Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA237003 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Amplification and activation of the Met receptor tyrosine kinase occurs up to 23% of gastric cancers, suggesting that Met is a therapeutic target in these cancers. However, the steady-state signaling events that occur during chronic Met activation, and mechanisms for resistance to Met small-molecule inhibitors, are poorly understood. Here we show that multiple gastric cancer cell lines harboring MET amplifications are dependent on Met signaling for proliferation and anchorage-independent growth. In these cells, short-term inhibition of Met leads to coordinated changes in gene expression; these include a rapid loss in expression of immediate-early genes, followed by decreased expression of genes involved in cell cycle and proliferation. Activation of Ras-Erk, PI3K-Akt and STAT3 pathways is attenuated by acute Met inhibition. STAT3 inhibition alone, but not individual inhibition of Mek or Akt, is sufficient to abrogate Met-dependent growth of these cells. However, following chronic Met inhibition, reactivation of Mek-dependent Erk phosphorylation occurs even in the presence of Met inhibitor corresponding with a downregulation of Erk negative regulators DUSP4/6. This provides a mechanism for the emergence of drug resistance. Our findings provide insights into innate resistance to a small-molecule Met inhibitor and highlight rational combination therapies that could be evaluated in clinical trials. Time series experiment, four cell lines, 2 treatments
2014-05-19 | E-GEOD-54532 | biostudies-arrayexpress
Project description:Amplification and activation of the Met receptor tyrosine kinase occurs up to 23% of gastric cancers, suggesting that Met is a therapeutic target in these cancers. However, the steady-state signaling events that occur during chronic Met activation, and mechanisms for resistance to Met small-molecule inhibitors, are poorly understood. Here we show that multiple gastric cancer cell lines harboring MET amplifications are dependent on Met signaling for proliferation and anchorage-independent growth. In these cells, short-term inhibition of Met leads to coordinated changes in gene expression; these include a rapid loss in expression of immediate-early genes, followed by decreased expression of genes involved in cell cycle and proliferation. Activation of Ras-Erk, PI3K-Akt and STAT3 pathways is attenuated by acute Met inhibition. STAT3 inhibition alone, but not individual inhibition of Mek or Akt, is sufficient to abrogate Met-dependent growth of these cells. However, following chronic Met inhibition, reactivation of Mek-dependent Erk phosphorylation occurs even in the presence of Met inhibitor corresponding with a downregulation of Erk negative regulators DUSP4/6. This provides a mechanism for the emergence of drug resistance. Our findings provide insights into innate resistance to a small-molecule Met inhibitor and highlight rational combination therapies that could be evaluated in clinical trials.
2014-05-19 | GSE54532 | GEO
Project description:The development of acquired resistance (AR) to tyrosine kinase inhibitors (TKIs) of FGFR1 activation is currently not well understood. To gain a deeper insight into this matter in lung cancer, we used the FGFR1-amplified DMS114 cell line and generated multiple clones with AR to an FGFR1-TKI. We molecularly scrutinized the resistant cells, using whole-exome sequencing, RNA sequencing and global DNA methylation analysis. Our results show a de novo activation of AKT and ERK, and a reactivation of mTOR. Furthermore, the resistant cells exhibited strong upregulation and activation of MET, indicating crosstalk between the FGFR1 and MET axes. The resistant cells also underwent a global decrease in promoter hypermethylation of the CpG islands. Finally, we observed clonal expansion of a pre-existing change in AKT1, leading to S266L substitution, within the kinase domain of AKT. Our results demonstrate that AR to FGFR1-TKI involves deep molecular changes that promote the activation of MET and AKT, coupled with common gene expression and DNA methylation profiles. The expansion of a substitution at AKT was the only shared genetic change, and this may have contributed to the AR.
2018-11-01 | GSE115777 | GEO
Project description:This experiment records the transcriptional responses of mES cells (line OG2) to FGF/ERK stimulation in the presence of LIF, to LIF/STAT3 inhibition in the presence of an FGF/ERK inhibitor, and to combined FGF/ERK stimulation / LIF/STAT3 inhibition.
