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Genome-wide association studies (GWAS) have identified numerous loci linked to breast cancer susceptibility, but few of these loci have been convincingly linked to causal variants. We identified genes whose mRNA expression is linked to germline variation in normal mammary tissue and breast tumors by performing a genome-wide expression Quantitative Trait Locus (eQTL) analysis in 97 samples of normal mammary tissue and 286 breast adenocarcinomas. In the tumors we found 164 cis-acting loci, which affect expression of nearby genes. Twenty nine of these loci are previously unreported in other eQTL studies, including a cis-acting locus at 5p12 affecting expression of the mitochondrial ribosomal 28S subunit protein MRPS30 in estrogen receptor-positive but not estrogen receptor-negative tumors. This locus has been associated with susceptibility to estrogen receptor-positive breast cancer in several GWAS, with MRPS30 being the suggested candidate gene. One of these studies found that the rs771660 variant was most significantly associated with breast cancer in the 5p12 region, and we found that rs771660 was most strongly associated with MRPS30 gene expression. We provide the first evidence that this breast cancer susceptibility locus affects MRPS30 expression specifically in estrogen receptor-positive tumors and suggest a mechanism for estrogen activation of MRPS30 via proteins in the AP-1 complex. [ABSTRACT FROM AUTHOR]

Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case-control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine studies of Asian ancestry (6,269 cases and 6,624 controls). The BRCA2 c.9104A>C, p.Tyr3035Ser (OR = 2.52; P = 0.04), and BRCA1 c.5096G>A, p.Arg1699Gln (OR = 4.29; P = 0.009) variant were associated with moderately increased risks of breast cancer among Europeans, whereas BRCA2 c.7522G>A, p.Gly2508Ser (OR = 2.68; P = 0.004), and c.8187G>T, p.Lys2729Asn (OR = 1.4; P = 0.004) were associated with moderate and low risks of breast cancer among Asians. Functional characterization of the BRCA2 variants using four quantitative assays showed reduced BRCA2 activity for p.Tyr3035Ser compared with wild-type. Overall, our results show how BRCA2 missense variants that influence protein function can confer clinically relevant, moderately increased risks of breast cancer, with potential implications for risk management guidelines in women with these specific variants. Cancer Res; 77(11); 2789-99. ©2017 AACR ., (©2017 American Association for Cancer Research.)

By affecting immunological presentation, the presence of cytomegalovirus in some glioblastomas may impact progression. In this study, we examined a hypothesized role for natural killer (NK) cells in impacting disease progression in this setting. We characterized 108 glioblastoma patients and 454 healthy controls for HLA-A,-B,-C, NK-cell KIR receptors, and CMV-specific antibodies and correlated these metrics with clinical parameters. Exome sequences from a large validation set of glioblastoma patients and control individuals were examined from in silico databases. We demonstrated that the KIR allele KIR2DS4*00101 was independently prognostic of prolonged survival. KIR2DS4*00101 displayed 100% concordance with cognate HLA-C1 ligands in glioblastoma patients, but not controls. In the context of both HLA-C1/C2 ligands for the KIR2DS4 receptor, patient survival was further extended. Notably, all patients carrying KIR2DS4*00101 alleles were CMV seropositive, but not control individuals, and exhibited increased NK-cell subpopulations, which expressed the cytotoxicity receptors CD16, NKG2D, and CD94/NKG2C. Finally, healthy controls exhibited a reduced risk for developing glioblastoma if they carried two KIR2DS4*00101 alleles, where protection was greatest among Caucasian individuals. Our findings suggest that KIR2DS4*00101 may offer a molecular biomarker to identify intrinsically milder forms of glioblastoma. Cancer Res; 76(18); 5326-36. ©2016 AACR., (©2016 American Association for Cancer Research.)

The 19p13.1 breast cancer susceptibility locus is a modifier of breast cancer risk in BRCA1 mutation carriers and is also associated with the risk of ovarian cancer. Here, we investigated 19p13.1 variation and risk of breast cancer subtypes, defined by estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) status, using 48,869 breast cancer cases and 49,787 controls from the Breast Cancer Association Consortium (BCAC). Variants from 19p13.1 were not associated with breast cancer overall or with ER-positive breast cancer but were significantly associated with ER-negative breast cancer risk [rs8170 OR, 1.10; 95% confidence interval (CI), 1.05-1.15; P = 3.49 × 10(-5)] and triple-negative (ER-, PR-, and HER2-negative) breast cancer (rs8170: OR, 1.22; 95% CI, 1.13-1.31; P = 2.22 × 10(-7)). However, rs8170 was no longer associated with ER-negative breast cancer risk when triple-negative cases were excluded (OR, 0.98; 95% CI, 0.89-1.07; P = 0.62). In addition, a combined analysis of triple-negative cases from BCAC and the Triple Negative Breast Cancer Consortium (TNBCC; N = 3,566) identified a genome-wide significant association between rs8170 and triple-negative breast cancer risk (OR, 1.25; 95% CI, 1.18-1.33; P = 3.31 × 10(-13)]. Thus, 19p13.1 is the first triple-negative-specific breast cancer risk locus and the first locus specific to a histologic subtype defined by ER, PR, and HER2 to be identified. These findings provide convincing evidence that genetic susceptibility to breast cancer varies by tumor subtype and that triple-negative tumors and other subtypes likely arise through distinct etiologic pathways., (©2012 AACR.)

The ability of a motif of the CYP17 5' untranslated region, created by a polymorphic T to C substitution, to bind to the human transcription factor Sp-1 was investigated. No binding of any of the polymorphic alleles was observed in electromobility shift assay. No other sequence within +1 to +100 of each of the CYP17 alleles formed complex with the Sp-1 or enhanced binding to the polymorphic CACC box. Genotyping of 510 breast cancer patients and 201 controls revealed no difference in genotype frequencies. Age at onset, tumor grade, lymph node status and distant metastases, stage, and estrogen and progesterone receptor status were not associated with the CYP17 genotype.