DNA methyltransferase inhibitors upregulate CD38 protein expression and enhance daratumumab efficacy in multiple myeloma

Objective: Our recent work demonstrates that PTEN (phosphatase and tensin homolog) is an important regulator of smooth muscle cell (SMC) phenotype. SMC-specific PTEN deletion promotes spontaneous vascular remodeling and PTEN loss correlates with increased atherosclerotic lesion severity in human coronary arteries. In mice, PTEN overexpression reduces plaque area and preserves SMC contractile protein expression in atherosclerosis and blunts Ang II (angiotensin II)-induced pathological vascular remodeling, suggesting that pharmacological PTEN upregulation could be a novel therapeutic approach to treat vascular disease. Approach and Results: To identify novel PTEN activators, we conducted a high-throughput screen using a fluorescence based PTEN promoter-reporter assay. After screening ≈3400 compounds, 11 hit compounds were chosen based on level of activity and mechanism of action. Following in vitro confirmation, we focused on 5-azacytidine, a DNMT1 (DNA methyltransferase-1) inhibitor, for further analysis. In addition to PTEN upregulation, 5-azacytidine treatment increased expression of genes associated with a differentiated SMC phenotype. 5-Azacytidine treatment also maintained contractile gene expression and reduced inflammatory cytokine expression after PDGF (platelet-derived growth factor) stimulation, suggesting 5-azacytidine blocks PDGF-induced SMC de-differentiation. However, these protective effects were lost in PTEN-deficient SMCs. These findings were confirmed in vivo using carotid ligation in SMC-specific PTEN knockout mice treated with 5-azacytidine. In wild type controls, 5-azacytidine reduced neointimal formation and inflammation while maintaining contractile protein expression. In contrast, 5-azacytidine was ineffective in PTEN knockout mice, indicating that the protective effects of 5-azacytidine are mediated through SMC PTEN upregulation. Conclusions: Our data indicates 5-azacytidine upregulates PTEN expression in SMCs, promoting maintenance of SMC differentiation and reducing pathological vascular remodeling in a PTEN-dependent manner.

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DNA methyltransferase inhibitors modulate histone methylation: epigenetic crosstalk between H3K4me3 and DNA methylation during sperm differentiation

Zygote ◽

10.1017/s0967199420000684 ◽

2021 ◽

pp. 1-6

Author(s):

Liliana Burlibaşa ◽

Alina-Teodora Nicu ◽

Carmen Domnariu

Keyword(s):

Dna Methylation ◽

Histone Methylation ◽

Dna Methyltransferase ◽

Integrated Approach ◽

Regulatory Mechanisms ◽

Temporal Expression ◽

Dna Methyltransferase Inhibitors ◽

Expression Of Genes ◽

Species Survival ◽

Advanced Stages

Summary The process of cytodifferentiation in spermatogenesis is governed by a unique genetic and molecular programme. In this context, accurate ‘tuning’ of the regulatory mechanisms involved in germ cells differentiation is required, as any error could have dramatic consequences on species survival and maintenance. To study the processes that govern the spatial–temporal expression of genes, as well as analyse transmission of epigenetic information to descendants, an integrated approach of genetics, biochemistry and cytology data is necessary. As information in the literature on interplay between DNA methylation and histone H3 lysine 4 trimethylation (H3K4me3) in the advanced stages of murine spermatogenesis is still scarce, we investigated the effect of a DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine, at the cytological level using immunocytochemistry methodology. Our results revealed a particular distribution of H3K4me3 during sperm cell differentiation and highlighted an important role for regulation of DNA methylation in controlling histone methylation and chromatin remodelling during spermatogenesis.

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Expanding the Structural Diversity of DNA Methyltransferase Inhibitors

Pharmaceuticals ◽

10.3390/ph14010017 ◽

2020 ◽

Vol 14 (1) ◽

pp. 17

Author(s):

K. Eurídice Juárez-Mercado ◽

Fernando D. Prieto-Martínez ◽

Norberto Sánchez-Cruz ◽

Andrea Peña-Castillo ◽

Diego Prada-Gracia ◽

...

Keyword(s):

Histone Deacetylases ◽

Dna Methyltransferase ◽

Structural Diversity ◽

Dna Methyltransferases ◽

Dna Methyltransferase Inhibitors ◽

Epigenetic Drug ◽

Ic50 Values ◽

Dietary Component ◽

Approved Drugs ◽

Epigenetic Processes

Inhibitors of DNA methyltransferases (DNMTs) are attractive compounds for epigenetic drug discovery. They are also chemical tools to understand the biochemistry of epigenetic processes. Herein, we report five distinct inhibitors of DNMT1 characterized in enzymatic inhibition assays that did not show activity with DNMT3B. It was concluded that the dietary component theaflavin is an inhibitor of DNMT1. Two additional novel inhibitors of DNMT1 are the approved drugs glyburide and panobinostat. The DNMT1 enzymatic inhibitory activity of panobinostat, a known pan inhibitor of histone deacetylases, agrees with experimental reports of its ability to reduce DNMT1 activity in liver cancer cell lines. Molecular docking of the active compounds with DNMT1, and re-scoring with the recently developed extended connectivity interaction features approach, led to an excellent agreement between the experimental IC50 values and docking scores.

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