Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA282079 | ENA |
REPOSITORIES: ENA
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Project description:Small molecule inhibition of ERK dimerization prevents tumorigenesis by Ras-ERK pathway oncogenes
2019-05-14 | E-GEOD-68230 | ExpressionAtlas
Project description:About 50% of human malignancies exhibit unregulated signalling through the Ras-ERK1/2 (ERK) pathway, as a consequence of activating mutations in members of Ras and Raf families. However, the quest for alternative Ras-ERK pathway-directed therapies is desirable. Upon phosphorylation ERK dimerize. We had previously demonstrated that dimerization is essential for ERK extranuclear but not nuclear signaling. Furthermore, by molecular biology approaches, we showed that specifically inhibiting ERK extranuclear component, by impeding ERK dimerization, is sufficient for curtailing tumor progression. Here, we have identified a small molecule inhibitor for ERK dimerization in vitro and in vivo that, without affecting ERK phosphorylation, prevents tumorigenesis driven by Ras-ERK pathway oncogenes, both in cellular and animal models. Importantly, this compound is unaffected by resistance-acquisition processes that hamper “classical” Ras-ERK pathway inhibitors. Thus, ERK dimerization inhibitors provide the proof of principle for two novel concepts in cancer therapy: 1) The blockade of sublocalization-specific sub-signals, rather than total signals, as a means of effectively counteracting oncogenic Ras-ERK signaling. 2) Targeting regulatory protein-protein interactions such as dimerization, rather than catalytic activities, within a signaling route, as an approach for producing effective anti-tumoral agents. Strategies aimed at preventing aberrant flux through this route remain an attractive option for therapeutic intervention in cancer. In this respect, drugs inhibiting the kinase activities of BRaf and MEK have yielded promising results. A375p cells treated with10 μM of either DEL22379, SCH772984 or DMSO as a control for two hours. mRNA from A375p cells was extrated using RNeasy mini kit (Qiagen, Germany) according to the manufacturer's instructions. Cells were previously treated with10 μM of either DEL22379, SCH772984 or DMSO as a control for two hours.
2015-04-24 | E-GEOD-68230 | biostudies-arrayexpress
Project description:About 50% of human malignancies exhibit unregulated signalling through the Ras-ERK1/2 (ERK) pathway, as a consequence of activating mutations in members of Ras and Raf families. However, the quest for alternative Ras-ERK pathway-directed therapies is desirable. Upon phosphorylation ERK dimerize. We had previously demonstrated that dimerization is essential for ERK extranuclear but not nuclear signaling. Furthermore, by molecular biology approaches, we showed that specifically inhibiting ERK extranuclear component, by impeding ERK dimerization, is sufficient for curtailing tumor progression. Here, we have identified a small molecule inhibitor for ERK dimerization in vitro and in vivo that, without affecting ERK phosphorylation, prevents tumorigenesis driven by Ras-ERK pathway oncogenes, both in cellular and animal models. Importantly, this compound is unaffected by resistance-acquisition processes that hamper “classical” Ras-ERK pathway inhibitors. Thus, ERK dimerization inhibitors provide the proof of principle for two novel concepts in cancer therapy: 1) The blockade of sublocalization-specific sub-signals, rather than total signals, as a means of effectively counteracting oncogenic Ras-ERK signaling. 2) Targeting regulatory protein-protein interactions such as dimerization, rather than catalytic activities, within a signaling route, as an approach for producing effective anti-tumoral agents. Strategies aimed at preventing aberrant flux through this route remain an attractive option for therapeutic intervention in cancer. In this respect, drugs inhibiting the kinase activities of BRaf and MEK have yielded promising results.
2015-04-24 | GSE68230 | GEO
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:The RAF family kinases function in the RAS-ERK pathway to transmit signals from activated RAS to the downstream kinases MEK and ERK. This pathway regulates cell proliferation, differentiation, and survival enabling mutations in RAS and RAF to act as potent drivers of human cancers. Drugs targeting the prevalent oncogenic mutant BRAFV600E have shown great efficacy in the clinic but long-term effectiveness is limited by resistance mechanisms that often exploit the dimerization-dependent process by which RAF kinases are activated. Here, we investigated a proteolysis targeting chimera (PROTAC) approach to BRAF inhibition. The most effective PROTAC termed P4B displayed superior specificity and inhibitory properties relative to non-PROTAC controls in BRAFV600E cell lines. In addition, P4B displayed utility in two cell lines harboring alternate BRAF mutations that impart resistance to conventional BRAF inhibitors. This work provides a rationale for optimizing the drug-like properties of P4B to enable proof of concept studies in vivo.
