Combined effects of genetic polymorphisms in six selected genes on lung cancer susceptibility

Gender Differences in Oxidative Stress in Relation to Cancer Susceptibility and Survival

Genetic, developmental, biochemical, and environmental variables interact intricately to produce sex differences. The significance of sex differences in cancer susceptibility is being clarified by numerous studies. Epidemiological research and cancer registries have revealed over the past few years that there are definite sex variations in cancer incidence, progression, and survival. However, oxidative stress and mitochondrial dysfunction also have a significant impact on the response to treatment of neoplastic diseases. Young women may be more protected from cancer than men because most of the proteins implicated in the regulation of redox state and mitochondrial function are under the control of sexual hormones. In this review, we describe how sexual hormones control the activity of antioxidant enzymes and mitochondria, as well as how they affect several neoplastic diseases. The molecular pathways that underlie the gender-related discrepancies in cancer that have been identified may be better understood, which may lead to more effective precision medicine and vital information on treatment options for both males and females with neoplastic illnesses.

Association of NQO1Pro187Ser polymorphism with clinical outcomes and survival of lung cancer patients treated with platinum chemotherapy

Background: The study was carried out to evaluate the association of NQO1 P187S polymorphism in North Indian lung cancer (LC) patients. We determined the effect of this polymorphic variant on the survival of LC patients. Patients & methods/results: This case-control study comprised a total of 1100 subjects. The genotyping was carried out using PCR-RFLP and statistical analysis was carried out. The variant TT genotype exhibited 3.5-fold higher odds in subjects with stage III (p = 0.0006), fivefold higher odds of lymph-node invasion (p = 0.007) and an odd of <1 in case of metastasis (p = 0.0028). Patients possessing TT genotype and administered with paclitaxel, exhibited a poor survival (3.57 vs 12.20 months; hazard ratio = 7.95; p = 0.0098). Conclusion: These results suggest that NQO1 variant genotype was not found to modulate risk toward LC. However, the variant genotype was found to be strongly correlated with stage III LC, lymph node invasion and was found to be positively correlating with metastasis.

Association between MPO-463G > A polymorphism and cancer risk: evidence from 60 case-control studies

BACKGROUND

Though a number of studies have been conducted to explore the association between myeloperoxidase (MPO)-463G > A polymorphism and cancer risk, the results remain inconsistent. Therefore, we performed a meta-analysis to derive a more systematic estimation of this relationship.

METHOD

Relevant studies were searched by PubMed, EMBASE, CNKI, Google Scholar, Ovid, and Cochrane library prior to December 2015. The strength of the association between MPO-463G > A polymorphism and cancer risk was estimated by odds ratios (OR) with 95% confidence interval (95%CI). Cumulative analysis was used to evaluate the stability of results through time.

RESULTS

The current analysis consisted of 16,858 cases and 21,756 controls from 60 studies. Pooled results showed that MPO-463G > A polymorphism were associated with the overall decreased cancer susceptibility in all the genetic models included in this study (additive model: OR = 0.84, 95%CI = 0.76-0.94; allele genetic model: OR = 0.90, 95%CI = 0.840-0.954; recessive genetic model: OR = 0.89, 95%CI = 0.83-0.95). However, in the stratified analysis of cancer type, the significant results were only found in lung cancer (dominant model: OR = 0.93, 95%CI = 0.87-0.99) and digestive system cancer groups (dominant model: OR = 0.67 0.53-0.84; allele frequency model = 0.71, 95%CI = 0.57-0.87), but not in the blood system cancer or breast cancer group. When we further stratified the digestive system cancer group into digestive tract and digestive gland cancer groups, results showed a significant association between allele A of MPO-463G > A and digestive gland cancer in all the genetic models (allele frequency model: OR = 0.63, 95%CI = 0.40-0.99; additive model: OR = 0.41, 95%CI = 0.23-0.73; recessive model: OR = 0.51, 95%CI = 0.29-0.89; dominant model: OR = 0.58, 95%CI = 0.35-0.96), digestive tract cancers in allele frequency model (OR = 0.75, 95%CI = 0.59-0.95), and dominant model (OR = 0.72, 95%CI = 0.56-0.92). When stratified by ethnicity, results demonstrated that the genotype A might be a protect factor for both Caucasians and Asians. In group analysis according to source of controls, significant results were found in population from hospital in all the genetic models. In cumulative analysis, result of allele contrast showed a declining trend and increasingly narrower 95% overall, while the inclination toward non-significant association with lung cancer risk.

CONCLUSIONS

This meta-analysis suggested that MPO-463G > A polymorphism was associated with the overall reduced cancer susceptibility significantly. It might be a more reliable predictor of digestive system cancer instead of lung cancer, blood system cancer, and breast cancer. In cumulative analysis, the stable trend indicated that evidence was sufficient to show the association between MPO-463G > A polymorphism and cancer risk.

Genetic polymorphisms in GSTM1, GSTT1 and GSTP1 genes and risk of lung cancer in a North Indian population

BACKGROUND

A number of studies done so far in different populations have shown that polymorphisms within the GST genes play an important role in determining individual susceptibility to lung cancer; however, data obtained so far have been contradictory within the same or different populations. Few studies have focused on the combinatorial effect of the GST genes on susceptibility to lung cancer and also for different histological subtypes. Our aim is to investigate the roles of GSTM1, GSTT1, and GSTP1 polymorphisms as genetic modifiers of risk for lung cancer and histological subtypes using a larger sample size in a North Indian population.

METHODS

In total 540 subjects (270 lung cancer cases and 270 controls) were evaluated for the GST polymorphism. Genotyping for the GSTM1, GSTT1 and GSTP1 gene was done by using a multiplex PCR and PCR-RFLP method.

RESULTS

GSTM1 null genotype was found to be associated with lung cancer (OR=1.65, 95%CI: 116-2.3, P=0.005) and this risk was higher in cases of adenocarcinoma (ADCC). GSTT1 and GSTP1 did not show any significant association with lung cancer; however, when stratified for histological subtypes a significant association was observed for ADCC and small-cell lung cancer (SCLC) for both GSTT1 null and variant GSTP1 genotypes. The combined 'at risk' genotypes of null GSTM1 and GSTT1 genes were found to be associated with lung cancer risk, and this risk was higher in cases of ADCC (OR=4.09, 95%CI: 110-10.2, P=0.002). There is a twofold increased risk for lung cancer with the null GSTM1 and wild-type GSTP1 genotypes (P=0.0004); similarly, a fourfold increased risk was observed with the null GSTT1 and wild-type GSTP1 genotypes (P=0.0001).

CONCLUSIONS

The deficient GST genotypes seem thus to be important risk modifiers for lung cancer and related histological subtypes, especially in combination.

