An outlook on chlorogenic acids-occurrence, chemistry, technology, and biological activities

Phenolics are widespread dietary antioxidants. Among these, chlorogenic acids (CGAs) received considerable attention for their wide distribution and part of human diet with potential biological effects. CGAs (71 compounds), being esters of derivatives of cinnamic acids with quinic acid are widely distributed in plant materials. Coffee is among the highest found in plants, ranging from 4 to 14%. Besides, these are reported in plant foods such as apples, pears, carrot, tomato, sweet potato, Phyllostachys edulis, oilseeds, Prunus domestica L, cherries, and eggplant. The traditional Chinese medicinal plants such as flowers and buds of Lonicera japonica Thunb and the leaves of Eucommia ulmodies contained CGAs as bioactive compound. These play an important role in the formation of roasted coffee flavor and have a marked influence on coffee cup quality. CGAs are considered as main precursors of coffee flavor and pigments. Recent technological advancements in the separation and purification of CGAs such as molecular-imprinted polymer technique; microwave-assisted extraction; pH gradient counter current chromatography has also been described. The consumption of coffee correlated to several health benefits such as reducing the risk of human chronic diseases such as inflammation, diabetes, and cardiovascular disease owing to its antioxidant potential.

Campylobacter pylori associated gastritis in patients with rheumatoid arthritis taking nonsteroidal anti-inflammatory drugs

Fifty-two patients with rheumatoid arthritis taking nonsteroidal anti-inflammatory drugs were studied in order to assess the carriage rate of Campylobacter pylori (C. pylori) with reference to dyspeptic symptoms, endoscopic appearance and antral histology. All patients were interviewed using a standard gastrointestinal symptom scoring questionnaire and underwent endoscopy at which two antral biopsies were obtained. Sections were examined for the presence and severity of gastritis and of C. pylori. Forty-four of 52 patients (85%) had histological evidence of gastritis. Twenty-six of 44 (59%) patients with gastritis were positive for C. pylori. Twenty-six of 28 patients with 'active' (polymorph infiltration) chronic gastritis were positive for C. pylori (p less than 0.002). Sixteen of 26 bacteria-positive patients had gastrointestinal symptoms compared with eight of 26 bacteria-negative patients (p less than 0.05) and this may have therapeutic implications. There was no correlation between the presence of organisms and the appearances at endoscopy.

Role of xenobiotic-metabolizing enzyme gene polymorphisms and interactions with environmental factors in susceptibility to gastric cancer in Kashmir Valley

BACKGROUND

Kashmir Valley has elevated incidence rate of gastric cancer (GC) and several environmental, host genetic factors have been suspected for it. Xenobiotic carcinogen exposure and interindividual differences in its cellular metabolism may modulate susceptibility to GC.

AIM OF THE STUDY

The aim of this study is to investigate the role of genetic variants of xenobiotic-metabolizing genes with susceptibility to GC in Kashmir Valley.

METHODS

A case-control study was performed in 303 subjects (108 GC and 195 healthy controls) to analyze the association of polymorphisms in GSTM1, GSTT1, GSTP1, GSTM3, CYP1A1, and CYP2E1 genes in susceptibility to GC in Kashmir Valley. All subjects were genotyped through polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

GSTM1null and CYP2E1c1c2 genotypes imparted risk for GC (odds ratio [OR] = 1.98, 95% confidence interval [95%CI] = 1.22-3.21, P = 0.006 and OR = 2.56, 95%CI = 1.25-5.25, P = 0.010, respectively). GSTM3AB genotype/B allele was found to be associated with low risk for GC. Smokers and high salted tea consumers themselves were at higher risk for GC (OR = 8.98, 95%CI = 5.16-15.62, P = 0.0001 and OR = 14.78, 95%CI = 8.02-27.23, P = 0.0001, respectively). Cancer risk was further enhanced in smokers with the GSTM1null genotype.

CONCLUSION

The results suggest that GSTM1null, GSTM3AB, and CYP2E1c1c2 genotypes modulate the risk of GC whereas GSTM1null genotypes enhance the risk of GC for smokers in the Kashmir population.

