Chromatin immunoprecipitation assay of EVI1 in MCF7 and HCC1937 breast cancer cells untreated and everolimus-adapted
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE50905 | GEO | 2016/12/22
SECONDARY ACCESSION(S): PRJNA219486
REPOSITORIES: GEO
Similar Datasets
Project description:Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.
2016-12-22 | GSE39693 | GEO
Project description:Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.
2016-12-22 | GSE85801 | GEO
Project description:Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.
2016-12-22 | GSE39691 | GEO
Project description:Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.
2016-12-22 | GSE50712 | GEO
Project description:Evi1 is essential for proliferation of hematopoietic stem cells and implicated in the development of myeloid disorders. Particularly, high Evi1 expression defines one of the largest clusters in acute myeloid leukemia and is significantly associated with extremely poor prognosis. Improvement of the therapeutic outcome of leukemia with activated Evi1 is one of the most challenging issues. However, mechanistic basis of Evi1-mediated leukemogenesis has not been fully elucidated. Here we show that Evi1 directly represses PTEN transcription in the murine bone marrow, which leads to activation of AKT/mTOR signaling. In a murine bone marrow transplantation model, Evi1 leukemia showed remarkable sensitivity to an mTOR inihibitor rapamycin. Furthermore, we found that Evi1 binds to several polycomb group proteins and recruits polycomb repressive complexes for PTEN downregulation, which reveals a novel epigenetic mechanism of AKT/mTOR activation in leukemia. Expression analyses and chromatin immunoprecipitation assays using human samples indicate that our findings in mice models are recapitulated in human leukemic cells. Dependence of Evi1-expressing leukemic cells on AKT/mTOR signaling provides the first example of targeted therapeutic modalities that suppress the leukemogenic activity of Evi1. The PTEN/AKT/mTOR signaling pathway and the Evi1-polycomb interaction can be promising therapeutic targets for leukemia with activated Evi1. Gene expression analysis for the purpose of identifying the target genes of Evi1 in primary bone marrow. 5-FU-primed mononuclear bone marrow cells harvested from C57/B6 mice were retrovirally transduced with Evi1-GFP or GFP. GFP positive cells were sorted and analyzed by Affymetrix® Mouse Genome 430 2.0 Array® for gene expression. Four independent experiments were performed.
2010-07-08 | E-GEOD-22434 | biostudies-arrayexpress
Project description:SOX9 is a master transcription factor that regulates development and stem cell programs. However, its potential oncogenic activity and regulatory mechanisms that control SOX9 protein stability are poorly understood. Here we show that SOX9 is a substrate of FBW7, a tumor suppressor and a SCF (Skp1-Cul1-F-box)-type ubiquitin ligase. FBW7 recognizes a conserved degron surrounding threonine 236 (T236) in SOX9 that is phosphorylated by GSK3 kinase. Specifically, FBW7-alpha targets T236-phosphorylated SOX9 for ubiquitylation and proteasomal degradation. Further, we demonstrate that FBW7 inactivation stabilizes SOX9 protein promoting migration, metastasis and treatment resistance in medulloblastoma, one of the most common childhood brain tumors. Notably, expression of mutationally stabilized SOX9-T236/240A in medulloblastoma cells coincides with activation of pro-metastatic genes. FBW7 is frequently downregulated in all medulloblastoma subgroups and mutated specifically in SHH-driven medulloblastoma. In cases where FBW7 mRNA levels are low, SOX9 protein is significantly elevated and this phenotype is associated with metastasis at diagnosis and poor patient outcome. Finally, pharmacological inhibition of PI3K/Akt/mTOR activity destabilizes SOX9 in a GSK3/FBW7-dependent manner, rendering medulloblastoma cells sensitive to cytostatic treatment.
2016-09-13 | GSE84320 | GEO
Project description:Evi1 is essential for proliferation of hematopoietic stem cells and implicated in the development of myeloid disorders. Particularly, high Evi1 expression defines one of the largest clusters in acute myeloid leukemia and is significantly associated with extremely poor prognosis. Improvement of the therapeutic outcome of leukemia with activated Evi1 is one of the most challenging issues. However, mechanistic basis of Evi1-mediated leukemogenesis has not been fully elucidated. Here we show that Evi1 directly represses PTEN transcription in the murine bone marrow, which leads to activation of AKT/mTOR signaling. In a murine bone marrow transplantation model, Evi1 leukemia showed remarkable sensitivity to an mTOR inihibitor rapamycin. Furthermore, we found that Evi1 binds to several polycomb group proteins and recruits polycomb repressive complexes for PTEN downregulation, which reveals a novel epigenetic mechanism of AKT/mTOR activation in leukemia. Expression analyses and chromatin immunoprecipitation assays using human samples indicate that our findings in mice models are recapitulated in human leukemic cells. Dependence of Evi1-expressing leukemic cells on AKT/mTOR signaling provides the first example of targeted therapeutic modalities that suppress the leukemogenic activity of Evi1. The PTEN/AKT/mTOR signaling pathway and the Evi1-polycomb interaction can be promising therapeutic targets for leukemia with activated Evi1.
