APEX1 Asp148Glu gene polymorphism is a risk factor for lung cancer in relation to smoking in Japanese.

DNA repair enzymes play an important role in the development of various kinds of cancer. We here analyzed associations of XPD Lys751Gln, APEX1 Asp148Glu, XRCC1 Arg399Gln, and XRCC3 Thr241Met gene polymorphisms in DNA repair pathways in relation to the risk of lung cancer using PCR-RFLP. The study involved 104 lung cancer patients and 120 non-cancer controls divided into non-smokers and smokers. We found a statistically significant interaction between APEX1 Asp148Glu and the risk for lung cancer (adjusted OR 2.78, 95% CI 1.58-4.90, p=0.0004), of both adenocarcinoma (adjusted OR 2.24, 95%CI 1.18-4.25, p=0.014) and squamous cell carcinoma (adjusted OR 4.75, 95%CI 1.79-12.6, p=0.002) types. XRCC1 Arg399Gln showed a borderline significant association with adenocarcinoma (adjusted OR 1.89, 95%CI 1.00-3.57, p=0.051). The combined effect of smoking and presence of the APEX1 Asp148Glu demonstrated a significant association with risk of lung cancer (adjusted OR 3.61, 95% CI 1.74-7.50, p=0.001). The XPD Lys751Gln and XRCC3 Thr241Met genotypes displayed no statistically significant risk. Our findings suggest that the APEX1 Asp148Glu is associated with increased risk for primary lung cancer in Japanese individuals partaking in smoking.

MUTYH Gln324His gene polymorphism and genetic susceptibility for lung cancer in a Japanese population.

BACKGROUND: Genetic polymorphisms of DNA repair enzymes in the base excision repair (BER) pathway, may lead to genetic instability and lung cancer carcinogenesis. We investigated the interactions among the gene polymorphisms in DNA repair genes and lung cancer. METHODS: We analyzed associations among OGG1 Ser326Cys and MUTYH Gln324His gene polymorphisms in relation to lung cancer risk using PCR-RFLP. The study involved 108 lung cancer patients and 121 non-cancer controls divided into non-smokers, smokers according to pack-years smoked in Japanese. RESULTS: The results showed that the MUTYH His/His genotype compared with Gln/Gln genotype showed an increased risk for lung cancer (adjusted odds ratio [OR] 3.03, confidence interval [95%CI], 1.31-7.00, p = 0.010), whereas there was no significant increase for the Gln/His genotype (adjusted OR 1.35, 95%CI 0.70-2.61, p = 0.376). The MUTYH His/His genotype was at a borderline increased risk for both adenocarcinoma and squamous cell carcinoma (adjusted OR 2.50, 95%CI 0.95-6.62, p = 0.065 for adenocarcinoma; adjusted OR 3.20, 95%CI 0.89-11.49, p = 0.075 for squamous cell carcinoma, respectively). However, the OGG1 Ser/Cys or Cys/Cys genotypes compared with the Ser/Ser genotype did not have significantly increased risk for lung cancer, containing either adenocarcinoma or squamous cell carcinoma. The joint effect of tobacco exposure and the MUTYH His/His genotype compared with the Gln/Gln genotype showed a significant association with lung cancer risk in smokers, and there was not significantly increased in non-smokers (adjusted OR 3.82, 95%CI 1.22-12.00, p = 0.022 for smokers; adjusted OR 2.60, 95%CI 0.60-11.25, p = 0.200 for non-smokers, respectively). The effect of tobacco exposure and the OGG1 Ser326Cys showed also no significant risk for lung cancer. CONCLUSION: Our findings suggest that the MUTYH Gln324His polymorphism appear to play an important role in modifying the risk for lung cancer in the Japanese population.

Association of MUTYH Gln324His and APEX1 Asp148Glu with colorectal cancer and smoking in a Japanese population.

BACKGROUND: Genetic polymorphisms of DNA repair enzymes may lead to genetic instability and colorectal cancer carcinogenesis. Our objective was to measure the interactions between polymorphisms of repair genes and tobacco smoking in colorectal cancer. METHODS: The case-control study involved sixty-eight colorectal cancer patients and 121 non-cancer controls divided into non-smokers and smokers according to pack-years of smoking. The genetic polymorphisms of DNA repair enzymes,OGG1 Ser326Cys, MUTYH Gln324His, APEX1 Asp148Glu and XRCC1 Arg399Gln, were examined using PCR-RFLP. RESULTS: The MUTYH Gln324His showed strong significant associations with a risk of colorectal cancer (crude odds ratio [OR] 3.30, 95% confidence interval [95%CI] 1.44-7.60, p = 0.005; adjusted OR3.53, 95%CI 1.44-8.70, p = 0.006). The ORs for the APEX1 Asp148Glu were statistically significant (crude OR 2.69, 95%CI 1.45-4.99, p = 0.002; adjusted OR 2.33, 95%CI 1.21-4.48, p = 0.011). The ORs for the MUTYH Gln324His and the APEX1 Asp148Glu were statistically significant for colon cancer (adjusted OR 3.95, 95%CI 1.28-12.20, p = 0.017 for MUTYH Gln324His ; adjusted OR 3.04, 95%CI 1.38-6.71, p = 0.006 for APEX1 Asp148Glu). The joint effect of tobacco exposure and the MUTYH Gln324His showed a significant association with colorectal cancer risk in non-smokers (adjusted OR 4.08, 95%CI 1.22-13.58, p = 0.022) and the APEX1 Asp148Glu was significantly increased in smokers (adjusted OR 5.02, 95%CI 1.80-13.99, p = 0.002). However, the distributions of OGG1 Ser326Cys and XRCC1 Arg399Gln were not associated with a colorectal cancer risk. CONCLUSION: Our findings suggest that the MUTYH Gln324His and the APEX1 Asp148Glu constitutes an increased risk of colorectal cancer, especially colon cancer. The MUTYH Gln324His is strongly associated with colorectal cancer susceptibility in never smoking history, whereas the APEX1 Asp148Glu genotype constitutes an increased risk of colorectal cancer when accompanied by smoking exposure.

