DNMT1 Expression Research Articles

Do Anticancer Medicinal Compounds have DNMT1 Regulating Activity: An In silico Investigation

Background: DNA methyltransferases (DNMTs) are a group of epigenetic enzymes implicated in regulating gene expression in actively dividing cells. Among these enzymes, DNMT1 plays a leading role in causing increased DNA methylation of tumor suppressors and other genes in cancer cells. This methylation event disrupts the cell cycle regulating genes, allowing an uninterrupted proliferation of cancer cells, and stimulating the inhibition of the degradation of proteins and aberrant transcription activation. Cytosine analog drugs have been shown to reduce DNA methylation but provoke the expression of other prometastatic genes. On the other hand, medicinal compounds act similarly to cytosine analogs by reducing the expression and activity of DNMT1, as reported in some in vitro cancer studies. However, it remains a mystery what those promising medicinal compounds are that show such activity. Objectives: The objective of this study was to screen medicinal compounds that reduce the expression and interact with the active site residues of DNMT1. Methods: To analyze medicinal compounds against DNMT1, two in silico tools were employed: DIGEP-pred and IGEMDOCK to discover and identify 98 lead medicinal compounds having anticancer potential, capable of regulating DNMT1 expression and activity. Results: Our results have identified twenty (20) medicinal compounds that reduced the expression of DNMT1 up to 50-77% as compared to the standard cytosine analog (91.5%). These compounds have also interacted with the reported active site residues of DNMT1, as predicted by IGEMDOCK. These compounds have adequate druglikeness, toxicity, and pharmacokinetic properties as described by Protox-II and ADMET lab 2.0. Conclusion: Thus, our study provides an initial report of those medicinal compounds that have DNMT1 targeting ability and have a relatively safer pharmacokinetic and toxicity profile.

Urinary sediment mRNA as a potent biomarker of IgA nephropathy

BackgroundThe quantification of mRNA expression in urinary sediments is a reliable biomarker for various diseases. However, few studies have investigated the clinical relevance of urinary mRNA levels in IgA nephropathy (IgAN). Thus, we investigated the expression of urinary mRNAs and their clinical significance in IgAN.MethodsOverall, 200 patients with biopsy-proven IgAN, 48 disease controls, and 76 healthy controls were enrolled. We identified the differential expression of mRNAs in renal tissue between patients with IgAN and normal subjects using the Gene Expression Omnibus dataset and selected candidate mRNAs. mRNA expression in the urinary sediment was measured using quantitative real-time polymerase chain reaction. Associations between urinary mRNA levels and clinicopathological parameters were analyzed and the predictive value of mRNAs for disease progression was evaluated.ResultsThe urinary expression of CCL2, CD14, DNMT1, FKBP5, Nephrin, and IL-6 was significantly upregulated in patients with IgAN compared with healthy controls. C3, FLOT1, and Podocin levels were significantly correlated with renal function, where C3, FLOT1, and TfR levels were significantly correlated with urinary protein excretion. During follow-up, 26 (13.0%) patients with IgAN experienced disease progression, defined as a greater than 50% reduction in the estimated glomerular filtration rate or progression to end-stage renal disease. Urinary mRNA levels of FLOT1 (HR 3.706, 95% CI 1.373–10.005, P = 0.010) were independently associated with an increased risk of disease progression.ConclusionsOur results suggest that urinary sediment mRNAs are a useful biomarker in IgAN patients. Further studies with larger sample sizes and longer follow-up durations are required.

Genome-wide methylation and transcriptome differential analysis of skeletal muscle in broilers with valgus-varus deformity

