Aberrant DNA Methylation and Histone Modifications in Cancer

2016 ◽  
pp. 1-9
Author(s):  
Petra Hudler
Keyword(s):  
Dna Methylation ◽  
Histone Modifications ◽  
Aberrant Dna Methylation

scholarly journals Neuroblastoma and the epigenome

2021 ◽  
Author(s):  
Irfete S. Fetahu ◽  
Sabine Taschner-Mandl
Keyword(s):  
Dna Methylation ◽  
Histone Modifications ◽  
Disease Diagnosis ◽  
Dna Methyltransferases ◽  
Epigenetic Alterations ◽  
Aberrant Expression ◽  
Tet Proteins ◽  
Relative Paucity ◽  
Underlying Causes ◽  
Aberrant Dna Methylation

AbstractNeuroblastoma (NB) is a pediatric cancer of the sympathetic nervous system and one of the most common solid tumors in infancy. Amplification of MYCN, copy number alterations, numerical and segmental chromosomal aberrations, mutations, and rearrangements on a handful of genes, such as ALK, ATRX, TP53, RAS/MAPK pathway genes, and TERT, are attributed as underlying causes that give rise to NB. However, the heterogeneous nature of the disease—along with the relative paucity of recurrent somatic mutations—reinforces the need to understand the interplay of genetic factors and epigenetic alterations in the context of NB. Epigenetic mechanisms tightly control gene expression, embryogenesis, imprinting, chromosomal stability, and tumorigenesis, thereby playing a pivotal role in physio- and pathological settings. The main epigenetic alterations include aberrant DNA methylation, disrupted patterns of posttranslational histone modifications, alterations in chromatin composition and/or architecture, and aberrant expression of non-coding RNAs. DNA methylation and demethylation are mediated by DNA methyltransferases (DNMTs) and ten-eleven translocation (TET) proteins, respectively, while histone modifications are coordinated by histone acetyltransferases and deacetylases (HATs, HDACs), and histone methyltransferases and demethylases (HMTs, HDMs). This article focuses predominately on the crosstalk between the epigenome and NB, and the implications it has on disease diagnosis and treatment.

scholarly journals Targeting Epigenetic Modifications in Uveal Melanoma

2020 ◽  
Vol 21 (15) ◽  
pp. 5314
Author(s):  
Pooneh Chokhachi Baradaran ◽  
Zuzana Kozovska ◽  
Alena Furdova ◽  
Bozena Smolkova
Keyword(s):  
Dna Methylation ◽  
Uveal Melanoma ◽  
Histone Modifications ◽  
Tumor Suppressor Genes ◽  
Primary Therapy ◽  
Epigenetic Alterations ◽  
Combination Therapies ◽  
Non Coding Rna ◽  
Aberrant Dna Methylation ◽  
New Generation

Uveal melanoma (UM), the most common intraocular malignancy in adults, is a rare subset of melanoma. Despite effective primary therapy, around 50% of patients will develop the metastatic disease. Several clinical trials have been evaluated for patients with advanced UM, though outcomes remain dismal due to the lack of efficient therapies. Epigenetic dysregulation consisting of aberrant DNA methylation, histone modifications, and small non-coding RNA expression, silencing tumor suppressor genes, or activating oncogenes, have been shown to play a significant role in UM initiation and progression. Given that there is no evidence any approach improves results so far, adopting combination therapies, incorporating a new generation of epigenetic drugs targeting these alterations, may pave the way for novel promising therapeutic options. Furthermore, the fusion of effector enzymes with nuclease-deficient Cas9 (dCas9) in clustered regularly interspaced short palindromic repeats (CRISPR) associated protein 9 (Cas9) system equips a potent tool for locus-specific erasure or establishment of DNA methylation as well as histone modifications and, therefore, transcriptional regulation of specific genes. Both, CRISPR-dCas9 potential for driver epigenetic alterations discovery, and possibilities for their targeting in UM are highlighted in this review.

