Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-29T22:55:50Z No. of bitstreams: 1 StefaniaJeronimoFerreira_TESE.pdf: 1963411 bytes, checksum: 83b197f2ea9b0bdbd5ac4b4732412733 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-02T19:57:46Z (GMT) No. of bitstreams: 1 StefaniaJeronimoFerreira_TESE.pdf: 1963411 bytes, checksum: 83b197f2ea9b0bdbd5ac4b4732412733 (MD5) / Made available in DSpace on 2016-03-02T19:57:46Z (GMT). No. of bitstreams: 1 StefaniaJeronimoFerreira_TESE.pdf: 1963411 bytes, checksum: 83b197f2ea9b0bdbd5ac4b4732412733 (MD5) Previous issue date: 2015-02-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / As vias de reparo por excis?o de base (BER) e por excis?o de nucleot?deo (NER) desempenham um papel crucial na manuten??o da integridade gen?mica. Polimorfismos em genes das vias BER e NER, que modulam a capacidade de reparo do DNA, podem estar relacionados ao risco de desenvolvimento e progn?stico do c?ncer oral. O presente trabalho teve como objetivo investigar a frequ?ncia de polimorfismos de nucleot?deos simples, em dois genes da via de reparo do DNA por excis?o de base (XRCC1 ? rs25487 e APEX1 ? rs1130409) e dois genes da via de reparo por excis?o de nucleot?deo (XPD ? rs13181 e XPF ? rs1799797), em pacientes com carcinoma de c?lulas escamosas oral (CCEO), buscando associa??es com o risco de desenvolver esta neoplasia maligna e o seu progn?stico. Um total de 92 amostras de DNA de pacientes com CCEO e 130 controles foram genotipadas utilizando o m?todo da rea??o em cadeia da polimerase em tempo real. O software estat?stico GraphPad Prism version 6.0.1. foi utilizado para a aplica??o dos testes apropriados. Odds ratio (OR) e hazard ratio (HR), e seus intervalos de confian?a (IC) de 95%, foram calculados pela regress?o log?stica. A avalia??o do progn?stico foi realizada por meio da curva de Kaplan-Meier e an?lise multivariada de Cox. A presen?a das variantes polim?rficas nos genes XRCC1, APEX1, XPD, e XPF n?o foram associadas ao risco de desenvolver CCEO. A intera??o da presen?a da variante polim?rfica com o h?bito de fumar n?o foi significativa para nenhum dos polimorfismos analisados. J? a presen?a do polimorfismo em XPD, somada ao h?bito de beber, aumentou o risco de desenvolver CCEO (OR 1,86, 95% IC: 0,86 ? 4,01, p=0,03). Apenas o SNP do APEX1 (rs1130409) esteve associado a uma diminui??o da sobrevida espec?fica (HR 3,94, 95% IC: 1,31 ? 11,88, p=0,01). O presente estudo sugere uma intera??o entre o consumo de ?lcool e a presen?a do polimorfismo estudado no gene XPD. Al?m disso, indica um pior progn?stico para pacientes que possuem o polimorfismo estudado em APEX1. / Base excision repair (BER) and nucleotide excision repair (NER) pathways play critical role in maintaining genome integrity. Polymorphisms in BER and NER genes which modulate the DNA repair capacity may affect the susceptibility and prognosis of oral cancer. This study was conducted with genomic DNA from 92 patients with oral squamous cell carcinomas (OSCC) and 130 controls. The cases were followed up to explore the associations between BER and NER genes polymorphisms and the risk and prognosis of OSCC. Four single-nucleotide polymorphisms (SNPs) in XRCC1 (rs25487), APEX1 (rs1130409), XPD (rs13181) and XPF (rs1799797) genes were tested by polymerase chain reaction ? quantitative real time method. The GraphPad Prism version 6.0.1 statistical software was applied for statistical analysis of association. Odds ratio (OR), hazard ratio (HR), and their 95 % confidence intervals (CIs) were calculated by logistic regression. Kaplan-Meier curve and Cox proportional hazard model were used for prognostic analysis. The presence of polymorphic variants in XRCC1, APEX1, XPD and XPF genes were not associated with an increased risk of OSCC. Gene-environment interactions with smoking were not significant for any polymorphism. The presence of polymorphic variants of the XPD gene in association with alcohol consumption conferred an increased risk of 1.86 (95% CI: 0.86 ? 4.01, p=0.03) for OSCC. Only APEX1 was associated with decreased specific survival (HR 3.94, 95% CI: 1.31 ? 11.88, p=0.01). These results suggest an interaction between polymorphic variants of the XPF gene and alcohol consumption. Additionally APEX1 may represent a prognostic marker for OSCC.