Interactive effect of smoking and NQO1 haplotypes on lung cancer risk

The role of genetic polymorphisms of

NAD(P)H

quinone oxidoreductase 1 (NQO1), which is known to be related to carcinogen metabolism and oxidative status, was evaluated for lung cancer development. The genotypes of two NQO1 polymorphisms, namely, IVS1-27C>G and Ex6+40C>T, were determined in 616 lung cancer cases and 616 lung cancer-free controls and haplotypes composed of the two polymorphisms were estimated. In the evaluation of the effect of the NQO1 genotypes or diplotypes, we did not find any significant association with lung cancer risk after adjusting for body mass index and smoking status. However, when we evaluated the effect of the NQO1 diplotypes for lung cancer risk in combination with smoking, smokers without the C-T/C-T diplotype showed a significantly increased risk of lung cancer compared with nonsmokers without the C-T/C-T diplotype (adjusted OR, 2.2; 95% CI, 1.67-3.02), and smokers with the C-T/C-T diplotype showed the highest OR of lung cancer (adjusted OR, 2.7; 95% CI, 1.78-4.21). Moreover, a trend test showed an additive interaction between smoking and the NQO1 C-T/C-T diplotype (P trend < 0.01). The additive effect of smoking and the NQO1 C-T/C-T diplotype was more apparent in squamous cell carcinoma, although this effect was statistically significant in all lung cancer cell types (all cell types, P trend < 0.05). This result suggests that haplotypes of the NQO1 gene play an important role in the development of lung cancer by interaction with smoking.

Glutathione S-transferase θ1 polymorphism contributes to lung cancer susceptibility: A meta-analysis of 26 case-control studies

The GSTT1 gene encodes a key enzyme involved in the metabolism of xenobiotics and its polymorphisms have been associated with individual susceptibility to various malignancies. Numerous molecular epidemiological studies have been performed to investigate the association between GSTT1 gene polymorphisms and lung cancer susceptibility; however, the results of previous studies were inconsistent. Therefore, the aim of the present study was to conduct a meta-analysis in order to derive a more precise estimation of the association in the East Asian populations. The meta-analysis included 7,415 lung cancer cases and 6,084 controls from 26 published studies in East Asia, which were selected from the PubMed and China National Knowledge Infrastructure databases, up to March 20, 2014. Using crude odds ratios (ORs) with 95% confidence intervals (CIs), a statistically significant association was identified between the GSTT1 null genotype and lung cancer in the East Asian populations (OR=1.17; 95% CI, 1.09–1.25; P_{heterogeneity}=0.003). Furthermore, subgroup analyses revealed that the lung cancer risk in smokers carrying the GSTT1 null genotype was significantly increased compared with non-smokers (OR=1.71; 95% CI, 1.04–2.81; P_{heterogeneity}=0.002). Thus, the GSTT1 null genotype may increase the risk of lung cancer among the East Asian populations.

Meta-analysis of GSTM1 null genotype and lung cancer risk in Asians

BACKGROUND

Several molecular epidemiological studies have been conducted to examine the association between glutathione S-transferase M 1 (GSTM1) null genotype and lung cancer in Asians; however, the conclusions remained controversial. We therefore performed an extensive meta-analysis on 31 published case-control studies with a total of 5347 lung cancer cases and 6072 controls.

MATERIAL/METHODS

PubMed and EMBASE were searched to identify case-control studies investigating the associations of GSTM1 null genotype with risk of lung cancer in Asians. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association between lung cancer risk and polymorphism of GSTM1.

RESULTS

GSTM1 null genotype was significantly associated with lung cancer risk (OR=1.43; 95% CI, 1.30-1.58). This result remained statistically significant when the adjusted ORs were combined (OR=1.38; 95% CI, 1.23-1.54). In the subgroup analysis by sex, there were significant associations in women and men. When stratifying for histology, this genotype showed increased adenocarcinoma risk and squamous cell carcinoma risk. In the subgroup analysis stratified by smoking status, lung cancer risk was increased in both smokers and non-smokers.

CONCLUSIONS

This study suggests that GSTM1 null genotype is a risk factor for lung cancer in Asians.

HapMap-based study on the association between MPO and GSTP1 gene polymorphisms and lung cancer susceptibility in Chinese Han population

AIM

Myeloperoxidase (MPO) and glutathione S-transferase pi 1 (GSTP1) are important carcinogen-metabolizing enzymes. The aim of this study was to investigate the association between the common polymorphisms of MPO and GSTP1 genes and lung cancer risk in Chinese Han population.

METHODS

A total of 266 subjects with lung cancer and 307 controls without personal history of the disease were recruited in this case control study. The tagSNPs approach was used to assess the common polymorphisms of MOP and GSTP1 genes and lung cancer risk according to the disequilibrium information from the HapMap project. The tagSNP rs7208693 was selected as the polymorphism site for MPO, while the haplotype-tagging SNPs rs1695, rs4891, rs762803 and rs749174 were selected as the polymorphism sites for GSTP1. The gene polymorphisms were confirmed using real-time PCR, cloning and sequencing.

RESULTS

The four GSTP1 haplotype-tagging SNPs rs1695, rs4891, rs762803 and rs749174, but not the MPO tagSNP rs7208693, exhibited an association with lung cancer susceptibility in smokers in the overall population and in the studied subgroups. When Phase 2 software was used to reconstruct the haplotype for GSTP1, the haplotype CACA (rs749174+rs1695 + rs762803+rs4891) exhibited an increased risk of lung cancer among smokers (adjust odds ratio 1.53; 95%CI 1.04-2.25, P=0.033). Furthermore, diplotype analyses demonstrated that the significant association between the risk haplotype and lung cancer. The risk haplotypes co-segregated with one or more biologically functional polymorphisms and corresponded to a recessive inheritance model.

CONCLUSION

The common polymorphisms of the GSTP1 gene may be the candidates for SNP markers for lung cancer susceptibility in Chinese Han population.

GSTP1 Ile105Val polymorphism is associated with lung cancer risk among Asian population and smokers: an updated meta-analysis

Many studies have examined the association between the GSTP1 Ile105Val (rs 1695) gene polymorphism and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. The PubMed and CNKI database was searched for case-control studies published up to July 2012. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 42 studies, comprising 12,304 lung cancer cases and 15,729 controls were included. Overall, for G allele carriers (GA + GG) versus homozygote AA, the pooled OR was 1.05 (95% CI 0.99-1.10 P = 0.092 for heterogeneity), for GG versus AA the pooled OR was 1.04 (95% CI 0.96-1.12 P = 0.084 for heterogeneity). In the stratified analysis by ethnicity, gender, histological types of lung cancer and smoking status, a significant association was found in Asians and smokers, not in Caucasian or mixed population, Male, Female population, lung AC, SCC, SCLC or non-smokers. Publication bias was found by using the funnel plot and Egger's test. Overall, there is no evidence showing a significant correlation between GSTP1 Ile105Val gene polymorphism and lung cancer risk in overall population, however stratified analysis by ethnicity, histology, gender and smoking status, it correlate with increased lung cancer susceptibility among Asians and smokers.

