Polimorfismos de nucleotídeo único em genes de metalotioneína e o risco de carcinoma epidermoide oral em uma população brasileira

Abstract

Squamous cell carcinoma is the most common malignancy of the oral cavity. The main risk factors for this disease are chronic consumption of tobacco and alcohol, but the cellular response against carcinogens depends on several factors, including genetic variations. Metallothionein are proteins that have been implicated in a number of functions, including cellular protection against heavy metal toxicity and free radicals, and it is important in cell proliferation and apoptosis. The aim of this study was to investigate the possible influence of single nucleotide polymorphisms (SNP) in genes metallothionein (MT) on the risk of oral squamous cell carcinoma (OSCC). The study case- control hospital-based demonstrated that SNP rs11076161, located in intron region of MT1A, was associated with the risk of OSCC. Carriers of AA genotype of this polymorphism seem more prone to the occurrence of this tumor. It was verified paucity of information about the OSCC occurence in women. Then, further investigation was carried out, to describe on this topic. Peculiarities in the analyzed sample were identified, especially the lowest proportion of brown skinned women and in the sixth decade of life than expected, as well as increased number of women among patients with gums lesions. The survival comparative analysis between men and women showed higher survival rate for women, but this difference was not significant. These features should be better evaluated in future studies to further clarify their biological and clinical importance. Finally, it was also carried out a literature review in search of studies that have investigated the influence of SNP on the risk of salivary gland tumors in order to facilitate further research on the subject. The currently available information on the frequency and relevance of the genetic variants involved in susceptibility to salivary gland tumors is still very restricted, but seen promising because several potential genetic risk factors have been identified. On the other hand, the molecular pathogenesis of salivary gland tumors will be better understood by analyzing the genetic polymorphisms combined with various environmental factors. In addition, the results showed that susceptibility of one population may not be the same in another population, justifying the necessity of studies in the Brazilian population.