ABSTRACT 1. Valgus-varus deformity (VVD) is a disease that severely affects leg function in broilers and for which there is no effective control method current available. Although DNA methylation has an important impact on most physiological and pathological processes, its involvement in skeletal muscle growth and development in VVD broilers is unknown. In this study, genome-wide DNA methylation was analysed in VVD-affected and normal broilers using whole genome resulphite sequencing. 2. The results showed that in the cytosine-phosphoric acid-guanine (CG) sequence environment there was a methylation rate of about 55% and 4,265 differentially methylated regions (DMRs) were found in the CG. Of these, 550 were located in the promoter, 547 in the exon region, and 1,718 in the intron region. 3. All differentially methylated genes (DMGs) were analysed for enrichment of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The GO was enriched in pathways related to protein degradation such as proteasome complex, endopeptidase complex and extracellular region. The KEGG pathways were enriched in signalling pathways related to protein degradation and catabolism such as proteasome, nitrogen metabolism, adherens junction and alanine. 4. Protein interactions analysis revealed that FOS, MYL9, and FRAS1 had a high degree of interactions, in which the DNA methylation level of the MYL9 promoter region was negatively correlated with mRNA expression level. Further studies showed that 5-azacytidine (5-AzaC) inhibited DNMT1 and DNMT3A gene expression and promoted MYL9 expression. 5. This study systematically investigated overall DNA methylation patterns in the leg muscle of VVD and normal broilers. It screened common differential genes in conjunction with transcriptomic data to further identify genes associated with muscle growth and development. This study provides new insights to better understand the pathogenesis of VVD from an epigenetic perspective.

G9a/DNMT1 co-targeting inhibits non-small cell lung cancer growth and reprograms tumor cells to respond to cancer-drugs through SCARA5 and AOX1

The treatment of non-small cell lung cancer (NSCLC) patients has significantly improved with recent therapeutic strategies; however, many patients still do not benefit from them. As a result, new treatment approaches are urgently needed. In this study, we evaluated the antitumor efficacy of co-targeting G9a and DNMT1 enzymes and its potential as a cancer drug sensitizer. We observed co-expression and overexpression of G9a and DNMT1 in NSCLC, which were associated with poor prognosis. Co-targeting G9a/DNMT1 with the drug CM-272 reduced proliferation and induced cell death in a panel of human and murine NSCLC cell lines. Additionally, the transcriptomes of these cells were reprogrammed to become highly responsive to chemotherapy (cisplatin), targeted therapy (trametinib), and epigenetic therapy (vorinostat). In vivo, CM-272 reduced tumor volume in human and murine cell-derived cancer models, and this effect was synergistically enhanced by cisplatin. The expression of SCARA5 and AOX1 was induced by CM-272, and both proteins were found to be essential for the antiproliferative response, as gene silencing decreased cytotoxicity. Furthermore, the expression of SCARA5 and AOX1 was positively correlated with each other and inversely correlated with G9a and DNMT1 expression in NSCLC patients. SCARA5 and AOX1 DNA promoters were hypermethylated in NSCLC, and SCARA5 methylation was identified as an epigenetic biomarker in tumors and liquid biopsies from NSCLC patients. Thus, we demonstrate that co-targeting G9a/DNMT1 is a promising strategy to enhance the efficacy of cancer drugs, and SCARA5 methylation could serve as a non-invasive biomarker to monitor tumor progression.

DNMT1 silencing induces KIR2DL1/2/3 expression via methylation to alleviate graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Natural killer (NK) cells are the promoters in graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), while demethylation can regulate NK cell function. We explored the mechanism of demethylation regulating NK cell function to affect GVHD after allo-HSCT. BALB/c mice were transfused with C57BL/6 mouse-derived NK and bone marrow cells to establish GVHD models, followed by isolation and in-vitro expansion of NK cells. NK cell purity, cytokine levels, proliferation, and cytokine-producing NK cell levels were measured via flow cytometry. KIR2DL1/2/3 methylation was tested by Methylation-specific polymerase chain reaction (MSP), with determination of mouse survival and GVHD scores. KIR2DL1/2/3 and DNMT1 expression was detected through qRT-PCR and/or western blot. Methylation levels were upregulated and KIR2DL1/2/3 expression was downregulated in GVHD mouse model-derived NK cells following IL-2 stimulation. DNMT1 silencing promoted KIR2DL1/2/3 expression, proliferation, and the secretion of Granzyme, Perforin, and Interferon-γ (IFN-γ) in C57BL/6 mouse-derived NK cells. DNMT1 silencing also enhanced mouse survival, reduced GVHD scores, promoted KIR2DL1/2/3 expression on the NK cell surface, and increased the secretion of Granzyme, Perforin, IFN-γ, and the number of cytokine-producing NK cells in the spleen, liver, and lung tissues of the models. Collectively, DNMT1 silencing induced KIR2DL1/2/3 expression in NK cells through reducing methylation to alleviate GVHD after allo-HSCT.

Triphenyl Phosphate Alters Methyltransferase Expression and Induces Genome-Wide Aberrant DNA Methylation in Zebrafish Larvae.

