The Relationship between the Methylation of Promoter Regions of Tumor Suppressor Genes PTEN and APC with Endometrial Cancer

CRABP2 accelerates epithelial mesenchymal transition in serous ovarian cancer cells by promoting TRIM16 methylation via upregulating EZH2 expression

Recently, it was covered that cellular retinoic acid-binding protein 2 (CRABP2) is upregulated in ovarian cancer and participates in tumor progression, however, the specific mechanism remains to be explored. The pcDNA-CRABP2 or si-CRABP2 was transfected into SKOV3 and OVCAR3 ovarian cancer cells, respectively, and we observed that overexpression of CRABP2 inhibited cell apoptosis, promoted cell invasion and expression of epithelial mesenchymal transition (EMT) marker proteins, and transfection of si-CRABP2 had the opposite effect. Furthermore, we predicted that EZH2 interacted with CRABP2, and overexpression of CRABP2 promoted EZH2 expression, knockdown of CRABP2 inhibited EZH2 expression, and co-immunoprecipitation assay confirmed their binding relationship. The SKOV3 and OVCAR3 cells were then incubated with pcDNA-CRABP2 alone together with si-EZH2, and we found that si-EZH2 reversed the effect of pcDNA-CRABP2 on promotion of EZH2 expression, cell invasion and EMT maker protein levels. Next, we found that EZH2 could bind to DNMT1, and overexpression of EZH2 inhibited TRIM16 expression and knockdown of EZH2 promoted TRIM16 expression. Moreover, the promoter of TRIM16 contains the CpG island, and ChIP assay observed enriched DNMT1 on the promoter of TRIM16, and overexpression of EZH2 increased the promoter methylation level of TRIM16 and knockdown of EZH2 suppressed the methylation. The SKOV3 cells were incubated with si-EZH2 alone or combined with si-TRIM16, and we found that si-TRIM16 reversed the effect of si-EZH2. In vivo studies showed that knockdown of CRABP2 inhibited tumor volume and weight, suppressed the expression of EZH2 and EMT related proteins vimentin and snail, and increased the expression of TRIM16 and E-cadherin.

Research Progress of DNA Methylation in Endometrial Cancer

Endometrial cancer (EC)) is one of the most common malignant tumors of the female genital system, with an increasing incidence and mortality, worldwide. Although the therapeutic strategy of EC is still complicated and challenging, further understanding of carcinogenesis from a gene perspective would allow an effort to improve therapeutic precision in this complex malignancy. DNA methylation is the most widely studied epigenetic alteration in human tumors. Aberrant DNA methylation events, resulting in altered gene expression, are features of many tumor types. In this review, we provide an update on evidence about the roles of aberrant DNA methylation within some classical tumor suppressor genes and oncogenes in endometrial carcinogenesis, and report on recent advances in the understanding of the contribution of aberrant DNA methylation to EC, as well as opportunities and challenges of DNA methylation in EC management and prevention.

DNA Methylation Level of Transcription Factor Binding Site in the Promoter Region of Acyl-CoA Synthetase Family Member 3 (ACSF3) in Saudi Autistic Children

BACKGROUND

DNA methylation (DNAm) is one of the main epigenetic mechanisms that affects gene expression without changing the underlying DNA sequence. Aberrant DNAm has an implication in different human diseases such as cancer, schizophrenia, and autism spectrum disorder (ASD). ASD is a neurodevelopmental disorder that affects behavior, learning, and communication skills. Acyl-CoA synthetase family member 3 (ACSF3) encodes malonyl-CoA synthetase that is involved in the synthesis and oxidation of fatty acids. The dysregulation in such gene has been reported in combined malonic and methylmalonic aciduria associated with neurological symptoms such as memory problems, psychiatric diseases, and/or cognitive decline. This research aims to study DNAm in the transcription factor (TF) binding site of ACSF3 in Saudi autistic children. To determine whether the DNAm of the TF-binding site is a cause or a consequence of transcription regulation of ACSF3.

METHODS

RT-qPCR and DNA methylight qPCR were used to determine the expression and DNAm level in the promoter region of ACSF3, respectively. DNA and RNA were extracted from 19 cases of ASD children and 18 control samples from their healthy siblings.

RESULTS

The results showed a significant correlation between the gene expression of ACSF3 and specificity protein 1 (SP1) in 17 samples of ASD patients, where both genes were upregulated in 9 samples and downregulated in 8 samples.

CONCLUSION

Although this study found no DNAm in the binding site of SP1 within the ACSF3 promoter, the indicated correlation highlights a possible role of ACSF3 and SP1 in ASD patients.

Identification of methylation-driven genes prognosis signature and immune microenvironment in uterus corpus endometrial cancer

Background

Uterus corpus endometrial cancer (UCEC) is the main malignant tumor in gynecology, with a high degree of heterogeneity, especially in terms of prognosis and immunotherapy efficacy. DNA methylation is one of the most important epigenetic modifications. Studying DNA methylation can help predict the prognosis of cancer patients and provide help for clinical treatment. Our research aims to discover whether abnormal DNA methylation can predict the prognosis of UCEC and reflect the patient's tumor immune microenvironment.

