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
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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.
KeywordsTLR2 ∆22 Gastric cancer Logistic regression Smoking Interaction analysis
This work was supported by the Indian Council of Medical Research (ICMR), India.
Compliance with ethical standards
The institutional ethical committee of the Regional Medical Research Centre, Dibrugarh, approved this study. All the subjects were explained about the nature of the study. All the subjects, both the cases, and the controls signed a written consent before donating blood for the study.
Conflicts of interest
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