Association of xenobiotic metabolizing enzymes genetic polymorphisms with esophageal cancer in Kashmir Valley and influence of environmental factors

The Kashmir Valley has an elevated incidence rate of esophageal cancer (EC). Several environmental and genetic factors have been suspected for development of EC. A case-control study was performed in 135 EC patients and 195 healthy controls to analyze association of polymorphisms in glutathione S-transferase (GST) mu (GSTM1), GST theta (GSTT1), GST pi (GSTP1), GSTM3, Cytochrome P450 (CYP)1A1, and CYP2E1 genes with susceptibility to EC as well as their interaction with environmental factors such as smoking and high consumption of salted tea in Kashmir valley. All subjects were genotyped through polymerase chain reaction restriction fragment length polymorphism. Data was statistically analyzed using the chi-square test and logistic regression model. Results showed that GSTP1313 val/val and CYP2E1c1c2 genotypes imparted risk for esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma [EADC; odds ratio (OR) = 3.24, 95% confidence interval (CI) = 1.30-8.05; OR = 4.20, 95% CI = 1.65-10.70], respectively. GSTM3AB genotype/B allele was found to be associated with low risk for EC. Tobacco smoking through hukka (water pipe) and consumption of salted tea itself were high risk factors for developing EC (OR = 21.44, 95% CI = 11.63-39.54; OR = 14.86, 95% CI = 8.41-26.24), and the risks were modulated through the interaction of GSTM3AB, GSTP1val/val genotypes. In conclusion, GSTP1val/val and CYP2E1c1c2 genotypes/c2 allele increased the risk of ESCC and EADC, respectively, in the Kashmiri population; whereas GSTM3AB genotype imparted lower risk for both ESCC and EADC.

Role of survivin gene promoter polymorphism (-31G>C) in susceptibility and survival of esophageal cancer in northern India

BACKGROUND AND AIM

Survivin is an upregulated inhibitor of apoptosis protein in esophageal cancer (EC), and a promoter region polymorphism (-31G>C) in the survivin gene has been reported as a modulator of gene expression. We aim to explore the role of survivin -31G>C polymorphism in susceptibility and survival of EC patients in northern Indian population.

MATERIALS AND METHODS

A case-control study was performed in 500 subjects (250 EC patients and 250 controls), and genotyping was done by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method.

RESULTS

Survivin CC genotype was found to be significantly associated with EC susceptibility [odds ratio (OR) = 2.29; 95% confidence interval (CI) = 1.27-4.14; P = 0.006], particularly in males (OR = 4.91; 95% CI = 2.19-11.02; P = 0.0001) having squamous cell carcinoma (SCC) histopathology (OR = 2.4; 95% CI = 1.36-4.21; P = 0.002) at middle third esophagus location (OR = 2.60; 95% CI = 1.40-4.82; P = 0.002). Patients carrying CC genotype were found to have higher susceptibility to lymph node metastasis (OR = 2.82; 95% CI = 1.46-5.48; P = 0.002). However, on survival analysis, no prognostic role of survivin -31G>C polymorphism was detected. In case-only analysis, no gene-environment interaction was observed.

CONCLUSION

Survivin promoter region polymorphism (-31G>C) is associated with susceptibility and clinical characteristics but not prognosis of esophageal cancer in northern Indian population.

Functional polymorphisms of cyclooxygenase-2 (COX-2) gene and risk for esophageal squmaous cell carcinoma

Cyclooxygenase-2 (COX-2) influences carcinogenesis through regulation of angiogenesis, apoptosis and cytokine expression. We aimed to evaluate association of COX-2 polymorphisms with predisposition to esophageal squamous cell carcinoma (ESCC), its phenotype variability and modulation of environmental risk in northern Indian population. We genotyped 174 patients with ESCC and 216 controls for COX-2 gene polymorphisms (-765G>C; -1195G>A; -1290A>G; 3'UTR 8473T>C) using PCR-RFLP. Data were statistically analyzed using chi-square test and logistic regression model. COX-2 -765C allele carriers were at increased risk for ESCC (OR=1.66; 95% CI=1.08-2.54; P=0.004). However, -1195G>A; -1290A>G; 3'UTR 8473T>C polymorphisms of COX-2 gene were not significantly associated with ESCC. We observed significantly enhanced risk for ESCC due to interaction between COX-2 -1195GAx-765GC+CC genotypes (OR=4.60; 95% CI=1.63-13.01; P=0.004). High risk to ESCC was also observed with respect to COX-2 haplotypes, A(-1290)G(-1195)C(-765)T(8473) and A(-1290)A(-1195)C(-765)T(8473) [OR=3.35; 95% CI=0.83-13.44; P=0.089; OR=4.28; 95% CI=0.43-42.40; P=0.246] however, it was not statistically significant. Stratification of subjects based on gender showed that females were at higher risk for ESCC due to COX-2 -765C carrier genotypes (OR=2.97; 95% CI=1.23-7.18; P=0.016). In association of genotypes with clinical characteristics, -765C carrier genotype conferred risk of ESCC in middle third of esophagus (OR=1.78; 95% CI=1.08-2.93; P=0.023). In case-only analysis, interaction of environmental risk factors and COX-2 genotypes did not further modulate the risk for ESCC. In summary, COX-2 -765G>C polymorphism confers ESCC susceptibility particularly in females and patients with middle third anatomical location of the tumor. Interaction of COX-2 -1195GA and -765C carrier genotypes also modulates ESCC risk.

