Association between survival after treatment for breast cancer and glutathione S-transferase P1 Ile105Val polymorphism

A glutathione S-transferase (GST) P1 polymorphism results in an amino acid substitution, Ile105Val; the Val-containing enzyme has reduced activity toward alkylating agents. Cancer patients with the variant enzyme may differ in removal of treatment agents and in outcomes of therapy. We evaluated survival according to GSTP1 genotype among women (n = 240) treated for breast cancer. Women with the low-activity Val/Val genotype had better survival. Compared with Ile/Ile, hazard ratios for overall survival were 0.8 (95% confidence interval, 0.5-1.3) for Ile/Val and 0.3 (95% confidence interval, 0.1-1.0) for Val/Val (P for trend = 0.04). Inherited metabolic variability may influence treatment outcomes.     

Glutathione S-transferase P1 Ile105Val polymorphism, cigarette smoking and prostate cancer

The enzyme glutathione S-transferase P1 (GSTP1) detoxifies carcinogenic products of tobacco smoke. This exploratory case-control study evaluates the possible effect modification by the GSTP1 Ile105Val polymorphism (replacement of isoleucine by valine at codon 105) on smoking and prostate cancer. Because the Val variant possesses up to a five-fold greater enzymatic activity towards the carcinogenic metabolites of tobacco smoke, the Ile allele is expected to be related to an increase in the risk of prostate cancer among smokers. GSTP1 genotype and epidemiological data were obtained from 122 cases of prostate cancer and 135 healthy males as controls. A logistic regression model was used to estimate odds ratios and 95% confidence intervals. The adjusted OR of homozygous Ile compared to other genotypes for prostate cancer was 1.21 (95% CI: 0.61-2.83). Smoking was not significantly associated with prostate cancer with an adjusted OR of 1.56 (95% CI: 0.78-3.12). However, among individuals with the Ile/Ile genotype, smoking was strongly associated with an increased risk of prostate cancer with an adjusted odds ratio of 4.09 (95% CI: 1.25-13.35). A potential multiplicative interaction was suggested between GSTP1 and smoking on the risk of prostate cancer with the adjusted OR for the interaction of 4.52 (95% CI: 1.07-19.17). To our knowledge, this is the first time that a potential effect modification by the GSTP1 Ile/Ile genotype on smoking and the risk of prostate cancer is suggested.     

Glutathione S-transferase P1 Ile105Val polymorphism and colorectal cancer risk: A meta-analysis and HuGE review

Colorectal cancer is the third most common form of cancer and the fourth most frequent cause of cancer deaths worldwide. Its development is influenced by both environmental and genetic factors. The glutathione S-transferase P1 gene (GSTP1) is a particularly attractive candidate for colorectal cancer susceptibility because it codes the enzyme involved in the metabolism of environmental carcinogens such as polycyclic aromatic hydrocarbons (PAHs). However, epidemiologic findings have been inconsistent. To investigate a putative association of GSTP1 Ile105Val polymorphism with the risk of colorectal cancer, we performed a meta-analysis and HuGE review of 16 published case-control studies (involving a total of 4386 colorectal cancer patients and 7127 controls). We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Overall, the comparison of Val versus Ile allele showed no differential susceptibility to colorectal cancer (OR = 0.98, 95% CI: 0.92–1.04). A protective effect was found in recessive, with an OR of 0.86 (95% CI: 0.76–0.98). Whereas no significant association was observed in either dominant or codominant model. In stratified subgroup analysis, no effect of Val allele was seen in subjects of Caucasian and Asian descent, and in healthy and hospital controls. In conclusion, the meta-analysis suggests that the GSTP1 Ile105Val polymorphism is unlikely to increase considerably the risk of sporadic colorectal cancer, and it should be confirmed in further studies.     

