Project description:Breast cancer (BC) in the Asia Pacific regions is enriched in younger patients and rapidly rising in incidence yet its molecular bases remain poorly characterized. Here we analyze the whole exomes and transcriptomes of 187 primary tumors from a Korean BC cohort (SMC) enriched in pre-menopausal patients and perform systematic comparison with a primarily Caucasian and post-menopausal BC cohort (TCGA). SMC harbors higher proportions of HER2+ and Luminal B subtypes, lower proportion of Luminal A with decreased ESR1 expression compared to TCGA. We also observe increased mutation prevalence affecting BRCA1, BRCA2, and TP53 in SMC with an enrichment of a mutation signature linked to homologous recombination repair deficiency in TNBC. Finally, virtual microdissection and multivariate analyses reveal that Korean BC status is independently associated with increased TIL and decreased TGF-? signaling expression signatures, suggesting that younger Asian BCs harbor more immune-active microenvironment than western BCs.
Project description:We observed higher proportions of HER2+ and Luminal B but lower proportions of ER+ and Luminal A subtypes along with lower estrogen receptor (ER) expression in SMC compared to TCGA. Germline pathogenic mutations affecting BRCA1 or BRCA2 were found in 11% of SMC but only 5% of TCGA. TP53 was also more frequently mutated in SMC (48%) than in TCGA (32%).
Project description:Transcriptomic profiling of human breast tumors. Genomic and expression profiling using 38K BAC array-CGH and Illumina HT-12 beadchips were performed on 53 invasive breast tumors to assess the impact of gene dosage on gene expression patterns and the effect of other mechanisms on transcriptional levels. Array-CGH results was validated by FISH using tumors showing 8p11-p12 DNA amplification and expression profiling was confirmed using qPCR for 11 transcripts. Low-level gain, high-level gain/amplification, heterozygous loss and homozygous deletion (henceforth referred to as gain, amplification, loss and deletion) were defined as log2 ratio thresholds set at +0.2, >= +0.5, -0.2 and <=-1.0, respectively.
Project description:Molecular Profiling of BRCA1-and BRCA2-associated Breast Cancers Identifies FGFR2 as a Gene More Highly Expressed in BRCA2-associated Tumors BRCA1- and BRCA2-associated tumors have many morphologic characteristics in common, but appear to have distinct molecular signatures. BRCA1-associated tumors are predominantly basal-like cancers, whereas BRCA2-associated tumors have a predominant luminal-like phenotype. These two molecular signatures reflect in part the two cell types, basal/myoepithelial and luminal, found in the terminal duct lobular unit of the breast. To elucidate novel genes involved in these two spectra of breast cancer tumorigenesis we performed global gene expression analysis on breast tumors from germline BRCA1 and BRCA2 mutation carriers. Breast tumor RNAs from 7 germline BRCA1 and 6 germline BRCA2 carriers were profiled using UHN human 19K cDNA microarrays. Supervised univariate analyses were conducted to identify genes differentially expressed between BRCA1 and BRCA2-associated tumors. Selected discriminatory genes were validated using real time reverse transcription polymerase chain reaction (RT-PCR) in the tumor RNAs, and/or by immunohistochemistry (IHC) or by in situ hybridization (ISH) on tissue microarrays (TMAs) containing an independent set of 58 BRCA1 and 64 BRCA2-associated tumors. Genes more highly expressed in BRCA1-associated tumors included stathmin/oncoprotein 18, osteopontin, TGFß2 and Jagged 1 in addition to genes previously identified as characteristic of basal-like breast cancers. Genes more highly expressed in BRCA2-associated tumors had functions related to transcription, signal transduction (particularly MAPK signaling), cell proliferation, cell adhesion and extracellular matrix remodeling. BRCA2-associated cancers were characterized by the higher relative expression of amongst others, FGF1 and FGFR2. Tissue microarrays were used to validate the expression of FGFR2 protein by immunohistochemistry and Jagged 1 expression by in situ hybridization. BRCA2-associated cancers expressed higher levels of FGFR2 protein than BRCA1-associated cancers (p=0.004); whereas BRCA1-associated tumors exhibited elevated levels of Jagged1 mRNA compared to BRCA2-associated cancers (p=0.02). FGFR2 and FGF1 were more highly expressed in BRCA2-associated cancers compared with BRCA1-associated breast cancers, suggesting the existence of an autocrine or paracrine stimulatory loop. In addition to corroborating the basal-like signature of BRCA1-associated tumors, we identified osteopontin, stathmin/oncoprotein 18, TGFβ2, and Jagged 1 as being more highly expressed in BRCA1-associated tumors. Keywords: Gene expression profiling, genetic comparison
Project description:We used microarrays to profile 30 human primary breast tumors and determine global gene expression patterns and molecular subtypes Keywords: Basal gene expression in human tumor samples
Project description:As Asians are underrepresented across many omics databases limiting the potential of precision medicine of the global population. It is thus important for multi-omics derived quantitative trait loci (QTLs) to fill the knowledge gap of complex traits in the Asian ancestry. Integrating omics data from genomics and epigenomics (including DNA methylation and RNA-seq from blood), we developed iMOMdb, an open-acesss database to enhance disease prediction models and precision medicine outcomes in Asian pregnant women.