Project description:A variety of mechanotransduction forces are altered in the tumor microenvironment (TME) and these biophysical forces can influence cancer progression. One such force is interstitial fluid flow (IFF) - the movement of fluid through the tissue matrix. IFF was previously shown to induce invasion of cancer cells, but the activated signaling cascades remain poorly understood. Here, it is demonstrated that IFF induces invasion of ERBB2/HER2 expressing breast cancer cells via activation of phosphoinositide-3-kinase (PI3K). In constitutively activate ERBB2 expressing cells that have undergone epithelial-to-mesenchymal transition (EMT), IFF-mediated invasion requires the chemokine receptor CXCR4, a gradient of its ligand CXCL12, and activity of the PI3K catalytic subunits p110a and ?. In wild-type ERBB2 expressing cells, IFF-mediated invasion is chemokine receptor-independent and requires only p110a activation. To test whether cells undergoing EMT alter their signaling response to IFF, TGFb1 was used to induce EMT in wild-type ERBB2-expressing cells resulting in IFF-induced invasion dependent on CXCR4 and p110?. 2 cell lines (NeuN, NeuT), 2 conditions (flow, static), 3 replicates each, 12 samples total
Project description:A variety of mechanotransduction forces are altered in the tumor microenvironment (TME) and these biophysical forces can influence cancer progression. One such force is interstitial fluid flow (IFF) - the movement of fluid through the tissue matrix. IFF was previously shown to induce invasion of cancer cells, but the activated signaling cascades remain poorly understood. Here, it is demonstrated that IFF induces invasion of ERBB2/HER2 expressing breast cancer cells via activation of phosphoinositide-3-kinase (PI3K). In constitutively activate ERBB2 expressing cells that have undergone epithelial-to-mesenchymal transition (EMT), IFF-mediated invasion requires the chemokine receptor CXCR4, a gradient of its ligand CXCL12, and activity of the PI3K catalytic subunits p110a and β. In wild-type ERBB2 expressing cells, IFF-mediated invasion is chemokine receptor-independent and requires only p110a activation. To test whether cells undergoing EMT alter their signaling response to IFF, TGFb1 was used to induce EMT in wild-type ERBB2-expressing cells resulting in IFF-induced invasion dependent on CXCR4 and p110β.
Project description:Osteocytes, positioned within boneâs interstitial space, are subject to fluid flow upon whole bone loading. Such fluid flow is widely theorized to be a mechanical signal transduced by osteocytes, initiating a poorly understood cascade of signaling events mediating bone metabolism. The objective of this study was to utilize high-throughput approaches to examine the time course of flow-induced changes in osteocyte gene transcript and protein levels. Microarray analysis demonstrated fluid flow regulation of genes consistent with known anabolic loading responses, including Ptgs2, NF-κB inhibitors, MAP3 kinases, and Wnt/β-catenin pathway signaling molecules. However, two of the most highly up-regulated gene productsâCxcl1 and Cxcl2, confirmed by qPCRâhave not previously been reported to be responsive to fluid flow. Gene ontology analysis suggested a highly significant inflammatory and immune response, with cellular functions including trafficking, cell-to-cell signaling, and tissue development. Proteomic analysis of the same samples demonstrated greatest up-regulation of the ATP-producing enzyme NDK, calcium-binding Calcyclin, and G protein-coupled receptor kinase 6. An integrative pathway analysis merging fold changes in transcript and protein levels predicted signaling nodes not directly detected at the sampled time points, including STAT3 and c-Myc. These results extend our knowledge of the osteocytic response to fluid flow, most notably up-regulation of Cxcl1 and Cxcl2 as a possible paracrine agent for osteoblastic and osteoclastic recruitment. Osteocyte-like MLO-Y4 cells were subjected to 2 hours of 10 dyn/cm2 oscillating fluid flow in parallel-plate fluid flow chambers and harvested for analysis at 0, 2, 8, and 24 hours post-flow incubation. Parallel control samples from sham treated cells were also collected at each time point.
