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Updated: Jun 30, 2026
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Genome-Wide Analysis of DNA Methylation in Gastrointestinal Cancer
Published on: September 18, 2020
DNA methylotype analysis in colorectal cancer
Jinsheng Yu1, Robert R Freimuth, Robert Culverhouse
1Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA.
Oncology Reports
|September 25, 2008
Summary
Distinct DNA methylation patterns in colorectal cancer genes (CDKN2A, DPYD, MLH1) were identified. These unique tumor methylotypes, unlike normal tissue, may reveal distinct tumor biology in colorectal cancer.
Area of Science:
- Molecular Biology
- Genetics
- Oncology
Background:
- Gene promoter methylation is crucial in colorectal cancer development.
- Multi-locus DNA methylation patterns offer greater insight than single CpG sites.
Purpose of the Study:
- To investigate multi-CpG methylation patterns of CDKN2A, DPYD, and MLH1 in colorectal cancer.
- To determine if distinct DNA methylotypes characterize colorectal tumors.
Main Methods:
- Pyrosequencing technology was used to analyze DNA methylation.
- Nested PCR amplified bisulfite-converted DNA from tumor samples.
- Five to six CpG loci per gene were assessed to define DNA methylotypes.
Main Results:
- Prevalence of methylation: 20.4% for CDKN2A, 12.5% for DPYD, and 28.6% for MLH1.
- Tumor DNA showed high-degree, multi-site methylation, distinct from normal DNA's low-degree, dispersed methylation.
- An inverse correlation between MLH1 DNA methylation and RNA expression was observed (RS=-0.62, P=0.003).
Conclusions:
- Colorectal cancer exhibits distinctive DNA methylotypes.
- These methylotypes may represent unique biological characteristics within seemingly homogeneous tumors.
