Influence of the OGG1 Ser326Cys polymorphism on oxidatively damaged DNA and repair activity

TY - JOUR

T1 - Influence of the OGG1 Ser326Cys polymorphism on oxidatively damaged DNA and repair activity

AU - Jensen, Annie

AU - Løhr, Mille

AU - Eriksen, Louise

AU - Grønbæk, Morten

AU - Dorry, Elad

AU - Loft, Steffen

AU - Møller, Peter

N1 - Copyright © 2011 Elsevier Inc. All rights reserved.

PY - 2012/1/1

Y1 - 2012/1/1

N2 - Oxidatively damaged DNA base lesions are considered to be mainly repaired by 8-oxoguanine DNA glycosylase (OGG1) mediated pathways. We investigated the effect of the OGG1 Ser326Cys polymorphism on the level and repair of oxidatively damaged DNA in mononuclear blood cells (MNBC) by means of the comet assay. We collected blood samples from 1,019 healthy subjects and genotyped for the OGG1 Ser326Cys polymorphism. We found 49 subjects homozygous for the variant genotype (Cys/Cys) and selected same numbers of age-matched subjects with the heterozygous (Ser/Cys) and homozygous wild-type genotype (Ser/Ser). Carriers of the Cys/Cys genotype had higher levels of formamidopyrimidine DNA glycosylase (FPG) sensitive sites in MNBC (0.31 ± 0.03 lesions/10 6 bp) compared to Ser/Ser (0.19 ± 0.02 lesions/10 6 bp, P < 0.01). The level of hOGG1 sensitive sites in MNBC from the Ser326Cys carriers (0.19 ± 0.16 lesions/10 6 bp) was also higher compared to the Ser/Ser genotype (0.11 ± 0.09 lesions/10 6 bp, P < 0.05). Still, there was no genotype-related difference in DNA repair incision activity of MNBC extracts on nucleoids with oxidatively damaged DNA induced by Ro19-8022/white light (P = 0.20). In addition, there were no differences in the expression of OGG1 (P = 0.69), ERCC1 (P = 0.62), MUTYH (P = 0.85), NEIL1 (P = 0.17) or NUDT1 (P = 0.48) in whole blood. Our results indicate that the OGG1 Ser326Cys polymorphism has limited influence on the DNA repair incisions by extracts of MNBC, whereas the apparent increased risk of cancer in subjects with the Cys/Cys genotype may be because of higher levels of oxidatively damaged DNA.

AB - Oxidatively damaged DNA base lesions are considered to be mainly repaired by 8-oxoguanine DNA glycosylase (OGG1) mediated pathways. We investigated the effect of the OGG1 Ser326Cys polymorphism on the level and repair of oxidatively damaged DNA in mononuclear blood cells (MNBC) by means of the comet assay. We collected blood samples from 1,019 healthy subjects and genotyped for the OGG1 Ser326Cys polymorphism. We found 49 subjects homozygous for the variant genotype (Cys/Cys) and selected same numbers of age-matched subjects with the heterozygous (Ser/Cys) and homozygous wild-type genotype (Ser/Ser). Carriers of the Cys/Cys genotype had higher levels of formamidopyrimidine DNA glycosylase (FPG) sensitive sites in MNBC (0.31 ± 0.03 lesions/10 6 bp) compared to Ser/Ser (0.19 ± 0.02 lesions/10 6 bp, P < 0.01). The level of hOGG1 sensitive sites in MNBC from the Ser326Cys carriers (0.19 ± 0.16 lesions/10 6 bp) was also higher compared to the Ser/Ser genotype (0.11 ± 0.09 lesions/10 6 bp, P < 0.05). Still, there was no genotype-related difference in DNA repair incision activity of MNBC extracts on nucleoids with oxidatively damaged DNA induced by Ro19-8022/white light (P = 0.20). In addition, there were no differences in the expression of OGG1 (P = 0.69), ERCC1 (P = 0.62), MUTYH (P = 0.85), NEIL1 (P = 0.17) or NUDT1 (P = 0.48) in whole blood. Our results indicate that the OGG1 Ser326Cys polymorphism has limited influence on the DNA repair incisions by extracts of MNBC, whereas the apparent increased risk of cancer in subjects with the Cys/Cys genotype may be because of higher levels of oxidatively damaged DNA.

U2 - 10.1016/j.freeradbiomed.2011.09.038

DO - 10.1016/j.freeradbiomed.2011.09.038

M3 - Journal article

C2 - 22019439

SN - 0891-5849

VL - 52

SP - 118

EP - 125

JO - Free Radical Biology & Medicine

JF - Free Radical Biology & Medicine

IS - 1

ER -