title: Allelic variants of XRCC1 and XRCC3 repair genes and susceptibility of oral cancer in Brazilian patients.
abstract: BACKGROUND
  The capacity for DNA repair is essential in maintaining cellular functions and homeostasis; however, this capacity can be altered based on DNA sequence variations in DNA repair genes, which may contribute to the onset of cancer. Many single-nucleotide polymorphisms (SNPs) in repair genes have been found to be associated with oral cancer. The aim of this study was to investigate the relationship between the presence of allelic variants Arg194Trp (rs:1799782) and Arg399Gln (rs: 25487) of XRCC1 gene and Thr241Met (rs: 861539) of XRCC3 gene and susceptibility to oral cancer. We also attempted to correlate the frequencies obtained for each of the SNPs to histopathological parameters.
  
  
  METHODS
  A case-control study was conducted with genomic DNA from 150 patients with oral squamous cell carcinomas and 150 controls. SNPs were genotyped by RFLP-PCR.
  
  
  RESULTS
  The presence of the polymorphic variants of the XRCC1 gene within codon 194 (OR 0.82, 95% CI: 0.44-1.51) and codon 399 (OR 0.94, 95% CI: 0.59-1.50) and within the XRCC3 gene (OR 0.72; 95% CI: 0.45-1.16) were not associated with an increased risk of oral cancer. A combinational analysis of SNPs in both genes indicated no association. The presence of the allelic variants of these two genes had no statistically significant effect on tumor differentiation, lymph node invasion or tumor size.
  
  
  CONCLUSIONS
  These results suggest that allelic variants of XRCC1 and XRCC3 are not suitable markers for susceptibility to carcinomas of the oral cavity and are also not related to the later stages of such tumors.
authors: Departamento de Biologia Geral, Universidade Estadual de Londrina, Londrina, PR, Brazil.
authors: Mariana Bisarro
authors: MB
authors: Dos Reis
authors: Roberta
authors: R
authors: Losi-Guembarovski
authors: Enilze Maria
authors: EM
authors: de Souza Fonseca Ribeiro
authors: Iglenir João
authors: IJ
authors: Cavalli
authors: Maria Celeste
authors: MC
authors: Morita
authors: Gyl Henrique Albrecht
authors: GH
authors: Ramos
authors: Benedito Valdecir
authors: BV
authors: de Oliveira
authors: Lauro Toyoshi
authors: LT
authors: Mizuno
authors: Silvia Regina
authors: SR
authors: Rogatto
authors: Ilce Mara
authors: IM
authors: de Syllos Cólus
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001120:Arginine / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D016022:Case-Control Studies; D003062:Codon / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D005973:Glutamine / Q000235:genetics; D006801:Humans; D008207:Lymphatic Metastasis / Q000235:genetics; D008297:Male; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics* / Q000473:pathology; D011110:Polymorphism, Genetic / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012307:Risk Factors; D013912:Threonine / Q000235:genetics; D014364:Tryptophan / Q000235:genetics; D000076105:X-ray Repair Cross Complementing Protein 1; D055815:Young Adult
chemical_list: D003062:Codon; D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C110901:X-ray repair cross complementing protein 3; C000619371:XRCC1 protein, human; D005973:Glutamine; D013912:Threonine; D014364:Tryptophan; D001120:Arginine; D008715:Methionine