Project description:Breast cancer is genetically and clinically heterogeneous. Triple negative cancer (TNBC) is a subtype of breast cancer usually associated with poor outcome and lack of benefit from target therapy. A pathway analysis in a microarray study was performed using TNBC compared with non-triple negative breast cancer (non-TNBC). Overexpression of several Wnt pathway genes, such as frizzled homolog 7 (FZD7), Low density lipoprotein receptor-related protein 6 (LRP6) and transcription factor 7 (TCF7) has been observed in TNBC. Focus was given to the Wnt pathway receptor, FZD7. To validate its function, inhibition of FZD7 using FZD7shRNA was carried out. Notably decreased cell proliferation, suppressed invasiveness and colony formation in triple negative MDA-MB-231 and BT-20 cells were observed. Mechanism study indicated that these effects occurred through silencing the canonical Wnt signaling pathway, as evidenced by loss of nuclear accumulation of ï?¢-catenin and decreased transcriptional activity of TCF7. In vivo study revealed that FZD7shRNA significantly suppressed the tumor formation in xenotransplation mice due to decrease cell proliferation. Our finding suggests that FZD7 involved canonical Wnt signaling pathway is essential for tumorigenesis of TNBC. Thus, FZD7 may be a biomarker and a potential therapeutic target for triple negative breast cancer. 14 pretreatment non-triple negative breast tumors compare with 5 triple negative breast tumor.
Project description:Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer that exhibits extremely high levels of genetic complexity and yet a relatively uniform transcriptional program. We postulate that TNBC might be highly dependent on uninterrupted transcription of a key set of genes within this gene expression program and might therefore be exceptionally sensitive to inhibitors of transcription. Utilizing a novel kinase inhibitor and CRISPR/Cas9-mediated gene editing, we show here that triple-negative but not ER/PR+ breast cancer cells are exceptionally dependent on CDK7, a transcriptional cyclin-dependent kinase. TNBC cells are unique in their dependence on this transcriptional CDK and suffer apoptotic cell death upon CDK7 inhibition. An “Achilles cluster” of TNBC-specific genes are extremely sensitive to CDK7 inhibition and frequently associated with super-enhancers. We conclude that CDK7 mediates transcriptional addiction to a vital cluster of genes in TNBC and CDK7 inhibition may be useful therapy for this challenging cancer. Expression microarrays in H3K27ac in triple-negative breast cancer +/- treatment with covalent CDK7 inhibitor THZ1 treatment
Project description:The goal of the second gene expression analysis (samples 17-83) was to determine the molecular subtypes of human breast cancers of a triple-negative breast cancer (TNBC) biobank.
Project description:To identify novel molecular targets for triple negative breast cancer (TNBC), we have employed whole genome microarray expression profiling. We purified 30 surgically resected breast cancer tissue diagnosed triple negative by means of immunohistochemical staining and 13 normal mammary ductal cells with lasermicrobeam microdissection system (PALM MicroBeam, Carl Zeiss MicroImaging Co., Ltd), performed whole human genome microarray, and compared gene expression levels of TNBC, normal mammary ductal cells, and normal vital organs to develop molecular targets with a minimum risk. Gene expression levels of 30 TNBC, 13 normal mammary ductal cells, and 4 normal vital tissues were evaluated. to clarify the molecular mechanism involved in TNBC, we analyzed gene expression profiles of 30 TNBC as well as 13 normal epithelial ductal cells purified by laser microbeam microdissection, and identified 301 transcripts that were significantly up-regulated and 321 transcripts that were significantly down-regulated in TNBC. In addition, gene-expression profiles analysis of normal human vital organs including heart, lung, liver, and kidney allowed us to identify 90 cancer-specific genes involved in breast carcinogenesis such as NEK2, PBK, DTL, MELK and GPSM2. Among them, we focused on cell cycle regulators, asp (abnormal spindle) homolog, microcephaly associated (Drosophila) (ASPM) and centromere protein K (CENPK) as novel therapeutic targets for TNBC.
Project description:This study identifies progression in breast ductal carcinoma in situ (DCIS) as it progresses towards triple negative invasive breast cancer (TNBC). Bulk DNA arrayCGH was performed on the C3Tag genetically engineered mouse model that forms human breast-like DCIS and TNBC.
Project description:To identify novel molecular targets for triple negative breast cancer (TNBC), we have employed whole genome microarray expression profiling. We purified 30 surgically resected breast cancer tissue diagnosed triple negative by means of immunohistochemical staining and 13 normal mammary ductal cells with lasermicrobeam microdissection system (PALM MicroBeam, Carl Zeiss MicroImaging Co., Ltd), performed whole human genome microarray, and compared gene expression levels of TNBC, normal mammary ductal cells, and normal vital organs to develop molecular targets with a minimum risk.