epz005687 and Neoplasms

Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that can change the expression of downstream target genes by catalyzing the trimethylation of lysine 27 of histone H3 (H3K27me3). Studies have found that EZH2 is highly expressed in a variety of tumor tissues and is closely related to the occurrence, development, invasion, and metastasis of tumors; therefore, EZH2 is becoming a new molecular target in antitumor therapy. Tazemetostat (EPZ-6438) was approved in 2020 as the first inhibitor targeting catalytic EZH2 for the treatment of epithelioid sarcoma. In addition, a variety of EZH2 inhibitors are being investigated in basic and clinical research for the treatment of tumors, and encouraging results have been obtained. This article systematically reviews the research progress on EZH2 inhibitors and proteolysis targeting chimera (PROTAC)-based EZH2 degradation agents with a focus on their design strategies, structure-activity relationships (SARs), and safety and clinical manifestations.

Topics: Animals; Enhancer of Zeste Homolog 2 Protein; Enzyme Inhibitors; Hematologic Neoplasms; Histone Methyltransferases; Humans; Molecular Targeted Therapy; Neoplasms; Structure-Activity Relationship

EZH2, the catalytic subunit of PRC2, catalyzes histone H3 lysine 27 (H3K27) trimethylation to induce the agglutination of chromosomes and in turn represses the transcription of the target genes. Numerous reports indicate that EZH2 is overexpressed in a variety of malignant tumor tissues. Therefore, targeting EZH2 protein is a promising strategy for cancer treatment. So far, many small molecule EZH2 specific inhibitors have entered clinical trials, but many of them harbored limited clinical efficacy. New technologies and methods are imperative to enhance the anticancer activity of EZH2. In this review, the structure and biological functions of EZH2 protein will be reviewed. The internal relationship between EZH2 and various diseases will be expounded. The development status of specific inhibitors for EZH2, and the latest progress of new strategies such as drug combination, dual-target inhibitors, targeted protein degradation technology and protein-protein interactions (PPI) inhibitors will be emphatically summarized and analyzed.

Topics: Catalytic Domain; Enhancer of Zeste Homolog 2 Protein; Enzyme Inhibitors; Humans; Neoplasms

The polycomb repressive complex 2 (PRC2) is composed of three core subunits, enhancer of zeste 2 (EZH2), embryonic ectoderm development (EED), and suppressor of zeste 12 (SUZ12), along with a number of accessory proteins. It is the key enzymatic protein complex that catalyzes histone H3 lysine 27 (H3K27) methylation to mediate epigenetic silencing of target genes. PRC2 thus plays essential roles in maintaining embryonic stem cell identity and in controlling cellular differentiation. Studies in the past decade have reported frequent overexpression or mutation of PRC2 in various cancers including prostate cancer and lymphoma. Aberrant PRC2 function has been extensively studied and proven to contribute to a large number of abnormal cellular processes, including those that lead to uncontrolled proliferation and tumorigenesis. Significant efforts have recently been made to develop small molecules targeting PRC2 function for potential use as anticancer therapeutics. In this review, we describe recent approaches to identify and develop small molecules that target PRC2. These various strategies include the inhibition of the function of individual PRC2 core proteins, the disruption of PRC2 complex formation, and the degradation of its subunits.

Topics: Animals; Antineoplastic Agents; Enhancer of Zeste Homolog 2 Protein; Histones; Humans; Indoles; Neoplasms; Polycomb Repressive Complex 2; Small Molecule Libraries; Structure-Activity Relationship

Recent genomic studies have resulted in an emerging understanding of the role of chromatin regulators in the development of cancer. EZH2, a histone methyl transferase subunit of a Polycomb repressor complex, is recurrently mutated in several forms of cancer and is highly expressed in numerous others. Notably, both gain-of-function and loss-of-function mutations occur in cancers but are associated with distinct cancer types. Here we review the spectrum of EZH2-associated mutations, discuss the mechanisms underlying EZH2 function, and synthesize a unifying perspective that the promotion of cancer arises from disruption of the role of EZH2 as a master regulator of transcription. We further discuss EZH2 inhibitors that are now showing early signs of promise in clinical trials and also additional strategies to combat roles of EZH2 in cancer.

Topics: Benzamides; Biphenyl Compounds; Drug Resistance, Neoplasm; Enhancer of Zeste Homolog 2 Protein; Humans; Indazoles; Indoles; Molecular Targeted Therapy; Morpholines; Mutation; Neoplasms; Polycomb Repressive Complex 2; Polycomb-Group Proteins; Pyridones

Polycomb Repressive Complex 2 (PRC2) modulates the chromatin structure and transcriptional repression by trimethylation lysine 27 of histone H3 (H3K27me3), a process that necessitates the protein-protein interaction (PPI) between the catalytic subunit EZH2 and EED. Deregulated PRC2 is intimately involved in tumorigenesis and progression, making it an invaluable target for epigenetic cancer therapy. However, until now, there have been no reported small molecule compounds targeting the EZH2-EED interactions. In the present study, we identified astemizole, an FDA-approved drug, as a small molecule inhibitor of the EZH2-EED interaction of PRC2. The disruption of the EZH2-EED interaction by astemizole destabilizes the PRC2 complex and inhibits its methyltransferase activity in cancer cells. Multiple lines of evidence have demonstrated that astemizole arrests the proliferation of PRC2-driven lymphomas primarily by disabling the PRC2 complex. Our findings demonstrate the chemical tractability of the difficult PPI target by a small molecule compound, highlighting the therapeutic promise for PRC2-driven human cancers via targeted destruction of the EZH2-EED complex.

Topics: Astemizole; Binding, Competitive; Catalysis; Catalytic Domain; Cell Line, Tumor; Cell Proliferation; Cell Survival; Disease Progression; Enhancer of Zeste Homolog 2 Protein; Histones; Humans; Lymphoma; Magnetic Resonance Spectroscopy; Methylation; Models, Molecular; Molecular Docking Simulation; Neoplasms; Polycomb Repressive Complex 2; Protein Interaction Mapping; Protein Processing, Post-Translational