RAGE gene polymorphism and environmental factor in the risk of oral cancer

Oral squamous cell carcinoma is a common neoplasm that is known to be causally associated with genetic factors and environmental carcinogens. The receptor for advanced glycosylation endproducts (RAGE) is a transmembrane protein of the immunoglobulin superfamily with broad specificity for multiple ligands, and it has been shown to play vital roles in several pathophysiologic processes, including diabetes, Alzheimer disease, renal disease, cardiovascular disease, and cancer. The present study aimed to assess the influences of RAGE gene polymorphisms, combined with environmental carcinogens on the predisposition to oral tumorigenesis. Five polymorphisms of the RAGE gene - including 374T>A (rs1800624), 429T>C (rs1800625), 1704G>T (rs184003), Gly82Ser (rs2070600), and a 63-bp deletion allele (407 to 345) - were examined from 592 controls and 618 patients with oral cancer. We found that individuals carrying the polymorphic allele of rs1800625 are more susceptible to oral cancer (odds ratio [OR], 1.899; 95% confidence interval [CI], 1.355 to 2.661; adjusted OR [AOR], 2.053; 95% CI, 1.269 to 3.345) after adjustment for age, sex, betel nut chewing, and tobacco consumption. Moreover, we observed a significant association of rs1800625 variants with late-stage tumors (stage III/IV, OR, 1.736; 95% CI, 1.126 to 2.677; AOR, 1.771; 95% CI, 1.101 to 2.851) and large-size tumors (>2 cm in the greatest dimension; OR, 1.644; 95% CI, 1.083 to 2.493; AOR, 1.728; 95% CI, 1.089 to 2.741). Based on behavioral exposure of environmental carcinogens, the presence of 4 RAGE single-nucleotide polymorphisms (SNPs), combined with betel quid chewing and/or tobacco use, greatly augmented the risk of oral cancer. In addition, carriers of particular haplotypes of the 4 RAGE SNPs examined are more prone to develop oral cancer. These results indicate an involvement of RAGE SNP rs1800625 in the development of oral squamous cell carcinoma and implicate the interaction between RAGE gene polymorphisms and environmental mutagens as a predisposing factor of oral carcinogenesis.