5-Aza-2′-deoxycytidine, a DNA methylation inhibitor, induces cytotoxicity, cell cycle dynamics and alters expression of DNA methyltransferase 1 and 3A in mouse hippocampus-derived neuronal HT22 cells

Abstract

Epigenetic processes such as DNA methylation are essential for processes of gene expression in normal mammalian development. DNA methyltransferases (DNMT) are responsible for initiating and maintaining DNA methylation. It is known that 5-Aza-CdR, an inhibitor of DNMT induces cytotoxicity by reducing DNMT activity in various tumor cell lines. However, disturbances in neuronal DNA methylation may also play a role in altered brain functions. Thus, it was of interest to determine whether alterations in DNA methylation might be associated with neuronal functions by using 5-Aza-CdR, on mouse hippocampus-derived neuronal HT22 cell line. In particular, the aim of this study was to investigate the effects of 5-Aza-CdR on cell growth inhibition, cell cycle arrest, apoptosis as well as the expression levels of DNMT in HT22 cells. HT22 cells were incubated with 5 or 20 μmol/L 5-Aza-CdR for 24 h. Data showed that 5-Aza-CdR at both concentrations significantly inhibited proliferation of HT22 cells and exacerbated cytoplasmic vacuolization. Flow cytometry analysis demonstrated that 5-Aza-CdR treatment at both concentrations decreased early apoptosis but enhanced late apoptosis. Cell cycle analysis illustrated that 5-Aza-CdR treatment induced S phase arrest. Further, incubation with 5-Aza-CdR produced a down-regulation in expression of mRNA and protein DNMT1 and 3A but no marked changes were noted in DNMT 3B and p21 expression. In addition, DNMT1 activity was significantly decreased at both 5-Aza-CdR concentrations. Evidence indicates that 5-Aza-CdR induced cytotoxicity was associated with altered mRNA and protein expression of DNMT 1 and 3A associated with reduced DNMT1 activity in HT22 cells which might affect brain functions.

The Differential Antitumor Activity of 5-Aza-2'-deoxycytidine in Prostate Cancer DU145, 22RV1, and LNCaP Cells

“…It was reported that tumor suppressive p53 and maspin repressed c-Myc activity through both transcriptional and posttranscriptional mechanisms, ultimately inhibiting cell growth 14 , 51 , 52 . Thus, it was reasonable to hypothesize that tumor suppressive maspin and the p53/p21 signaling pathway are involved in 5-Aza-induced antitumor activity 44 , 50 .…”

Effect of Decitabine (5-aza-2ˈ-deoxycytidine, 5-aza-CdR) in Comparison with Vorinostat (Suberoylanilide Hydroxamic Acid, SAHA) on DNMT1, DNMT3a and DNMT3b, HDAC 1-3, SOCS 1, SOCS 3, JAK2, and STAT3 Gene Expression in Hepatocellular Carcinoma HLE and LCL-PI 11 Cell Lines

“…The effect of 5-Aza-CdR co-treatment with sodium butyrate on DNMT3a and DNMT3b inhibition is significantly higher than that of 5-AzaCdR alone (Shen et al, 2008). In mouse hippocampus-derived neuronal HT22 cell line, 5-Aza-CdR down-regulates the expression of mRNA and protein DNMT1 and 3a (but no DNMT 3b) (Yang et al, 2017). In myelodysplastic syndrome (MDS), 5-Aza-CdR can re-activate the expression of the p15INK4B gene in MUTZ-1 cells by demethylation of the p15INK4B gene through inhibition of DNMT3a gene expression which is a mechanism of 5-Aza-CdR in the treatments of MDS (Tong et al, 2004).…”

Coeloglossum viride var. bracteatum extract attenuates staurosporine induced neurotoxicity by restoring the FGF2-PI3K/Akt signaling axis and Dnmt3

“…With this in mind, we intended to test whether DNA methyltransferases are involved in CE-mediated neuroprotective functions. 5-azacytidine (5-AZ), an analog of cytidine, effectively inhibits DNA methyltransferase and induces DNA hypomethylation ( Jiemjit et al., 2008 ; Yang et al., 2017 ). In the experiments, neurons were pretreated with 5-AZ followed by STS or CE treatment ( Figure 4 A and B, Supplementary Material Figure S8).…”