Association between the XPG gene Asp1104His polymorphism and lung cancer risk

Association of genetic polymorphisms in DNA repair genes ERCC2 Asp312Asn (rs1799793), ERCC2 Lys 751 Gln (rs13181), XRCC1 Arg399 Gln (rs25487) and XRCC3 Thr 241Met (rs861539) with the susceptibility of lung cancer in Saudi population

This study demonstrated the association of polymorphisms in ERCC2 (Asp312Asn) rs1799793, ERCC2 (Lys751Gln) rs13181, XRCC1 (Arg399Gln) rs25487 and XRCC3(Thr241Met) rs861539 polymorphisms with a susceptibility of lung cancer (LC) onset in the Saudi population. The study was performed on 134 LC patients and 270 controls. The data revealed that there was no significant association of LC with subtype squamous cell carcinoma (SCC), small cell lung cancer (SCLC) and adenocarcinoma with the ERCC2 rs1799793 polymorphism. The data showed that the CC genotype for ERCC2 rs13181, the AA genotype for XRCC1 rs25487, and the genotype TT for XRCC3 rs861539 were significantly associated with SCC susceptibility (p < 0.05). Similarly, the CC genotype for ERCC2 rs13181 and the AA genotype for XRCC1 rs25487 were significantly associated with adenocarcinoma susceptibility (p < 0.05). Whereas, the TT genotype for XRCC3 rs861539 was significantly associated with SCLC susceptibility (p = 0.005). In total, significant association of LC susceptibility was found in the following combination models of recessive genotypes: AC heterozygous for ERCC2 rs13181 + AA homozygous for XRCC1 rs25487, CC homozygous for ERCC2 rs13181 + GA heterozygous for rs25487, CC homozygous for rs13181 + AA homozygous for XRCC1 rs25487, CC homozygous for ERCC2 rs13181 + TT homozygous for XRCC3 rs861539, GA heterozygous for XRCC1 rs25487 + CT heterozygous for XRCC3 rs861539, GA heterozygous for XRCC1 rs25487 + TT homozygous for XRCC3 rs861539, AA homozygous for XRCC1 rs25487 + CT heterozygous for XRCC3 rs861539, AA homozygous for XRCC1 rs25487+ TT homozygous for XRCC3 rs861539. These data clearly demonstrated that the combination of recessive genotypes may be associated with susceptibility of LC onset (p < 0.05). In short, the data indicated that DNA repair genes increase LC risk via gene-gene interaction rather than independent variants.

Association between the XPG gene rs2094258 polymorphism and risk of gastric cancer

BACKGROUND

Xeroderma pigmentosum group G (XPG) plays an important role in maintaining the stability and integrity of genomic DNA. Previous studies demonstrate some XPG gene polymorphisms are associated with susceptibility to gastric cancer (GC).

METHODS

The association between XPG rs2094258 polymorphism and GC risk was investigated first by a hospital-based case-control study involving 386 patients and 439 controls and then by a meta-analysis. The polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLR).

RESULTS

Xeroderma pigmentosum group G rs2094258 polymorphism was associated with an increased risk of GC in a Chinese population. The meta-analysis did not reveal any significant difference in the overall population. Subgroup analysis of geographic locations showed a significant association between the XPG gene rs2094258 polymorphism and GC risk in Southern China. Stratification analysis further indicated significant associations in hospital-based studies and studies using PCR-RFLR.

CONCLUSION

Xeroderma pigmentosum group G gene rs2094258 polymorphism may be associated with an increased risk of GC in Southern China. Nevertheless, the findings of this meta-analysis should be validated by well-designed large-scale case-control studies among other ethnicities.

