title: GSTM1 and GSTT1 polymorphism and susceptibility to esophageal cancer in high- and low-risk regions of India.
abstract: Glutathione transferases, a super family of dimeric phase II metabolic enzymes play a vital role in biotransformation of many substances. This study evaluates the influence of genetic polymorphism of GSTM1 and GSTT1 gene loci on esophageal cancer risk in Assam and Delhi from India. DNA from blood samples of esophageal cancer cases (203,112) and controls (286,150) from Assam and Delhi, respectively, were extracted. GSTM1 and GSTT1 polymorphisms were analyzed by multiplex PCR procedure. Differences in proportions were tested using Pearson's chi-square test with odds ratio (OR) and 95 % confidence interval (CI). Risk of esophageal cancer was approximately twice in individuals having homozygous GSTM1 (OR-2.1, 95 % CI, 1.44-3.13) and GSTT1 null genotypes (OR-1.7,95 % CI, 0.99-2.77) in Assam, and around three times in GSTT1 null genotype (OR-2.9, 95 % CI, 1.56-5.27) in Delhi population. GSTM1 null genotype seems to play a protective role (OR-0.7, 95 % CI, 0.39-1.27) in Delhi. A significant association of GSTM1 null genotype with esophageal cancer was observed in a younger age group in Assam (OR-2.7, 95 % CI, 1.48-5.01), and in Delhi population association was observed in smokers with GSTT1 null genotype (OR-2.5, 95 % CI, 1.04-6.07), and alcoholics having GSTM1 null genotype (OR-2.6, 95 % CI, 0.99-6.77). Significant association of GSTM1 null genotype in Assam was observed between cancer cases and controls in fermented betel nut chewers only (OR-2.8, 95 % CI, 1.19-6.72), whereas, smoking and alcohol failed to show any correlation with GSTM1/GSTT1 genotypes. Cancer development is not only due to exogenous or endogenous carcinogens but depends on their interaction with genes that are involved in the detoxification of these carcinogens.
authors.affiliation: Division of Molecular Diagnostics, Institute of Cytology and Preventive Oncology (ICMR), I-7, Sector 39, Noida, 201301, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Sharma
authors.forename: Bhudev Chander
authors.initials: BC
authors.lastname: Das
authors.forename: Ashok
authors.initials: A
authors.lastname: Sehgal
authors.forename: Ravi
authors.initials: R
authors.lastname: Mehrotra
authors.forename: Premashish
authors.initials: P
authors.lastname: Kar
authors.forename: Sarita
authors.initials: S
authors.lastname: Sardana
authors.forename: Rup
authors.initials: R
authors.lastname: Phukan
authors.forename: Jagdish
authors.initials: J
authors.lastname: Mahanta
authors.forename: Joydeep
authors.initials: J
authors.lastname: Purkayastha
authors.forename: Sunita
authors.initials: S
authors.lastname: Saxena
authors.forename: Sujala
authors.initials: S
authors.lastname: Kapur
authors.forename: Indranil
authors.initials: I
authors.lastname: Chatterjee
authors.forename: Joginder Kumar
authors.initials: JK
authors.lastname: Sharma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000009:adverse effects; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000235:genetics*; D016022:Case-Control Studies; D004938:Esophageal Neoplasms / Q000201:enzymology / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014030:Tobacco, Smokeless / Q000009:adverse effects; D055815:Young Adult
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1