Gastric antral vascular ectasia (watermelon stomach)--therapeutic options

We have encountered five cases of chronic iron deficiency anaemia due to bleeding from gastric antral vascular ectasia (watermelon stomach). Two cases were associated with a lymphoma and in three cases there was evidence of portal hypertension. Two patients were treated conservatively by blood transfusions. The other patients required either surgery or tranexamic acid or endoscopic laser therapy to control the chronic haemorrhage.

Association of interleukin-6 (-174G>C) promoter polymorphism with risk of squamous cell esophageal cancer and tumor location: an exploratory study

Chronic inflammation plays a role in transformation from normal cell to malignant state. Interleukin-6 (IL-6) regulates inflammation and various physiological processes. IL-6 promoter polymorphism (-174G>C) is associated with transcription differences in vitro and in vivo. High expression of IL-6 may result in oxidative DNA damage and enhance risk of carcinogenesis. Therefore, we aimed to evaluate association of IL-6 -174G>C polymorphism with predisposition to esophageal cancer (EC) in 369 subjects (168 patients with EC and 201 controls). We observed significant association of IL-6 -174C non-carrier genotype with risk of EC, (OR=2.29; P=0.001), with squamous cell carcinoma (SCC) histology (OR=2.26; P=0.001) and tumor at upper and lower anatomical locations (OR=5.97; P=0.009 and OR=2.34; P=0.034). Patients having IL-6 -174C non-carrier genotype were at elevated risk of metastasis (OR=2.49; P=0.005). In conclusion, IL-6 -174G>C gene polymorphism may confer high risk for EC and its clinical characteristics.

Helicobacter pylori: bridging the credibility gap

In summary, therefore, there are interesting associations between H pylori, duodenal ulcer, and non-ulcer dyspepsia. In type B gastritis there may be enough evidence to suggest a causal role. The relation between gastritis and upper gastrointestinal symptomatology, however, remains contentious. The relation between H pylori and acid secretion may be more intimate than was previously thought. 'Pylorites' must temper their enthusiasm and provide hard data; 'Schwartzians' must broaden their horizons.

Evaluation of common genetic variants in pre-microRNA in susceptibility and prognosis of esophageal cancer

Genetic variants in micro-RNAs (miRNA) have been shown to affect progression, diagnosis, and prognosis of various malignancies; however, their role in esophageal squamous cell carcinoma (ESCC) susceptibility is controversial. Therefore, we aimed to determine role of common genetic variants in cancer related pre-miRNA in susceptibility and survival outcome of north Indian ESCC patients. We genotyped four common polymorphisms in pre-miRNA: mir-196a-2C>T, mir-146aG>C, mir-499T>C, and mir-423C>A in 289 incident ESCC cases (including 153 follow-up cases) and 309 controls using PCR/PCR RFLP-based methods. Binary logistic regression was applied for risk estimation, while Kaplan-Meier and Cox Regression tests were performed for survival analysis. We observed that none of the pre-miRNA genetic variants were associated with ESCC or its clinical phenotypes independently, however, combined risk genotypes of four pre-miRNA polymorphisms increased risk of ESCC in dose-response manner (Ptrend = 0.011). Specifically, patients with 2-4 risk genotypes of pre-miRNA polymorphisms had 1.4-fold higher risk of ESCC compared to patients with 0-1 risk genotypes (OR = 1.43, 95% CI = 1.02-1.09, P-value = 0.037). The risk was more pronounced in ESCC cases with upper-third esophageal tumors. Moreover, cumulative but not independent effect of risk genotypes of pre-miRNA polymorphisms was observed on survival outcome of ESCC patients. Cases with 2-4 risk genotypes had significantly lower median survival (11.60 vs. 30.2 months) and 2.3-fold greater hazard of death compared to patients with 0-1 risk genotypes. In conclusion, the four studied common pre-miRNA polymorphisms cumulatively affect susceptibility and survival of ESCC patients in north Indian population. © 2012 Wiley Periodicals, Inc.