Single nucleotide polymorphisms of nucleotide excision repair pathway are significantly associated with outcomes of platinum-based chemotherapy in lung cancer

Nucleotide excision repair (NER) pathway plays critical roles in repairing DNA disorders caused by platinum. To comprehensively understand the association between variants of NER and clinical outcomes of platinum-based chemotherapy, 173 SNPs in 27 genes were selected to evaluate association with toxicities and efficiency in 1004 patients with advanced non-small cell lung cancer. The results showed that consecutive significant signals were observed in XPA, RPA1, POLD1, POLD3. Further subgroup analysis showed that GTF2H4 presented consecutive significant signals in clinical benefit among adenocarcimoma. In squamous cell carcinoma, rs4150558, rs2290280, rs8067195 were significantly associated with anemia, rs3786136 was significantly related to thrombocytopenia, ERCC5 presented consecutive significant signals in response rate. In patients receiving TP regimen, significant association presented in neutropenia, thrombocytopenia and gastrointestinal toxicity. Association with anemia and neutropenia were found in GP regimen. rs4150558 showed significant association with anemia in NP regimen. In patients > 58, ERCC5 showed consecutive significant signals in gastrointestinal toxicity. Survival analysis showed SNPs in POLD2, XPA, ERCC6 and POLE were significantly associated with progression free survival, SNPs in GTF2H4, ERCC6, GTF2HA, MAT1, POLD1 were significantly associated with overall survival. This study suggests SNPs in NER pathway could be potential predictors for clinical outcomes of platinum-based chemotherapy among NSCLC.

Genetic polymorphisms and lung cancer risk: Evidence from meta-analyses and genome-wide association studies

A growing number of studies investigating the association between Single Nucleotide Polymorphisms (SNPs) and lung cancer risk have been published since over a decade ago. An updated integrative assessment on the credibility and strength of the associations is required. We searched PubMed, Medline, and Web of Science on or before August 29^th, 2016. A total of 198 articles were deemed eligible for inclusion, which addressed the associations between 108 variants and lung cancer. Among the 108 variants, 63 were reported to be significantly associated with lung cancer while the remaining 45 were reported non-significant. Further evaluation integrating the Venice Criteria and false-positive report probability (FPRP) was performed to determine the strength of cumulative epidemiological evidence for the 63 significant associations. As a result, 15 SNPs on or near 12 genes and one miRNA with strong evidence of association with lung cancer risk were identified, including TERT (rs2736098), CHRNA3 (rs1051730), AGPHD1 (rs8034191), CLPTM1L (rs401681 and rs402710), BAT3 (rs3117582), TRNAA (rs4324798), ERCC2 (Lys751Gln), miR-146a2 (rs2910164), CYP1B1 (Arg48Gly), GSTM1 (null/present), SOD2 (C47T), IL-10 (-592C/A and -819C/T), and TP53 (intron 6). 19 SNPs were given moderate rating and 17 SNPs were rated as having weak evidence. In addition, all of the 29 SNPs identified in 12 genome-wide association studies (GWAS) were proved to be noteworthy based on FPRP value. This review summarizes and evaluates the cumulative evidence of genetic polymorphisms and lung cancer risk, which can serve as a general and useful reference for further genetic studies.

The Association Between XPG Gene Polymorphism and Gastric Cancer Risk

PURPOSE

Studies exploring the association between the Xeroderma pigmentosum group G (XPG) gene polymorphisms and gastric cancer (GC) risk provide conflicting findings. Thus, this meta-analysis was performed.

MATERIALS AND METHODS

The PubMed and EMBASE databases were comprehensively searched to identify studies for the inclusion in the meta-analysis. The strength of the association was evaluated by calculating pooled odds ratios and 95% confidence intervals.

RESULTS

Nine case-control studies involving 3540 cases and 3953 controls were included in the meta-analysis, which revealed that the XPG rs751402 polymorphism is positively associated with GC risk and could be viewed as a risk factor of GC in three genetic models.

CONCLUSION

The XPG gene rs751402 polymorphism is associated with an increased risk of GC in Chinese Han populations. This finding should be verified by larger studies that include additional ethnic groups.