Quantitative assessment of the association between GSTP1 gene Ile105Val polymorphism and susceptibility to hepatocellular carcinoma

Glutathione S-transferase P1 (GSTP1) gene Ile105Val polymorphism has been suggested to be involved in the development of cancer. However, the results from the studies regarding the association between GSTP1 Ile105Val polymorphism and hepatocellular carcinoma risk have been inconsistent. Thus, we performed a meta-analysis to investigate the association. Published literature from PubMed, Chinese Biomedical Literature, and Wanfang databases was searched for eligible publications. Pooled odds ratios (ORs) with 95 % confidence intervals (95 %CIs) were calculated using random- or fixed-effects model. Six studies with a total of 1,843 participants were finally included into this meta-analysis. The results suggested there was no association between GSTP1 Ile105Val polymorphism and hepatocellular carcinoma risk under all genetic models (for ValVal vs. IleIle, OR?=?0.79, 95 %CI 0.48–1.29, P?=?0.341; for IleVal vs. IleIle, OR?=?1.05, 95 %CI 0.84–1.30, P?=?0.678; for the dominant model, OR?=?0.91, 95 %CI 0.68–1.20, P?=?0.498; and for the recessive model, OR?=?0.76, 95 %CI 0.47–1.24, P?=?0.269). Subgroup analyses by ethnicity showed there was also no association between GSTP1 Ile105Val polymorphism and hepatocellular carcinoma risk in Asians under all genetic models (All P values were more than 0.05), but GSTP1 Ile105Val polymorphism was associated with decreased risk of hepatocellular carcinoma in European under the recessive model (ValVal vs. IleVal/IleIle) (OR?=?0.44, 95 %CI 0.20–0.98, P?=?0.044). In conclusion, the meta-analysis suggests that there is little evidence for the association between GSTP1 Ile105Val polymorphism and hepatocellular carcinoma risk. However, more well-designed studies are needed to further assess this association.     

Glutathione S-transferase P1 Ile105Val polymorphism and breast cancer risk: a meta-analysis involving 34,658 subjects

Glutathione S-transferase P1 (GSTP1) is involved in a wide range of detoxifying reactions. Any alteration in the structure, function, or expression of GSTP1 gene may alter the ability of a cell to inactivate carcinogens or mutagens, and thus modify an individual’s risk to cancer. Previous epidemiological studies on the potential association between GSTP1 Ile105Val polymorphism and breast cancer risk have produced inconsistent results. In order to drive a more precise estimation of this association, we performed a meta-analysis of 30 published case–control studies including 15,901 cases and 18,757 controls. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. The results of this meta-analysis showed that GSTP1 Ile105Val polymorphism was not associated with breast cancer susceptibility in overall population. However, in subgroup analysis by ethnicity, we found a significant association among Asian population (for Val/Val vs. Ile/Ile: OR 1.27, 95% CI 1.02–1.83; for the recessive model Val/Val vs. Ile/Ile + Ile/Val: OR 1.42, 95% CI 1.20–1.69). When stratified by study design, significantly elevated susceptibility to breast cancer was found among hospital-based studies (for Val/Val vs. Ile/Ile: OR 1.38, 95% CI 1.16–1.63; for recessive model Val/Val vs. Ile/Val + Ile/Ile: OR 1.31, 95% CI 1.12–1.55; for dominant model: Val/Val + Ile/Val vs. Ile/Ile: OR 1.10, 95% CI 1.02–1.19). In conclusion, our meta-analysis suggests that GSTP1 Ile105Val polymorphism may increase susceptibility to breast cancer in Asian population.     

Glutathione S-transferase P1 Ile105Val polymorphism contributes to increased risk of gastric cancer in East Asians

Glutathione S-transferase P1 (GSTP1) is an important enzyme playing critical roles in the phase II detoxification pathway. There were many studies investigating the association between GSTP1 gene Ile105Val polymorphism and gastric cancer risk, but studies from East Asians reported inconsistent findings. We performed a meta-analysis to investigate the association in East Asians. Published literature from PubMed and Chinese Biomedical Literature databases were searched for eligible publications. Pooled odds ratios (ORs) with 95 % confidence intervals (95 %CIs) were calculated using random or fixed-effect model according the between-study heterogeneity. A total of 12 studies with 2,552 cases and 5,474 controls were finally included into the meta-analysis. Meta-analysis of those 12 studies showed that there was an obvious association between GSTP1 Ile105Val polymorphism and gastric cancer risk in East Asians under three genetic models (for valine vs. isoleucine, OR?=?1.32, 95 %CI 1.05–1.66, P?=?0.015; for ValVal vs. IleIle, OR?=?2.00, 95 %CI 1.34–2.98, P?=?0.001; for the recessive model, OR?=?1.96, 95 %CI 1.35–2.83, P?<?0.001). Sensitivity analysis by removing one study at a time suggested the pooled results were stable under the three genetic models above. There was no risk of publication bias. In conclusion, the meta-analysis suggests that there is a strong evidence for the association between GSTP1 Ile105Val polymorphism and increased risk of gastric cancer in East Asians and contributes to increased risk of gastric cancer in East Asians.     

