RESUMO
AIM: To study the contribution of genetic variation in RAD51 to risk of esophageal squamous cell carcinoma (ESCC). METHODS: Three single nucleotide polymorphisms (SNPs) in RAD51 (rs1801320, rs4144242 and rs4417527) were genotyped in 316 ESCC patients and 316 healthy controls in Anyang area of China using PCR- RFLP (polymerase chain reaction-restriction fragment length polymorphism). Demographic variables between cases and controls were statistically compared by T test and Chi-square test. Hardy-Weinberg equilibrium was evaluated by the Chi-square test. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure any association with ESCC. Haplotype frequencies were estimated by Phase 2.1. RESULT: The genotype frequencies of rs1801320, rs4144242 and rs4417527 in patients with ESCC demonstrated no significant differences from those in control group (P>0.05). When the haplotypes of these three SNPs were constructed and their relationships with ESCC risk investigated, however, CGG was observed to increase the risk (P=0.020, OR=2. 289). CONCLUSIONS: There was no association between the three SNPs of RAD51 and ESCC susceptibility in our Chinese population. However, the CGG haplotype might be a risk factor.
Assuntos
Povo Asiático/genética , Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Polimorfismo de Nucleotídeo Único/genética , Rad51 Recombinase/genética , Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , China/epidemiologia , Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/patologia , Feminino , Seguimentos , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Prognóstico , Fatores de RiscoRESUMO
BACKGROUND AND OBJECTIVE: Mutations in DNA repair system are related to carcinogenesis. This study was to evaluate the correlations of polymorphisms and haplotypes of XPD gene with individual susceptibility to gastric cancer. METHODS: Genomic DNA were extracted from peripheral blood leukocytes of 207 gastric cancer patients and 212 healthy controls. Genotypes at codon 312 and codon 751 polymorphic sites were identified by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) or polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP), respectively. RESULTS: At codon 312, the frequency of GA or AA genotype was higher in the gastric cancer patients than in the healthy controls (P<0.01, OR=3.41, 95% CI: 2.06-4.79; P<0.01, OR=3.47, 95% CI: 1.39-8.68). No significant difference was found in the distribution of the polymorphism at codon 751 between the two groups (P>0.05). By the haplotype AA (codon 312A-codon 751A) analysis, the frequency of heterozygote (-/AA) or homozygote (AA/AA) was higher in the patients than in the controls (P<0.01,OR=2.81, 95% CI:1.82-4.34;P=0.02,OR=3.92, 95% CI:1.31-11.70, respectively). Whereas there were no significant differences of the other three haplotypes between the patients and the controls (P>0.05). CONCLUSIONS: The polymorphism of XPD at codon 312 might contribute to the etiology of gastric cancer. The haplotype AA (codon 312A-codon 751A) would be a critical risk factor of the susceptibility to gastric cancer.