Project description:Triple-negative breast cancer (TNBC) patients with residual disease after neoadjuvant chemotherapy generally have worse outcome; however, some patients with residual tumor after neoadjuvant chemotherapy do not relapse. We hypothesize that there are subgroups of chemoresistant TNBC patients with different prognosis. In this study, 25 chemoresistant samples from 47 neoadjuvant chemotherapy-treated TNBC (The Methodist Hospital) are chosen for study We used gene expression data of TNBC patients with residual disease and different prognosis to molecularly define the clinically relevant subgroups, and developed a 7-gene prognostic signature for chemoresistant TNBCs
Project description:An iTRQA-based quantitative proteome analysis using liquid chromatography–coupled tandem mass spectrometry was performed to acquire proteome-wide expression data on Triple-negative Breast Cancer (TNBC) cells treated with Rocaglamide A for 24 hours.
Project description:<p>Overcoming resistance to chemotherapies remains a major unmet need for cancers such as triple negative breast cancer (TNBC). Therefore, mechanistic studies to provide insight for drug development are urgently needed to overcome TNBC therapy resistance. Recently, an important role of fatty acid β-Oxidation (FAO) in chemoresistance has been shown. But how FAO might mitigate tumor cell apoptosis by chemotherapy is unclear. Here, we show that elevated FAO activates STAT3 by acetylation via elevated acetyl-CoA. Acetylated STAT3 upregulates expression of long-chain acyl-CoA synthetase 4 (ACSL4), resulting in increased phospholipid synthesis. Elevating phospholipids in mitochondrial membranes leads to heightened mitochondrial integrity, which in turn overcomes chemotherapy-induced tumor cell apoptosis. Conversely, in both cultured tumor cells and xenograft tumors, enhanced cancer cell apoptosis by inhibiting ASCL4 or specifically targeting acetylated-STAT3 is associated with a reduction in phospholipids within mitochondrial membranes. This study demonstrates a critical mechanism underlying tumor cell chemoresistance.</p>
Project description:Triple-Negative Breast Cancer (TNBC) is a poorly targetable cancer subtype that exhibits a high metastatic potential. To develop new intervention strategies, it is crucial to understand the mechanisms governing migratory and invasive features of TNBC cells. Previously it was shown that high expression of the non-receptor tyrosine kinase FER is an independent prognostic factor that correlates with poor survival in high grade and basal breast cancer. Here, we show that FER controls proliferation and invasion of TNBC cells through the direct substrates MAPK1 and Dynactin 2 (DCTN2; Dynamitin). Our data demonstrate that FER regulates tumor cell proliferation through phosphorylation of MAPK1 on tyrosine 187, and recycling endosome function and subsequent invasion of breast cancer cells through tyrosine 6 residue (Y6) of DCTN2. We show that DCTN2-Y6 is essential for Dynein complex formation and the development of tubular recycling domains at the early endosome. By controlling this crucial step in endosomal recycling, FER drives and sustains adhesion and invasion of (triple negative) breast cancer cells. Our data provide clinical ramification by demonstrating that high grade and basal breast cancers expressing elevated FER levels are more susceptible to taxane-based chemotherapy interventions. In conclusion, our study links FER to kinase-dependent control of intracellular vesicular transport and tumor progression in breast cancer. Importantly, our results indicate that FER represents a predictive and functional biomarker in high grade basal breast cancers.
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) patients with residual disease after neoadjuvant chemotherapy generally have worse outcome; however, some patients with residual tumor after neoadjuvant chemotherapy do not relapse. We hypothesize that there are subgroups of chemoresistant TNBC patients with different prognosis. In this study, 25 chemoresistant samples from 47 neoadjuvant chemotherapy-treated TNBC (The Methodist Hospital) are chosen for study
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:In this study, we analyzed the differential spatial transcriptome of Triple-Negative Breast Cancer (TNBC) patients who responded in an opposite manner to neoadjuvant chemotherapy (NACT): we compared responders displaying pathological complete response (pCR) with no-responders who showed disease progression during therapy. Diagnostic TruCut biopsies were analyzed using the GeoMx Cancer Transcriptome Atlas (Nanostring).
Project description:DNA repair competency is one determinant of sensitivity to certain chemotherapy drugs, such as cisplatin. Cancer cells with intact DNA repair can avoid the accumulation of genome damage during growth and also can repair platinum-induced DNA damage. We sought genomic signatures indicative of defective DNA repair in cell lines and tumors and correlated these signatures to platinum sensitivity. The number of subchromosomal regions with allelic imbalance extending to the telomere (NtAI) predicted cisplatin sensitivity in vitro and pathologic response to preoperative cisplatin treatment in patients with triple-negative breast cancer (TNBC). In serous ovarian cancer treated with platinum-based chemotherapy, higher levels of NtAI forecast a better initial response. We found an inverse relationship between BRCA1 expression and NtAI in sporadic TNBC and serous ovarian cancers without BRCA1 or BRCA2 mutation. Thus, accumulation of telomeric allelic imbalance is a marker of platinum sensitivity and suggests impaired DNA repair. SNP data from 27 and 40 primary triple negative breast cancer tumor samples from two clinical trials treated with cisplatin and cisplatin + bevacizumab. Labeling, hybridization and data processing was performed by Affymetrix using 70k MIP arrays and 330k MIP arrays. In the cisplatin trial, matched normal samples based on blood from all patients and an additional three samples based on FFPE negative lymph nodes were used as references (30 normal references in total). In the cisplatin+bevacizumab trial, mathed normal samples based on blood from 10 patients were used as references.