Emerging environmental contaminants, organophosphate flame retardants (OPFRs), pose significant threats to ecosystems and human health. Despite numerous studies reporting the toxic effects of OPFRs, research on their epigenetic alterations remains limited. In this study, we investigated the effects of exposure to 2-ethylhexyl diphenyl phosphate (EHDPP), tricresyl phosphate (TMPP), and triphenyl phosphate (TPHP) on DNA methylation patterns during zebrafish embryonic development. We assessed general toxicity and morphological changes, measured global DNA methylation and hydroxymethylation levels, and evaluated DNA methyltransferase (DNMT) enzyme activity, as well as mRNA expression of DNMTs and ten-eleven translocation (TET) methylcytosine dioxygenase genes. Additionally, we analyzed genome-wide methylation patterns in zebrafish larvae using reduced-representation bisulfite sequencing. Our morphological assessment revealed no general toxicity, but a statistically significant yet subtle decrease in body length following exposure to TMPP and EHDPP, along with a reduction in head height after TPHP exposure, was observed. Eye diameter and head width were unaffected by any of the OPFRs. There were no significant changes in global DNA methylation levels in any exposure group, and TMPP showed no clear effect on DNMT expression. However, EHDPP significantly decreased only DNMT1 expression, while TPHP exposure reduced the expression of several DNMT orthologues and TETs in zebrafish larvae, leading to genome-wide aberrant DNA methylation. Differential methylation occurred primarily in introns (43%) and intergenic regions (37%), with 9% and 10% occurring in exons and promoter regions, respectively. Pathway enrichment analysis of differentially methylated region-associated genes indicated that TPHP exposure enhanced several biological and molecular functions corresponding to metabolism and neurological development. KEGG enrichment analysis further revealed TPHP-mediated potential effects on several signaling pathways including TGFβ, cytokine, and insulin signaling. This study identifies specific changes in DNA methylation in zebrafish larvae after TPHP exposure and brings novel insights into the epigenetic mode of action of TPHP.

Comparison of Gene Expression for Preimplantation Genes in Bovine Embryos Fertilized in vitro

Background: In vitro fertilization (IVF) the technique is useful for understanding early mammalian development and maximizing and speeding up genetic improvement in livestock. Genes that function as genetic markers and are involved in the pre-implantation development of embryos may be used to evaluate the quality of an embryo and the expression of these genes is correlated with the timing of embryonic genomic activation. Methods: Maturing the oocytes of bovine, then fertilizing these matured oocytes and finally culturing the fertilized oocytes to develop into embryos. Determined the gene expression of different certain genes HSP70, OCT4, GLUT1, BAX and DNMT1 in these different cell stages of embryos that were produced. Result: The mRNA expression of these genes was estimated after collecting the embryos listed above that were produced by the in vitro technique. The results showed statistically significant differences in the relative abundance between some of the genes mentioned above in each embryo stage. The timing of the zygotic genome activation process (ZGA) can result in differences in gene expression levels between the early embryonic genes in each developmental stage of in vitro-produced bovine embryos.

Azacitidine and cytarabine induce sustained lymphopenia with abnormal differentiation of common lymphoid progenitors and prolonged suppression of Dnmt3a and Dnmt3b expression in mice.

Myelosuppression is a major side effect of chemotherapy. Although decreased blood cells are restored with the recovery of bone marrow cells, insufficient recovery of decreased lymphocytes was observed in mice given azacitidine (AZA), a DNA methyltransferase (DNMT) inhibitor, even following the restoration of bone marrow cells. To understand the mechanisms behind this sustained lymphopenia, we examined AZA's impact on the hematopoietic progenitor cells and the expression of Dnmts and differentiation-related genes. An antimetabolite of cytidine analog, cytarabine (Ara-C), was used as a reference compound. Decreases in almost all blood parameters and common lymphoid progenitors (CLPs) and the downregulation of Dnmts and differentiation-related genes in Lineage-Sca-1+c-kit+ (LSK) cells were observed in mice administered AZA or Ara-C for 7 d. In the posttreatment observation, all parameters, except for lymphocytes and monocytes, exhibited recovery within 3 wk after the final dosing in both treated groups. However, no recovery from the decreases in lymphocytes, especially B cells, and monocytes occurred even after 5 wk. The number of CLPs was elevated after 3 wk. There was a tendency toward recovery from the decreased expression of Dnmt1 and differentiation-related genes, but the expression levels of Dnmt3a and Dnmt3b did not fully recover even 5 wk after the final dosing. Taken together, the findings revealed that the mechanism of sustained lymphopenia observed in mice treated with AZA or Ara-C is associated, at least in part, with the abnormal differentiation of CLPs into B cells accompanied by the prolonged suppression of Dnmt3a and Dnmt3b expression on LSK cells.