Association between glutathione S-transferase T1 null genotype and risk of lung cancer: a meta-analysis of 55 studies

The relationship between glutathione S-transferase T1 (GSTT1) gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between GSTT1 polymorphism and the risk of lung cancer. A comprehensive research was conducted through the databases, and 55 studies were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 15,140 patients with lung cancer and 16,662 controls. There was a significant association between GSTT1 null genotype and lung cancer risk in the overall populations (OR = 1.138, 95% CI = 1.032-1.255, P heterogeneity = 0.000, P = 0.009). Furthermore, GSTT1 null genotype was associated with the lung cancer risk in Asians (OR = 1.469, 95% CI = 1.228-1.757, P heterogeneity = 0.000, P = 0.000). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians and Africans. In conclusion, GSTT1 null genotype is associated with the lung cancer in overall populations and in Asians.

A meta-analysis of the relationship between glutathione S-transferase T1 null/presence gene polymorphism and the risk of lung cancer including 31802 subjects

The relationship between glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between GSTT1 null/presence gene polymorphism and the risk of lung cancer using meta-analysis method. The association studies were identified from PubMed, and Cochrane Library on July 1, 2012, and eligible investigations were included and synthesized using meta-analysis method. 51 reports were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 15,140 patients with lung cancer and 16,662 controls. There was a marked association between GSTT1 null genotype and lung cancer risk in overall populations (OR = 1.15, 95 % CI 1.04-1.27, P = 0.007). Furthermore, GSTT1 null genotype was associated with the lung cancer risk in Asians (OR = 1.47, 95 % CI 1.23-1.76, P < 0.0001). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians, Brazilian population and Africans. In conclusion, GSTT1 null genotype is associated with the lung cancer in overall populations and in Asians.

Association between MPO 463G>A polymorphism and risk of lung cancer: a meta-analysis

There is a possible association between myeloperoxidase (MPO) 463G>A polymorphism and risk of lung cancer, but previous studies report conflicting results. We performed a meta-analysis of available molecular epidemiologic studies to comprehensively assess the association between MPO 463G>A polymorphism and risk of lung cancer. A systemic literature search was performed in Pubmed, Embase, and Wanfang databases for molecular epidemiologic studies on the association MPO 463G>A polymorphism and risk of lung cancer on March 16, 2013. The pooled odds ratios (ORs) with their 95% confidence interval (95% CI) were calculated to assess the strength of the association. Twenty-six individual case-control studies with a total of 18,433 subjects (7,752 cases and 10,681 controls) were finally included into the meta-analysis. Overall, MPO 463G>A polymorphism was significantly associated with decreased risk of lung cancer under two main genetic comparison models (for A versus G, OR = 0.91, 95 % CI 0.83-0.99, P = 0.035; for AG/AA versus GG, OR = 0.90, 95% CI 0.81-0.99, P = 0.029). Meta-analysis of studies with high quality also showed that MPO 463G>A polymorphism was significantly associated with decreased risk of lung cancer under two main genetic comparison models (for A versus G, OR = 0.91, 95% CI 0.83-0.99, P = 0.035; for AG/AA versus GG, OR = 0.90, 95% CI 0.80-0.99, P = 0.048). Subgroup analysis by ethnicity further showed that there was a significant association between MPO 463G>A polymorphism and decreased risk of lung cancer in Caucasians but not in Asians. The meta-analysis suggests that MPO 463G>A polymorphism is associated with decreased risk of lung cancer, especially in Caucasians.

Association between myeloperoxidase G-463A polymorphism and lung cancer risk

Many epidemiologic studies have investigated the association between myeloperoxidase (MPO) G-463A polymorphism and lung cancer risk, but the results were controversial. We performed a meta-analysis of 25 studies on MPO polymorphism and lung cancer risk published before July 2013. The allele of A was found to be associated with decreased risk of lung cancer compared with G allele (OR, 0.90; 95% CI, 0.82-0.98) in the general population. The significant association remained in the comparison between AA + AG and GG (OR, 0.92; 95% CI, 0.87-0.98). When it was stratified according to Asian population, the association between MPO polymorphism and lung cancer risk was further strengthened. However, no associations were found in the Caucasian population. This meta-analysis has demonstrated that MPO polymorphism might contribute to individual's susceptibility to lung cancer in Asian population. Caucasian authors could re-investigate the association between MPO polymorphism and lung cancer risk with more specific participants. Future studies focusing on interactions between combined genes and environmental risk factors are warranted.

The NQO1 polymorphism C609T (Pro187Ser) and cancer susceptibility: a comprehensive meta-analysis

Background:

Evidence is increasingly emerging about multiple roles for the NAD(P)H quinone oxidoreductase 1 enzyme in cancer. The C609T (rs1800566, Pro187Ser) null polymorphism of the NQO1 gene contributes significantly to the variation in enzymatic activity across different populations. NQO1 C609T polymorphism was thoroughly investigated with respect to cancer susceptibility. The results were inconsistent partly due to low sample sizes. The aim of the present work was to perform a meta-analysis to assess association for all common cancer sites separately and in combination.

Methods:

Our meta-analysis involved 92 studies including 21 178 cases and 25 157 controls. Statistical analysis involved individual cancer sites and the combined cancer risk. Association was tested under different genetic models.

Results:

We found a statistically significant association between the variant T allele and overall cancer risk in the worldwide population (for the TT vs CC model, OR=1.18 (1.07–1.31), P=0.002, I²=36%). Stratified analysis revealed that this association was largely attributed to the Caucasian ethnicity (for the TT vs CC model, OR=1.28 (1.12–1.46), P=0.0002, I²=1%). Stratification by tumour site showed significant association for bladder cancer in the worldwide population (for the TT vs CC model, OR=1.70 (1.17–2.46), P=0.005, I²=0%), and in the Asian population (for the TT vs CC model, 1.48 (1.14–1.93), P=0.003, I²=16%). Positive association was also found for gastric cancer in the worldwide population under the dominant model (OR=1.34 (1.09–1.65), P=0.006, I²=15%).

Conclusion:

Our results indicate that the C609T polymorphism of the NQO1 gene is an important genetic risk factor in cancer.

Myeloperoxidase G463A polymorphism and lung cancer risk in Asians: a pooled analysis

Myeloperoxidase (MPO) is an endogenous oxidant enzyme and can generate reactive oxygen species. The MPO G463A polymorphism influences MPO transcription levels and has been proposed to be associated with risk of lung cancer. To assess the effect of MPO G463A polymorphism on lung cancer risk in Asians, a pooled analysis of published case-control studies was performed. PubMed, Embase, China Biomedical Literature, and Wanfang Medicine databases were searched for eligible studies. The strength of the association between MPO G463A polymorphism and lung cancer risk was measured by odds ratio (OR) with 95 % confidence interval (95% CI). Finally, eight studies with a total of 1,679 lung cancer cases and 1,876 non-cancer controls were included. Overall, MPO G463A polymorphism was associated with decreased risk of lung cancer risk in Asians under two genetic models (OR AA vs. GG = 0.58, 95% CI 0.36-0.96, P = 0.033; OR AA vs. GG+AG = 0.60, 95% CI 0.37-0.98, P = 0.040). There was no obvious risk of publication bias in this meta-analysis. In conclusion, the pooled analysis suggests that MPO G463A polymorphism is associated with decreased risk of lung cancer risk in Asians.

