title: Association of a pre-miR-27a polymorphism with cancer risk: an updated meta-analysis.
abstract: MicroRNA-27a is highly expressed in cancers and has been identified as an oncogenic microRNA. A genetic variant in pre-miR-27a (rs895819) with a transition of A to G has been demonstrated to be associated with cancer risk; however, the results of these studies remain conflicting rather than conclusive. Therefore, we performed a meta-analysis to derive a more precise estimation. Through searching PubMed or other databases up to March 2014 using the following MeSH terms and keywords, "miR-27a", "polymorphism" and "cancer", seventeen case-control studies were identified in this meta-analysis, including 7,813 cases and 9,602. Crude odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to investigate the association strength between rs895819 and the susceptibility of cancer. The results of the overall meta-analysis did not suggest any association between rs895819 polymorphism and cancer susceptibility, and this remained in Asians as a sub- group. In Caucasians, however, the rs895819 was associated with a reduced cancer risk in heterozygous (OR, 0.83; 95%CI, 0.75-0.93) and dominant models (OR, 0.84; 95%CI, 0.76-0.93), and the [G] allele of rs895819 showed a protective effect (OR, 0.90, 95%CI, 0.84-0.97). Further studies showed a significant association between the [G] allele of rs895819 and decreased risk of breast cancer (0.91; 95%CI, 0.85-0.98), and stratified analyses indicated a protective effect of the [G] allele in Caucasians (OR, 0.89; 95%CI, 0.82-0.98), younger breast cancer cases (OR, 0.87; 95%CI, 0.79-0.96), and in the group of unilateral breast cancer patients (OR, 0.90; 95%CI, 0.83-0.97). These findings suggest an association between pre-miR-27a polymorphism rs895819 and cancer risk in Caucasians. The protective effect of rs895819 [G] allele in younger breast cancer and in the group of unilateral breast cancer patients await further confirmation since the included studies in this meta-analysis were limited.
authors.affiliation: Institute of Environmental Health, Zhejiang Univerisity School of Medicine, Hangzhou, China E-mail : chenguangdi@gmail.com or llq199@yahoo.com.cn.
authors.forename: Rong-Pan
authors.initials: RP
authors.lastname: Bai
authors.forename: Yu
authors.initials: Y
authors.lastname: Weng
authors.forename: Li-Ling
authors.initials: LL
authors.lastname: Su
authors.forename: Ming-Juan
authors.initials: MJ
authors.lastname: Jin
authors.forename: Zheng-Ping
authors.initials: ZP
authors.lastname: Xu
authors.forename: Li-Qin
authors.initials: LQ
authors.lastname: Lu
authors.forename: Guang-Di
authors.initials: GD
authors.lastname: Chen
mesh_terms: D044466:Asian People / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D044465:White People / Q000235:genetics
chemical_list: C531388:MIRN27 microRNA, human; D035683:MicroRNAs