DNA Methylation Pattern as Important Epigenetic Criterion in Cancer

Abstract

Epigenetic modifications can affect the long-term gene expression without any change in nucleotide sequence of the DNA. Epigenetic processes intervene in the cell differentiation, chromatin structure, and activity of genes since the embryonic period. However, disorders in genes' epigenetic pattern can affect the mechanisms such as cell division, apoptosis, and response to the environmental stimuli which may lead to the incidence of different diseases and cancers. Since epigenetic changes may return to their natural state, they could be used as important targets in the treatment of cancer and similar malignancies. The aim of this review is to assess the epigenetic changes in normal and cancerous cells, the causative factors, and epigenetic therapies and treatments.

The complexity of the Nrf2 pathway: beyond the antioxidant response

“…Epigenetic modulations can be caused by DNA methylation, histone modifications, and microRNAs [85]. DNA methylation is catalyzed by DNA methyltransferases (DNMTs) that transfer a methyl group to the 5′ position of the cytosine residue within CpG dinucleotides [86, 87].…”

“…DNA methylation is catalyzed by DNA methyltransferases (DNMTs) that transfer a methyl group to the 5′ position of the cytosine residue within CpG dinucleotides [86, 87]. Inappropriate DNA methylation of CpG islands in tumor suppressor genes and oncogenes has been observed in many cancer cells and is one of the potential carcinogenic mechanisms during the development of human cancers [85, 88–91]. …”

Quantitative assessment of the association between APC promoter methylation and breast cancer

“…As we know that breast cancer onset and progression are caused by a series of epigenetic and genetic changes. DNA methylation is a commonly observed epigenetic modification in human malignancies [3, 4]. Methylation in tumor suppressor gene is one of the most common methylation, in cancer, including breast cancer [5, 6].…”

Antitumor activity of SA12, a novel peptide, on SKBr-3 breast cancer cells via the mitochondrial apoptosis pathway

“…As a transcriptional repressor, MECP2 contains two functional domains, ie, a methylated DNA binding domain and a transcriptional repression domain, both of which are involved in the regulation of transcription activity, especially for tumor suppressor genes, thus plays an important role in the development of cancer 19,21. Hypermethylation of tumor suppression gene promoter in CpG islands region is critical in the progression of carcinogenesis 22. MECP2, through binding to the methylated CpG of the gene 5′ flanking sequence, prevents formation of a gene transcriptional complex, and silences the tumor suppressor genes.…”