CYP1A1 exon7 polymorphism is associated with lung cancer risk among the female population and among smokers: a meta-analysis

The genetic polymorphism of the CYP1A1 exon7 (rs1048943) gene is thought to have a significant effect on lung cancer risk, but the results are inconsistent. To assess this relationship more precisely, a meta-analysis was performed. Ultimately, 45 case-control studies, involving 19,689 subjects were included. A significantly increased lung cancer risk was associated with two exon7 genotype variants (for Val/Val vs Ile/Ile: odds ratio [OR] = 1.23, 95% confidence interval [CI] = 1.10-1.43; for (Ile/Val + Val/Val) vs Ile/Ile: OR = 1.16, 95% CI = 1.08-1.24) in the overall population. In the stratified analysis by ethnicity, gender, and smoking status, a significant association was found in Asians, Caucasians, and the female population, not the male population. Additionally, a significant association was found in the smoker population, not in the nonsmoker population. This meta-analysis suggests that the exon7 polymorphisms of CYP1A1 correlate with increased lung cancer susceptibility and there is an interaction between CYP1A1 exon7 polymorphisms and smoking, but these associations vary in different genders of the case and control populations.

The MPO-463G>A polymorphism and lung cancer risk: a meta-analysis based on 22 case-control studies

Background

Myeloperoxidase (MPO) is an endogenous oxidant enzyme that produces reactive oxygen species (ROS) and may be involved in lung carcinogenesis. The MPO−463G>A polymorphism influences MPO transcription and has been associated with lung cancer susceptibility. However, the association between the MPO−463G>A polymorphism and lung cancer risk remains controversial.

Method

To investigate the effect of this polymorphism on lung cancer susceptibility, we performed a meta-analysis based on 22 published case–control studies including 7,520 patients with lung cancer and 8,600 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association.

Results

Overall, there was no evidence for significant association between MPO−463G>A polymorphism and lung cancer susceptibility (for AA versus GG: OR = 0.91, 95%CI = 0.67–1.24; for GA versus GG: OR = 0.87, 95% CI = 0.78–0.98; for AA/GA versus GG: OR = 0.90, 95% CI = 0.80–1.01; for AA versus GA/GG: OR = 0.96, 95% CI = 0.72–1.28). In the stratified analyses by ethnicity, source of controls and smoking status, we also did not find any significant association between them.

Conclusions

In summary, this meta-analysis suggests MPO−463G>A polymorphism may not be a risk factor for developing lung cancer. However, further prospective well-designed population-based studies with larger sample size are expected to validate the results.

GSTT1 null genotype contributes to lung cancer risk in asian populations: a meta-analysis of 23 studies

BACKGROUND

Genetic variation in glutathione S-transferases (GSTs) may contribute to lung cancer risk. Many studies have investigated the correlation between the Glutathione S-transferase T1 (GSTT1) null genotype and lung cancer risk in Asian population but yielded inconclusive results.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a meta-analysis of 23 studies including 4065 cases and 5390 controls. We assessed the strength of the association of GSTT1 with lung cancer risk and performed sub-group analyses by source of controls, smoking status, histological types, and sample size. A statistically significant correlation between GSTT1 null genotype and lung cancer in Asian population was observed (OR = 1.28, 95% CI = 1.10, 1.49; Pheterogeneity<0.001 and I(2) = 62.0%). Sub-group analysis revealed there was a statistically increased lung cancer risk in ever-smokers who carried the GSTT1 null genotype (OR = 1.94, 95% CI = 1.27, 2.96; P heterogeneity = 0.02 and I(2) = 58.1%). It was also indicated that GSTT1 null genotype could increase lung cancer risk among population-based studies (OR = 1.25, 95% CI = 1.04, 1.50; Pheterogeneity = 0.003 and I(2) = 56.8%). The positive association was also found in studies of sample size (≤500 participants) (OR = 1.34, 95% CI = 1.10, 1.62; Pheterogeneity<0.001 and I(2) = 65.4%).

CONCLUSIONS

These meta-analysis results suggest that GSTT1 null genotype is associated with a significantly increased risk of lung cancer in Asian population.

Lack of association between NADPH quinone oxidoreductase 1 (NQO1) gene C609T polymorphism and lung cancer: a case-control study and a meta-analysis

Background

The association between NAD(P)H:quinone oxidoreductase 1 (NQO1) gene C609T polymorphism (rs1800566) and lung cancer has been widely evaluated, and a definitive answer so far is lacking. We first conducted a case-control study to assess this association in northeastern Han Chinese, and then performed a meta-analysis to further address this issue.

Methodology/Principal Findings

This case-control study involved 684 patients clinically diagnosed as lung cancer and 602 age-matched cancer-free controls from Harbin city, Heilongjiang province, China. Genotyping was conducted using the PCR-LDR (ligase detection reactions) method. Meta-analysis was managed by STATA software. Data and study quality were assessed in duplicate. Our case-control association study indicated no significant difference in the genotype and allele distributions of C609T polymorphism between lung cancer patients and controls, consistent with the results of the further meta-analysis involving 7286 patients and 9167 controls under both allelic (odds ratio (OR) = 0.99; 95% confidence interval (CI): 0.92–1.06; P = 0.692) and dominant (OR = 0.98; 95% CI: 0.89–1.08; P = 0.637) models. However, there was moderate evidence of between-study heterogeneity and low probability of publication bias. Further subgroup analyses by ethnicity, source of controls and sample size detected no positive associations in this meta-analysis.

Conclusions

Our study in northeastern Han Chinese, along with the meta-analysis, failed to confirm the association of NQO1 gene C609T polymorphism with lung cancer risk, even across different ethnic populations.

Association of glutathione S-transferase P1 gene polymorphism with the susceptibility of lung cancer

The conclusions of the published reports on the relationship between glutathione S-transferase P1 (GSTP1) gene polymorphism and the risk of lung cancer are still debated. GSTP1 is one of the important mutant sites reported at present. This meta-analysis was performed to evaluate the association between GSTP1 and the risk of lung cancer. The association investigations were identified from PubMed and Cochrane Library, and eligible studies were included and synthesized using meta-analysis method. Forty-four reports were included into this meta-analysis for the association of GSTP1 A/G gene polymorphism and lung cancer susceptibility, consisting of 12,363 patients with lung cancer and 13,948 controls. The association between GSTPI G allele and lung cancer risk was found in this meta-analysis (OR 1.08, 95 % CI 1.02-1.15, P = 0.01). However, the GG genotype and AA genotype were not associated with the susceptibility of lung cancer. Furthermore, there was no association between GSTP1 A/G gene polymorphism and the risk of lung cancer in Caucasians, and East-Asians. In conclusion, GSTP1 G allele is associated with the lung cancer susceptibility. However, more studies on the relationship between GSTP1 A/G gene polymorphism and the risk of lung cancer should be performed in the future.

