title: Association of toll-like receptor 2 ∆22 and risk for gastric cancer considering main effects and interactions with smoking: a matched case-control study from Mizoram, India.
abstract: Toll-like receptors (TLRs) are evolutionary conserved cell surface receptors of the innate immune system. Smoking has significant immunological effects which are mediated via TLRs on various receptor-mediated innate response pathways. Polymorphisms of TLR genes are associated with susceptibility toward various malignancies. The present study was undertaken to examine the association between TLR2 ∆22 and gastric cancer. In this study, we also investigated the interaction between TLR2 ∆22 and smoking. A total of 133 histologically confirmed gastric cancer cases and 266 age-sex-matched controls were selected for this study. TLR2 ∆22 genotypes were determined by allele-specific polymerase chain reaction (PCR). Binary conditional logistic regression analysis was used to find the association of TLR2 ∆22 with risk of gastric cancer. Logistic regression using hierarchically well-formulated models was used for interaction analysis between smoking and TLR2 ∆22. Persons having TLR2 ∆22 heterozygous genotype had two times increased risk of gastric cancer in multivariate logistic regression model. The interaction analysis using hierarchical logistic regression models between smoking and TLR2 ∆22 by calculating separate X (2) for interaction model and only main effect model, the difference of X (2) 57.68-47.70 = 9.98 and degrees of freedom (df) 5-3 = 2, revealed significant (α = 0.05, df = 2) omnibus interaction. Our present study revealed TLR2 ∆22 to be significantly and independently associated with gastric cancer risk in Mizoram, and there is also evidence of significant interaction between smoking and TLR2 ∆22 with risk of gastric cancer.
authors.affiliation: Regional Medical Research Centre, N.E. Region (Indian Council of Medical Research), Post Box #105, Dibrugarh, 786 001, Assam, India.
authors.forename: Debdutta
authors.initials: D
authors.lastname: Mukherjee
authors.affiliation: Regional Medical Research Centre, N.E. Region (Indian Council of Medical Research), Post Box #105, Dibrugarh, 786 001, Assam, India.
authors.forename: Kangjam Rekha
authors.initials: KR
authors.lastname: Devi
authors.affiliation: Department of Biological Sciences, Gauhati University, Guwahati, Assam, India.
authors.forename: Manab
authors.initials: M
authors.lastname: Deka
authors.affiliation: Regional Medical Research Centre, N.E. Region (Indian Council of Medical Research), Post Box #105, Dibrugarh, 786 001, Assam, India.
authors.forename: Mridul
authors.initials: M
authors.lastname: Malakar
authors.affiliation: Indian Council of Medical Research, New Delhi, India.
authors.forename: Tanvir
authors.initials: T
authors.lastname: Kaur
authors.affiliation: Aizawl Endoscopy Centre, Aizawl, Mizoram, India.
authors.forename: Debajit
authors.initials: D
authors.lastname: Barua
authors.affiliation: Regional Medical Research Centre, N.E. Region (Indian Council of Medical Research), Post Box #105, Dibrugarh, 786 001, Assam, India.
authors.forename: Jagadish
authors.initials: J
authors.lastname: Mahanta
authors.affiliation: Regional Medical Research Centre, N.E. Region (Indian Council of Medical Research), Post Box #105, Dibrugarh, 786 001, Assam, India. kanwar_narain@hotmail.com.
authors.forename: Kanwar
authors.initials: K
authors.lastname: Narain
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013274:Stomach Neoplasms / Q000235:genetics*; D051195:Toll-Like Receptor 2 / Q000235:genetics*
chemical_list: C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2
keywords: Gastric cancer; Interaction analysis; Logistic regression; Smoking; TLR2 ∆22