Association of CYP1A1, CYP1A2, GSTM1 and NAT2 gene polymorphisms with colorectal cancer and smoking.

We investigated CYP1A1*2A, CYP1A1*2C, CYP1A2*1C, CYP1A2*1F, GSTM1 and NAT2 gene polymorphisms, involving enzymes which metabolize many carcinogens, with reference to colorectal cancer risk. The distribution of these genotypes was not associated with risk overall. However, the CYP1A1*2A T/C genotype showed a significant association with colorectal cancer risk in never-smokers (odds ratio [OR], 3.06; 95% confidence interval [95% CI], 1.11-8.40; p = 0.030). The risk of the NAT2 rapid genotype in never-smokers was also statistically significantly increased (OR, 5.38; 95%CI, 1.80-16.1; p = 0.003). Furthermore, the joint effects of NAT2 rapid plus other genotypes were associated with colorectal cancer overall (OR, 3.12; 95%CI, 1.15-8.51; p = 0.026, for NAT2 rapid plus combined CYP1A1*2C Ile/Val and Val/Val, OR, 3.25; 95%CI, 1.09-9.74; p = 0.035, for NAT2 rapid plus CYP1A2*1C G/G, and OR, 4.20; 95%CI, 1.09-16.1; p = 0.037, for NAT2 rapid plus GSTM1 null, respectively). In never-smokers, the joint effects of NAT2 rapid plus other genotypes were remarkable (OR, 15.9; 95%CI, 1.87-135.8; p = 0.011, for NAT2 rapid plus combined CYP1A1*2A T/C and C/C, OR, 5.71; 95%CI, 1.49-21.9; p = 0.011, for NAT2 rapid plus combined CYP1A1*2C Ile/Val and Val/Val, and OR, 9.14; 95%CI, 2.05-40.7; p = 0.004, for NAT2 rapid plus CYP1A2*1F A/A, respectively). The joint effect of CYP1A2*1F A/A plus CYP1A2*1C G/G genotypes was also increased in never-smokers (OR, 6.16; 95%CI, 1.26-30.1; p = 0.025). Our findings suggest that the CYP1A1*2A T/C and NAT2 rapid genotypes is associated with colorectal cancer susceptibility without smoking exposure. These results also indicate that the NAT2 in combination with CYP1A1*2C, CYP1A2*1C, or GSTM1 genotypes may strongly confer susceptibility to colorectal cancer. In particular, the combination of NAT2 plus CYP1A1*2A, CYP1A1*2C, or CYP1A2*1F genotypes, and that of CYP1A2*1F plus CYP1A2*1C genotype may define a group of persons who are genetically susceptible to colorectal cancer in never smokers.

NAT2 and CYP1A2 polymorphisms and lung cancer risk in relation to smoking status.

We investigated the associations between lung cancer and the gene polymorphisms of the drug metabolizing enzymes, containing cytochrome P450 1A1 (CYP1A1), cytochrome P450 1A2 (CYP1A2), glutathione S-transferase class mu (GSTM1), and N-acetyltransferase 2 (NAT2). The study involved 113 lung cancer patients and 121 non-cancer controls divided into never, light and heavy smokers according to pack-years of smoking in Japanese by using PCR-RFLP. For light smokers, the lung cancer risk of NAT2 intermediate-slow was significantly increased [the adjusted odds ratio (OR): 10.9, 95% confidence intervals (95%CI): 1.75-67.5, P-value: 0.010]. Moreover, never smokers having joint genotypes of NAT2 intermediate-slow and CYP1A2*1F A/A was also associated with increased the lung cancer risk (OR: 4.95, 95% CI: 1.19-20.6, P-value: 0.028). We suggested that light smokers with intermediate-slow NAT2 activity were at highest risk for lung cancer and the gene-gene interaction based on intermediate-slow NAT2 activity and high CYP1A2 activity would be increased a lung cancer risk among never smokers.