CYP1A1 Ile462Val polymorphism contributes to lung cancer susceptibility among lung squamous carcinoma and smokers: a meta-analysis

Many studies have examined the association between the CYP1A1 Ile462Val gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. Ultimately, 43 case-control studies, comprising 19,228 subjects were included. A significantly elevated lung cancer risk was associated with 2 Ile462Val genotype variants (for Val/Val vs Ile/Ile: OR = 1.22, 95% CI = 1.08-1.40; for (Ile/Val +Val/Val) vs Ile/Ile: OR = 1.15, 95% CI = 1.07-1.23) in overall population. In the stratified analysis, a significant association was found in Asians, Caucasians and lung SCC, not lung AC and lung SCLC. Additionally, a significant association was found in smoker population and not found in non-smoker populations. This meta-analysis suggests that the Ile462Val polymorphisms of CYP1A1 correlate with increased lung cancer susceptibility in Asian and Caucasian populations and there is an interaction with smoking status, but these associations vary in different histological types of lung caner.

The effect of CYP1A1, GSTT1 and GSTM1 polymorphisms on the risk of lung cancer: a case-control study

Lung cancer, which is mainly affected by environmental factors, is a lethal malignancy. It is also important to investigate the effect of genetic factors on lung cancer aetiology. In this study, we aimed to investigate the distribution of CYP1A1*2C, GSTT1 and GSTM1 polymorphisms in Turkish lung cancer patients to determine whether any promoting effect of polymorphisms could cause development of lung cancer. For this purpose, genomic DNA samples obtained from peripheral blood of 128 patients with lung cancer and 122 healthy subjects were analyzed. Genotyping of polymorphic enzymes were carried out by polymerase chain reaction-restriction fragment length polymorphism methods. Although there were no significant differences between groups in terms of CYP1A1 polymorphism, the carriers of CYP1A1 Ile/Val genotype (odds ratio [OR] = 1.224, 95% confidence interval [CI]: 0.585-2.564) or CYP1A1 Val/Val genotype (OR = 3.058, 95% CI: 0.312-30.303) had an increased risk of lung cancer development. There was no statistical difference between groups in terms of both GSTT1 null genotype (OR = 1.114, 95% CI: 0.590-2.105) and GSTM1 null genotype (OR = 0.776, 95% CI: 0.466-1.290). This is the first case-control study investigating CYP1A1 Ile/Val, GSTT1 and GSTM1 polymorphisms in Turkish lung cancer patients. Although we suggest that other genes in addition to the proposed genes could play a role in lung cancer development, the results of our study will contribute to the possible associations between CYP1A1 Ile/Val, GSTT1 and GSTM1 gene polymorphism on the risk of lung cancer.

Common genetic variants in the myeloperoxidase and paraoxonase genes and the related cancer risk: a review

Modern approaches in health care are moving toward the model of "personalized medicine." Today, current research in molecular biology and medicine is focused on developing genomic markers with predictive, therapeutic, and prognostic significance. One of the most widespread and significant genomic markers is the single nucleotide polymorphism (SNP), which represents a variation in DNA sequence when a single nucleotide differs between members of a biological species or paired chromosomes in an individual. Antioxidant defense enzymes break down dangerous reactive compounds, called reactive oxygen species, and prevent DNA strand from carcinogen-specific mutations. It is well known that inherited variations in genes that encode antioxidant defense enzymes may modulate individual susceptibility to cancer. In our previous study we have determined the predictive significance of several SNPs of superoxide dismutase (SOD) and glutathione peroxidase gene families in the context of cancer risk. The present review includes a summary and discussion of the current findings evaluating the role of SNPs of the myeloperoxidase (MPO) and paraoxanase (PON) genes in cancer occurrence and development. We suggest that rs2333227 (MPO_ -463G/A) and rs854560 polymorphisms have a great predictive significance; they could probably be utilized as cancer predictors in the future. Also, we recommend further in-depth research for rs11079344 (MPO), rs8178406 (MPO), rs2243828 (MPO), rs662 (PON1), rs705379 (PON1), and PON1_304A/G polymorphisms. These SNPs may become significant cancer-associated biomarkers.

Association between GSTM1, GSTT1, and GSTP1 polymorphisms and lung cancer risk in a Turkish population

Several studies focused on investigating genetic polymorphisms in order to estimate genetic contribution to lung cancer often showed conflicting results. In this study, we investigated the role of GSTM1, GSTT1, GSTP1 exon 5 and exon 6 polymorphisms on developing lung cancer and histological subtypes in 213 lung cancer patients and 231 controls. GSTM1 null, GSTT1 null, and GSTP1 exon 5 variant genotypes did not show a significant risk for developing lung cancer overall. Significant association was noted between GSTP1 exon 6 variant genotypes and overall lung cancer risk (OR 2.17, 95% CI 1.25-3.78; P = 0.006). These results show that GSTP1 exon 6 polymorphism might be an important factor in determining lung cancer susceptibility in a Turkish population.

The epistasis between vascular homeostasis genes is apparent in essential hypertension

OBJECTIVE

The epistasis influence of vascular homeostasis genes is vital to multigenetic diseases. This study was designed to perceive the possible role of epistasis in the etiology of essential hypertension.

METHODS

We investigated seven polymorphisms of ACE, CYP11B2 and NOS3 epistatically, and SBP, DBP, MAP, ACE activity, plasma aldosterone concentration (PAC) and NOx level in 860 age- and ethnicity-matched unrelated north-Indian subjects.

RESULTS

The hypertension risk in individuals with interacted-genotypes (IwIw+IwIc)+(4aa), (IcIc)+(4bb+4ba) and IcIc+4aa of the CYP11B2 and NOS3 was significantly higher with odds ratio 5.5 (95% CI=2.9-10.6, P<0.0001), 2.4 (95% CI=1.4-4.1, P<0.0008) and 7.5 (95% CI=1.6-34.8, P=0.010), respectively. The odds ratio for hypertension with interacted-haplotypes (-344T/Ic)+(-922A/-786T/4a/894G) and (-344T/Ic)+(-922G/-786C/4a/894G) of CYP11B2 and NOS3 was 5.3 (95% CI=2.0-14.2, P=0.005) and 3.9 (95% CI=1.4-10.4, P=0.04), respectively; whereas for the protective interacted-haplotypes (-344T/Iw)+(-922A/-786T/4b/894G), the odds ratio was 0.7 (95% CI=0.5-0.9, P=0.03). While the interacted-genotypes, IcIc+4aa correlated with higher SBP and MAP (P=0.006; P=0.04), the interacted-haplotypes, (-344T/Ic)+(-922A/-786T/4a/894G) and (-344T/Ic)+(-922G/-786C/4a/894G) correlated with higher MAP and lower NOx level (P=0.02 and P=0.03, respectively), and the protective interacted-haplotypes (-344T/Iw)+(-922A/-786T/4b/894G) correlated with lower PAC and MAP (P=0.024 and P=0.018, respectively).