Quantitative synthesis of the association between the cytochrome P450 1A1 Ile462Val polymorphism and prostate cancer risk

The association between the cytochrome P450 1A1 (CYP1A1) Ile462Val polymorphism and prostate cancer risk remains inconclusive owing to the conflicting findings from previous studies. To get a more precise estimate of the possible association, we performed the present meta-analysis. We searched the PUBMED, EMBASE, and Wanfang databases for the studies which met the inclusion criteria. The pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was used to estimate the association between CYP1A1 Ile462Val polymorphism and prostate cancer risk. A total of 13 studies with 2,350 cases and 2,992 controls were included in the meta-analysis. The results indicated that there was an obvious association between CYP1A1 Ile462Val polymorphism and increased risk of prostate cancer (for Val versus Ile: OR?=?1.27, 95 % CI 1.13–1.43, P?<?0.001; for ValVal versus IleIle: OR?=?1.51, 95 % CI 1.14–2.01, P?=?0.004; for ValVal?+?ValIle versus IleIle: OR?=?1.31, 95 % CI 1.14–1.51, P?<?0.001; for ValVal versus IleIle + ValIle: OR?=?1.38, 95 % CI 1.05–1.81, P?=?0.020). Subgroup analyses by ethnicity suggested that CYP1A1 Ile462Val polymorphism was associated with prostate cancer risk in Asians but not in Caucasians. This meta-analysis suggests that there is an association between CYP1A1 Ile462Val polymorphism and increased risk of prostate cancer. More studies with large sample are needed to further assess the association in Caucasians.     

Glutathione S-transferase P1 gene Ile105Val polymorphism might be associated with lung cancer risk in the Chinese Han population

Genetic variations in glutathione S-transferase P1 (GSTP1) gene have been suggested to be involved in the development of cancer. However, the results from the studies regarding the association between GSTP1 Ile105Val polymorphism and lung cancer risk in the Chinese population have been inconsistent. Thus, we conducted a meta-analysis to investigate the association. Published literature from PubMed, Chinese Biomedical Literature Database, Chinese Wanfang Data, and Chinese National Knowledge Infrastructure databases were searched for eligible publications. Pooled odds ratios (ORs) with 95?% confidence intervals (CIs) were calculated using random or fixed effect model. Ten studies (1,506 cases/1,714 controls) were included in the meta-analysis. The results suggested that GSTP1 Ile105Val polymorphism was marginally associated with lung cancer risk in the Chinese Han population under a multiplicative model (G vs. A, odds ratio (OR)?=?1.22, 95?% confidence interval?=?1.02?C1.46), under a homogeneous codominant model (GG vs. AA, OR?=?1.67, 95?% CI?=?1.14?C2.45), under a heterogeneous codominant model (GA vs. AA, OR?=?1.15, 95?% CI?=?0.98?C1.35), under a dominant model (GG + GA vs. AA, OR?=?1.21, 95?% CI?=?1.04?C1.39), and under a recessive model (GG vs. GA + AA, OR?=?1.59, 95?% CI?=?1.09?C2.31), respectively. Moreover, after adjusted for age, gender, and smoking status, the significant association under dominant model remained (OR?=?1.27, 95?% CI?=?1.07?C1.51). This meta-analysis suggested that there might be an association between GSTP1 Ile105Val polymorphism and lung cancer in the Chinese Han population.     