2020-05-25 | GSE148500 | GEO
Project description:Targeting “oncogene addiction” is a promising strategy for anti-cancer therapy. Here, we report a potent inhibition of crucial oncogenes by p53 upon reactivation with small molecule RITA in vitro and in vivo. RITA-activated p53 unleashes transcriptional repression of anti-apoptotic proteins Mcl-1, Bcl-2, MAP4, and survivin, blocks Akt pathway on several levels and downregulates c-Myc, cyclin E and B-catenin. p53 ablates c-Myc expression via several mechanisms at transcriptional and posttranscriptional level. We show that transrepression of oncogenes correlated with higher level of p53 bound to chromatin-bound p53 than transactivation of pro-apoptotic targets. Inhibition of oncogenes by p53 reduces the cell’s ability to buffer pro-apoptotic signals and elicits robust apoptosis. Our study highlights the role of transcriptional repression for p53-mediated tumor suppression. Experiment Overall Design: Breast carcinoma cell-line MCF7 was treated with the small-molecule p53 activator RITA for 2h, 8h, 16h and 24h.
2009-05-15 | E-GEOD-13291 | biostudies-arrayexpress
Project description:RSK2 is a serine/threonine kinase downstream signaling mediator in the RAS/ERK signaling pathway and may be a therapeutic target in mantle cell lymphoma (MCL). RSK2-Ser227 in the N-terminal kinase domain (NTKD) of RSK2 was found to be ubiquitously active in five MCL-derived cell lines and in tumor tissues derived from five MCL patients. BI-D1870, an inhibitor specific to RSK2-NTKD, caused RSK2-Ser227 dephosphorylation, and thereby, induced dose-dependent growth inhibition via G2/M cell cycle blockade and apoptosis. Comparative gene expression profiling of the MCL-derived cell lines showed that inhibition of RSK2-Ser227 by BI-D1870 caused downregulation of oncogenes, such c-MYC and MYB; anti-apoptosis genes, such as BCL2 and BCL2L1; genes for B cell development, including IKZF1, IKZF3 and PAX5; and genes constituting the B cell receptor signaling pathway, such as CD19, CD79B and BLNK. These findings show that targeting of RSK2-Ser227 enables concomitant blockade of pathways that are critically important in B cell tumorigenesis.
2020-03-25 | GSE147484 | 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: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 protein tyrosine phosphatase SHP2 is crucial for oncogenic transformation of acute myeloid leukemia (AML) cells expressing mutated receptor tyrosine kinases (RTKs), as it is required for full RAS-ERK activation to promote cell proliferation and survival programs. SHP2 allosteric inhibitors act by stabilizing SHP2 in its auto-inhibited conformation and they are currently being tested in clinical trials for tumors with over-activation of the RAS/ERK pathway, alone and in various drug combinations. Using in vitro models, we established acquired resistant cell lines to the allosteric SHP2 inhibitor SHP099 from two FLT3-ITD-positive AML cell lines. We performed both label-free and isobaric labeling quantitative mass spectrometry-based phosphoproteomics to reveal that AML cells can restore phosphorylated ERK (pERK) in presence of SHP099, thus developing adaptive resistance. Mechanistically, SHP2 inhibition induces the tyrosine phosphorylation and feedback-activation of the FLT3 receptor, which in turn phosphorylates SHP2 on Tyrosine 62. This phosphorylation stabilizes SHP2 in its open conformation, preventing SHP099 binding, thus resulting in resistance. Combinatorial inhibition of SHP2 and MEK or SHP2 and FLT3 prevents pERK rebound and resistant cell growth. We observed the same mechanism in a FLT3-mutated B-ALL cell line and in the inv(16)/KITD816Y AML mouse model. Finally, we show that allosteric SHP2 inhibition does not impair the clonogenic ability of normal bone marrow progenitors, supporting its future use for clinical applications.
2023-03-10 | PXD030338 | Pride