XPD Asp312Asn polymorphism is a risk factor for prostate cancer

Association Between the Asp312Asn, Lys751Gln, and Arg156Arg Polymorphisms in XPD and the Risk of Prostate Cancer

Prostate cancer is the most common solid cancer and genetic factors play important roles in its pathogenesis. XPD is one of the 8 core genes involved in the nucleotide excision repair pathway. The relationship between Asp312Asn, Lys751Gln, and Arg156Arg polymorphisms in XPD and prostate cancer risk is a controversial topic. Therefore, we conducted a meta-analysis to explore the relationship between these 3 polymorphisms and the risk of developing prostate cancer. We searched the electronic literature in PubMed and Google Scholar for all relevant studies (last updated January 1, 2017). The pooled odds ratios and 95% confidence intervals for the associations between the Asp312Asn, Lys751Gln, or Arg156Arg polymorphisms in XPD and prostate cancer risk were calculated. To evaluate the effects of specific study characteristics on the association of these 3 polymorphisms and prostate cancer risk, we performed subgroup analysis if 2 or more studies were available. After an extensive literature review, 7 publications regarding Asp312Asn genotype distribution with 8 case–controls, 9 publications regarding Lys751Gln genotype distribution with 10 case–controls, and 3 publications regarding Arg156Arg genotype distribution with 4 case–controls were selected. The results showed that Asp312Asn (odds ratio = 1.34, 95% confidence interval: 0.96-1.87, P = .000), Lys751Gln (odds ratio = 0.98, 95% confidence interval: 0.89-1.08, P = .986), and Arg156Arg (odds ratio = 1.05, 95% confidence interval: 0.91-1.22, P = .57) polymorphisms do not increase the risk of prostate cancer in the dominant model. Further, in the subgroup analysis by ethnicity, no relationships were observed between Lys751Gln and Arg156Arg polymorphisms and prostate cancer risk. However, stratified analysis by ethnicity revealed that Asp312Asn affects African (odds ratio = 1.57, 95% confidence interval: 1.06-2.33, P = .382) and Asian populations (odds ratio = 2.09, 95% confidence interval: 1.39-3.14, P = .396) in homozygote comparison. In conclusion, this meta-analysis suggests that there is no general association between the Asp312Asn, Lys751Gln, and Arg156Arg polymorphisms in XPD and prostate cancer susceptibility.

Polymorphisms in nucleotide excision repair genes and risk of primary prostate cancer in Chinese Han populations

Genetic variants of nucleotide excision repair (NER) genes have been extensively investigated for their roles in the development of prostate cancer (PCa); however, the published results have been inconsistent. In a hospital-based case-control study of 1,004 PCa cases and 1,055 cancer-free controls, we genotyped eight potentially functional single nucleotide polymorphisms (SNPs) of NER genes (i.e., XPC, rs2228001 T>G and rs1870134 G>C; XPD, rs13181 T>G and rs238406 G>T; XPG, rs1047768 T>C, rs751402 C>T, and rs17655 G>C; and XPF, rs2276464 G>C) and assessed their associations with risk of PCa by using logistic regression analysis. Among these eight SNPs investigated, only XPC rs1870134 CG/CC variant genotypes were associated with a decreased risk of prostate cancer under a dominant genetic model (adjusted odds ratio [OR] = 0.77, 95% confidence interval [CI] = 0.64-1.91, P = 0.003). Phenotype-genotype analysis also suggested that the XPC rs1870134 CG/CC variant genotypes were associated with significantly decreased expression levels of XPC mRNA in a mix population of different ethnicities. These findings suggested that XPC SNPs may contribute to risk of PCa in Eastern Chinese men.

Role of DNA repair-related gene polymorphisms in susceptibility to risk of prostate cancer

AIM

We assessed the association between genetic variants of XPG, XPA, XPD, CSB, XPC and CCNH in the nucleotide excision repair (NER) pathway and risk of prostate cancer.

METHODS

We genotyped the XPG, XPA, XPD, CSB, XPC and CCNH polymorphisms by a 384-well plate format on the MassARRAY® platform. Multivariate logistical regression analysis was used to assess the associations between the six gene polymorphisms and risk of prostate cancer.