Influence of apoptosis (BCL2, FAS), cell cycle (CCND1) and growth factor (EGF, EGFR) genetic polymorphisms on survival outcome: an exploratory study in squamous cell esophageal cancer

The study aimed at investigating whether genetic polymorphisms in BCL2, FAS, CCND1, EGF and EGFR genes influence the outcome of patients of esophageal squamous cell cancer treated with radiotherapy, with or without chemotherapy. Sixty nine histologically confirmed, previously untreated, patients with a squamous cell esophageal cancer were inducted into this study. Genotyping of BCL2 (ala43thr), FAS (A-670G), CCND1 (G870A), EGF (+61A/G) and EGFR (G497A) polymorphisms were determined using the polymerase chain reaction followed by restriction fragment length polymorphism methodology. Genotyped data was analyzed using univariate and multivariate logistic regression statistical tests for predicting the survival outcome. Genotypes of BCL2, FAS, CCND1 and EGFR polymorphisms independently did not influence outcome significantly. However, patients with EGF +61AG genotype had median survival of 25.5 months (95% CI = 5.2-45.5), whereas those with EGF +61GG genotype had survival of only 3.7 months (95% CI = 0.0-9.8, p = 0.006). In univariate cox-regression analysis, interaction of genotypes EGF+61GG*radiotherapy tumor dose (< or =50 Gy) and EGF +61GG *upper third tumor location showed high hazard of death, 6.6 (95% CI = 2.0-21.5, p = 0.002) and 26.8 (95% CI = 3.7-194.2, p = 0.001) while EGF+61AG*middle third tumor location had reduced hazard 0.20 (95%CI = 0.06-0.60, p = 0.004). The pilot study suggests that EGF +61AG and +61GG genotypes may predict clinical outcome in esophageal cancer patients treated with radiotherapy with or without chemotherapy. EGF +61AG genotype was associated with improved survival, however +61GG genotype adversely affected the outcome in patients particularly with upper third location of tumor and lower dose (< or =50) of radiotherapy.

Microsomal epoxide hydrolase (EPHX1), slow (exon 3, 113His) and fast (exon 4, 139Arg) alleles confer susceptibility to squamous cell esophageal cancer

Genetic polymorphisms in xenobiotic metabolizing enzymes may alter risk of various cancers. Present case-control study evaluated the influence of EPHX1 genetic variations on squamous cell esophageal cancer (ESCC) susceptibility in 107 patients and 320 controls. EPHX1 polymorphic alleles were genotyped by direct sequencing (exon 3, Tyr113His) or PCR-RFLP (exon 4, His139Arg). Patients with exon 3 genotypes (Tyr113His, His113His) and 113His allele were at risk of ESCC (OR(Tyr113His) 2.0, 95% CI=1.2-3.4, p=0.007; OR(His113His) 2.3 95% CI=1.0-5.2, p=0.03 and OR(His) 1.5, 95% CI=1.0-2.1, p=0.01). In contrast, individuals with exon 4, 139Arg allele were at low risk of cancer (OR 0.34, 95% CI=0.20-0.56, p=0.001). However, none of haplotype combinations of exon 3 (Tyr113His) and exon 4 (His139Arg) polymorphisms showed modulation of risk for ESCC. Sub-grouping of patients based on anatomical location of tumor predicted that patients with exon 3, His113His and Tyr113His genotypes were at higher risk for developing ESCC tumor at upper and middle third locations (OR 4.4, 95% CI=1.0-18.5, p=0.04; OR 2.5, 95% CI=1.3-5.0, p=0.005 respectively). The frequency of exon 4, His139Arg genotype was significantly lower in ESCC patients with lower third tumor location as compared to controls (14.8% vs. 36.3%, p=0.02). In case-only study, gene-environment interaction of EPHX1 genotypes with tobacco, alcohol and occupational exposures did not appear to modulate the cancer susceptibility. In conclusion, exon 3, Tyr113His genotype was associated with higher risk of ESCC particularly at upper and middle-third anatomical locations of tumor. However, His139Arg genotype of exon 4, exhibited low risk for ESCC as well as its clinical characteristics.