Berberine Inhibits KLF4 Promoter Methylation and Ferroptosis to Ameliorate Diabetic Nephropathy in Mice.

Inflammation, oxidative stress, fibrosis, and ferroptosis play important roles in diabetic nephropathy development. Krüppel-like factor 4 (KLF4) is a transcriptional factor, which regulates multiple cell processes and is involved in diabetic nephropathy. Berberine has various biological activities, including anti-inflammation, antioxidative stress, and antiferroptosis. Berberine has been shown to inhibit diabetic nephropathy, but whether it involves KLF4 and ferroptosis remains unknown. We established a diabetic nephropathy mice model and administered berberine to the mice. The kidney function, renal structure and fibrosis, expression of KLF4 and DNA methylation enzymes, DNA methylation of the KLF4 promoter, mitochondria structure, and expression of oxidative stress and ferroptosis markers were analyzed. Berberine rescued kidney function and renal structure and prevented renal fibrosis in diabetic nephropathy mice. Berberine suppressed the expression of DNMT1 and DNMT2 and upregulated KLF4 expression by preventing KLF4 promoter methylation. Berberine inhibited the expression of oxidative stress and ferroptosis markers, maintained mitochondria structure, and prevented ferroptosis. Berberine ameliorates diabetic nephropathy by inhibiting Klf4 promoter methylation and ferroptosis.

Zuogui Pills Improve the Learning and Memory Ability of Brain-Aging Mice through the Estrogen Receptor ERα Methylation Pathway.

Sex hormones are important factors in maintaining brain function and acting as brain protectors. Recent research suggests that neuronal damage in brain aging may be linked to the methylation of the estrogen receptor α (ERα). However, the mechanism of Zuogui Pills (ZGW) in brain-aging ERα DNA methylation and neuronal repair remains unknown. D-galactose-induced ovary removal mice were used as a model of aging. Changes in estrous cycle were detected in mice by vaginal cell smear. Animal behavior tests, including the Morris water maze (MWM) and new object recognition (NOR) test, were conducted. Hematoxylin-eosin (HE) and Nissl-staining were carried out to assess hippocampal neurogenesis. Enzyme-linked immunosorbent assay (ELISA) was performed for 5- methylcytosine methylation levels, and immunohistochemistry (IHC) and western blotting (WB) experiments were performed to assess ERα/DNA methyltransferase 1 (DNMT1) expression after ZGW treatment. Finally, bisulfite sequencing PCR (BSP) analysis was performed to identify methylated differentially expressed estrogen receptor 1 (ESR1) gene in D-gal-induced senescent neurons before and after ZGW treatment. We found that ERα methylation was involved in the delayed brain ageing process of ZGW. Mechanistically, ZGW can improve the learning and memory ability of brain-aging mice, reduce the expression of 5-methylcytosine (5-mc) in serum, increase the amount of ERα, inhibit the expression of DNMT1, and significantly reduce methylated expression of the ESRI gene. Our data suggested that ZGW slowed down D-gal-induced brain aging in mice, and these results showed that ZGW is beneficial for aging. It may be used for neuronal protection in aging.

Differential Expression of DNA Methyltransferase (DNMT1 and DNMT3), Histone Deacetylase (HDAC1 and HDAC2), and Upstream Target Regulators MiR-145 and Mir-152 among Oral Cancers

Epigenetic modulation of DNA and histones facilitated by and histone deacetylases (HDAC) is associated with the development and progression of many cancers, although less is known about DNA methyltransferase (DNMT) in oral cancers and the regulation of these targets. Using commercially available cell lines, oral squamous cell carcinomas (SCC4, SCC9, SCC15, SCC25, and CAL27), and normal gingival fibroblasts (HGF-1), growth assays and mRNA expression were evaluated using ANOVA. These results revealed homeostasis enzyme DNMT1 expression was significantly higher among slow-growing HGF-1 cells than among fast-growing oral cancers, p < 0.05. In contrast, DNMT3A and DNMT3B expression was significantly higher among oral cancers compared with HGF-1 cells, p < 0.05. However, differential expression of HDAC1 and HDAC2 was observed among SCC4, SCC25, and CAL27 cells. Further analysis of miR-152 (regulation and control of DNMT expression) and miR-21, miR-221, and miR-145 (regulation of HDAC expression) revealed all oral cancers produced miR-21, but none produced miR-221. However, differential expression of miR-145 (SCC15) and miR-152 (SCC25) suggested alternative epigenetic pathways and mechanisms of DNMT and HDAC regulation may be responsible for some of the observations revealed in this study.

