Project description:Emerging evidence suggests that tumor cells metastasize by co-opting stem cell transcriptional networks, although the molecular underpinnings of this process are poorly understood. Here, we show for the first time that the high mobility group A1 (HMGA1) gene drives metastatic progression in triple negative breast cancer cells (MDA-MB-231) by reprogramming cancer cells to a stem-like state. We discovered an HMGA1 signature in triple negative breast cancer cells that is highly enriched in embryonic stem cells. Together, these findings indicate that HMGA1 is a master regulator of tumor progression in breast cancer by reprogramming cancer cells through stem cell transcriptional networks. Future studies are needed to determine how to target HMGA1 in therapy. HMGA1 was knocked-down in MDA-MB-231 cells using siRNA as we previously described (Tesfaye A 2007). RNA from three independent knockdown experiements along with 3 control populations were collected by Rneasy miniprep (Qiagen) and analyzed by Affymetrix Human Exon 1.0 ST platform.
Project description:Emerging evidence suggests that tumor cells metastasize by co-opting stem cell transcriptional networks, although the molecular underpinnings of this process are poorly understood. Here, we show for the first time that the high mobility group A1 (HMGA1) gene drives metastatic progression in triple negative breast cancer cells (MDA-MB-231) by reprogramming cancer cells to a stem-like state. We discovered an HMGA1 signature in triple negative breast cancer cells that is highly enriched in embryonic stem cells. Together, these findings indicate that HMGA1 is a master regulator of tumor progression in breast cancer by reprogramming cancer cells through stem cell transcriptional networks. Future studies are needed to determine how to target HMGA1 in therapy.
Project description:One of the factors involved in TNBC aggressiveness is HMGA1, a member of non-histone chromatin proteins. The High mobility group A1 is an architectural transcription factor which, by altering chromatin structure and interacting with transcription factors, can regulate the transcription of several genes. HMGA1 protein is defined as an oncofetal protein as it is highly expressed during the embryogenesis while its expression decreases or is absent in adults, and it is re-expressed in a variety of tumors, including breast cancer. Several works established that, in breast cancer, HMGA1 expression is correlated with high tumor grade and tumor metastasis, resistance to therapies and poor prognosis. The goal of this project is to find out in details, which are the genes that are modulated by HMGA1 in MDA-MB-231 triple negative breast cancer cell line model.
Project description:HMGA1 is a well-established oncogene and is a master regulator in breast cancer cells controlling the shift from a non-tumorigenic epithelial-like phenotype towards a highly aggressive mesenchymal-like one. In this work we compared HMGA1-silenced versus control MDA-MB-231 by means of a label free shotgun proteomics approach and crossed these data with DNA microarray expression profile obtained on the same cells. Resulting data were then filtered for genes linked to poor prognosis in breast cancer gene expression meta-datasets. This workflow allows us to establish a small molecular signature composed by 21 members with a prognostic value as regards overall-, recurrence free-, and distant metastasis free-survival in breast cancer.
Project description:Cancer development and progression depend on tumor cell intrinsic factors, the tumor microenvironment and host characteristics. Despite the identification of the plasticity of adipocytes, the primary breast stromal cells, both in physiology and cancer, we lack a complete understanding of mechanisms that regulate adipocyte-tumor cell crosstalk. Here we dissected the breast cancer crosstalk with adipocytes and studied relevant molecules. We identified that the ability of breast cancer cells to dedifferentiate adipocytes is intrinsic subtype-dependent, with all breast cancer subtypes, except for HER2+ER+ subtype, capable of inducing this phenomenon. Crosstalk between breast cancer cells and adipocytes in vitro increased cancer stem-like features and recruitment of pro-tumorigenic immune cells, through chemokine production. Serum amyloid A1 (SAA1) was in vitro identified as a regulator of the adipocyte dedifferentiation program in triple-negative breast cancer (TNBC) through CD36 and P2XR7 signaling. In human TNBCs, SAA1 expression was associated with CAA infiltration, inflammation, stimulated lipolysis, stem-like properties and distinct tumor immune microenvironment. Our findings provide evidence that interaction between tumor cells and adipocytes through SAA1 release is relevant to the aggressiveness of TNBC, potentially supporting its targeting.
Project description:Gene expressional analysis with single cell scale by next generation sequencer revealed clonal dissemination in cancer metastasis. To reveal expressional heterogeneity and cell-cell interaction in the primary tumor and the metastasis, we performed transcriptome analysis of micro-tissues dissected from triple negative breast cancer (TNBC) cell line MDA-MB-231 xenograft model by our automated tissue micro-dissection punching technology. This “multiple micro-tissue transcriptome analysis” revealed that there existed three clusters in primary tumor and axillary lymph-node metastasis, two of which were cancer stem cell-like clusters (CD44/MYC-high, HMGA1-high).
Project description:LCM was perfomed on adjacent tumor and stromal cells to identify differentially expressed genes in triple negative breast cancer. To determine differences in tumor and adjacent stromal tissue, laser-capture microdissction was perfomed on 10 triple negative breast cancer specimans to isolate tumor and stromal cells for gene expression analysis. RNA was isolated from captured cells and hybridized to affymetrix gene expression microarrays.
Project description:Arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) combination safely cures fatal acute promyelocytic leukemia, but the mechanisms underlying their action and synergy remain elusive. ATRA inhibits APL, breast and liver cancers by targeting isomerase Pin1, a master regulator of oncogenic signaling. Here we show that ATO targets Pin1 and cooperates with ATRA to exert potent anticancer activity. ATO inhibits and degrades Pin1, and suppresses its oncogenic function by noncovalent binding to Pin1’s active site. ATRA increases cellular ATO uptake through upregulating aquaporin-9. ATO and ATRA, at clinically safe doses, cooperatively ablate Pin1 to block numerous cancer-driving pathways and inhibit the growth of triple-negative breast cancer cells and tumor-initiating cells in cell and animal models including patient-derived orthotopic xenografts, similar to Pin1 CRISPR knockout, which is substantiated by comprehensive protein and microRNA analyses. Thus, synergistic Pin1 inhibition by ATO and ATRA offers an attractive approach to combating breast and other cancers.
Project description:Analysis of lung and liver metastases derived from M-Wnt primary tumor. Results provide insight into genes associated with progression of triple negative breast cancer to metastatic disease.
Project description:Epithelial-mesenchymal transition (EMT) is a reversible transcriptional program subverted by cancer cells to drive cancer progression. Transcription factor ZEB1 is a master regulator of EMT, driving disease recurrence in poor outcome triple negative breast cancer (TNBC). Here, we silence ZEB1 in TNBC models by CRISPR-mediated epigenetic editing, resulting in nearly complete repression of ZEB1 in vivo, accompanied by long-lasting tumor inhibition. Integrated transcriptomic and epigenetic profiling identified a ZEB1-dependent gene-signature associated with transcriptional up-regulation, promoter DNA demethylation and enhanced chromatin accessibility in core cell adhesion loci, demonstrating epigenetic reprogramming towards a more epithelial state. Epigenetic shifts induced by ZEB1-silencing are enriched in a subset of human breast tumors, illuminating a clinically-relevant hybrid-like state. Thus, the synthetic epi-silencing of ZEB1 induces stable “lock-in” epigenetic reprogramming of mesenchymal tumors associated with a distinct epigenetic landscape. We outline approaches to stably reprogram EMT for targeting poor outcome breast cancers driven by oncogenic transcription factors.