Association of NAT2 gene polymorphisms with susceptibility to esophageal and gastric cancers in the Kashmir Valley

BACKGROUND AND AIMS

The high incidence of gastrointestinal cancers in the Kashmir Valley has been attributed to the presence of many chemical carcinogens such as nitrosamines and heterocyclic amines in tobacco and salted tea. Due to functional polymorphisms of the N-acetyltransferase 2 (NAT2) gene, there may be interindividual differences in the metabolism of heterocyclic amines. We undertook this study to determine the influence of NAT2 gene polymorphisms (rs1799929, rs1799930, rs1799931) as well as their interactions with environmental carcinogens on the modulation of risk of esophageal and gastric cancers (EC and GC) in the Kashmir Valley.

METHODS

A case/control study was performed involving 398 study subjects (182 controls, 123 EC and 93 GC). DNA samples were genotyped by PCR-RFLP method.

RESULTS

None of the three NAT2 polymorphic alleles was found to be independently associated with risk of EC/GC but haplotypes C(481)A(590)G(857) and T(481)A(590)G(857) significantly modulated the risk of EC and GC, respectively (OR=0.56; 95% CI=0.34-0.91; p=0.018 and OR=4.61; 95% CI=1.90-11.17; p=0.001). NAT2 slow acetylator genotypes (NAT2 *5, NAT2 *6, NAT2 *7) significantly increased the risk of esophageal squamous cell carcinoma (ESCC, OR=1.73; 95% CI=1.01-2.97; p=0.047). Smoking and salted tea consumption were independent risk factors, but they did not show any interaction with NAT2 slow acetylator genotypes.

CONCLUSIONS

NAT2 slow acetylator genotype may increase susceptibility to ESCC, and NAT2 haplotypes (C(481)A(590)G(857) and T(481)A(590)G(857)) may predict susceptibility to EC and GC in the Kashmir Valley.

Genetic polymorphisms in RNA binding proteins contribute to breast cancer survival

The RNA-binding proteins TTP and HuR control expression of numerous genes associated with breast cancer pathogenesis by regulating mRNA stability. However, the role of genetic variation in TTP (ZFP36) and HuR (ELAVL1) genes is unknown in breast cancer prognosis. A total of 251 breast cancer patients (170 Caucasians and 81 African-Americans) were enrolled and followed up from 2001 to 2011 (or until death). Genotyping was performed for 10 SNPs in ZFP36 and 7 in ELAVL1 genes. On comparing both races with one another, significant differences were found for clinical and genetic variables. The influence of genetic polymorphisms on survival was analyzed by using Cox-regression, Kaplan-Meier analysis and the log-rank test. Univariate (Kaplan-Meier/Cox-regression) and multivariate (Cox-regression) analysis showed that the TTP gene polymorphism ZFP36*2 A > G was significantly associated with poor prognosis of Caucasian patients (HR = 2.03; 95% CI = 1.09-3.76; p = 0.025; log-rank p = 0.022). None of the haplotypes, but presence of more than six risk genotypes in Caucasian patients, was significantly associated with poor prognosis (HR=2.42; 95% CI = 1.17-4.99; p = 0.017; log-rank p = 0.007). The effect of ZFP36*2 A > G on gene expression was evaluated from patients' tissue samples. Both TTP mRNA and protein expression was significantly decreased in ZFP36*2 G allele carriers compared to A allele homozygotes. Conversely, upregulation of the TTP-target gene COX-2 was observed ZFP36*2 G allele carriers. Through its ability to attenuate TTP gene expression, the ZFP36*2 A > G gene polymorphism has appeared as a novel prognostic breast cancer marker in Caucasian patients.