Exogenous miR-29b Reduces DNA Methylation and Apoptosis in Transgenic Cells

Background: MicroRNA-29b (miR-29b) is a 22-base pair long nucleotide, that post-transcriptionally affects the processes like proliferation, differentiation and apoptosis by changes in DNA methyl transferes expressions (DNMTs family gene), which regulate DNA methylation. Methods: This study aimed to investigate the effect of miR-29b mimic and inhibitor on buffalo fibroblast cells containing the human insulin (hINS) gene. Transgenic buffalo cell line containing (hINS) gene was treated with 40 nM miR-29b mimic and inhibitor by lipofectamin-3000. Result: miRNA-29b mimic treated cells showed a significant decrease (P less than 0.05) in expression of DNMT1, DNMT3A, DNMT3B genes but did not find any significant change (P less than 0.05) in HDAC1 expression as compared to control. Whereas, miR-29b inhibitor-treated cells revealed significantly increased (P less than 0.05) the expression of DNMT1, DNMT3A, DNMT3B and HDAC1 genes as compared to control. These miR-29b mimic-treated cells had significantly increased (P less than 0.05) expression of BCL-XL and MCL-1 whereas miR-29b inhibitor-treated cells showed a significantly decreased (P less than 0.05) expression of MCL-1 while BCL-XL showed no significant (P less than 0.05) change in expression. These findings indicate that treatment of miR-29b mimic on transgenic cells reduces the DNA methylation which helps in the reduction of apoptosis levels in cells. miR-29b mimic reduces the methylation status and help in nuclear reprogramming of transgenic cells. Thus in future, these cells can be a better choice as a nuclear donor for efficient animal cloning.

Effects of Glycine on epigenetic modification and early embryonic development in porcine oocytes exposed to monobutyl phthalate

Monobutyl phthalate (MBP) is the primary active metabolite of dibutyl phthalate (DBP), the key plasticizer component. A substantial body of evidence from studies conducted on both animals and humans indicates that MBP exposure could result in harmful impacts on toxicity pathways. In addition, it can seriously affect human and animal reproductive health. In our present study, we showed that exposure to MBP causes abnormal epigenetic modifications in porcine oocytes and failure of early embryonic development. However, glycine (Gly) can protect oocytes and early embryos from damage caused by MBP. Our study indicated a significant decrease in the percentage of porcine oocytes that reached the metaphase II (MII) phase when exposed to MBP. SET-domain-containing 2(SETD2)-mediated H3K36me3 histone methylation was detected, and the results showed that MBP significantly decreased the protein expression of H3K36me3 and SETD2. Moreover, the expression of the DNA break markers γH2AX and the mRNA expression of Asf1a, and Asf1b increased in the MBP group. The detection of DNA methylation marker proteins showed that MBP significantly increased the fluorescence intensity of 5-methylcytosine (5mC). The results from our RT-qPCR analysis demonstrated a significant decrease in the mRNA expression of the DNA methylation-related genes Dnmt1 and Dnmt3a, as well as the embryonic developmental potential-related genes Oct4 and Nanog, in porcine oocytes following exposure to MBP. Additionally, the mRNA expression of p53 significantly increased. Subsequently, the effects of MBP on early embryonic development were examined via parthenogenesis activation (PA) and in vitro fertilization (IVF). Exposure to MBP significantly impacted the development of embryos in both PA and IVF processes. The TUNEL staining data showed that MBP significantly increased embryonic apoptosis. However, Gly can ameliorate MBP-induced defects in oocyte epigenetic modifications and early embryonic development.

