title: Pre-miR-27a rs895819A/G polymorphisms in cancer: a meta-analysis.
abstract: BACKGROUND
  MicroRNAs (miRNAs) negatively regulate the 3' untranslated region (3'-UTR) of coding genes by suppressing translation or degrading mRNAs, and they act as oncogenes or tumor suppressors. Recently, several studies investigated the association between pre-miR-27a rs895819 polymorphism and the risks of various cancers, but the results were inconsistent.
  
  
  RESULTS
  We conducted a meta-analysis of 13 studies that included 6501 cancer cases and 7571 controls to address this association. Overall, this meta-analysis showed that the pre-miR-27a rs895819 A/G polymorphism was not statistically associated with cancers risk in all genetic models. In the stratified analysis by cancer types, when compared with the ancestral A allele, individuals with the variant G allele was consistently associated with reduced risks of breast cancer (OR = 0.92, 95% CI = 0.85-0.99), renal cell cancer (OR = 0.81, 95% CI = 0.67-0.97) and nasopharyngeal cancer (OR = 0.84, 95% CI = 0.72-0.97). Inversely, individuals with the heterozygote AG was associated with an increased risk of digestive tract cancers compared with AA genotype (AG vs. AA: OR = 1.16, 95% CI = 1.01-1.32). In the stratified analysis by ethnicity, the pre-miR-27a rs895819 polymorphism showed statistically significant association with decreased risks of cancers in Caucasians (G vs. A allele: OR = 0.90, 95% CI = 0.83-0.97; AG vs. AA: OR = 0.84, 95% CI = 0.75-0.94; AG/GG vs. AA: OR = 0.85, 95% CI = 0.76-0.94) but not in Asians.
  
  
  CONCLUSIONS
  This meta-analysis suggests that the pre-miR-27a rs895819 polymorphism may contribute to the susceptibilities of some specific-type of cancers, including breast cancer, renal cell cancer, nasopharyngeal cancer and digestive tract cancers, as well as the susceptibilities of cancers in Caucasians to some extent.
authors.affiliation: Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, the Key Laboratory of Cancer Etiology and Prevention in Liaoning Province, Shenyang, Liaoning Province, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.forename: Cai-Yun
authors.initials: CY
authors.lastname: He
authors.forename: Jing-Wei
authors.initials: JW
authors.lastname: Liu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
mesh_terms: D016001:Confidence Intervals; D018740:Genetic Heterogeneity; D020022:Genetic Predisposition to Disease; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D017594:Publication Bias
chemical_list: C531388:MIRN27 microRNA, human; D035683:MicroRNAs