[Correlation of polymorphisms of UDP-glucuronosyltransferase 1A7 gene to genetic susceptibility of lung cancer].

BACKGROUND & OBJECTIVE: UDP-glucuronosyltransferase 1A7 (UGT1A7) plays an important role in detoxification through catalyzing combination of glucuronic acid and tobacco carcinogens, including benzo [alpha] pyrene, nitrosamine, and heterocyclic amine PhIP, therefore, inactivates the carcinogens. This study was to examine the correlation of polymorphisms of UGT1A7 gene to genetic susceptibility of lung cancer. METHODS: Polymorphisms of UGT1A7 gene at 12-131 and 208 sites in peripheral lymph cells of 312 patients and 317 age- and sex-matched controls were detected by polymerase chain reaction-denaturized high performance liquid chromatography (PCR-DHPLC) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP); the correlation of these polymorphisms to genetic susceptibility of lung cancer was analyzed. RESULTS: Compared with the UGT1A7*1/*1 genotype carriers, the UGT1A7*3/*1 genotype carriers had a 1.80-fold increased risk of lung adenocarcinoma [adjusted odds ratio (OR), 1.80; 95% confidence interval (CI), 1.03-3.12], the UGT1A7*3 genotype carriers had a 1.59-fold increased risk of lung adenocarcinoma (adjusted OR, 1.59; 95% CI, 0.96-2.63). The UGT1A7 polymorphisms had no correlation with risk of lung squamous cell carcinoma. CONCLUSION: UGT1A7 gene polymorphisms may increase the genetic susceptibility of lung adenocarcinoma in Chinese.

[Association of functional polymorphisms in matrix metalloproteinase-2 (MMP-2) and MMP-9 genes with risk of gastric cancer in a Chinese population].

BACKGROUND & OBJECTIVE: Matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) play important roles in the development of gastric cancer. This study was to investigate the association of functional polymorphisms in the MMP-2 and MMP-9 genes with risk of gastric cancer in a Chinese population. METHODS: MMP-2 -1306T/C,and MMP-9 -1562C/T polymorphisms in 228 patients with gastric cancer, and 774 matched healthy controls were detected by polymerase chain reaction (PCR)-based denaturing high performance liquid chromatography, and PCR-based restriction fragment length polymorphism analysis. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression model. The effect-modified model was used to evaluate the gene-gene interaction. RESULTS: Subjects with the MMP-2 -1306CC genotype had an increased risk of developing gastric cancer compared with those with the MMP-2 -1306TT or CT genotype (adjusted OR, 1.67; 95% CI, 1.17-2.38). No significant association between MMP-9 -1562C/T polymorphism and risk of gastric cancer was observed. However, the polymorphisms in these 2 genes seem to display a gene-gene interaction, with OR of 1.72 (95% CI, 1.07-2.78) for subjects carrying both MMP-2 -1306CC and MMP-9 -1562TT or CT genotypes compared with those carrying both MMP-2 -1306TT or CT and MMP-2 -1306T/C genotypes (likelihood ratio test, P=0.02). CONCLUSION: MMP-2 -1306T/C and MMP-9 -1562C/T polymorphisms may be associated with genetic susceptibility to gastric cancer.

[Association between genetic polymorphisms in methylenetetrahydrofolate reductase and risk of breast cancer].

OBJECTIVE: To investigate the association between genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and risk of breast cancer among women. METHODS: Two hundred seventeen cases with breast cancer and 218 matched controls were genotyped for the MTHFR C677T and A1298C polymorphisms by PCR-RFLP methods. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression model. RESULTS: We found that the frequency of the MTHFR C677TT genotype among cases was significantly different from that among controls (32.7% vs. 24.8%; P = 0.02). The MTHFR C677TT genotype had an increased risk of breast cancer compared with the 677CC genotype (95% CI, 1.09 - 3.14). No significant association between the MTHFR C677T or A1298C polymorphism and risk of the cancer was observed. CONCLUSION: These findings suggest that 677CT polymorphism in MTHFR may be a genetic susceptibility factor for breast cancer among Chinese women.

[Association of genetic polymorphisms in the DNA repair gene XPD with risk of lung and esophageal cancer in a Chinese population in Beijing].

OBJECTIVE: XPD polymorphisms at Asp312Asn and Lys751Gln sites have been shown to modulate DNA repair capacity. The authors therefore assessed the relationship between these XPD polymorphisms and susceptibility to lung and esophageal cancer in a Chinese population via a hospital-based, case-control study. METHODS: Genotypes were determined by PCR-restriction fragment length polymorphism approaches in 383 healthy controls, 351 patients with lung cancer, and 325 patients with esophageal squamous cell carcinoma (SCC). The adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate logistic regression. RESULTS: Individuals carrying at least one 312Asn variant allele (Asp/Asn and Asn/Asn genotypes) were at an increased risk for lung SCC as compared with those with the Asp/Asp genotype (OR 1.80; 95% CI: 1.10-2.93; adjusted for age, sex and smoking), but this increased risk was not observed among patients with adenocarcinoma of the lung (adjusted OR: 1.07; 95% CI: 0.55-2.08). Furthermore, stratified analysis indicated a multiplicative interaction between tobacco smoking and the variant XPD 312Asn and 751Gln alleles on risk of lung SCC. The ORs of lung SCC for the variant XPD 312Asn and 751Gln alleles with smoking>or=29 pack/year were 12.44 (95% CI: 4.97-31.17) and 10.74 (95% CI: 4.51-25.57), respectively. No significant association between the Asp312Asn or Lys751Gln polymorphism and the risk of esophageal cancer was found. CONCLUSION: The above findings indicate that the Asp312Asn and Lys751Gln polymorphisms in the XPD locus are associated with the risk of lung SCC but not lung adenocarcinoma or esophageal SCC in this Chinese population.