CONCLUSIONS

The epistasis between CYP11B2 and NOS3 and its correlation with varied clinical and biochemical parameters signify its possible contribution in the complex etiology of hypertension.

CYP1A1 MspI and exon7 gene polymorphisms and lung cancer risk: an updated meta-analysis and review

BACKGROUND

Many studies have examined the association between the CYP1A1 MspI and exon 7 gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent.

METHODS

To assess this relationship more precisely, a meta-analysis and review were performed. The PubMed, Embase, Web of Science, and CNKI database was searched for case-control studies published up to June 2010. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.

RESULTS

Ultimately, 64 studies, comprising 18,397 subjects from 49 case-control studies of the MspI genotype and 18,518 patients from 40 case-control studies of the exon 7 genotype, were included. A significantly elevated lung cancer risk was associated with 2 MspI genotype variants (for type C vs. Type A: OR = 1.26, 95% CI = 1.12-1.42; for types B and C combined vs. Type A: OR = 1.20, 95% CI = 1.13-1.28) in overall population. In the stratified analysis, a significant association was found in Asians, Caucasians, lung SCC, lung AC and Male population, not in mixed population, lung SCLC and female population. However, inconsistent results were observed for CYP1A1 exon7 in our meta-analysis, two variants of the exon 7 polymorphism were associated with a significantly higher risk for lung cancer (for Val/Val vs. Ile/Ile: OR = 1.24, 95% CI = 1.09-1.42; for (Ile/Val +Val/Val) vs. Ile/Ile: OR = 1.15, 95% CI = 1.07-1.24) in overall population. In the stratified analysis, a significant assocation was found in Asians, Caucasians, lung SCC and Female population, not in mixed population, lung AD, lung SCLC and Male population. Additionally, a significant association was found in smoker population and not found in non-smoker populations for CYP1A1 MspI and exon7 gene.

CONCLUSIONS

This meta-analysis suggests that the MspI and exon 7 polymorphisms of CYP1A1 correlate with increased lung cancer susceptibility and there is an interaction between two genotypes of CYP1A1 polymorphism and smoking, but these associations vary in different ethnic populations, histological types of lung cancer and gender of case and control population.

Molecular epidemiology of female lung cancer

Lung cancer is still a leading cause of cancer mortality in the world. The incidence of lung cancer in developed countries started to decrease mainly due to global anti-smoking campaigns. However, the incidence of lung cancer in women has been increasing in recent decades for various reasons. Furthermore, since the screening of lung cancer is not as yet very effective, clinically applicable molecular markers for early diagnosis are much required. Lung cancer in women appears to have differences compared with that in men, in terms of histologic types and susceptibility to environmental risk factors. This suggests that female lung cancer can be derived by carcinogenic mechanisms different from those involved in male lung cancer. Among female lung cancer patients, many are non-smokers, which could be studied to identify alternative carcinogenic mechanisms independent from smoking-related ones. In this paper, we reviewed molecular susceptibility markers and genetic changes in lung cancer tissues observed in female lung cancer patients, which have been validated by various studies and will be helpful to understand the tumorigenesis of lung cancer.

Assessment of cumulative evidence for the association between glutathione S-transferase polymorphisms and lung cancer: application of the Venice interim guidelines

OBJECTIVE

There is an overwhelming abundance of genetic association studies available in the literature, which can often be collectively difficult to interpret. To address this issue, the Venice interim guidelines were established for determining the credibility of the cumulative evidence. The objective of this report is to evaluate the literature on the association of common glutathione S-transferase (GST) variants (GSTM1 null, GSTT1 null and GSTP1 Ile105Val polymorphism) and lung cancer, and to assess the credibility of the associations using the newly proposed cumulative evidence guidelines.

METHODS

Information from the literature was enriched with an updated meta-analysis and a pooled analysis using data from the Genetic Susceptibility to Environmental Carcinogens database.

RESULTS

There was a significant association between GSTM1 null and lung cancer for the meta-analysis (meta odds ratio=1.17, 95% confidence interval: 1.10-1.25) and pooled analysis (adjusted odds ratio=1.10, 95% confidence interval: 1.04-1.16), although substantial heterogeneity was present. No overall association between lung cancer and GSTT1 null or GSTP1 Ile105Val was found. When the Venice criteria was applied, cumulative evidence for all associations were considered 'weak', with the exception of East Asian carriers of the G allele of GSTP1 Ile105Val, which was graded as 'moderate' evidence.

CONCLUSION

Despite the large amounts of studies, and several statistically significant summary estimates produced by meta-analyses, the application of the Venice criteria suggests extensive heterogeneity and susceptibility to bias for the studies on association of common genetic polymorphisms, such as with GST variants and lung cancer.

Genetic polymorphism in metabolism and host defense enzymes: implications for human health risk assessment

Genetic polymorphisms in xenobiotic metabolizing enzymes can have profound influence on enzyme function, with implications for chemical clearance and internal dose. The effects of polymorphisms have been evaluated for certain therapeutic drugs but there has been relatively little investigation with environmental toxicants. Polymorphisms can also affect the function of host defense mechanisms and thus modify the pharmacodynamic response. This review and analysis explores the feasibility of using polymorphism data in human health risk assessment for four enzymes, two involved in conjugation (uridine diphosphoglucuronosyltransferases [UGTs], sulfotransferases [SULTs]), and two involved in detoxification (microsomal epoxide hydrolase [EPHX1], NADPH quinone oxidoreductase I [NQO1]). This set of evaluations complements our previous analyses with oxidative and conjugating enzymes. Of the numerous UGT and SULT enzymes, the greatest likelihood for polymorphism effect on conjugation function are for SULT1A1 (*2 polymorphism), UGT1A1 (*6, *7, *28 polymorphisms), UGT1A7 (*3 polymorphism), UGT2B15 (*2 polymorphism), and UGT2B17 (null polymorphism). The null polymorphism in NQO1 has the potential to impair host defense. These highlighted polymorphisms are of sufficient frequency to be prioritized for consideration in chemical risk assessments. In contrast, SNPs in EPHX1 are not sufficiently influential or defined for inclusion in risk models. The current analysis is an important first step in bringing the highlighted polymorphisms into a physiologically based pharmacokinetic (PBPK) modeling framework.

Polymorphisms of glutathione-S-transferase genes and the risk of aerodigestive tract cancers in the Northeast Indian population

BACKGROUND

Widespread use of tobacco and betel quid consumption and a high incidence of tobacco-associated aerodigestive tract cancers have been reported in different ethnic groups from several regions of Northeast (NE) India. This study was done to explore the possibility of phase II metabolic enzymes being responsible for the high prevalence of cancers in this region of India.

