LRA development

THE PRC2 MOLECULE EED IS A TARGET OF EPIGENETIC THERAPY FOR NEUROBLASTOMA

埼玉大学博士(学術)主指導教員 : 上條 岳彦textapplication/pdfdoctoral thesi

THE PRC2 MOLECULE EED IS A TARGET OF EPIGENETIC THERAPY FOR NEUROBLASTOMA

学位記号番号 : 博理工乙第271号博士の専攻分野の名称 : 博士(学術) 学位授与年月日 : 令和4年9月22日textapplication/pdfthesi

Recent novel tumor gatekeepers and potential therapeutic approaches (2017)

Tumor remains a challenging task for oncology community. Drug resistance due to chemotherapy remain principal impediments  toward potential therapeutic strategies. Development of novel anti-cancer drugs or new targeted strategies to conquer drug  resistance is a key goal of cancer research. In this respect, novel tumor gatekeepers and innovative targeted strategies can be  helpful in overcoming drug resistance as well as improve currently used targeted therapies. In this review, efforts have been made to present some of the latest knowledge about novel tumor gatekeepers and new therapeutic strategies to improve the efficacy of  chemotherapy and give new hope to cancer patients to fight against cancer.Keywords: Cancer, Potent inhibitors, Gatekeepers, Therapeutic approaches, Oncogenic pathway

Degradation of Polycomb Repressive Complex 2 with an EED-Targeted Bivalent Chemical Degrader

Protein degradation via the use of bivalent chemical degraders provides an alternative strategy to block protein function and assess the biological roles of putative drug targets. This approach capitalizes on the advantages of small-molecule inhibitors while moving beyond the restrictions of traditional pharmacology. Here, we report a chemical degrader (UNC6852) that targets polycomb repressive complex 2 (PRC2). UNC6852 contains an EED226-derived ligand and a ligand for VHL which bind to the WD40 aromatic cage of EED and CRL2VHL, respectively, to induce proteasomal degradation of PRC2 components, EED, EZH2, and SUZ12. Degradation of PRC2 with UNC6852 blocks the histone methyltransferase activity of EZH2, decreasing H3K27me3 levels in HeLa cells and diffuse large B cell lymphoma (DLBCL) cells containing EZH2 gain-of-function mutations. UNC6852 degrades both wild-type and mutant EZH2, and additionally displays anti-proliferative effects in this cancer model system. Using an EED-targeted chemical degrader, Potjewyd et al. demonstrate successful degradation of the PRC2 complex. UNC6852 provides a unique tool to study PRC2 function and downregulation of PRC2 activity in cancer and demonstrates the feasibility of developing PRC2-targeted degraders as potential therapeutics

Characterization and functional analysis of glycosylation in mouse pluripotent stem cells

マウス胚幹細胞細胞（ESCs）およびエピブラスト様細胞（EpiLCs）は、in vitro で胚の初期発生を再現する多能性幹細胞（PSCs）であり、ESCsであるナイーブ状態のPSCsからEpiLCsであるプライム状態のPSCs への遷移メカニズムの解明を可能するモデルとなる。はじめに、ESCs とEpiLCs の網羅的糖鎖プロファイリングを行い、糖鎖構造が発生の初期段階から劇的な変化を遂げることを明らかにした。この変化は、クロマチンリモデラーであるpolycomb repressive complex 2 (PRC2)によって制御されており、全体の糖鎖構造を調節するネットワークの存在を見出した。さらに、ESCsにおける糖鎖の機能解析も行い、O-結合型でムチン型糖鎖の一種であるT 抗原（Galβ1-3GalNAc）とその構造を合成するC1galt1 がESCsの多能性の維持に関与していることを示した。本研究では、多能性の状態遷移中に発生する糖鎖のダイナミクスを明らかにし、糖鎖によるESCs多能性の制御メカニズムを特定した。創価大

Peptide Technologies in the Development of Chemical Tools for Chromatin‐Associated Machinery

Discerning a mechanistic understanding of the cause‐and‐effect relationships between chromatin post‐translational modifications (PTMs) and DNA accessibility for replication, transcription, and repair is an elusive goal being pursued using molecular and cellular biology, biochemistry, and more recently chemical inhibition. Chemical intervention of the chromatin‐associated complexes that regulate PTM maintenance and chromatin structure faces numerous challenges due to the broad surface‐groove interactions between many of these proteins and histones; yet, the increasing interest in understanding chromatin‐modifying complexes suggests tractable lead compounds will be critical for elucidating the mechanisms of chromatin dysregulation in disease states and validating the druggability of these domains. Peptides and peptidomimetics afford several advantages to efficient inhibitor development including a rational starting point, modular assembly, and retention of secondary structure. Numerous peptide technologies have been employed in the chromatin field to characterize substrate interactions, evaluate ligand selectivity, and optimize potent peptidomimetic inhibitors. We describe the progress and advantages of these efforts, and provide a perspective on their implications for future chemical probe and drug discovery efforts. Drug Dev Res 78 : 300–312, 2017. © 2017 Wiley Periodicals, Inc

Polycomb group proteins EZH2 and EED directly regulate androgen receptor in advanced prostate cancer

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149265/1/ijc32118.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149265/2/ijc32118_am.pd

Aspirin Inhibits Natural Killer/T-Cell Lymphoma by Modulation of VEGF Expression and Mitochondrial Function

Extranodal nasal-type natural killer/T-cell lymphoma (NKTCL) is an Epstein-Barr virus (EBV)-associated lymphoma with a strong tendency relapse or be refractory in response to chemotherapy. Development of a new strategy for NKTCL treatment is still quite necessary. In this study, we found that aspirin treatment suppresses VEGF expression in NKTCL SNK-6 cells. Further investigation showed that aspirin treatment increases histone methylation in the range of −100~0 that is proximal to the transcription start site on the VEGF promoter, subsequently decreasing the binding ability of Sp1 to the VEGF promoter with VEGF suppression. Furthermore, aspirin treatment modulates mitochondrial function with increased ROS formation and apoptosis in NKTCL cells. Aspirin treatment alone slightly inhibits NKTCL SNK-6 tumor growth and EBV replication; while in the presence of histone deacetylase inhibitor (HDACi) chidamide (CDM), aspirin significantly suppresses the VEGF signaling pathway with increased ROS overgeneration and EBV inhibition. We also showed that with the addition of chidamide, aspirin significantly suppresses NKTCL tumor growth in both in vitro cell culture and in vivo mouse model with prolonged mouse survival. This is the first time that the potential mechanism for aspirin-mediated VEGF suppression and anti-tumor effect has been discovered, and this study provides a new strategy for anti-tumor drug development for NKTCL treatment based on aspirin-mediated targeting of the VEGF signaling pathway and ROS formation