A systemic review of glutathione S-transferase P1 Ilel05Val polymorphism and colorectal cancer risk

Objectives： To investigate the correlation between glutathione S-transferase P1 （GSTP1） Ilel05Val polymorphism and colorectal cancer （CRC） risk. Methods： Studies were identified to investigate the association between GSTP1 Ilel05Val polymorphism and CRC risk. Systematic computerized searches of the PubMed, Chinese National Knowledge Infrastructure, WANFANG and SinoMed were performed. Summary odds ratios （OR） and 95% confidence intervals （95 % CI） were used to measure GSTP 1 Ile 105Val polymorphisms and CRC risk. Results： A total of 23 retrospective studies were included in the meta-analysis. During all studies including 6,981 cases and 8,977 controls, sample sizes ranged from 146 to 2,144. Overall, the pooled results revealed that lie 105Val polymorphism was not associated with CRC risk and confused results were found in subgroup analyses. Further meta-analyses were conducted after excluding low-quality studies. GSTP1 Ilel05Val is associated with increased risk of CRC limited in studies with matched control. There was no significant heterogeneity in all genetic comparisons, but heterogeneity existed in subgroup analyses of heterozygous and dominant comparisons. The meta-regression analyses indicated that matched controls were the significant factor influencing between-study heterogeneity in all possible influential factors including published year, ethnicity, source of control, sample size, Hardy-Weinberg equilibrium （HWE） in control and matched controls. Sensitivity analysis revealed the pooled ORs were not changed before and after removal of each single study in all genetic comparisons, indicating the robustness of the results. Conclusions： GSTP1 Ilel05Val might be associated with increased risk of CRC. However, more high- quality case-control studies should be performed to confirm the authenticity of our conclusion.     

Association between the GSTP1 Ile105Val polymorphism and prostate cancer risk: a systematic review and meta-analysis

Many studies have reported the role of glutathione S-transferase P1 (GSTP1) Ile105Val polymorphism with prostate cancer (PCa) risk. However, these studies have yielded conflicting results. Hence, we performed this meta-analysis to investigate the association between GSTP1 Ile105Val polymorphism and PCa in different inheritance models. A total of 13 eligible studies were pooled into this meta-analysis. There was significant association between the GSTP1 Ile158Val variant genotypes and PCa for Ile/Ile vs Val/Val comparison [odds ratio (OR)?=?0.705; I ²?=?63.7 %; 95 % confidence interval (95 % CI)?=?0.508–0.977], Ile/Val vs Val/Val comparison (OR?=?0.736; I ²?=?8.0 %; 95 % CI?=?0.613–0.883), and dominant model (OR?=?0.712; I ²?=?45.5 %; 95 % CI?=?0.555–0.913). However, no associations were detected for other genetic models. In the stratified analysis by ethnicity, significant associations between GSTP1 Ile105Val polymorphism and PCa risk were also found among Caucasians (Ile/Ile vs Val/Val comparison OR?=?0.818, I ²?=?0.0 %, 95 % CI?=?0.681–0.982; Ile/Val vs Val/Val comparison OR?=?0.779, I ²?=?0.0 %, 95 % CI?=?0.651–0.933; and dominant model OR?=?0.794, I ²?=?0.0 %, 95 % CI?=?0.670–0.941), while there were no associations found for other genetic models. However, no associations were found in Asians and African-Americans for all genetic models when stratified by ethnicity. In conclusion, our meta-analysis indicates that GSTP1 Ile105Val polymorphisms contributed to the PCa susceptibility. However, a study with the larger sample size is needed to further evaluate gene–environment interaction on GSTP1 Ile105Val polymorphisms and PCa risk.     

Glutathione S-transferase P1 polymorphism (Ile105Val) predicts cumulative neuropathy in patients receiving oxaliplatin-based chemotherapy.

