Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA277432 | ENA |
REPOSITORIES: ENA
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Project description:Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations have shown a dramatic response to EGFR inhibitors (EGFR-TKI). EGFR T790M mutation and MET amplification have been recognized as major mechanisms of acquired resistance to EGFR-TKI. Therefore, MET inhibitors have recently been used in NSCLC patients in clinical trials. In this study, we tried to identify the mechanism of acquired resistance to MET inhibitor. We analyzed the antitumor effects of two MET inhibitors, PHA-665752 and crizotinib, in 10 NSCLC cell lines. EBC1 cells with MET amplification were the only cells that were sensitive to both MET inhibitors. We established PHA-665752-resistant EBC1 cells, namely EBC1-R cells. EBC1-R cells showed overexpression of ATP-binding cassette sub-family B member 1 (ABCB1) as well as phosphorylation of MET. EBC1-R cells grew as cell spheres that exhibited cancer stem cell-like (CSC) properties and epithelial mesenchymal transition (EMT). The levels of two miRNAs, miR-374a and miR-138 which targeted ABCB1, were decreased in EBC1-R cells. ABCB1 siRNA and ABCB1 inhibitor elacridar could reduce sphere numbers and suppress EMT. Elacridar could also reverse the resistance to PHA-665752 in EBC1-R cells. Our study demonstrated that ABCB1 overexpression which was associated with CSC properties and EMT was involved in the acquired resistance to MET inhibitor. Inhibition of ABCB1 might be a novel therapeutic strategy for NSCLC patients with acquired resistance to MET inhibitor.
2015-03-07 | GSE66604 | GEO
Project description:Acquired resistance mechanisms to capmatinib, a MET inhibitor in MET-amplified non-small cell lung cancer cells
| PRJNA369611 | ENA
Project description:Targeted therapies have the potential to revolutionize cancer care by providing personalized treatment strategies that are less toxic and more effective but it is clear that for most solid tumors suppression of a single target is not sufficient to prevent development of resistance. A powerful method to identify mechanisms of resistance and targets for combination therapy is to use an in vivo genetic approach. We have developed a novel retroviral gene delivery mouse model of melanoma that permits control of gene expression post-delivery using the tetracycline (tet)-regulated system. In this study we used this melanoma model to select for resistant tumors following genetic inhibition of mutant NRAS. Analysis of tumors that became resistant to NRAS suppression revealed that the most common mechanism of resistance was overexpression of the Met receptor tyrosine kinase (RTK). Importantly, inhibition of Met overcomes NRAS resistance in this context. Analysis of NRAS mutant human melanoma cells revealed that inhibition of MEK is also associated with adaptive RTK signaling. Furthermore, co-inhibition of RTK signaling and MEK overcomes acquired MEK inhibitor resistance in NRAS mutant melanoma. These data suggest that combined inhibition of RTK and MEK signaling is a rational therapeutic strategy in mutant NRAS driven melanoma. Reversible NRAS Q61R expression in the melanocytes of DCT-TVA;Ink4a/Arf lox/lox mice (FVB/n) was achieved by transducing the animals with Tet-off and TRE-NRASQ61R-IRES-Cre avian leukosis viruses. After tumor initiation, the expression of NRAS Q61R was turned off by administrating doxycycline. Despite initial regression, tumors in 40% of mice developed resistance to NRAS Q61R withdraw. Seven resistant tumors and one control tumor where NRAS Q61R expression was not interrupted were subjected to genome-wide gene expression profiling.
