Association of polymorphisms in X-ray repair cross complementing 1 gene and risk of esophageal squamous cell carcinoma in a Chinese population.

OBJECTIVES: To investigate the association between three single nucleotide polymorphisms (SNPs) in the X-ray repair cross complementing 1 gene (XRCC1) and the risk of esophageal squamous cell carcinoma (ESCC) in Chinese population. METHODS: A case-control study including 381 primary ESCC patients recruited from hospital and 432 normal controls matched with patients by age and gender from Chinese Han population was conducted. The genotypes of three XRCC1 polymorphisms at -77T>C (T-77C), codon 194 (Arg194Trp), and codon 399 (Arg399Gln) were studied by means of polymerase chain reaction-restriction fragment length polymorphism techniques (PCR-RFLP). Unconditional logistic regression model and haplotype analysis were used to estimate associations of these three SNPs in XRCC1 gene with ESCC risk. RESULTS: Polymorphisms at these three sites in XRCC1 gene were not found to be associated with risk for developing ESCC; however the haplotype C(codon 194)G(codon 399)C(-77T>C) was significantly associated with reduced risk of ESCC (OR: 0.62, 95% CI: 0.40-0.96) upon haplotype analysis. CONCLUSION: These results suggested that the gene-gene interactions might play vital roles in the progression on esophageal cancer in Chinese Han population and it would be necessary to confirm these findings in a large and multiethnic population.

CYP1A1 genetic polymorphisms and risk for esophageal cancer: a case-control study in central China.

The purpose of this study was to evaluate the associations of CYP1A1 genetic polymorphisms with the risk of developing esophageal cancer (EC). A case-control study was carried out in a Chinese population in which 157 hospital based EC cases and 157 population based healthy controls with 1:1 match by age and sex were included. PCR based restriction fragment length polymorphisms (PCR-RFLP) were used to detect genotypes in case and control groups. For the CYP1A1 Ile/Val polymorphism, comparing with wild genotype Ile/Ile, both the heterozygote genotype Ile/Val and the combined variant genotype Ile/Val+Val/Val increased the risk of esophageal cancer (OR: 2.05, 95%CI: 1.19-3.54, OR: 1.86, 95%CI: 1.11-3.12). No significant association was found between the CYP1A1 MspI polymorphism and EC. According to analysis of combined genotypes, the TC/AG combined genotype which contained both variant alleles of these two polymorphisms increased the risk of developing EC (OR: 2.12, 95%CI: 1.16-3.85). Our results suggested that genetic polymorphisms of CYP1A1 may increase the susceptibility to EC.

[A meta-analysis of susceptibility to pneumoconiosis and polymorphism of tumor necrosis factor-α 308 and 238 locus].

OBJECTIVE: To explore the relationship between the polymorphism of TNF-α gene 308, 238 locus and the susceptibility to pneumoconiosis. METHODS: Eighteen published case-control studies about TNF-α gene 308, 238 locus polymorphism and pneumoconiosis susceptibility were searched out from sino-foreign databases from January 1994 to December 2010. Meta-analysis was applied on the published research to calculate the pooled OR value (95%CI) and stratified analyze the types and species of pneumoconiosis. RESULTS: Eleven of the published research articles were selected into the analysis, including 10 research focusing on TNF-α gene 308 locus, with 1408 cases and 1639 controls in total. The meta-analysis showed that comparing with Gln/Gln carriers, Arg/Arg, Arg/Gln, Gln/Arg + Arg/Arg carriers were 1.89-fold (95%CI: 1.10 - 3.24), 1.53-fold (95%CI: 1.25 - 1.87), and 1.56-fold (95%CI: 1.28 - 1.90) more susceptible to pneumoconiosis, respectively. The stratified analysis showed that among coal workers, the TNF-α gene 308 locus Arg/Arg, Arg/Gln, Gln/Arg + Arg/Arg carriers were separately 2.29-fold (95%CI: 1.22 - 4.29), 1.56-fold (95%CI: 1.20 - 2.03), 1.64-fold (95%CI: 1.28 - 2.11) more susceptible to pneumoconiosis than Gln/Gln carriers; and among Asian people, the TNF-α gene 308 locus Gln/Arg, Gln/Arg + Arg/Arg carriers were separately 1.58-fold (95%CI: 1.28 - 1.95) and 1.57-fold (95%CI: 1.28 - 1.94) more susceptible to pneumoconiosis than the Gln/Gln carriers. Four case-control research focus on the study of TNF-α gene 238 locus, including 391 cases and 391 controls in total. The analysis showed that comparing with the non-carriers, TNF-α gene 238 locus Arg/Arg, Arg/Gln, Gln/Arg + Arg/Arg carriers were 6.03-fold (95%CI: 1.35 - 26.97), 1.87-fold (95%CI: 1.07 - 3.30) and 2.36-fold (95%CI: 1.37 - 4.07) more susceptible to pneumoconiosis. CONCLUSION: TNF-α gene 308, 238 locus Arg/Arg, Gln/Arg, Gln/Arg + Arg/Arg carriers are more susceptible to pneumoconiosis.

[Improvement on PCR-CTPP: a SNP genotyping approach based on mismatch technique].

To explore the technique principle of PCR with confronting two-pair primers (PCR-CTPP) and improve the accuracy of SNP genotyping by taking the 1298 locus of human gene MTHFR as an example, the reliability between conventional PCR-CTPP and improved PCR-CTPP was compared using reconstructed PCR-CTPP detecting system in terms of designing appropriate primers and optimizing annealing temperature and the final concentration of primers. The improved PCR-CTPP detection system proved to be more accurate, which supported the viewpoint on the theoretical defects of conventional PCR-CTPP. The large-scale study verified the reliability of the improved method. It is expected that this improved technique would be widely used in the field of medicine and molecular biology.