PURPOSE: Glutathione S-transferases (GST) are xenobiotic metabolizing enzymes involved in the detoxification of a variety of chemotherapeutic drugs, including platinum derivatives. Genetic polymorphisms of GSTs have been associated with enzyme activity variations. Thus, a study was done to investigate the relationship between GST polymorphisms and oxaliplatin-related cumulative neuropathy in gastrointestinal cancer patients treated with oxaliplatin-based chemotherapy. EXPERIMENTAL DESIGN: Ninety patients were included. Clinical neurologic evaluation was done at baseline and before each cycle of treatment. We determined genetic variants for GSTP1 exon 5 (Ile105Val), GSTP1 exon 6 (Ala114Val), GSTM1 (homozygous deletion), and GSTT1 (homozygous deletion). We conducted analyses in a subgroup of 64 patients receiving a minimal cumulative dose of 500 mg/m2 of oxaliplatin to examine whether the GST polymorphisms are associated with oxaliplatin-related cumulative neuropathy. RESULTS: Among patients receiving a minimal cumulative dose of 500 mg/m2 of oxaliplatin, 15 patients showed clinically evident oxaliplatin-related cumulative neuropathy scored grade 3 according to an oxaliplatin-specific scale. The oxaliplatin-related cumulative neuropathy scored grade 3 was significantly more frequent in patients homozygous for the GSTP1 105Ile allele than in patients homozygous or heterozygous for the GSTP1 105Val allele (odds ratio, 5.75; 95% confidence interval, 1.08-30.74; P = 0.02). No association was found with respect to any of the GSTM1, GSTT1, or GSTP1 exon 6 genotypes. Conclusions: The results of the current study suggest that the 105Val allele variant of the GSTP1 gene at exon 5 confers a significantly decreased risk of developing severe oxaliplatin-related cumulative neuropathy.     

Genetic polymorphism of glutathione S-transferase P1 gene and lung cancer risk

Objectives: The human GSTTP1 gene is polymorphic with an A G transition in exon 5 causing a replacement 105 IleVal in the GSTP1 protein. The two isoforms, encoded by the alleles GSTP1*A and GSTP1*B, respectively, show different catalytic efficiencies towards some carcinogenic epoxides. In this study we have addressed the possible role of the Ile105Val GSTP1 polymorphism in lung cancer susceptibility.Methods: The polymorphic site was genotyped by RFLP in a group of lung cancer patients (n=164) and in two control groups (healthy smokers, n=132; general population, n=200). All patients and controls were Northwestern Mediterranean Caucasians of the same ethnic origin.Results and Conclusions: The cancer patients showed frequencies of GSTP1*A/A; GSTP1*A/B and GSTP1*B/B (50%, 38%, 11%, respectively) very similar to those of both control groups (healthy smokers: 48%, 41%, 11%). After adjusting for age, sex and smoking status, no association was found between the GSTP1*B allele and lung cancer risk (OR: 1.18; 95% CI: 0.67–2.07). The Ile105val GSTP1 polymorphism was also analysed in combination with the GSTM1 and GSTT1 genes. The results showed that allelism at GSTP1 did not increase the risk associated with the GSTM1 or GSTT1 deletions.     

Quantitative assessment of the association between XPG Asp1104His polymorphism and bladder cancer risk

Published data regarding the association between XPG Asp1104His polymorphism and bladder cancer risk remained controversial. This meta-analysis of literatures was performed to draw a more precise estimation of the relationship. We systematically searched PubMed, Embase, and Web of Science with a time limit of June 22, 2013. Summary odds ratios (ORs) with 95 % CIs were used to assess the strength of the association between XPG Asp1104His polymorphism and bladder cancer risk using random effects model. A total of eight case–control studies including 2,613 cases and 2,934 controls were included for analysis. Overall, no significant association was found between XPG Asp1104His polymorphism and bladder cancer susceptibility for CC vs. GG (OR?=?1.12, 95 % CI?=?0.74–1.69), GC vs. GG (OR?=?1.12, 95 % CI?=?0.86–1.46), the dominant model CC + GC vs. GG (OR?=?1.08, 95 % CI?=?0.85–1.38), and the recessive model CC vs. GC + GG (OR?=?0.92, 95 % CI?=?0.66–1.29). In the subgroup analysis, no significant associations were found in either Asian or non-Asian population. This meta-analysis suggested that XPG Asp1104His polymorphism was not associated with bladder cancer risk.     