Patients and methods

The clinical data, DNA methylation data, gene expression data and somatic mutation data of UCEC patients were all downloaded from the TCGA database. The MethylMix algorithm was used to integrate DNA methylation data and mRNA expression data. Univariate Cox regression analysis, Multivariate Cox regression analysis, and Lasso Cox regression analysis were used to determine prognostic DNA methylation-driven genes and to construct an independent prognostic index (MDS). ROC curve analysis and Kaplan–Meier survival curve analysis were used to evaluate the predictive ability of MDS. GSEA analysis was used to explore possible mechanisms that contribute to the heterogeneity of the prognosis of UCEC patients.

Results

3 differential methylation-driven genes (DMDGs) (PARVG, SYNE4 and CDO1) were considered as predictors of poor prognosis in UCEC. An independent prognostic index was finally established based on 3 DMDGs. From the results of ROC curve analysis and survival curve analysis, MDS showed excellent prognostic ability in TCGA-UCEC. A new nomogram based on MDS and other prognostic clinical indicators has also been successfully established. The C-index of the nomogram for OS prediction was 0.764 (95% CI = 0.702–0.826). GSEA analysis suggests that there were differences in immune-related pathways among patients with different prognosis. The abundance of M2 macrophages and M0 macrophages were significantly enhanced in the high-risk group while T cells CD8, Eosinophils and Neutrophils were markedly elevated in the low-risk group. Meanwhile, patients in the low-risk group had higher levels of immunosuppressant expression, higher tumor mutational burden and immunophenoscore (IPS) scores. Joint survival analysis revealed that 7 methylation-driven genes could be independent prognostic factors for overall survival for UCEC.

Conclusion

We have successfully established a risk model based on 3 DMDGs, which could accurately predict the prognosis of patients with UCEC and reflect the tumor immune microenvironment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02038-z.

Thymoquinone Is a Multitarget Single Epidrug That Inhibits the UHRF1 Protein Complex

Silencing of tumor suppressor genes (TSGs) through epigenetic mechanisms, mainly via abnormal promoter DNA methylation, is considered a main mechanism of tumorigenesis. The abnormal DNA methylation profiles are transmitted from the cancer mother cell to the daughter cells through the involvement of a macromolecular complex in which the ubiquitin-like containing plant homeodomain (PHD), and an interesting new gene (RING) finger domains 1 (UHRF1), play the role of conductor. Indeed, UHRF1 interacts with epigenetic writers, such as DNA methyltransferase 1 (DNMT1), histone methyltransferase G9a, erasers like histone deacetylase 1 (HDAC1), and functions as a hub protein. Thus, targeting UHRF1 and/or its partners is a promising strategy for epigenetic cancer therapy. The natural compound thymoquinone (TQ) exhibits anticancer activities by targeting several cellular signaling pathways, including those involving UHRF1. In this review, we highlight TQ as a potential multitarget single epidrug that functions by targeting the UHRF1/DNMT1/HDAC1/G9a complex. We also speculate on the possibility that TQ might specifically target UHRF1, with subsequent regulatory effects on other partners.

MicroRNA as Epigenetic Modifiers in Endometrial Cancer: A Systematic Review

Simple Summary

Endometrial cancer (EC) is the 2nd most common gynecologic cancer worldwide. MicroRNAs (miRNAs) are small noncoding RNAs that contribute to epigenetic regulation. The objective of this systematic review is to summarize our current knowledge on the role of miRNAs in the epigenetic deregulation of tumor-related genes in EC. It includes all miRNAs reported to be involved in EC including their roles in DNA methylation and RNA-associated silencing. This systematic review should be useful for development of novel strategies to improve diagnosis and risk assessment as well as for new treatments aimed at miRNAs, their target genes or DNA methylation.

Abstract

The objective of this systematic review is to summarize our current knowledge on the influence of miRNAs in the epigenetic deregulation of tumor-related genes in endometrial cancer (EC). We conducted a literature search on the role of miRNAs in the epigenetic regulation of EC applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following terms were used: microRNA, miRNA, miR, endometrial cancer, endometrium, epigenetic, epimutation, hypermethylation, lynch, deacetylase, DICER, novel biomarker, histone, chromatin. The miRNAs were classified and are presented according to their function (tumor suppressor or onco-miRNA), their targets (when known), their expression levels in EC tissue vs the normal surrounding tissue, and the degree of DNA methylation in miRNA loci and CpG sites. Data were collected from 201 articles, including 190 original articles, published between November 1, 2008 and September 30, 2020 identifying 313 different miRNAs implicated in epigenetic regulation of EC. Overall, we identified a total of 148 miRNAs with decreased expression in EC, 140 miRNAs with increased expression in EC, and 22 miRNAs with discordant expression levels. The literature implicated different epigenetic phenomena including altered miRNA expression levels (miR-182, -230), changes in the methylation of miRNA loci (miR-34b, -129-2, -130a/b, -152, -200b, -625) and increased/decreased methylation of target genes (miR-30d,-191). This work provides an overview of all miRNAs reported to be involved in epigenetic regulation in EC including DNA methylation and RNA-associated silencing. These findings may contribute to novel strategies in diagnosis, risk assessment, and treatments aimed at miRNAs, their target genes or DNA methylation.