Project description:SNP6 profiling of metaplastic breast carcinoma Metaplastic breast carcinoma (MBC) is a rare and aggressive histologic type of breast cancer, preferentially displaying a triple-negative phenotype (i.e. lacking estrogen receptor, progesterone receptor and HER2 expression). We sought to define the transcriptomic heterogeneity of MBCs on the basis of current gene expression microarray-based classifiers and to determine whether MBCs display gene copy number profiles consistent with those of BRCA1-associated breast cancers.
Project description:SNP6 profiling of papillary carcinoma of the breast Affymetrix SNP6 arrays were performed according ro manufacturer's directions on DNA extracted from 16 papillary carcinomas of the breast.
Project description:Metaplastic breast carcinoma (MpBC) typically consists of carcinoma of no special type (NST) with various metaplastic components. The intracase transcriptomic alterations between metaplastic components and paired NST components, which are critical for understanding the pathogenesis underlying the metaplastic processes, remain unclear. Herein, 59 NST components and paired metaplastic components (spindle sarcomatous [SPS], matrix-producing, rhabdomyoid [RHA], and squamous carcinomatous [SQC] components) were microdissected from specimens obtained from 27 patients with MpBC for gene expression profiling. Hierarchical clustering and principal component analysis revealed a heterogeneous gene expression profile (GEP) corresponding to the NST components, but the GEP of metaplastic components exhibited subtype dependence. Compared with the paired NST components, the SPS components demonstrated the upregulation of genes related to stem cells and epithelial–mesenchymal transition, and displayed enrichment in claudin-low and macrophage signatures. Despite certain overlap in the enriched functions and signatures between the RHA and SPS components, the specific differentially expressed genes differed. We observed the RHA-specific upregulation of genes associated with vascular endothelial growth factor signaling. The chondroid matrix-producing components demonstrated the upregulation of hypoxia-related genes and the downregulation of the immune-related MHC2 signature and the TIGIT gene. In the SQC components, TGF-β and genes associated with cell adhesion were upregulated. The differentially expressed genes among metaplastic components in the 22 MpBC cases with one or predominantly one metaplastic component clustered paired NST samples into clusters with correlation with their associated metaplastic types. These genes could be used to separate the 31 metaplastic components according to respective metaplastic types with an accuracy of 74.2%, suggesting that intrinsic signatures of NST may determine paired metaplastic type. The EMT activity and stem cell traits in the NST components were correlated with specimens displaying lymph node metastasis. In summary, we presented the distinct transcriptomic alterations underlying metaplasia into specific metaplastic components in MpBCs.
Project description:Genome wide DNA methylation profiling of phyllodes tumour, fibroadenoma and metaplastic breast cancer samples. The Illumina Infinium Methylation EPIC v1.0 BeadChip Array was used to obtain DNA methylation profiles across approximately 866,000 CpGs from primary tumours. Samples included a range of grades of phyllodes tumours (n=29), fibroadenoma (n=2), and metaplastic breast cancer (n=2).
Project description:Metaplastic breast carcinoma (MBC) is the most aggressive form of triple-negative cancer (TNBC), defined by the presence of “metaplastic” components of spindle, squamous, or sarcomatoid histology. The protein profiles underpinning the pathological subtypes and metastatic behavior of MBC are unknown. Using multiplex quantitative tandem mass tag-based proteomics we quantified 5,798 proteins in MBC, TNBC, and normal breast from 27 patients. MBC showed increased epithelial-to-mesenchymal transition and extracellular matrix, and reduced metabolic pathways compared to TNBC. MBC subtypes exhibited distinct upregulated profiles; translation and ribosomal events in spindle, inflammation and apical junctions in squamous, and extracellular matrix in sarcomatoid. Comparison of the proteomes of spindle MBC with MMTV-cre;Ccn6fl/fl spindle MBC tumors revealed a shared spindle-specific signature of 17 upregulated proteins involved in translation (e.g. RPL4,6,18, P3H1, PYCR1) and 19 downregulated proteins with roles in cell metabolism (e.g. ADH1B, ADH1C, LIPE, SOD1, FABP4). These data identify subtype specific MBC protein profiles providing biomarkers and therapeutic targets.