Association between GSTP1 Ile105Val polymorphism and glioma risk: A systematic review and meta-analysis

Glutathione S-transferase P1 (GSTP1) gene Ile105Val polymorphism has been suggested to be involved in the development of glioma. However, the results from the studies regarding the association between GSTP1 Ile105Val polymorphism and glioma risk have been inconsistent. Thus, we performed a meta-analysis to investigate this association. Pooled odds ratios (ORs) with 95 % confidence intervals (95 %CIs) were calculated using random or fixed effects model. Nine studies with 2,078 cases and 3,970 controls were finally included into this meta-analysis. The results suggested there was no association between GSTP1 Ile105Val polymorphism and glioma risk under recessive model (OR?=?1.138, 95 %CI?=?0.966–1.341, P _{heterogeneity}?=?0.088, P?=?0.123). Subgroup analyses by ethnicity showed there was also no association between GSTP1 Ile105Val polymorphism and glioma risk in mixed populations under recessive model (OR?=?1.199, 95 %CI?=?0.928–1.549, P _{heterogeneity}?=?0.060, P?=?0.166) and Caucasian populations(OR?=?1.097, 95 %CI?=?0.885–1.360, P _{heterogeneity}?=?0.186, P?=?0.398). In conclusion, the meta-analysis suggests that there is no association between GSTP1 Ile105Val polymorphism and glioma risk. However, more well-designed and larger studies are needed to further assess this association.     

Genetic polymorphisms in glutathione S-transferases P1 (GSTP1) Ile105Val and prostate cancer risk: a systematic review and meta-analysis

Numerous epidemiological studies have evaluated the association between the glutathione S-transferases P1 (GSTP1) Ile105Val polymorphisms and prostate cancer (PCa) risk. However, these studies have yielded conflicting results. A comprehensive search was conducted through researching MEDLINE, PubMed, Web of Science, and EMBASE, and a total of 13 studies including 3,227 cases and 3,945 controls were identified. A meta-analysis was performed to obtain a summary of estimated odds ratios (ORs) and 95 % confidence intervals (CIs) of GSTP1 polymorphisms for PCa, with attention to study quality and publication bias. The GSTP1 Ile158Val variant genotypes are less associated with increased risk of PCa for the homozygote model (Val/Val vs Ile/Ile: OR?=?1.42; I ²? =?63.7 %; 95 % CI?=?1.02–1.97) and the recessive model (OR?=?1.41; I ²? =?45.5 %; 95 % CI?=?1.10–1.80). However, no associations were detected for other genetic models. In the stratified analysis by ethnicity, significant associations between GSTP1 Ile105Val polymorphism and PCa risk were also found among Caucasians for Val/Val vs Ile/Ile comparison (OR?=?1.22; I ²? =?0.0 %; 95 % CI?=?1.02–1.47) and for the recessive model (OR?=?1.26; I ²? =?0.0 %; 95 % CI?=?1.06–1.49), while there were no associations found for other genetic models. However, no associations were found in Asians and African-Americans for all genetic models when stratified by ethnicity. In conclusion, our meta-analysis provides evidence that GSTP1 Ile105Val gene polymorphisms contributed to PCa susceptibility.     

Prostate cancer risk from occupational exposure to polycyclic aromatic hydrocarbons interacting with the GSTP1 Ile105Val polymorphism

