title: Functional polymorphisms of interleukin-18 gene and risk of breast cancer in a Brazilian population.
abstract: Interleukin-18 (IL-18) is a key cytokine responsible for immune response and involved in the process of cancer development. In this case-control study, we tested whether IL-18 promoter polymorphism contributes to breast cancer susceptibility in Brazilian patients. The two groups studied were 154 patients with breast cancer and 118 healthy individuals. The frequency of IL-18 promoter single nucleotide polymorphisms (SNPs) at positions -607 (C/A) (rs1946518) and -137 (G/C) (rs187238) was determined by polymerase chain reaction analyses. The polymorphisms genotyped in this study showed a significant association with breast cancer under different genetic models. Both SNPs showed a positive association. For the IL18-607 polymorphism the best model was the codominant genetic model [CC vs AA, P = 0.004, odds ratio (OR) = 2.782, 95% confidence interval (CI) 1.385-5.589]. For IL18-137 statistical significance was found using the recessive genetic model (P = 0.008, OR = 3.896, 95% CI 1.427-10.639). The association between the haplotypes of the IL18 gene and breast cancer was further confirmed. Our results suggest that IL18-607 and IL18-137 polymorphism contributes to increase the breast cancer risk. To our knowledge, this is the first report regarding Brazilian breast cancer patients and IL18 promoter polymorphisms.
authors.affiliation: Departamento de Biologia, Embriologia e Genética (UFSC - BEG), Universidade Federal de Santa Catarina, Florianópolis, Brazil; Molecular Diagnostic, Biogenetika, Florianópolis, Brazil.
authors.forename: L K d C
authors.initials: LK
authors.lastname: Back
authors.forename: T D J
authors.initials: TD
authors.lastname: Farias
authors.forename: P A
authors.initials: PA
authors.lastname: da Cunha
authors.forename: Y C N
authors.initials: YC
authors.lastname: Muniz
authors.forename: M C M
authors.initials: MC
authors.lastname: Ribeiro
authors.forename: B L
authors.initials: BL
authors.lastname: Fernandes
authors.forename: C K
authors.initials: CK
authors.lastname: Fernandes
authors.forename: I R
authors.initials: IR
authors.lastname: de Souza
mesh_terms: D001938:Brazil; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics*; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors
chemical_list: C000589760:IL18 protein, human; D020382:Interleukin-18
keywords: breast cancer; interleukin-18; polymorphisms