METHODS

Samples from 370 cases with oral, gastric, and lung cancers and 270 controls were analyzed for polymorphism of glutathione-S-transferase (GST) genes using polymerase chain reaction-restriction fragment length polymorphism-based methods.

RESULTS AND CONCLUSIONS

Tobacco smoking and betel quid chewing were found to be high risk factors for oral and lung cancers but not for gastric cancer, whereas tobacco chewing was found to be a risk factor for oral cancer but not for gastric or lung cancer. The variant genotypes of GSTP1 were not associated with any of the aerodigestive tract cancers. GSTT1 and GSTM1 null genotypes appeared to play a protective role for lung cancer (odds ratio [OR] = 0.47, 95% confidence interval [95% CI]: 0.24-0.93, p = 0.03) and (OR = 0.52, 95% CI: 0.28-0.96, p = 0.04), but they were not associated with oral and gastric cancers. However, when data was analyzed in different geographic regions the GSTT1 null genotype was found to be a significant risk factor for oral (OR = 2.58, 95% CI 1.01-6.61, p = 0.05) as well as gastric cancer (OR = 3.08, 95% CI 1.32-7.19, p = 0.009) in samples obtained from the Assam region of NE India. This is the first study on the association of GST polymorphisms and aerodigestive tract cancers in the high-risk region of NE India.

NAD(P)H:quinone oxidoreductase 1 Pro187Ser polymorphism and the risk of lung cancer: A meta-analysis

BACKGROUND

NAD(P)H:quinine oxidoreductase 1 (NQO1) is a two-electron reductase that catalyzes quinine to hydroquinone. Variant genotypes of NQO1 Pro187Ser may be related to low enzyme activity and thus are suggested as affecting the risk of lung cancer. Our purpose was to study the NQO1 Pro187Ser polymorphism and the risk of lung cancer.

METHODS

We conducted a PubMed search and a China National Knowledge Infrastructure search using "NAD(P)H quinine reductase 1" ,"lung cancer", and " polymorphism" for articles published from January 1997 to March 2010. For each study, we calculated the crude odds ratios (OR) and 95% confidence intervals (CI) for lung cancer. Summary estimates for crude as well as adjusted OR were calculated with the statistical program stata.

RESULTS

The summary OR for carrying one variant allele and the homozygous variant genotype was 1.04 (95%CI, 0.97-1.13). In the Asian population, the summary OR for carrying one variant genotype was 1.09 (95%CI, 0.95-1.25).

CONCLUSIONS

Through our meta-analysis, we found that the Pro/Ser and Ser/Ser genotypes involving NQO1 were non-significantly associated with lung cancer. In the Asian population, the combined genotype was marginally associated with increased risk of lung cancer. When stratified on gender and smoking, the meta-analysis showed that there was no statistically significant difference between men and women, smokers and non-smokers, respectively.

The MPO -463G>A polymorphism and cancer risk: a meta-analysis based on 43 case-control studies

Myeloperoxidase (MPO) is an endogenous oxidant enzyme that generates reactive oxygen species and plays an important role in the aetiology of cancer. The MPO -463G>A polymorphism influences MPO transcription and has been implicated in cancer risk. However, results from published studies on the association between the MPO -463G>A polymorphism and risk of cancer are conflicting. To derive a more precise estimation of association between the MPO -463G>A polymorphism and risk of cancer, we performed a meta-analysis based on 43 case-control studies, including a total of 14 171 cancer cases and 17 319 controls. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Overall, individuals with the -463A allele had a 0.93-fold lower cancer risk in a dominant model (OR = 0.93, 95% CI = 0.87-1.00). In the stratified analyses, we observed a similar association in European populations (heterozygote comparison: OR = 0.90, 95% CI = 0.82-0.99) and hospital-based studies (dominant model: OR = 0.88, 95% CI = 0.79-0.99). When stratified by cancer type, however, no significant association was found. The results suggested that the MPO -463A allele does not contribute to the development of cancer. Additional well-designed large studies are required to validate these findings in different populations.

Association of angiotensin converting enzyme gene insertion/deletion polymorphism with lung cancer in Turkey

Angiotensin-converting enzyme (ACE) plays an important role in the physiological control of blood pressure and inflammation. We investigated an insertion/deletion (I/D) polymorphism of the gene for ACE in relation to cardiovascular, cerebrovascular, neurodegenerative, and inflammatory diseases. The purpose of the present study was to investigate a possible association between lung cancer and insertion/deletion polymorphism of the ACE gene. A total of 125 patients with lung cancer and 165 control subjects were enrolled in the present study. ACE I/D genotypes were determined by polymerase chain reaction. Allelic frequencies and genotype distribution of the ACE I/D polymorphism in the patient group were significantly different from control subjects (ACE II genotype 29.6 vs. 17.6%, P = 0.011; ACE I allele 49.6 vs. 39.4%, P =0.009). Our data suggest that the ACE I/D polymorphism could be a risk factor for patients with lung cancer.

[A meta analysis on the relationship between myeloperoxidase G-463A genetic polymorphisms and lung cancer susceptibility]

BACKGROUND AND OBJECTIVE

The relationship between myeloperoxidase G-463A genetic polymorphisms and lung cancer susceptibility has been studied extensively. However, the outcomes are not consistent. The aim of this study is to evaluate the relationship between myeloperoxidase genetic polymorphisms and lung cancer susceptibility by meta analysis.

METHODS

Documents published were retrieved through databases associated with the study. Taking into account the possibilities of heterogeneity of the studies, a statistical test for heterngeneity was performed. The odds ratio and 95% CI were used to evaluate the risks. The meta analysis was applied with RevMan software 4.2, and the forest plot and funnel plot of meta analysis were worked out.

RESULTS

A total of 5 381 cases and 5 827 controls from studies for Caucasian and a total of 1 558 cases and 1 755 controls from studies for East Asians were included. For Caucasian the pooled OR was 0.91 (95% CI: 0.81-1.02); For East Asians, the pooled OR is 0.83 (95% CI: 0.63-1.09). Publication bias exits in the study for Caucasian, but not for East Asians.

CONCLUSION

The results of this study indicated that the polymorphism of myeloperoxidase G-463A was not significantly associated with the lung cancer risk for Caucasian or East Asians. However, further studies for the East Asians is needed for the few subjects.

[Gene polymorphism and physical constitution theory: starting point of exploring syndromes of lung cancer]

Physical constitution theory is an important part of traditional Chinese medicine theory. Physical constitution is associated with the incidence, development and prognosis of diseases. Gene polymorphism is a result of the interaction between internal and external environments during the human evolution, and it is the reason for differences in biological characteristics and disease susceptibility of individuals. Current status of the research on physical constitution theory, lung cancer syndromes and gene polymorphism are summarized in this paper. Exploring lung cancer syndromes from the point of view of gene polymorphism may reveal the scientific connotation of lung cancer syndromes, and provide new evidence and method for diagnosis of lung cancer.