BACKGROUND: Variation in the glutathione S-transferase (GSTP1) gene and occupational polycyclic aromatic hydrocarbons (PAH) exposure are putative prostate cancer risk factors. An Ile/Val polymorphism in codon 105 of GSTP1 affects its enzymatic activity toward PAH detoxification, a possible mechanism in prostate carcinogenesis. METHODS: To determine whether the GSTP1 Ile105Val polymorphism modifies prostate cancer risk associated with occupational PAH exposure, we studied 637 prostate cancer cases and 244 controls of White and African-American race from the Henry Ford Health System in Detroit, Michigan. Occupational exposure to PAH from wood, petroleum, coal or other sources through respiratory and cutaneous routes was retrospectively assessed by expert review of job histories. The association of occupational PAH exposure and GSTP1 Ile105Val polymorphism with prostate cancer was tested in multiple logistic regression models adjusting for potential confounders. Cases were over sampled compared with controls to evaluate gene-environment interaction with the statistically efficient case-only analytic approach. RESULTS: Neither carriage of the GSTP1 Val(105) variant allele nor occupational PAH exposure was significantly associated with prostate cancer. However, case-only analyses revealed that carriage of the GSTP1 Val(105) variant allele was associated with increasing levels of occupational respiratory PAH exposures from any source and from petroleum (trend test p=0.01 for both). The GSTP1 Val(105) allele was observed most frequently in cases in the highest quartile of occupational respiratory PAH exposures from petroleum (OR=1.74; 95% CI=1.11-2.72) or from any source (OR=1.85; 95% CI=1.19-2.89). The gene-environment risk estimate in the highest PAH petroleum exposure quartile was greatest in men under age 60 (OR=4.52; 95% CI=1.96-10.41) or with a positive family history of prostate cancer (OR=3.02; 95% CI=1.15-7.92). CONCLUSIONS: Our results suggest men who carry the GSTP1 Val(105) variant and are exposed at high levels to occupational PAH have increased risk for prostate cancer. This increased risk is more pronounced in men under age 60 or with a family history of prostate cancer.     

The GSTP1 Ile105Val polymorphism is not associated with susceptibility to colorectal cancer

The glutathione S transferase (GST) family is a major part of cellular defense mechanisms against endogenous and exogenous substances, many of which have carcinogenic potential. Alteration in the expression level or structure of the glutathione-S-transferase (GST) enzymes may lead to inadequate detoxification of potential carcinogens and consequently contribute to cancer development. A member of the glutathione-S-transferase (GST) family, GSTP1, is an attractive candidate for involvement in susceptibility to carcinogen-associated colorectal cancer. An A>G transition in exon 5 resulting in an Ile105Val amino acid substitution has been identified which alters catalytic efficiency. The present study investigated the possible impact of Ile105Val GSTP1 polymorphism on susceptibility to colorectal cancer. in Jordan We examined 90 tissue samples previously diagnosed with colorectal carcinoma, and 56 non-cancerous colon tissues. DNA was extracted from paraffin embedded tissues and the status of the GSTP1 polymorphism was determined using a polymerase chain reaction restriction fragment length polymorphism (RFLP) method. No statistically significant differences were found between colorectal cancer cases and controls for the GSTP1 Ile/Ile, Ile/Val and Val/Val genotypes. The glutathione S-transferase polymorphism was not associated with risk in colorectal cancer cases in Jordan stratified by age, sex, site, grade or tumor stage. In conclusion, the GSTP1 Ile105Val polymorphism is unlikely to affect the risk of colorectal cancer.     

CYP1A1 Ile462Val polymorphism and colorectal cancer risk in Polish patients

Head and neck squamous epithelial cell cancer (HNSCC), the world’s fifth most common type of cancers, is associated with short life expectancy and high death rates if not detected in early stages. The aim of this study was to investigate hRRM1 and p53R2 gene polymorphisms by using real-time PCR technique in patients with head and neck cancer. In total, 87 patients with head and neck malignancies and 87 control group who have not any malignancies were included in the study between January 2011 and February 2012 in Istanbul University Faculty of Medicine Department of ORL. In the study, real-time PCR was used to detect hRRM1 (rs12806698 C/A) and p53R2 (rs2290707 G/T) gene polymorphisms in Turkish HNSCC patients and healthy individuals. Genomic DNA isolation was performed according to the kit protocol with spin column. LightCycler 1.5 system was used to perform SNP genotyping using hybridization probes consisting of 3′-fluorescein and a 5′-LightCycler Red labeled pair of oligonucleotide probes. There were significant differences in the distribution of hRRM1 genotypes. Frequency of individuals with hRRM1 AA genotype was higher in patients with less differentiation when compared with well differentiation [p 0.025, Fisher’s exact test, odds ratio (OR) 0.140, 95 % confidence intervals (CI) 0.024–0.797]. It is observed that A allele carriers have nearly twofold risk for development of the disease (p = 0.022; χ ² 5.24; OR 2.02, 95 % CI 1.10–3.72).