To evaluate the roles of CYP1A1 polymorphisms [Ile 462 Val and T 6235 C (MspI)] and deletion of GSTM1 and and GSTT1 in lung cancer development in Asian populations, a pooled analysis was conducted on 13 existing studies included in Genetic Susceptibility to Environmental Carcinogenesis database. This pooled analysis included 1,971 cases and 2,130 controls. Lung cancer risk was estimated as odds ratios (OR) and 95% confidence intervals (95% CI) using unconditional logistic regression model adjusting for age, sex, and pack-year. The CYP1A1 6235 C variant was associated with squamous cell lung cancer (TC versus TT: OR, 1.42; 95% CI, 0.96-2.09; CC versus TT: OR, 1.97; 95% CI, 1.26-3.07; P trend = 0.003). In haplotype analysis, 462 Val-6235 T and Ile-C haplotypes were associated with lung cancer risk with reference to the Ile-T haplotype (OR, 3.41; 95% CI, 1.78-6.53 and OR, 1.39; 95% CI, 1.12-1.71, respectively). The GSTM1-null genotype increased squamous cell lung cancer risk (OR, 1.36; 95% CI, 1.05-1.77). When the interaction was evaluated with smoking, increasing trend of lung cancer risk as pack-year increased was stronger among those with the CYP1A1 6235 TC/CC genotype compared with those with TT genotype (P interaction = 0.001) and with the GSTM1-null genotype compared with the present type (P interaction = 0.08, when no genotype effect with no exposure was assumed). These results suggest that genetic polymorphisms in CYP1A1 and GSTM1 are associated with lung cancer risk in Asian populations. However, further investigation is warranted considering the relatively small sample size when subgroup analyses were done and the lack of environmental exposure data other than smoking. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1120 -6)

No abstract

Polymorphism of AXIN2, a component of Wnt signaling, has been shown to play a role in tumorigenesis and dysregulated in cancer cells. In order to find out if AXIN2 polymorphism is a risk factor for prostate cancer, we analyzed eight polymorphic regions of this gene in 84 patients with prostate cancer and compared the results with 100 healthy controls in a Turkish population using PCR-RFLP methods. The genotype frequencies and risk factors of prostate cancer and control groups were analyzed by Chi-square test. We found a statistically significant result between prostate cancer risk and AXIN2 Intron2-956+16A/G (rs35285779) SNP. The frequency of the homozygous G/G (0%) and heterozygous A/G (18%) genotypes was significantly less in patients with prostate cancer than in healthy controls (7 and 32%, respectively) (P<0.05) for this SNP. When compared with the wild-type A/A genotype of the controls, prostate cancer patients with the A/G and G/G genotype showed reduced risk of cancer; the adjusted odds ratio (OR) for patients with the homozygous G/G genotype was 0.87 (95% CI: 0.81-0.95) and for heterozygous A/G genotype was 0.42 (95% CI: 0.20-0.85). We found no statistically significant association between controls and prostate cancer for other seven SNPs of AXIN2 including Exon1-148 C/T (rs2240308), Exon1-432 T/C (rs2240308), Exon5-1365 G/A (rs9915936), Exon5-1386 C/T (rs1133683), Intron5-1712+19 T/G, Exon7-2062 C/T, and Intron7-2141+73 G/A (rs4072245) (P>0.05). These results suggest that the AXIN2 Intron2 rs35285779 SNP is associated with development of prostate cancer as a protective SNP, while an association between other seven SNPs of the AXIN2 and risk of prostate cancer was not observed.

No abstract

Our preliminary results showed that GSTM1-null genotype was associated with shorter survival.

Prostate cancer is the most common cancer among men in many countries. Although the etiology of prostate cancer largely is unknown, both genetic and environmental factors may be involved. Advanced age, androgen metabolism, and heredity-race have been reported to be possible risk factors. On the other hand, several studies indicate that genetic polymorphisms in biotransformation enzymes play a role in prostate cancer development. In this study, association of the prostate cancer risk with genotype frequencies of the Phase I (CYP1A1) and Phase II (GSTM1 and GSTT1) biotransformation enzymes was investigated in 321 Turkish individuals (152 prostate cancer patients and 169 age-matched male controls). The presence or absences of the GSTM1 and GSTT1 genes were determined by a PCR-based method. Genotypes of CYP1A1 were determined by MspI-RFLP. The prevalence of GSTM1 null genotype in the cases was 64 percent, compared to 31 percent in the control group, indicating a strong association (OR = 4.08, 95%CI = 2.50-6.69). No association was observed between either GSTT1 null genotype or CYP1A1 polymorphism and prostate cancer incidence. No statistically significant association was observed between smoking status of the patients and any of the polymorphisms studied. In conclusion, results of this study indicate that only the GSTM1 null genotype may play an important role as a risk factor for prostate cancer development in Turkish population.

Human sulfotransferase 1A1 (SULT1A1), the most expressed isoform of the phenol SULT1 subfamily, is an important member of sulfotransferase superfamily. A transition, G to A at position 638, in SULT1A1 gene, results in Arg(213)His change. This single nucleotide polymorphism reduces the activity and thermostability of SULT1A1 enzyme. Thus, in the present study the relationship between SULT1A1 Arg(213)His polymorphism and lung cancer was investigated. One hundred and six case and 271 control samples were studied using PCR-RFLP. There was no significant difference in genotype and allele distribution between lung cancer and control populations (p = 0.07; p = 0.06, respectively). Compared with the SULT1A1*1/SULT1A1*1 genotype the variant SULT1A1 genotype (SULT1A1*1/SULT1A1*2 or SULT1A1*2/SULT1A1*2) was associated with a significantly increased lung cancer risk in cases (p = 0.027). In male populations, there was no significant difference between case and controls (p = 0.313). In female populations, however, this difference was found to be significant (p = 0.04). In smoker and non-smoker populations, no significant relationship was evident between lung cancer and control population (p = 0.170, p = 0.065, respectively). Statistical analyses of histological types of lung cancer in comparison with the control individuals indicated a significant difference between SULT1A1 Arg(213)His polymorphism and SCC (p = 0.027) and other types of cancer (p = 0.037), except SMCC (p = 0.854).

Our data do not support a role for polymorphisms of the GSTM1 and GSTT1 genes in the pathogenesis of pre-eclampsia, eclampsia and HELLP syndrome.