Iron deficiency anaemia in patients with rheumatic disease receiving non-steroidal anti-inflammatory drugs: the role of upper gastrointestinal lesions

Upper gastrointestinal lesions associated with non-steroidal anti-inflammatory drug (NSAID) treatment are commonly implicated as the cause for iron deficiency anaemia in patients with rheumatic diseases. Such patients, however, may also have other causes for iron deficiency, including blood loss from the intestine. One hundred and four patients (mean age 58 years; male 21, female 83; smokers 14) with rheumatic disease (rheumatoid 91, others 13) and absent bone marrow iron stores (mean haemoglobin 83 g/l) were examined. At endoscopy 47 of 104 (45%) had upper gastrointestinal lesions (oesophageal ulcer 4, gastric ulcer 25, gastric erosion 13, duodenal ulcer 4, gastric ulcer and duodenal ulcer 1). Endoscopic healing was assessed in 23 patients with upper gastrointestinal lesions. Eighteen of 23 (78%) lesions healed with treatment. An improvement of anaemia occurred in 10 of 18 (56%) patients with healed lesions. Twenty three of 104 (22%) patients had dyspeptic symptoms. Ten of 23 (43%) patients with dyspepsia had an upper gastrointestinal lesion as compared with 30 of 81 (37%) patients without dyspepsia. A faecal occult blood test result was available in 53 patients. Of these, 13 were positive while 40 were negative. An upper gastrointestinal lesion was present in seven of 13 (54%) patients positive for the faecal occult blood test as compared with 14 of 40 (35%) negative for the test. Thus upper gastrointestinal lesions have previously been overestimated as the cause of iron deficiency anaemia in patients receiving NSAIDs. A positive faecal occult blood test or the presence of dyspepsia is not associated with upper gastrointestinal lesions in such patients.

CASP8 -652 6N del and CASP8 IVS12-19G>A gene polymorphisms and susceptibility/prognosis of ESCC: a case control study in northern Indian population

BACKGROUND

Caspase8 influences carcinogenesis through regulation of apoptosis, hyperproliferation, and metastasis. Role of genetic variations in caspase8 has been explored in various cancers; however, their predictive and prognostic role in esophageal cancer is poorly understood.

METHODS

We investigated the association of two potential caspase8 polymorphisms: CASP8 -652 6N del and CASP8 IVS12-19 G>A polymorphisms with susceptibility and survival of 259 esophageal squamous cell carcinoma (ESCC) cases and 259 cancer-free controls from northern Indian population using PCR/PCR RFLP method.

RESULTS

CASP8 IVS12-19 AA genotype was found to be associated with significant increased risk of ESCC (odds ratio (OR) 3.28, 95% confidence interval (CI) 1.04-10.29) specifically in male subjects (OR 3.71, 95% CI 1.01-13.35) with lower third tumor anatomical location (OR 6.00, 95% CI 1.60-22.55). Kaplan-Meier and Cox Regression analysis showed lower median survival (7.13 months vs. 25.21 months) and greater hazard of death (HR 3.40, 95% CI 1.38-7.90) with CASP8 IVS12-19 AA genotype in ESCC cases compared to IVS12-19 GG genotype. However, no association of CASP8 -652 6N del polymorphism with susceptibility and prognosis of ESCC was observed.

CONCLUSION

CASP8 IVS12-19 G>A but not CASP8 -652 6N del polymorphism may modulate risk of ESCC and its survival outcome in northern Indian population.

OGG1 Ser326Cys polymorphism and susceptibility to esophageal cancer in low and high at-risk populations of northern India

BACKGROUND

Esophageal cancer has diverse incidence worldwide, and genetic/environmental risk factors are supposed to be responsible for it. OGG1 Ser326Cys gene polymorphism (rs1052133) has been found to be associated with different cancer susceptibilities and interaction with different environmental factors.

AIM OF THE STUDY

The aim of this study is to detect the role of OGG1 Ser326Cys polymorphism in susceptibility to esophageal cancer in two Northern Indian populations having different incidence rates.

METHODS

A total of 737 cases and controls from two high and low at-risk populations were selected for the study. All the subjects were genotyped by PCR with confronting two-pair primers.

RESULTS

No significant association was found between OGG1 Ser326Cys genotypes and esophageal cancer risk in both of the populations. Gene-environment analysis revealed no significant interaction between OGG1 Ser326Cys genotypes and smoking/high-salted tea intake habits.

CONCLUSION

OGG1 Ser326Cys polymorphism does not have a role in determining susceptibility to esophageal cancer either in high or in low at-risk populations of Northern India.