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: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: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: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:We show that triple-negative breast cancer (TNBC) exhibits a hyper-activated MVA-CB program that is strongly linked to nuclear receptor RORγ, compared to estrogen receptor-positive breast cancer. Genetic and pharmacological inhibition of RORγ reduces tumor cholesterol contents and synthesis rate while preserving host cholesterol homeostasis. We demonstrate, for the first time, that RORγ functions as a master activator of the entire MVA-CB program, dominantly over SREBP2, through its own direct binding and facilitating the recruitment of SREBP2. RORγ inhibition disrupts its association with SREBP2 and reduces MVA-CB chromatin acetylation. RORγ antagonists cause sustained TNBC tumor regression in patient-derived and immune-intact models. Their combination with cholesterol-lowering statins elicits superior anti-tumor synergy selectively in TNBC. Together, our studies uncover a previously unsuspected master regulator of MVA-CB and an attractive target for TNBC.