Related Experiment Video
Updated: Aug 26, 2026
Continuous Fluorescence-Based Endonuclease-Coupled DNA Methylation Assay to Screen for DNA Methyltransferase Inhibitors
Published on: August 5, 2022
Aberrant DNA methylation in cancer: potential clinical interventions
1Department of Medical Oncology, Cancer Research UK Beatson Laboratories, Glasgow University, Glasgow, G61 1BD, UK. g.strathdee@beatson.gla.ac.uk
Abstract:
DNA methylation, the addition of a methyl group to the carbon-5 position of cytosine residues, is the only common covalent modification of human DNA and occurs almost exclusively at cytosines that are followed immediately by a guanine (so-called CpG dinucleotides). The bulk of the genome displays a clear depletion of CpG dinucleotides, and those that are present are nearly always methylated. By contrast, small stretches of DNA, known as CpG islands, are comparatively rich in CpG nucleotides and are nearly always free of methylation. These CpG islands are frequently located within the promoter regions of human genes, and methylation within the islands has been shown to be associated with transcriptional inactivation of the corresponding gene. Alterations in DNA methylation might be pivotal in the development of most cancers. In recent years, it has become apparent that the pattern of DNA methylation observed in cancer generally shows a dramatic shift compared with that of normal tissue. Although cancers often exhibit clear reductions throughout their genomes in the levels of DNA methylation, this goes hand-in-hand with increased methylation at the CpG islands. Such changes in methylation have a central role in tumourigenesis; in particular, methylation of CpG islands has been shown to be important in transcriptional repression of numerous genes that function to prevent tumour growth or development. Studies of DNA methylation in cancer have thus opened up new opportunities for diagnosis, prognosis and ultimately treatment of human tumours.
Insights
DNA methylation patterns change in cancer, with reduced global levels but increased CpG island methylation. These epigenetic alterations are crucial for tumor development and offer new diagnostic and therapeutic avenues.
Area of Science:
- Epigenetics
- Molecular Biology
- Cancer Genomics
Background:
- DNA methylation, a key epigenetic mechanism, involves adding methyl groups to cytosine residues, primarily at CpG dinucleotides.
- CpG islands, CpG-rich regions in gene promoters, are typically unmethylated and regulate gene expression.
- Aberrant DNA methylation is implicated in various cancers, altering gene silencing and tumor progression.
Purpose of the Study:
- To investigate the distinct DNA methylation patterns in cancer compared to normal tissues.
- To elucidate the role of altered DNA methylation, particularly at CpG islands, in tumorigenesis.
- To explore the potential of DNA methylation analysis for cancer diagnosis, prognosis, and treatment.
Main Methods:
- Analysis of genome-wide DNA methylation profiles in cancerous and normal tissues.
- Identification and characterization of differentially methylated regions, focusing on CpG islands.
- Correlation of methylation status with gene expression and tumor characteristics.
Main Results:
- Cancer genomes exhibit global hypomethylation alongside significant hypermethylation at specific CpG islands.
- CpG island hypermethylation leads to transcriptional repression of tumor-suppressor genes.
- Distinct DNA methylation signatures are associated with different cancer types and stages.
Conclusions:
- Altered DNA methylation, especially CpG island hypermethylation, is a critical driver of cancer development.
- Understanding these epigenetic changes provides insights into tumor biology.
- DNA methylation markers hold promise for improving cancer management strategies.
Related Concept Videos
01:37Epigenetic Regulation
X-chromosome...
01:46Epigenetic Regulation
02:23Abnormal Proliferation
02:30Genomic Imprinting and Inheritance
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
02:57Targeted Cancer Therapies
There are several types of targeted therapies against specific...