Project description:Human T98G glioblastoma cells were stimulated with platelet-derived growth factor (PDGF) and analyzed by DNA microarrays, which identified 74 immediate-early gene transcripts. Cells were then treated with inhibitors to identify subsets of genes that are targets of the phosphatidylinositol 3-kinase (PI3K) and MEK/ERK signaling pathways. Four groups of PDGF-induced genes were defined: independent of PI3K and MEK/ERK signaling, dependent on PI3K signaling, dependent on MEK/ERK signaling, and dependent on both pathways. Cells were grown in Minimal Essential Medium (Invitrogen) supplemented with fetal calf serum (10%). For growth factor/inhibitor treatments, cells were incubated in serum-free medium for 72 h, and either left unstimulated, or stimulated for 30 min with human PDGF-BB (50 ng/ml) (Sigma). U0126 (Cell Signaling Technology) and LY294002 (BioMol) were added 60 min prior to PDGF addition. Keywords: other
Project description:In vtro and in vivo experiments revealed that Caulis Polygoni Multiflori (CPM) significantly induced megakaryocyte (MK) differentiation and maturation. To investigate the underlying mechanism of action of CPM in promoting MK differentiation, RNA-seq was performed to reveal the gene expression profile in MK differentiation induced by CPM. Our results showed that CPM up-regulated 850 differentially expressed genes (DEGs), down-regulated 1100 DEGs. Disease Ontology (DO) enrichment analysis revealed that CPM could regulate thrombocytopenia, blood platelet disease and blood coagulation disease. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome pathway enrichment analysis suggested that CPM regulated PI3K/Akt and ERK/MEK (MAPK) signaling pathways.
Project description:Objectives: To identify similarities and differences in gene expression data in the MEK/ERK and PI3K pathways and to determine how histone modification affects these same pathways. Goal: To identify and functionally characterize novel targets of these signaling pathways in the context of chondrocyte differentiation. Experiment Overall Design: Cartilage derived from the hind limbs of CD1 mice staged at 15.5 days of embryonic development were dissected and plated in primary chondrocyte monolayer cultures. Cells were treated with MEK/ERK pathway inhibitors (SB202190 and UO126), a PI3K inhibitor (LY294002), a histone deacetylase inhibitor (Trichostatin A) and the vehicle control (DMSO) for two hours. Total RNA was isolated from these samples and hybridized to Affymetrix MOE 430 2.0 chips at the London Regional Genomics facility. Experiment Overall Design: A total of 15 genechips were analyzed between 4 treatments and the vehicle (DMSO) control. Three biological replicates per treatment were executed.
Project description:Objectives: To identify similarities and differences in gene expression data in the MEK/ERK and PI3K pathways and to determine how histone modification affects these same pathways. Goal: To identify and functionally characterize novel targets of these signaling pathways in the context of chondrocyte differentiation. Experiment Overall Design: Cartilage derived from the hind limbs of CD1 mice staged at 15.5 days of embryonic development were dissected and plated in primary chondrocyte monolayer cultures. Cells were treated with MEK/ERK pathway inhibitors (SB202190 and UO126), a PI3K inhibitor (LY294002), a histone deacetylase inhibitor (Trichostatin A) and the vehicle control (DMSO) for 24 hours. Total RNA was isolated from these samples and hybridized to Affymetrix MOE 430 2.0 chips at the London Regional Genomics facility. Experiment Overall Design: A total of 15 genechips were analyzed between 4 treatments and the vehicle (DMSO) control. Three biological replicates per treatment were executed. Experiment Overall Design: Experiment Overall Design:
Project description:Objectives: To identify similarities and differences in gene expression data in the MEK/ERK and PI3K pathways and to determine how histone modification affects these same pathways. Goal: To identify and functionally characterize novel targets of these signaling pathways in the context of chondrocyte differentiation. Keywords: Treatment, signaling, one-colour array, signaling pathway comparison
Project description:Objectives: To identify similarities and differences in gene expression data in the MEK/ERK and PI3K pathways and to determine how histone modification affects these same pathways. Goal: To identify and functionally characterize novel targets of these signaling pathways in the context of chondrocyte differentiation. Keywords: Teatment, signaling, one-colour array, signaling pathway comparison
Project description:We discover drugs with a dual-inhibitory mechanism provides a unique pharmacological strategy against cancer and evidence of cross-activation between the Ras/Raf/MEK/ERK and PI3K/AKT/mTOR pathways via a Ras˧PIK3IP1˧PI3K signaling network Achieving robust cancer-specific lethality is the ultimate clinical goal. Here we identify a compound with dual-inhibitory properties, named a131, that selectively kills cancer cells, while protecting normal cells. Through an unbiased CETSA screen, we identify the PIP4K lipid kinases as the target of a131. Ablation of the PIP4Ks generates a phenocopy of the pharmacological effects of PIP4K inhibition by a131. Notably, PIP4Ks inhibition by a131 causes reversible growth arrest in normal cells by transcriptionally up-regulating PIK3IP1, a suppressor of the PI3K/Akt/mTOR pathway. Strikingly, Ras activation overrides a131-induced PIK3IP1 up-regulation and activates the PI3K/Akt/mTOR pathway. Consequently, Ras-transformed cells override a131-induced growth arrest and enter mitosis where a131’s ability to de-cluster supernumerary centrosomes in cancer cells eliminates Ras-activated cells through mitotic catastrophe. Our discovery of drugs with a dual-inhibitory mechanism provides a unique pharmacological strategy against cancer and evidence of cross-activation between the Ras/Raf/MEK/ERK and PI3K/AKT/mTOR pathways via a Ras˧PIK3IP1˧PI3K signaling network.
Project description:This model is from the article:
PI3K-dependent cross-talk interactions converge with Ras as quantifiable inputs integrated by Erk.
Wang CC, Cirit M, Haugh JM Mol. Syst. Biol.
2009;5:246. 19225459
,
Abstract:
Although it is appreciated that canonical signal-transduction pathways represent dominant modes of regulation embedded in larger interaction networks, relatively little has been done to quantify pathway cross-talk in such networks. Through quantitative measurements that systematically canvas an array of stimulation and molecular perturbation conditions, together with computational modeling and analysis, we have elucidated cross-talk mechanisms in the platelet-derived growth factor (PDGF) receptor signaling network, in which phosphoinositide 3-kinase (PI3K) and Ras/extracellular signal-regulated kinase (Erk) pathways are prominently activated. We show that, while PI3K signaling is insulated from cross-talk, PI3K enhances Erk activation at points both upstream and downstream of Ras. The magnitudes of these effects depend strongly on the stimulation conditions, subject to saturation effects in the respective pathways and negative feedback loops. Motivated by those dynamics, a kinetic model of the network was formulated and used to precisely quantify the relative contributions of PI3K-dependent and -independent modes of Ras/Erk activation.
This model is parameterized with the median of the estimated parameters given in the supplementary material of the original publication's (doi: 10.1038/msb.2009.4
) supplement
on pages 8 and 9.
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To cite BioModels Database, please use: Li C, Donizelli M, Rodriguez N, Dharuri H, Endler L, Chelliah V, Li L, He E, Henry A, Stefan MI, Snoep JL, Hucka M, Le Novère N, Laibe C (2010) BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. BMC Syst Biol., 4:92.
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
Project description:We found that 5-Aza-dC/decitabine induces various prosurvival pathways (JAK-STAT-, NFkB-, MEK/ERK- and PI3K/AKTpathway) in cHL cell lines. Inhibition of these pathways with specific small molecular weight inhibitors potentiates the antitumor effect of 5-Aza-dC.