2010-06-18 | GSE22434 | GEO
Project description:Cancer metastasis is a fetal problem that claims life of over 90% of cancer patients. It is hypothesized that cancer stem cells (CSCs) mediate cancer metastasis and such cells are often resistant to chemotherapy. Studying BRCA1 associated cancers, we found that CSCs form fillopodia and protrusions enriching for active forms of ezrin/radixin/moesin proteins and they have a much higher potential to metastasize than non-CSCs. Microarray analysis indicated that many pathways related to cell adhesion, extracellular matrix and cytoskeleton were differentially regulated in CSCs. Although inhibition of cytoskeleton remodeling by cisplatin treatment retarded CSC motility and cancer metastasis, drug resistant cancers eventually emerge containing markedly increased number of CSCs. This event is at least partially attributed to the activation of PI3K/mTOR signaling, and can be significantly inhibited by the treatment of rapamycin. These results provide strong evidence that cytoskeletal rearrangement and PI3K/mTOR signaling play a distinct role in mediating CSC mobility and viability, and blocking of both pathways in CSCs synergistically inhibits primary and metastatic cancer growth in BRCA1 associated tumors. The sorted subpopulations based upon CD24, CD29 expression were used in the microarray analysis that was performed with 3 independent biologic sample sets.
2012-04-13 | E-GEOD-26621 | biostudies-arrayexpress
Project description:Activation of the mechanistic target of rapamycin (mTOR) pathway is frequently found in cancer, but mTOR inhibitors have thus far failed to demonstrate significant antiproliferative efficacy in the majority of cancer types. Besides cancer cell-intrinsic resistance mechanisms, it is conceivable that mTOR inhibitors impact on non-malignant host cells in a manner that ultimately supports resistance of cancer cells. Against this background, we sought to analyze the functional consequences of mTOR inhibition in hepatocytes for the growth of metastatic colon cancer. To this end, we established liver epithelial cell (LEC)-specific knockout (KO) of mTOR (mTORLEC) mice. We used these mice to characterize the growth of colorectal liver metastases with or without partial hepatectomy to model different clinical settings. Although the LEC-specific loss of mTOR remained without effect on metastasis growth in intact liver, partial liver resection resulted in the formation of larger metastases in mTORLEC mice compared with wildtype controls. This was accompanied by significantly enhanced inflammatory activity in LEC-specific mTOR KO livers after partial liver resection. Analysis of NF-ĸB target gene expression and immunohistochemistry of p65 displayed a significant activation of NF-ĸB in mTORLEC mice, suggesting a functional importance of this pathway for the observed inflammatory phenotype. Taken together, we show an unexpected acceleration of liver metastases upon deletion of mTOR in LECs. Our results support the notion that non-malignant host cells can contribute to resistance against mTOR inhibitors and encourage testing whether anti-inflammatory drugs are able to improve the efficacy of mTOR inhibitors for cancer therapy.
2023-01-05 | PXD019998 | Pride
Project description:Abstract:
Accumulating experimental and clinical evidence suggest that the immune response to cancer is not exclusively anti-tumor. Indeed, the pro-tumor roles of the immune system - as suppliers of growth and pro-angiogenic factors or defenses against cytotoxic immune attacks, for example - have been long appreciated, but relatively few theoretical works have considered their effects. Inspired by the recently proposed "immune-mediated" theory of metastasis, we develop a mathematical model for tumor-immune interactions at two anatomically distant sites, which includes both anti- and pro-tumor immune effects, and the experimentally observed tumor-induced phenotypic plasticity of immune cells (tumor "education" of the immune cells). Upon confrontation of our model to experimental data, we use it to evaluate the implications of the immune-mediated theory of metastasis. We find that tumor education of immune cells may explain the relatively poor performance of immunotherapies, and that many metastatic phenomena, including metastatic blow-up, dormancy, and metastasis to sites of injury, can be explained by the immune-mediated theory of metastasis. Our results suggest that further work is warranted to fully elucidate the pro-tumor effects of the immune system in metastatic cancer.
2024-09-02 | BIOMD0000000926 | BioModels