bix-01294 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

Increasing studies show that methylation of histone lysine residues is implicated in the development and progression of varying disease states such as schizophrenia, diabetes, and multiple human cancers. Targeting the specific enzymes responsible for these processes has fueled global investigation into the understanding and correction of epigenetic pathology. This review aims to assemble a timely account of the current progress against chromatin-modifying histone lysine methyltransferases (KMTs) and demethylases (KDMs) to inform ongoing and future efforts into this promising field. In particular, we report on their role in tumor growth and progression and the development of small molecules that modulate these enzymes.

Topics: Animals; Epigenomics; Histone Demethylases; Histone-Lysine N-Methyltransferase; Histones; Humans; Lysine; Methylation; Neoplasms

Concomitant inhibition of key epigenetic pathways involved in silencing tumor suppressor genes has been recognized as a promising strategy for cancer therapy. Herein, we report a first-in-class series of quinoline-based analogues that simultaneously inhibit histone deacetylases (from a low nanomolar range) and DNA methyltransferase-1 (from a mid-nanomolar range, IC

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; DNA (Cytosine-5-)-Methyltransferase 1; Drug Design; Enzyme Inhibitors; Histocompatibility Antigens; Histone Deacetylase Inhibitors; Histone Deacetylases; Histone-Lysine N-Methyltransferase; Humans; Mice, Inbred BALB C; Molecular Docking Simulation; Neoplasms

Epigenetic mechanisms play important roles in the regulation of tumorigenesis, and hypoxia-induced epigenetic changes may be critical for the adaptation of cancer cells to the hypoxic microenvironment of solid tumors. Previously, we showed that loss-of-function of the hypoxia-regulated H3K9 methyltransferase G9A attenuates tumor growth. However, the mechanisms by which blockade of G9A leads to a tumor suppressive effect remain poorly understood. We show that G9A is highly expressed in breast cancer and is associated with poor patient prognosis, where it may function as a potent oncogenic driver. In agreement with this, G9A inhibition by the small molecule inhibitor, BIX-01294, leads to increased cell death and impaired cell migration, cell cycle and anchorage-independent growth. Interestingly, whole transcriptome analysis revealed that genes involved in diverse cancer cell functions become hypoxia-responsive upon G9A inhibition. This was accompanied by the upregulation of the hypoxia inducible factors HIF1α and HIF2α during BIX-01294 treatment even in normoxia that may facilitate the tumor suppressive effects of BIX-01294. HIF inhibition was able to reverse some of the transcriptional changes induced by BIX-01294 in hypoxia, indicating that the HIFs may be important drivers of these derepressed target genes. Therefore, we show that G9A is a key mediator of oncogenic processes in breast cancer cells and G9A inhibition by BIX-01294 can successfully attenuate oncogenicity even in hypoxia.

Topics: Apoptosis; Azepines; Cell Cycle; Cell Hypoxia; Cell Movement; Cell Proliferation; HeLa Cells; Histone-Lysine N-Methyltransferase; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; MCF-7 Cells; Methylation; Neoplasms; Oncogenes; Prognosis; Quinazolines; Signal Transduction

A series of α-branched α,β-unsaturated ketones were prepared via boron trifluoride etherate mediated reaction between arylalkynes and carboxaldehydes. The evaluation of the antiproliferative activity over hematological (NB4) and solid cancer (A549, MCF-7) cell lines provided a structure-activity relationship. 5-Parameter QSAR equations were built which were able to explain 80%-92% of the variance in activity. The resulting selective lead compound showed IC50 value 0.6 μM against the hematological cell line and did not cause apoptosis, but blocked cell cycle in G0/G1. Moreover, it was demonstrated that this compound enhances and accelerates retinoic acid induced granulocytic differentiation.

Topics: Cell Line, Tumor; Cell Proliferation; Hematologic Neoplasms; Humans; Ketones; Neoplasms; Quantitative Structure-Activity Relationship

EHMT2 is a histone lysine methyltransferase localized in euchromatin regions and acting as a corepressor for specific transcription factors. Although the role of EHMT2 in transcriptional regulation has been well documented, the pathologic consequences of its dysfunction in human disease have not been well understood. Here, we describe important roles of EHMT2 in human carcinogenesis. Expression levels of EHMT2 are significantly elevated in human bladder carcinomas compared with nonneoplastic bladder tissues (P < .0001) in real-time polymerase chain reaction analysis. Complementary DNA microarray analysis also revealed its overexpression in various types of cancer. The reduction of EHMT2 expression by small interfering RNAs resulted in the suppression of the growth of cancer cells and possibly caused apoptotic cell death in cancer cells. Importantly, we show that EHMT2 can suppress transcription of the SIAH1 gene by binding to its promoter region (-293 to +51) and by methylating lysine 9 of histone H3. Furthermore, an EHMT2-specific inhibitor, BIX-01294, significantly suppressed the growth of cancer cells. Our results suggest that dysregulation of EHMT2 plays an important role in the growth regulation of cancer cells, and further functional studies may affirm the importance of EHMT2 as a promising therapeutic target for various types of cancer.

Topics: Apoptosis; Azepines; Cell Line, Transformed; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; HEK293 Cells; Histocompatibility Antigens; Histone-Lysine N-Methyltransferase; Humans; Neoplasms; Nuclear Proteins; Quinazolines; Ubiquitin-Protein Ligases