title: RAD51 135G/C polymorphism and breast cancer risk: a meta-analysis from 21 studies.
abstract: Growing evidence suggests that RAD51 plays a pivotal role in the repair of DNA double-strand breaks and the maintenance of genomic stability. A single nucleotide polymorphism, 135G/C, has been identified in the 5' untranslated region of the RAD51 gene and has been shown to influence gene transcription activity. Previous studies yielded conflicting results as to the association of 135G/C polymorphism with breast cancer. We aimed to assess the effect of 135G/C of RAD51 on breast cancer susceptibility with the use of a meta-analysis. We performed a meta-analysis of 21 published case-control studies up to April 2010. We found that the CC genotype was associated with a significantly increased risk of breast cancer when compared with the GG, CG, and CG/GG genotypes. Subgroup analyses showed that individuals carrying the CC genotype were associated with an elevated tumor risk in European populations and in sporadic breast cancer. After stratified analyses according to manuscript quality, the CC genotype was associated with a significantly increased risk of breast cancer compared with the CG genotype in studies of both higher and lower quality. However, significantly elevated risk was found in studies of higher quality, but not in studies of lower quality when homozygote and a recessive comparison model were tested. This meta-analysis indicates that RAD51 135G/C polymorphism may be identified as a susceptibility locus for breast cancer.
authors.affiliation: Laboratory of Molecular Translational Medicine, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China.
authors.forename: Lin-Bo
authors.initials: LB
authors.lastname: Gao
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Pan
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Li
authors.forename: Wei-Bo
authors.initials: WB
authors.lastname: Liang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhu
authors.forename: Lu-Shun
authors.initials: LS
authors.lastname: Zhang
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Wei
authors.forename: Ming
authors.initials: M
authors.lastname: Tang
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
mesh_terms: D020121:5' Untranslated Regions; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D004260:DNA Repair; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008957:Models, Genetic; D009154:Mutation; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D051135:Rad51 Recombinase / Q000235:genetics*; D012306:Risk; D012307:Risk Factors
chemical_list: D020121:5' Untranslated Regions; D005819:Genetic Markers; C495153:RAD51 protein, human; D051135:Rad51 Recombinase