6-Gingerol modulates miRNAs and PODXL gene expression via methyltransferase enzymes in NB4 cells: an in silico and in vitro study

This investigation delves into the influence of predicted microRNAs on DNA methyltransferases (DNMTs) and the PODXL gene within the NB4 cell line, aiming to elucidate their roles in the pathogenesis of acute myeloid leukemia (AML). A comprehensive methodological framework was adopted to explore the therapeutic implications of 6-gingerol on DNMTs. This encompassed a suite of bioinformatics tools for protein structure prediction, docking, molecular dynamics, and ADMET profiling, alongside empirical assessments of miRNA and PODXL expression levels. Such a multifaceted strategy facilitated an in-depth understanding of 6-gingerol’s potential efficacy in DNMT modulation. The findings indicate a nuanced interplay where 6-gingerol administration modulated miRNA expression levels, decreasing in DNMT1 and DNMT3A expression in NB4 cells. This alteration indirectly influenced PODXL expression, contributing to the manifestation of oncogenic phenotypes. The overexpression of DNMT1 and DNMT3A in NB4 cells may contribute to AML, which appears modulable via microRNAs such as miR-193a and miR-200c. Post-treatment with 6-gingerol, DNMT1 and DNMT3A expression alterations were observed, culminating in the upregulation of miR-193a and miR-200c. This cascade effect led to the dysregulation of tumor suppressor genes in cancer cells, including downregulation of PODXL, and the emergence of cancerous traits. These insights underscore the therapeutic promise of 6-gingerol in targeting DNMTs and microRNAs within the AML context.

Promoter methylation and increased expression of PD-L1 in patients with active tuberculosis.

The PD-1/PD-L1 pathway plays a pivotal role in T cell activity and is involved in the pathophysiology of Mycobacterium tuberculosis (MTB) infection. DNA methylation is a mechanism that modulates PD-L1 expression in cancer cells. However, its effect on PD-L1 expression in macrophages after MTB infection remains unknown. We prospectively enrolled patients with active tuberculosis (TB) and non-TB subjects. The expression of PD-L1 and methylation-related genes in peripheral blood mononuclear cells (PBMCs) were investigated and their correlation with disease severity and treatment outcomes were examined. PD-L1 promoter methylation status was evaluated using bisulfite sequencing. Immunohistochemistry (IHC) and immunofluorescence (IF) staining were used to visualize PD-L1- and TET-1-expressing cells in lung tissues from patients with TB and in macrophage cell lines with MTB-related stimulation. In total, 80 patients with active TB and 40 non-TB subjects were enrolled in the analysis. Patients with active TB had significantly higher expression of PD-L1, DNMT3b, TET1, TET2, and lower expression of DNMT1, compared to that in the non-TB subjects. The expression of PD-L1 and TET-1 was significantly associated with 1-month smear and culture non-conversion. IHC and IF staining demonstrated the co-localization of PD-L1- and TET-1-expressing macrophages in patients with pulmonary TB and in human macrophage cell lines after MTB-related stimulation. DNMT inhibition and TET-1 knockdown in human macrophages increased and decreased PD-L1 expression, respectively. Overall, PD-L1 expression is increased in patients with active TB and is correlated with treatment outcomes. DNA methylation is involved in modulating PD-L1 expression in human macrophages.

Decursin Inhibits Expression and Nuclear Localization of DNMT and HDAC, and Suppresses the Growth and Survival of Prostate Cancer Cells

Background: DNA methyltransferases (DNMT) and histone deacetylases (HDAC) inhibitors have utility in cancer therapeutics. However, they are associated with toxicity, which limits their efficacy against carcinomas. Previously, we reported that decursin has anticancer activity against prostate cancer (PCa). In this study, we investigated its epigenetic role in inhibiting the survival of PCa cells. Methods and Results: PCa cell viability was evaluated using MTT and trypan blue assays. The effect of decursin on global methylation and gene-specific methylation was assessed by dot blot assay and MS-PCR, respectively. Differential expression of DNMTs and HDACs was analyzed through semi-quantitative RT-PCR and western blotting. The activity of these enzymes was measured using commercial kits. The nuclear localization of DNMTs and HDAC3 was assessed via immunoblotting. Results: Decursin decreased cell viability and global methylation in PCa cells. It diminished the expression of DNMT1, DNMT3A, DNMT3B, and pan-DNMT activities. Decursin also reduced nuclear levels and increased cytosolic levels of DNMT1 and DNMT3A. Additionally, it inhibited the expression and activity of HDACs, leading to increased total acetylation and H3K9/14 acetylation of histone H3. A reduction in nuclear localization of HDAC3 was observed in decursin-treated PCa cells. Overall, decursin reduced DNMT and HDAC expression and enhanced the nuclear export of DNMT1, DNMT3A, and HDAC3, leading to decreased activities of these enzymes. Conclusion: This study demonstrates the potent anticancer effects of decursin in prostate cancer cells through modulation of epigenetic mechanisms. Decursin decreased both overall and nuclear levels of DNMTs and HDACs. This effect is likely due to decursin’s inhibitory action on these enzymes, as indicated by decreased global methylation and increased histone H3 acetylation. These findings suggest that decursin has multi-faceted epigenetic modulatory properties, making it a promising therapeutic agent for prostate cancer prevention.