RESULTS

Individuals carrying the XPG rs229614 TT (OR=2.01, 95%CI=1.35-3.27) genotype and T allele (OR=1.73, 95%CI=1.37-2.57) were moderately significantly associated with a higher risk of prostate cancer. Subjects with XPD rs13181 G allele had a marginally increased risk of prostate cancer, with adjusted OR(95%CI) of 1.53 (1.04-2.37). Moreover, individuals carrying with CSB rs2228526 GG genotype (OR=2.05, 95% CI=1.23-3.52) and G allele (OR=1.56, 95%CI=1.17-2.05) were associated with a higher increased risk of prostate cancer. The combination genotype of XPG rs2296147 T and CSB rs2228526 G allele had accumulative effect on the risk of this cancer, with an OR (95% CI) of 2.23(1.37-3.59).

CONCLUSIONS

Our study indicates that XPG rs2296147 and CSB rs2228526 polymorphisms are significantly associated with increased risk of prostate cancer, and that combination of XPG rs2296147 T allele and CSB rs2228526 G allele is strongly associated with an increased risk.

Polymorphism of ERCC2 Asp312Asn with lung cancer risk: evidence from 20,101 subjects

The association between excision repair cross complementing group 2 (ERCC2) Asp312Asn polymorphism and lung cancer has been reported by many articles recently, but the results were controversial and inconclusive. Therefore, a meta-analysis was conducted to assess the relationship between them. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. A total of 22 full studies with 20,101 subjects (8719 cases and 11,382 controls) were included in our research. The meta-analysis result showed that no significant association was found between ERCC2 Asp312Asn polymorphism and lung cancer in overall analysis (AA vs. GG, OR=1.023, 95% CI=0.824-1.270, p=0.838; AG vs. GG, OR=1.003, 95% CI=0.936-1.074, p=0.942; AA+AG vs. GG, OR=1.013, 95% CI=0.949-1.082, p=0.697; AA vs. AG+GG, OR=1.033, 95% CI=0.841-1.270, p=0.755). In subset analyses of stratified ethnicity, significantly increased risk was found among Asians (AA vs. GG, OR=3.212, 95% CI=1.518-6.795, p=0.002; AA vs. AG+GG, OR=3.174, 95% CI=1.500-6.712, p=0.003), whereas the association was not found among Caucasians under any genetic models. When analyses were conducted based on the study design, it indicated that the risk of lung cancer might be significantly increased in a hospital-based study (AA vs. GG, OR=1.323, 95% CI=1.096-1.596, p=0.004; AA+AG vs. GG, OR=1.109, 95% CI=1.000-1.229, p=0.050; AA vs. AG+GG, OR=1.285, 95% CI=1.076-1.535, p=0.006). In addition, a significantly increased risk for nonsmokers was detected under the dominant model (AA+AG vs. GG, OR=1.460, 95% CI=1.095-1.948, p=0.010). In conclusion, this meta-analysis suggested ERCC2 Asp312Asn polymorphism may increase the risk of lung cancer among Asians, whereas not among Caucasians.

Genetic variability in DNA repair proteins in age-related macular degeneration

The pathogenesis of age-related macular degeneration (AMD) is complex and involves interactions between environmental and genetic factors, with oxidative stress playing an important role inducing damage in biomolecules, including DNA. Therefore, genetic variability in the components of DNA repair systems may influence the ability of the cell to cope with oxidative stress and in this way contribute to the pathogenesis of AMD. However, few reports have been published on this subject so far. We demonstrated that the c.977C>G polymorphism (rs1052133) in the hOGG1 gene and the c.972G>C polymorphism (rs3219489) in the MUTYH gene, the products of which play important roles in the repair of oxidatively damaged DNA, might be associated with the risk of AMD. Oxidative stress may promote misincorporation of uracil into DNA, where it is targeted by several DNA glycosylases. We observed that the g.4235T>C (rs2337395) and c.–32A>G (rs3087404) polymorphisms in two genes encoding such glycosylases, UNG and SMUG1, respectively, could be associated with the occurrence of AMD. Polymorphisms in some other DNA repair genes, including XPD (ERCC2), XRCC1 and ERCC6 (CSB) have also been reported to be associated with AMD. These data confirm the importance of the cellular reaction to DNA damage, and this may be influenced by variability in DNA repair genes, in AMD pathogenesis.