Epigenetics research and its significance in cancer

Epigenetics

Introduction to epigenetics and techniques

There has been a great interest in the study of epigenetic mechanisms and DNA methylation in many areas of research, including DNA repair, cell cycle control, developmental biology, cancer research, identification of biomarkers, predisposition factors and potential drug targets. Lately I’ve been immersed in this field via my close work with the Epigenetics Research Solution experts in QIAGEN. I thought that you, our readers, might also be interested in learning more about the techniques and controls that are important for epigenetic research.

DNA methylation and cancer studies

DNA methylation is an important topic in cancer research – previous studies have shown hypermethylation of tumor suppressor genes in multiple different cancer types (1). How can you detect methylation in your own DNA samples? Exposing DNA to bisulfite rapidly leads to the deamination of unmethylated cytosines which are converted to 6-sulfonyluracil. At a high pH, 6-sulfonyluracil is desulfonated to uracil, which ultimately after amplification will translate into thymidine, while methylated cytosines will not be converted. Comparing this converted DNA to the original unconverted sequence enables detailed evaluation of the location and abundance of methylated sites in CpG islands. High-resolution melting (HRM) analysis provides a rapid screening tool to accurately detect changes in the CpG methylation status of bisulfite converted DNA. Detailed quantitative measures of percent methylation at individual CpG sites are obtained by Pyrosequencing. Alternative methods for broad-scale methylation analysis include methylation-specific PCR (MSP) which is highly specific and sensitive. Commercial kits are available for all forms of analysis.

Complete details about the DNA methylation analysis based on restriction enzyme digest can be found on the QIAGEN website under our resource section.

In any methylation analysis experiment, control DNA is crucial. Below, I’ve provided a table that helps illustrate what each control will yield in your experiment.

Expected PCR results with controls
Type of DNA Primer for unmethylated target gene (PCR 1) Primer for unmethylated target gene (bisulfite converted) (PCR 2) Primer for methylated target gene (bisulfite converted) (PCR 3)
Unmethylated control DNA  PCR product  No PCR product  No PCR product
Unmethylated control DNA (bisulfite converted)  No PCR product  PCR product  No PCR product
Methylated control DNA (bisulfite converted)  No PCR product  No PCR product  PCR product
No-template control  No PCR product  No PCR product  No PCR product

 

Webinar series on DNA methylation and Pyrosequencing

To support all your needs of we have designed some work tips and tricks in a 3-part webinar series to learn more. Check out the slides on SlideShare!

 

More from QIAGEN

Epigenetics

Trying to overcome bottlenecks in epigenetics research? Read our article on the obstacles blocking bisulfite conversion of DNA for epigenetics research applications, and solutions to overcome them!


Reference: 

  1. 1. Kulis, M. and Esteller, M. (2010) DNA methylation and cancer. Adv. Genet. 70, 27. Link
Abhishek Sharma, Msc., MBA

Senior Global Market Manager, Discovery Sciences

Abhishek Sharma trained as a biochemist and has hands-on experience in nucleic acid and protein purification, tissue culturing and recombinant DNA technology. Previously, he was as a market analyst on emerging technologies in life science research. Sharma also worked in a USA-based healthcare consultancy on the discovery, development and commercialization of new disease treatments across multiple therapeutic areas. Currently, he’s involved with managing QIAGEN’s sample preparation portfolio, specializing in RNA technologies.

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