Terpenoids from quinoa reverse drug resistance of colon cancer by upregulating miR-495-3p.

Quinoa contains far more nutrients than any traditional grain crop. It is known that terpenoids in quinoa have anti-inflammatory and antitumor effects, but their role in reversing drug resistance remains unclear. Our previous studies showed that quinoa-derived terpenoid compounds (QBT) can inhibit the occurrence and development of colon cancer. This study further indicates that QBT markedly reverse drug resistance of colon cancer. The results showed that QBT combined with 5-fluorouracil (5-Fu) treatment significantly enhanced the chemotherapy sensitivity of HCT-8/Fu, compared with 5-Fu treatment alone. Moreover, we found that QBT significantly reduced the expression of drug-resistant proteins (P-gp, MRP1, BCRP), and increased the accumulation of chemotherapy drugs. Taking P-gp as the target for biogenesis prediction analysis, results showed that upregulation of miR-495-3p enhanced the chemosensitivity of drug-resistant HCT-8/Fu cells. Besides, the results showed that miR-495-3p was abnormally methylated in HCT-8/Fu compared with HCT-8 colon cancer cells. The expression of methyltransferases DNMT1, DNMT3a and DNMT3b was abnormal. After QBT treatment, the expression level of methyltransferases returned to normal. In addition, the QBT + 5Fu group showed inhibition of tumors in nude mice. QBT treatment downregulated the expression of drug-resistant protein P-gp by inhibiting the methylation of miR-495-3p, and enhanced the accumulation of 5-Fu in vivo, which in turn reversed its chemoresistance. This suggests that QBT has potential ability as a new drug-resistance reversal agent in colorectal cancer. © 2024 Society of Chemical Industry.

Dulaglutide reduces oxidative DNA damage and hypermethylation in the somatic cells of mice fed a high-energy diet by restoring redox balance, inflammatory responses, and DNA repair gene expressions.

Obesity is an established risk factor for numerous malignancies, although it remains uncertain whether the disease itself or weight-loss drugs are responsible for a greater predisposition to cancer. The objective of the current study was to determine the impact of dulaglutide on genetic and epigenetic DNA damage caused by obesity, which is a crucial factor in the development of cancer. Mice were administered a low-fat or high-fat diet for 12 weeks, followed by a 5-week treatment with dulaglutide. Following that, modifications of the DNA bases were examined using the comet assay. To clarify the underlying molecular mechanisms, oxidized and methylated DNA bases, changes in the redox status, levels of inflammatory cytokines, and the expression levels of some DNA repair genes were evaluated. Animals fed a high-fat diet exhibited increased body weights, elevated DNA damage, oxidation of DNA bases, and DNA hypermethylation. In addition, obese mice showed altered inflammatory responses, redox imbalances, and repair gene expressions. The findings demonstrated that dulaglutide does not exhibit genotoxicity in the investigated conditions. Following dulaglutide administration, animals fed a high-fat diet demonstrated low DNA damage, less oxidation and methylation of DNA bases, restored redox balance, and improved inflammatory responses. In addition, dulaglutide treatment restored the upregulated DNMT1, Ogg1, and p53 gene expression. Overall, dulaglutide effectively maintains DNA integrity in obese animals. It reduces oxidative DNA damage and hypermethylation by restoring redox balance, modulating inflammatory responses, and recovering altered gene expressions. These findings demonstrate dulaglutide's expediency in treating obesity and its associated complications.

