title: Association between interleukin-22 genetic polymorphisms and bladder cancer risk.
abstract: OBJECTIVE
  The cytokine interleukin-22 (IL-22), which is produced by T cells and natural killer cells, is associated with tumorigenesis and tumor progression in cancers. However, the role of IL-22 in bladder cancer has not been investigated.
  
  
  METHODS
  A prospective hospital-based case-control study comprising 210 patients with pathologically proven bladder cancer and 210 age- and gender-matched healthy controls was conducted. The genotypes of 3 common polymorphisms (-429 C/T, +1046 T/A and +1995 A/C) of the IL-22 gene were determined with fluorogenic 5' exonuclease assays.
  
  
  RESULTS
  Patients with bladder cancer had a significantly higher frequency of the IL-22 -429 TT genotype [odds ratio (OR)=2.04, 95% confidence interval (CI)=1.19, 3.49; p=0.009] and -429 T allele (OR=1.42, 95% CI=1.08, 1.87; p=0.01) than the healthy controls. These findings were still significant after a Bonferroni correction. When stratifying according to the stage of bladder cancer, we found that patients with superficial bladder cancer had a significantly lower frequency of the IL-22 -429 TT genotype (OR=0.48, 95% CI=0.23, 0.98; p=0.04). When stratifying according to the grade and histological type of bladder cancer, we found no statistical association. The IL-22 +1046 T/A and IL-22 +1995 A/C gene polymorphisms were not associated with the risk of bladder cancer.
  
  
  CONCLUSIONS
  To the authors' knowledge, this is the first report documenting that the IL-22 -429 C/T gene polymorphism is associated with bladder cancer risk. Additional studies are required to confirm this finding.
authors.affiliation: YongChuan Hospital, Department of Urology, Chongqing Medical University, YongChuan, Chongqing, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhao
authors.affiliation: The First Affiliated Hospital of Chongqing, Department of Urology, Medical University, Chongqing, China.
authors.forename: XiaoHou
authors.initials: X
authors.lastname: Wu
authors.affiliation: YongChuan Hospital, Department of Urology, Chongqing Medical University, YongChuan, Chongqing, China.
authors.forename: JiaJi
authors.initials: J
authors.lastname: Liu
mesh_terms: D000368:Aged; D002291:Carcinoma, Papillary / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007378:Interleukins / Q000145:classification / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D012307:Risk Factors; D001749:Urinary Bladder Neoplasms / Q000235:genetics*; D000097043:Interleukin-22
chemical_list: D007378:Interleukins; D000097043:Interleukin-22