Project description:Although ERBB2 amplification and overexpression is correlated with poor outcome in breast cancer, the molecular mechanisms underlying the aggressive nature of these tumors has not been fully elucidated. To investigate this further, we have used a transgenic mouse model of ErbB2-driven tumor progression (ErbB2KI model) that recapitulates clinically relevant events, including selective amplification of the core erbB2 amplicon. By comparing the transcriptional profiles of ErbB2KI mammary tumors and human ERBB2-positive breast cancers, we demonstrate that ErbB2KI tumors possess molecular features of the basal subtype of ERBB2-positive human breast cancer, including activation of canonical β-catenin signaling. Inhibition of β-catenin-dependent signaling in ErbB2KI-derived tumor cells using RNA interference impaired tumor initiation and metastasis. Furthermore, treatment of ErbB2KI or human ERBB2-overexpressing tumor cells with a selective β-catenin/CBP inhibitor significantly decreased proliferation and ErbB2 expression. Collectively, our data indicate that ERBB2-mediated breast cancer progression requires β-catenin signaling and can be therapeutically targeted by selective β-catenin/CBP inhibitors.
Project description:Although ERBB2 amplification and overexpression is correlated with poor outcome in breast cancer, the molecular mechanisms underlying the aggressive nature of these tumors has not been fully elucidated. To investigate this further, we have used a transgenic mouse model of ErbB2-driven tumor progression (ErbB2KI model) that recapitulates clinically relevant events, including selective amplification of the core erbB2 amplicon. By comparing the transcriptional profiles of ErbB2KI mammary tumors and human ERBB2-positive breast cancers, we demonstrate that ErbB2KI tumors possess molecular features of the basal subtype of ERBB2-positive human breast cancer, including activation of canonical β-catenin signaling. Inhibition of β-catenin-dependent signaling in ErbB2KI-derived tumor cells using RNA interference impaired tumor initiation and metastasis. Furthermore, treatment of ErbB2KI or human ERBB2-overexpressing tumor cells with a selective β-catenin/CBP inhibitor significantly decreased proliferation and ErbB2 expression. Collectively, our data indicate that ERBB2-mediated breast cancer progression requires β-catenin signaling and can be therapeutically targeted by selective β-catenin/CBP inhibitors. Common reference design. 9 samples (including 2 normal tissue, 2 NIC tumors, and 5 KI tumor tissue samples) replicated twice as dye swaps, generating a total of 18 arrays.
Project description:Osteocytes, positioned within bone’s interstitial space, are subject to fluid flow upon whole bone loading. Such fluid flow is widely theorized to be a mechanical signal transduced by osteocytes, initiating a poorly understood cascade of signaling events mediating bone metabolism. The objective of this study was to utilize high-throughput approaches to examine the time course of flow-induced changes in osteocyte gene transcript and protein levels. Microarray analysis demonstrated fluid flow regulation of genes consistent with known anabolic loading responses, including Ptgs2, NF-κB inhibitors, MAP3 kinases, and Wnt/β-catenin pathway signaling molecules. However, two of the most highly up-regulated gene products—Cxcl1 and Cxcl2, confirmed by qPCR—have not previously been reported to be responsive to fluid flow. Gene ontology analysis suggested a highly significant inflammatory and immune response, with cellular functions including trafficking, cell-to-cell signaling, and tissue development. Proteomic analysis of the same samples demonstrated greatest up-regulation of the ATP-producing enzyme NDK, calcium-binding Calcyclin, and G protein-coupled receptor kinase 6. An integrative pathway analysis merging fold changes in transcript and protein levels predicted signaling nodes not directly detected at the sampled time points, including STAT3 and c-Myc. These results extend our knowledge of the osteocytic response to fluid flow, most notably up-regulation of Cxcl1 and Cxcl2 as a possible paracrine agent for osteoblastic and osteoclastic recruitment.
Project description:EGFR-inhibition is required for targeted therapies of ERBB2-positive/EGFR high breast cancer. Approximately 30% of human ERBB2-positive breast tumors also express EGFR.
Project description:EGFR-inhibition is required for targeted therapies of ERBB2-positive/EGFR high breast cancer. Approximately 30% of human ERBB2-positive breast tumors also express EGFR.
Project description:EGFR-inhibition is required for targeted therapies of ERBB2-positive/EGFR high breast cancer. Approximately 30% of human ERBB2-positive breast tumors also express EGFR.
Project description:EGFR-inhibition is required for targeted therapies of EGFR high/ERBB2 positive breast cancer. Approximately 30% of human ERBB2 positive breast tumors also express EGFR.