Associação do polimorfismo do receptor 5Ht2A com as displasias em lesões bucais potencialmente malignas: um estudo de caso-controle

Abstract

Oral cancer is a multifactorial chronic disease and it is generally accepted that oral cancer development may be preceded by oral potentially malignant lesions (OPML). Studies have reported an increased risk for OPML development, associated with smoking and drinking alcohol, where genetic studies are being carried out in order to uncover the variety of phenotypes related to habits of dependence, which may occur due to genetic polymorphisms. The serotonin or 5-hydroxytryptamine (5-HT) molecule regulates some of the brains functions by inhibiting or stimulating the GABA system; and thus it is able to regulate alcoholism and smoking habits. In this study, we investigated the T102C polymorphism at the 5HT2A receptor in oral dysplasia in OPML and their association with smoking and alcohol habits. This case-control study included patients with OPML histopathologically diagnosed with dysplasia and within this group, patients with and without smoking and alcohol consumption habits. Cell samples from the oral lesions were collected with the patients previously anesthetized using disposable cytological brushes. DNA extraction was performed and the polymorphism was genotyped in real-time PCR allelic discrimination assays. A total of 109 individuals were included in this study (37 with dysplasia and 72 controls). The genotype (p=0.016), allele (p=0.020) and smoking habits (<0.001) distribution differed significantly between dysplasia and control group, where the CT and TT genotype, and the T allele showed a higher frequency in dysplasia (65.6, 18.8 and 84.4%, respectively) than in controls (55.7, 4.9 and 60.7%). In regard to smoking habits the higher frequency was in the dysplasia group. In the multivariate logistic regression analysis associating variables of interest and the presence of dysplasia showed that individuals with smoking habits present 7.58 increase risk to develop dysplasia then non-smokers; and individual carrying the T allele for the T102C polymorphism have a 4.6 increase risk to develop oral dysplasia in OPML. Overall the results in our study indicated a relationship between smoking habits and oral dysplasia in OPML. In addition our study indicated, for the first time, a possible relationship between the T102C polymorphism and oral dysplasia in OPML. Keywords: oral cancer, oral potentially malignant lesions, rs6313, serotonin.