Positive Association Between DNA Strand Breaks in Peripheral Blood Mononuclear Cells and Polyunsaturated Fatty Acids in Red Blood Cells From Women

Abstract

Lipid peroxidation of polyunsaturated fatty acids (PUFA) generates reactive products that may cause DNA damage. To examine the possible relationship between DNA damage in peripheral blood mononuclear cells (PBMC) and the concentration of PUFA in red blood cells (RBC), endogenous DNA strand breaks, formamidopyrimidine DNA glycosylase (FPG) sites, and hydrogen peroxide (H₂O₂) sensitive sites were evaluated by the comet assay in blood samples from 98 Icelandic women. Fatty acid composition of RBC was analyzed by gas chromatography. Endogenous DNA strand breaks in PBMC correlated positively with the concentration of total PUFA, total n-3 PUFA, docosahexaenoic acid, linoleic acid, oleic acid, and palmitic acid in RBC. However, there was no association between FPG sites or H₂O₂ sensitive sites in DNA in PBMC and the concentration of total PUFA or total saturated fatty acid in RBC. As there was no association between oxidative DNA damage or sensitivity of DNA to oxidative stress and the concentration of PUFA in RBC, the positive association between endogenous DNA strand breaks in PBMC and the concentration of total PUFA in RBC is probably not related to oxidative stress.

Acknowledgments and Notes

This study was supported by grants from the Icelandic Research Council and the Icelandic Association for Cancer Research (AYT). We are grateful to Sigrun Stefansdottir and Hafdis Hafsteinsdottir at The Icelandic Cancer Society for subject recruitment and sample collection from the study subjects. We are also grateful to Dr. Susan Duthie and Nik Vaughan at the Rowett Research Institute, Aberdeen, Scotland, for guidance on how to perform the comet assay and to Dr. Andrew Collins, University of Oslo, Norway, for providing the FPG enzyme. We thank the Department of Clinical Biochemistry at Landspitali—University Hospital for assays of iron status.

Notes

a: Abbreviations are as follows: SFA, saturated fatty acid; C, carbons; PA, palmitic acid; MUFA, monounsaturated fatty acid; OA, oleic acid; PUFA, polyunsaturated fatty acids; LA, linoleic acid; AA, arachidonic acid; EPA, eicosapentaenoic acid; DPA, docosapentaenoic acid; DHA, docosahexaenoic acid.

a: AU, arbitrary units; FPG, Formamidopyrimidine DNA glycosylase.

b: These data have been published previously (23).

a: Mean ± SD. Abbreviations are as follows: PBMC, peripheral blood mononuclear cells; AU, arbitrary units; FPG, formamidopyrimidine DNA glycosylase.

b: For FPG sites, n = 97.

a: Correlation is Pearson's correlation coefficient. Abbreviations are as follows: AU, arbitrary units; RBC, red blood cells; FPG, formamidopyrimidine DNA glycosylase; SFA, saturated fatty acid; C, carbons; PA, palmitic acid; MUFA, monounsaturated fatty acid; PUFA, polyunsaturated fatty acids; LA, linoleic acid; AA, arachidonic acid; EPA, eicosapentaenoic acid; DPA, docosapentaenoic acid; DHA, docosahexaenoic acid.

b: Correlation between variables statistically significant, P < 0.05.

c: Correlation between variables statistically significant, P < 0.01.

d: Correlation between variables near the set significance level, P = 0.051.

a: Correlation is Pearson's correlation coefficient. Abbreviations are as follows: PBMC, peripheral blood mononuclear cells; AU, arbitrary units; FPG, formamidopyrimidine DNA glycosylase.

b: For FPG sites, n = 97.

c: Correlation between variables statistically significant, P < 0.05.