由剑桥大学研究人员领导的国际研究小组通过全基因关联研究(GWAS)的荟萃分析,发现了15个与乳腺癌风险有明显关联的新位点。
以往的全基因组关联研究和大型验证性研究表明79个位点的变异可解释约14%的家族性乳腺癌风险。为了寻找新的与乳腺癌风险相关的位点,研究人员汇集了15748名欧洲乳腺癌患者及18084名对照的数据。研究者还融入了46785名乳腺癌病例和42892名对照的数据,这些样本曾在iCOGS芯片上进行了基因分型。该研究样本均来自于欧洲妇女。
从千人基因组计划获得信息之后,研究团队比较了1100多万个SNP在乳腺癌病例和对照中的模式。这项分析最终鉴定出15个新位点,之前均未曾与乳腺癌相关联。他们利用ENCODE计划产生的乳腺细胞的染色质免疫共沉淀数据鉴定出了两个区域的可能的目标基因:位于18q12.3的SETBP1、位于1q21.1的RNF115和PDZK1。位于EXO1的一个位点的氨基酸替换突变也可能与乳腺癌风险相关。
Abstract
Genome-wide association studies (GWAS) and large-scale replication studies have identified common variants in 79 loci associated with breastcancer, explaining ∼14% of the familial risk of the disease. To identify new susceptibility loci, we performed a meta-analysis of 11 GWAS, comprising15,748 breast cancer cases and 18,084 controls together with 46,785 cases and 42,892 controls from 41 studies genotyped on a 211,155-marker custom array (iCOGS). Analyses were restricted to women of European ancestry. We generated genotypes for more than 11 million SNPs by imputation using the 1000 Genomes Project reference panel, and we identified 15 new loci associated with breast cancer at P < 5 × 10(-8). Combining association analysis with ChIP-seq chromatin binding data in mammary cell lines and ChIA-PET chromatin interaction data from ENCODE, we identified likely target genes in two regions: SETBP1 at 18q12.3 and RNF115 and PDZK1 at 1q21.1. One association appears to be driven by an amino acid substitution encoded in EXO1.
文献来源:http://www.ncbi.nlm.nih.gov/pubmed/