Promising link of HLA-G polymorphism, tobacco consumption and risk of Head and Neck Squamous Cell Carcinoma (HNSCC) in North Indian population.

Human leukocyte antigen (HLA-G) is a potent immune-tolerant molecule and has a critical role in various pathological conditions of cancer. The aim of the study was to analyze the association of HLA-G polymorphism as a risk factor in Head and Neck Squamous Cell Carcinoma (HNSCC). The HLA-G polymorphism at 3'UTR 14bp INDEL (rs371194629) and +3142G/C (rs1063320) were studied in 383 HNSCC patients and 383 ethnically similar-aged healthy controls in North Indian population. The genotyping study of two polymorphisms of HLA-G was documented using DNA-PAGE and RFLP-PCR method. 14bp INDEL Del/Ins, Ins/Ins genotype and Ins allele were more pronounced in HNSCC patients in compared to controls. Whereas, +3142 C/C genotype and C allele were associated with risk factors in HNSCC. Furthermore, the dual effect of polymorphisms; both variants (Del/Ins-Ins/Ins & G/C-C/C) carrying loci was significantly (OR=2.78) associated with the disease compared to one variant (Del/Del-G/C or Del/Del-C/C or Ins/Ins-G/G). Moreover, both polymorphisms showed promising link in terms of tobacco influence on HNSCC risk. It can be concluded that this study first time reports that C/C, Del/Ins and Ins/Ins genotype as well as C and Ins allele could be major risk factors with strong impact of tobacco for HNSCC in North Indian population.