title: Association between the (GT)n polymorphism of the HO-1 gene promoter region and cancer risk: a meta-analysis.
abstract: BACKGROUND
  Several studies have previously focused on associations between the (GT)n repeat polymorphism of the heme oxygenase-1 (HO-1) gene promoter region and risk of cancers, but results are complex. We conducted the present meta-analysis to integrate relevant findings and evaluate the association between HO-1 (GT)n repeat polymorphism and cancer susceptibility.
  
  
  METHODS
  Published literature was retrieved from the PubMed/MEDLINE, EMBASE and ISI Web of Science databases before November 2013. For all alleles and genotypes, odds ratios were pooled to assess the strength of the associations using either fixed-effects or random-effects models according to heterogeneity. Subgroup analysis was conducted according to ethnicity and histopathology.
  
  
  RESULTS
  A total of 10 studies involving 2,367 cases and 2,870 controls were identified. The results showed there was no association between HO-1 (GT)n repeat polymorphism and the cancer risk both at the allelic and genotypic level. However, in the stratified analysis, we observed an increased risk of squamous cell carcinoma in persons carrying the LL genotype and the LL+LS genotype as compared with those carrying the SS genotype. When the LS and SS genotypes were combined, the odds ratio for squamous cell carcinoma in LL-genotype carriers, were also significantly increased. No publication bias was observed.
  
  
  CONCLUSIONS
  The LL genotype and L-allele carrying genotypes (LL+LS) of HO-1 (GT)n repeat polymorphism are potential genetic factors for developing squamous cell carcinoma. More large and well-designed studies are required for further validations.
authors: Department of Epidemiology and Biostatistics, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China E-mail : chenkexin@tijmu.edu.cn.
authors: Ling
authors: L
authors: Zhang
authors: Fang-Fang
authors: FF
authors: Song
authors: Yu-Bei
authors: YB
authors: Huang
authors: Hong
authors: H
authors: Zheng
authors: Feng-Ju
authors: FJ
authors: Song
authors: Ke-Xin
authors: KX
authors: Chen
mesh_terms: D000483:Alleles; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D051547:Heme Oxygenase-1 / Q000235:genetics*; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012306:Risk
chemical_list: C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1