DNA methylation as an epigenetic mechanism in the regulation of LEDGF expression and biological response in aging and oxidative stress

The physiological quantum of stress-inducible transcriptional protein, Lens Epithelium-Derived Growth Factor (LEDGF), is vital for the maintenance of cellular physiology. Erratic epigenetic reprogramming in response to oxidative stress or with advancing age is found to be a major cause in the gene silencing, leading to pathobiologies. Using aging human (h) eye lens/lens epithelial cells (LECs) coupled with redox-active Peroxiredoxin 6 (Prdx6)-deficient (Prdx6−/−) mLECs as model systems, herein, we showed that in aging/oxidative stress, the human LEDGF gene was regulated by unique methylation patterns of CGs nucleotides within and around the Sp1 binding site(s) of CpG island of the LEDGF promoter (−170 to −27nts). The process caused the repression of LEDGF and its target, Hsp27, resulting in reactive oxygen species (ROS) amplification and cellular insults. This phenomenon was opposed to the unmethylated promoter in LECs. Clinically, we observed that the loss of LEDGF in the Prdx6−/− mLECs or aging lenses/LECs, correlating with increased expression of DNMT1, DNMT3a, and DNMT3b along with the methyl CpG binding protein 2 (MeCP2). Upon oxidative stress, the expression of these molecules was increased with the dramatic reduction in LEDGF expression. While demethylating agent, 5-Aza deoxycytidine (5-AzaC) transposed the aberrant methylation status, and revived LEDGF and Hsp27 expression. Mechanistically, the chloramphenicol acetyltransferase (CAT) reporter gene driven by the LEDGF promoter (−170/ + 35) and ChIP assays uncovered that 5-AzaC acted on GC/Sp1 sites to release LEDGF transcription. The data argued, for the first time, that de novo methylation of CGs around and within Sp1 sites of the CpG island directly disrupted Sp1 activity, which ensued in LEDGF repression and its biological functions. The findings should improve our understanding of cellular insults-associated with aberrant DNMTs-mediated LEDGF’s activity, and can offer strategies for therapeutic intervention to halt aging/oxidative stress-induced abnormalities.

DNMT inhibitor, 5-aza-2′-deoxycytidine mitigates di(2-ethylhexyl) phthalate-induced aggravation of psoriasiform inflammation in mice via reduction in global DNA methylation in dermal and peripheral compartments

Psoriasis is classified as an autoimmune disorder characterized by abnormal immune response leading to the development of chronic dermal inflammation. Most individuals have a genetic vulnerability that may be further influenced by epigenetic changes occurring due to multiple variables such as pollutant exposure. Epigenetic modifications such as DNA methylation possess a dynamic nature, enabling cellular differentiation and adaptation by controlling gene expression. Di(2-ethylhexyl) phthalate (DEHP) and psoriatic inflammation are known to cause modification of DNA methylation via DNA methyltransferase (DNMT). However, it is not known whether DEHP, a ubiquitous plasticizer affects psoriatic inflammation via DNMT modulation. Therefore, this study investigated the effect of DNMT inhibitor, 5-aza-2′-deoxycytidine (AZA) on DEHP-induced changes in the expression of DNMT1, global DNA methylation, and anti-/inflammatory parameters (p-STAT3, IL-17A, IL-6, iNOS, IL-10, Foxp3, Nrf2, HO-1) in the skin and the peripheral adaptive/ myeloid immune cells (CD4+ T cells/CD11b+ cells) in imiquimod (IMQ) model of psoriasiform inflammation. Further, psoriasis-associated clinical/histopathological features (ear thickness, ear weight, ear PASI score, MPO activity, and H&E staining of the ear and the back skin) were also analyzed in IMQ model. Our data show that IMQ-treated mice with DEHP exposure had increased DNMT1 expression and DNA methylation which was associated with elevated inflammatory (p-STAT3, IL-17A, IL-6, iNOS) and downregulated anti-inflammatory mediators (IL-10, Foxp3, Nrf2, HO-1) in the peripheral immune cells (CD4+ T cells/CD11b+ cells) and the skin as compared to IMQ-treated mice. Treatment with DNMT1 inhibitor caused reduction in inflammatory and elevation in anti-inflammatory parameters with significant improvement in clinical/histopathological symptoms in both IMQ-treated and DEHP-exposed IMQ-treated mice. In conclusion, our study shows strong evidence indicating that DNMT1 plays an important role in DEHP-induced exacerbation of psoriasiform inflammation in mice through hypermethylation of DNA.