No association between the GSTP1 exon 5 polymorphism and susceptibility to advanced stage endometriosis in the Korean population

PROBLEM

To investigate whether the glutathione-S-transferase P1 (GSTP1) exon 5 polymorphism is associated with susceptibility to advanced stage endometriosis in Korean women.

METHOD OF STUDY

Case-control study in a collective of 260 patients and 164 controls. Genotyping of the GSTP1 exon 5 polymorphism was performed by using real-time TaqMan PCR assay.

RESULTS

The genotype distribution of the GSTP1 exon 5 polymorphism in the endometriosis group was not significantly different from that of the control group (AA/AG/GG rates were 64.2%/32.7%/3.1% and 65.2%/31.7%/3.0% for the endometriosis and control groups, respectively, P = 0.977). Further subgroup analysis according to either stage or bilaterality of ovarian endometrioma also found no significant difference in the genotype distribution between any of the endometriosis subgroups and the control group.

CONCLUSION

These findings suggest that the GSTP1 exon 5 polymorphism is not a major determinant of the development of advanced stage endometriosis in the Korean population.

Combination of polymorphisms in the beta2-adrenergic receptor and nitric oxide synthase 3 genes increases the risk for hypertension

OBJECTIVE

Hypertension is a major risk factor for cardiovascular disease. Polymorphism in the beta2-adrenergic receptor (ADRB2) and nitric oxide synthase 3 (NOS3) genes is associated with clinical cardiovascular phenotypes. The Arg16Gly and Glu298Asp polymorphisms of ADRB2 and NOS3 genes, respectively, have been reported to be associated with hypertension. We hypothesized that a combination of these two polymorphisms increases the risk for hypertension. Hence, we examined the effect of this combination of single-nucleotide polymorphisms on the risk for hypertension.

METHODS

Our cross-sectional study comprised 402 middle-aged and elderly human participants. We determined the genotypes of Arg16Gly and Glu298Asp single-nucleotide polymorphisms in ADRB2 and NOS3, respectively, by TaqMan PCR method; we also measured the resting blood pressure.

RESULTS

The odds ratio for the presence of hypertension in individuals having the Gly/Gly genotype of ADRB2 compared with those having the other genotypes (Arg/Arg and Arg/Gly) was 2.87. With regard to the Glu298Asp polymorphism in NOS3, the odds ratio for the presence of hypertension in individuals having the Glu/Glu genotype of NOS3 when compared with those having the other genotypes (Asp/Asp and Asp/Glu) was 2.79. Interestingly, the odds ratio was 7.64 for individuals having a combination of the Gly/Gly genotype of ADRB2 and Glu/Glu genotype of NOS3 when compared with those having a combination of Arg/Arg and Arg/Gly genotypes of ADRB2 and Asp/Asp and Asp/Glu genotypes of NOS3.

CONCLUSION

We revealed that a combination of the Arg16Gly and Glu298Asp polymorphisms in ADRB2 and NOS3, respectively, remarkably increased the risk for hypertension in middle-aged and elderly humans.

CYP1A2 genetic polymorphisms and adenocarcinoma lung cancer risk in the Tunisian population

AIMS

In this study, the effects of four single nucleotide polymorphisms (SNPs), -3860G>A, -2467delT, -739T>G and -163C>A, of CYP1A2 gene on lung cancer were evaluated in Tunisian population.

MAIN METHODS

Four polymorphisms of CYP1A2 gene were analysed in 109 healthy smokers and in 101 lung cancer cases, including 63 with squamous cell carcinoma (SCC) and 41 with adenocarcinoma (AD). The genotyping for the SNPs -3860 G>A, -2467delT, -739T>G and -163C>A was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis.

KEY FINDINGS

The results showed that smokers with CYP1A2 gene polymorphisms were associated with an increased risk for the development of lung AD. There was however no significant increased risk of developing lung SCC in smokers having CYP1A2 gene polymorphisms. An increased risk of developing AD was observed in smokers who are carriers of at least one copy of -3680A or -739G giving a significant odds ratio (OR) of 6.02 (CI=2.91-12.9) and 3.01 (CI=1.54-5.98), respectively.

SIGNIFICANCE

These genotyping data are consistent with the hypothesis that tobacco-specific-N-nitrosamines (TSN) such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are major contributors to the development of lung AD and that CYP1A2 gene product plays an important role in the metabolic activation of NNK. This study suggests that SNPs of CYP1A2 could be considered as promising biomarkers in the aetiology of lung AD in smokers.

Genetic polymorphism and variability of chemical carcinogenesis

Risk assessment in chemical carcinogenesis involves ratios of several factors. Individual responses of an organism to carcinogenic agents depend on polymorphism of enzymes responsible for metabolic activation/detoxification of carcinogens, DNA repair, and apoptosis, as well as promotion and progression in malignantly transformed cells. The effects of a particular polymorphic variant are manifested only in the case of its high penetrance. An integral effect is formed by the ratio of procarcinogenic and anticarcinogenic effects. The complexity of risk assessment depends on the gene polymorphism mosaic involved, directly or indirectly, in tumorigenesis and upstream/downstream interactions of gene products.

Association of the polymorphisms of MTHFR C677T, VDR C352T, and MPO G463A with risk for esophageal squamous cell dysplasia and carcinoma

BACKGROUND

From January 2004 to December 2006 a program of endoscopic screening for esophageal lesions was carried out in the high incidence area of esophageal cancer in Feicheng County, China. It provided the samples to evaluate the association of polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T, vitamin D receptor (VDR) C352T, and myeloperoxidase (MPO) G463A genotypes with esophageal squamous cell dysplasia and carcinoma.

METHODS

The subjects in the study were divided into 127 dysplasia cases, 126 squamous cell carcinoma cases, and 169 normal controls. Analyses of the MTHFR C677T, VDR C352T, and MPO G463A genotypes were performed using the PCR-restriction fragment length polymorphism (RFLP) method, whereas the multinomial logistic regression model was used in the data analysis to assess the odds ratios (ORs) related to dysplasia and carcinoma.

RESULTS

Compared with the CC genotype of MTHFR C677T, the TT/TC of the genotype significantly increased the risk of the esophageal squamous cells dysplasia [OR, 2.25; 95% confidence interval (CI), 1.18-4.31]; the OR of esophageal squamous cancer was 1.58 (95% CI, 0.85-2.97) after adjustments for age, sex, and years of education. There was an interaction between the TT/TC genotype and alcohol drinking, smoking, and family history of esophageal cancer in the risk of esophageal dysplasia and carcinoma.

CONCLUSIONS

Neither the VDR C352T nor the MPO G463A genotype had manifested association with the dysplasia and carcinoma of the disease, whereas the MTHFR 677TT genotype may be a genetic risk factor for esophageal dysplasia and carcinoma.