Aberrant DNA Methylation Is Associated with Reduced Response to SRC Inhibition in Primary Human Vestibular Schwannoma Cells

2019 ◽  
Author(s):  
Christine Dinh ◽  
Juan Young ◽  
Olena Bracho ◽  
Rahul Mittal ◽  
Denise Yan ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Vestibular Schwannoma ◽  
Aberrant Dna Methylation

245-LB: Aberrant DNA Methylation as a Contributor to Obesity-Associated Vascular Dysfunction

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 245-LB
Author(s):  
MOHAMED M. ALI ◽  
CHANDRA HASSAN ◽  
MARIO MASRUR ◽  
FRANCESCO BIANCO ◽  
SHANE A. PHILLIPS ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Vascular Dysfunction ◽  
Aberrant Dna Methylation

scholarly journals Epigenetic Regulation of MicroRNA Clusters and Families during Tumor Development

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1333
Author(s):  
Jana Gregorova ◽  
Petra Vychytilova-Faltejskova ◽  
Sabina Sevcikova
Keyword(s):  
Histone Modifications ◽  
Sequence Similarity ◽  
Tumor Development ◽  
Hematologic Malignancies ◽  
Seed Region ◽  
Cancer Therapies ◽  
Rna Molecules ◽  
Physiological Processes ◽  
Close Relationship ◽  
Aberrant Dna Methylation

MicroRNAs are small non-coding single-stranded RNA molecules regulating gene expression on a posttranscriptional level based on the seed sequence similarity. They are frequently clustered; thus, they are either simultaneously transcribed into a single polycistronic transcript or they may be transcribed independently. Importantly, microRNA families that contain the same seed region and thus target related signaling proteins, may be localized in one or more clusters, which are in a close relationship. MicroRNAs are involved in basic physiological processes, and their deregulation is associated with the origin of various pathologies, including solid tumors or hematologic malignancies. Recently, the interplay between the expression of microRNA clusters and families and epigenetic machinery was described, indicating aberrant DNA methylation or histone modifications as major mechanisms responsible for microRNA deregulation during cancerogenesis. In this review, the most studied microRNA clusters and families affected by hyper- or hypomethylation as well as by histone modifications are presented with the focus on particular mechanisms. Finally, the diagnostic and prognostic potential of microRNA clusters and families is discussed together with technologies currently used for epigenetic-based cancer therapies.

scholarly journals Hypermethylation of mismatch repair gene hMSH2 associates with platinum-resistant disease in epithelial ovarian cancer

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Hua Tian ◽  
Li Yan ◽  
Li Xiao-fei ◽  
Sun Hai-yan ◽  
Chen Juan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ovarian Cancer ◽  
Dna Methylation ◽  
Epithelial Ovarian Cancer ◽  
Upstream Region ◽  
Platinum Resistance ◽  
Maldi Tof Mass Spectrometry ◽  
Platinum Resistant ◽  
Aberrant Dna Methylation ◽  
Low Expression

Abstract Purpose One major reason of the high mortality of epithelial ovarian cancer (EOC) is due to platinum-based chemotherapy resistance. Aberrant DNA methylation may be a potential mechanism underlying the development of platinum resistance in EOC. The purpose of this study is to discover potential aberrant DNA methylation that contributes to drug resistance. Methods By initially screening of 16 platinum-sensitive/resistant samples from EOC patients with reduced representation bisulfite sequencing (RRBS), the upstream region of the hMSH2 gene was discovered hypermethylated in the platinum-resistant group. The effect of hMSH2 methylation on the cellular response to cisplatin was explored by demethylation and knockdown assays in ovarian cancer cell line A2780. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry was employed to examine the methylation levels of hMSH2 upstream region in additional 40 EOC patient samples. RT-qPCR and IHC assay was used to detect the hMSH2 mRNA and protein expression in extended 150 patients. Results RRBS assay discovered an upstream region from − 1193 to − 1125 of hMSH2 was significant hypermethylated in resistant EOC patients (P = 1.06 × 10−14). In vitro analysis demonstrated that global demethylation increased cisplatin sensitivity along with a higher expression of the hMSH2 mRNA and protein. Knockdown hMSH2 reduced the cell sensitivity to cisplatin. MALDI-TOF mass spectrometry assay validated the strong association of hypermethylation of hMSH2 upstream region with platinum resistance. Spearman’s correlation analysis revealed a significantly negative connection between methylation level of hMSH2 upstream region and its expression. The Kaplan-Meier analyses showed the high methylation of hMSH2 promoter region, and its low expressions are associated with worse survival. In multivariable models, hMSH2 low expression was an independent factor predicting poor outcome (P = 0.03, HR = 1.91, 95%CI = 1.85–2.31). Conclusion The hypermethylation of hMSH2 upstream region is associated with platinum resistant in EOC, and low expression of hMSH2 may be an index for the poor prognosis.

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