Project description:Analysis of MDA-MB-231 breast cancer cells depleted for High Mobility Group A1 (HMGA1) using siRNA. HMGA1 is involved in invasion and metastasis in breast cancer cells. Results identify the specific transcriptional program induced by HMGA1 in highly metastatic breast cancer cells.
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:Analysis of MDA-MB-231 breast cancer cells depleted for High Mobility Group A1 (HMGA1) using siRNA. HMGA1 is involved in invasion and metastasis in breast cancer cells. Results identify the specific transcriptional program induced by HMGA1 in highly metastatic breast cancer cells. MDA-MB-231 cells were transfected with HMGA1-specific siRNA or a control siRNA. Transfections were performed by using Lipofectamin RNAiMAX (Invitrogen) according to the manufacturer's procedure. Seventy-two hours after transfection, samples were processed for total RNA extraction and hybridization on Affymetrix microarrays. Four biological replicas (A, B, C, D) were used for each of the two conditions, for a total of 8 samples.
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: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:Epithelial-to-mesenchymal transition (EMT) plays a crucial role in metastasis, which is the leading cause of death in breast cancer patients. We show that Cdc42 GTPase-activating protein (CdGAP) promotes tumor formation and metastasis to lungs in the HER2-positive (HER2+) murine breast cancer model. CdGAP facilitates intravasation, extravasation, and growth at metastatic sites. CdGAP depletion in HER2+ murine primary tumors mediates crosstalk with a Dlc1-RhoA pathway and is associated with a transforming growth factor-β (TGF-β)-induced EMT transcriptional signature. To further delineate the molecular mechanisms underlying the pro-migratory role of CdGAP in breast cancer cells, we searched for CdGAP interactors by performing a proteomic analysis using HEK293 cells overexpressing GFP-CdGAP. We found that CdGAP interacts with the adaptor Talin to modulate focal adhesion dynamics and integrin activation. Moreover, HER2+ breast cancer patients with high CdGAP mRNA expression combined with a high TGF-β-EMT signature are more likely to present lymph node invasion. Our results suggest CdGAP as a candidate therapeutic target for HER2+ metastatic breast cancer by inhibiting TGF-β and Integrin/Talin signaling pathways.