Global Methylation and Hydroxymethylation in DNA from Blood and Saliva in Healthy Volunteers

Aims. We describe a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify and compare simultaneously global methylation and hydroxymethylation in human DNA of different tissues. Materials and Methods. Blood and saliva DNA from fourteen volunteers was processed for epigenetic e...

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Bibliographic Details
Main Authors: Lode Godderis, Caroline Schouteden, Ali Tabish, Katrien Poels, Peter Hoet, Andrea A. Baccarelli, Kirsten Van Landuyt
Format: Article
Language:English
Published: Hindawi Limited 2015-01-01
Series:BioMed Research International
Online Access:http://dx.doi.org/10.1155/2015/845041
Description
Summary:Aims. We describe a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify and compare simultaneously global methylation and hydroxymethylation in human DNA of different tissues. Materials and Methods. Blood and saliva DNA from fourteen volunteers was processed for epigenetic endpoints using LC-MS/MS and PCR-pyrosequencing technology. Results. Global DNA methylation was significantly lower in saliva (mean 4.61% ±  0.80%), compared to blood samples (5.70% ± 0.22%). In contrast, saliva (0.036% ± 0.011%) revealed significantly higher hydroxymethylation compared to blood samples (mean 0.027% ± 0.004%). Whereas we did not find significant correlations for both epigenetic measures between the tissues, a significant association was observed between global methylation and global hydroxymethylation in saliva DNA. Neither LINE-1 nor Alu elements of blood and saliva correlated, nor were they correlated with the DNA hydroxymethylation of blood or saliva, respectively. Conclusion. Global DNA methylation and hydroxymethylation of cytosine can be quantified simultaneously by LC-MS/MS. Saliva DNA cannot be considered as a surrogate for blood DNA to study epigenetic endpoints.
ISSN:2314-6133
2314-6141