2010-02-21 | GSE17136 | GEO
Project description:Muscle size is controlled by the PI3K-PKB/Akt-mTORC1-FoxO pathway, which integrates signals from growth factors, energy and amino acids to activate protein synthesis and inhibit protein breakdown. While mTORC1 activity is necessary for PKB/Akt-induced muscle hypertrophy, its constant activation alone induces muscle atrophy. Here we show that this paradox is based on mTORC1 activity promoting protein breakdown through the ubiquitin-proteasome system (UPS) by simultaneously inducing ubiquitin E3 ligase expression via feedback inhibition of PKB/Akt and proteasome biogenesis via Nuclear Factor Erythroid 2-Like 1 (Nrf1). Muscle growth was restored by reactivation of PKB/Akt, but not by Nrf1 knockdown, implicating ubiquitination as the limiting step. However, both PKB/Akt activation and proteasome depletion by Nrf1 knockdown led to an immediate disruption of proteome integrity with rapid accumulation of damaged material. These data highlight the physiological importance of mTORC1-mediated PKB/Akt inhibition and point to juxtaposed roles of the UPS in atrophy and proteome integrity.
2022-10-28 | PXD034117 | Pride
Project description:MET is an oncogene encoding the tyrosine kinase receptor for hepatocyte growth factor (HGF). Upon ligand binding, MET activates multiple signal transducers, including PI3K/AKT (survival/migration), STAT3 (differentiation), and MAPK (proliferation). When mutated or amplified, MET becomes a "driver" for the onset and progression of cancer. The most frequent mutations in the MET gene affect the splicing sites of exon 14, leading to its "skipping" from mRNA and consequent deletion of the receptor's juxtamembrane domain (MET∆14). It is currently believed that, as in gene amplification, MET∆14 kinase is constitutively active. Analysis of MET in carcinoma cell lines showed that MET∆14 strictly depends on HGF for kinase activation. Compared to WT MET, ∆14 is sensitive to lower HGF concentrations, with more sustained kinase response, ultimately leading to a robust phosphorylation of AKT, without affecting MAPK or STAT3. This altered kinase response leads to a distinctive transcriptomic signature. Functional studies revealed that ∆14 activation is predominantly responsible for enhanced protection from apoptosis and cellular migration. Thus, the unique HGF-dependent ∆14 oncogenic activity suggests consideration of HGF in the tumour microenvironment to select patients for clinical trials.
2022-05-27 | GSE194382 | GEO
Project description:KRAS is the most frequently mutated driver of pancreatic, colorectal, and non-small cell lung cancers. Direct KRAS blockade has proven challenging and inhibition of a key downstream effector pathway, the RAF-MEK-ERK cascade, has shown limited success due to activation of feedback networks that keep the pathway in check. We hypothesized that inhibiting SOS1, a KRAS activator and important feedback node, represents an effective approach to treat KRAS-driven cancers. We report the discovery of a highly potent, selective and orally bioavailable small-molecule SOS1 inhibitor, BI-3406, that binds to the catalytic domain of SOS1 thereby preventing the interaction with KRAS. BI-3406 reduces formation of GTP-loaded RAS and limits cellular proliferation of a broad range of KRAS-driven cancers. Importantly, BI-3406 attenuates feedback reactivation induced by MEK inhibitors and thereby enhances sensitivity of KRAS-dependent cancers to MEK inhibition. Combined SOS1 and MEK inhibition represents a novel and effective therapeutic concept to address KRAS-driven tumors.
2020-08-20 | GSE128385 | GEO
Project description:Hematopoietic stem cells (HSC) sustain hematopoiesis throughout life, exiting dormancy to replenish homeostatic or acute cell loss in the peripheral blood. HSC activation is supported by PI3-Kinase/AKT/mTORC1 pathway, which promotes mitochondrial expansion, oxidative phosphorylation, and reactive oxygen species production. Activated HSCs must return to dormancy to prevent exhaustion and bone marrow failure, but the cell-intrinsic mechanisms underlying this transition are unknown. Here we identify an ERK-dependent, rate-limiting feedback mechanism that controls the fitness of the HSC compartment. We show that the MEK/ERK and PI3-Kinase pathways are synchronously deployed in HSC during emergency hematopoiesis, and that feedback phosphorylation of MEK1 by activated ERK is required to constrain AKT/mTORC1 activation. Genetic or chemical ablation of this feedback tilts the balance between HSC dormancy and activation, increasing the output of differentiated cells and accelerating HSC exhaustion. MEK inhibitors developed for cancer therapy may thus be useful to modulate HSC activation.
2018-05-28 | GSE112842 | GEO
Project description:This experiment records the transcriptional responses of EpiSCs (line E3) to FGF/ERK inhibition, GSK3ß inhibition, LIF/STAT3 activation, as well as combined treatment for 12 hours each.
2010-02-21 | GSE17134 | GEO
Project description:This experiment records the transcriptional responses of EpiSCs (line E3) to FGF/ERK inhibition, GSK3ß inhibition, LIF/STAT3 activation, as well as combined treatment for 3 hours each.
2010-02-21 | GSE17133 | GEO