2014-10-31 | E-GEOD-51906 | 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. Time series experiment, four cell lines, 2 treatments
2014-05-19 | E-GEOD-54532 | biostudies-arrayexpress
Project description:Targeted therapies have the potential to revolutionize cancer care by providing personalized treatment strategies that are less toxic and more effective but it is clear that for most solid tumors suppression of a single target is not sufficient to prevent development of resistance. A powerful method to identify mechanisms of resistance and targets for combination therapy is to use an in vivo genetic approach. We have developed a novel retroviral gene delivery mouse model of melanoma that permits control of gene expression post-delivery using the tetracycline (tet)-regulated system. In this study we used this melanoma model to select for resistant tumors following genetic inhibition of mutant NRAS. Analysis of tumors that became resistant to NRAS suppression revealed that the most common mechanism of resistance was overexpression of the Met receptor tyrosine kinase (RTK). Importantly, inhibition of Met overcomes NRAS resistance in this context. Analysis of NRAS mutant human melanoma cells revealed that inhibition of MEK is also associated with adaptive RTK signaling. Furthermore, co-inhibition of RTK signaling and MEK overcomes acquired MEK inhibitor resistance in NRAS mutant melanoma. These data suggest that combined inhibition of RTK and MEK signaling is a rational therapeutic strategy in mutant NRAS driven melanoma.
2014-10-31 | GSE51906 | GEO
Project description:Small molecule BET bromodomain inhibitors (BETi) are actively being pursued in clinical trials for the treatment of a variety of cancers, however, the mechanisms of resistance to targeted BET protein inhibitors remain poorly understood. Using a novel mass spectrometry approach that globally measures kinase signaling at the proteomic level, we evaluated the response of the kinome to targeted BET inhibitor treatment in a panel of BRD4-dependent ovarian carcinoma (OC) cell lines. Despite initial inhibitory effects of BETi, OC cells acquired resistance following sustained treatment with the BETi, JQ1. Through application of Multiplexed Inhibitor Beads (MIBs) and mass spectrometry, we demonstrate that BETi resistance is mediated by adaptive kinome reprogramming, where activation of compensatory pro-survival kinase networks overcomes BET protein inhibition. Furthermore, drug combinations blocking these kinases may prevent or delay the development of drug resistance and enhance the efficacy of BET inhibitor therapy. RNAseq was employed to identify changes in kinase RNA expression following short term (48h) or chronic (JQ1R) JQ1 treatment in three different ovarian cancer cell lines.
2016-07-21 | E-GEOD-82329 | biostudies-arrayexpress
Project description:In an effort to understand the mechanisms of acquired resistance to BRAF inhibitors, we isolated clones that acquired resistance to the BRAF inhibitor GSK2118436 derived from the A375 BRAF V600E mutant melanoma cell line. This resistance clones acquired mutations in NRAS and MEK1. One clones, 16R6-4, acquired two mutations in NRAS – Q61K and A146T. Proliferation and western blot analyses demonstrated that these clones were insensitive to single agent GSK2118436 or GSK1120212 (an allosteric MEK inhibitor) but were sensitive to the combination of GSK2118436 and GSK1120212. To further characterize this combination, global transcriptomic analysis was performed in A375 and 16R6-4 after 24 hour treatment with GSK2118436, GSK1120212 or the combination of GSK2118436 and GSK1120212. This data set was published in Molecular Cancer Therapeutics with the title “Combined inhibition of BRAF and MEK, BRAF and PI3K/mTOR, or MEK and PI3K/mTOR overcomes acquired resistance to the BRAF inhibitor GSK2118436, mediated by NRAS or MEK mutations” by Greger, J.G., et.al. A375 and 16R6-4 (an A375 derived GSK2118436 resistance clone) were treated for 24 hours with 0.1 micromolar GSK2118436, 1 micromolar GSK2118436, 0.01 micromolar GSK1120212, 0.1 micromolar GSK2118436 + 0.01 micromolar GSK1120212, or 1 micromolar GSK2118436 + 0.01 micromolar GSK1120212.
2012-02-01 | E-GEOD-35230 | biostudies-arrayexpress
Project description:EGFR mutant non-small cell lung cancer patients disease demonstrates remarkable responses to EGFR targeted therapy, but inevitably they succumb to acquired resistance, which can be complex and difficult to treat. Analyzing acquired resistance through broad molecular testing is crucial to understanding the resistance mechanisms and developing new treatment options. We performed diverse clinical testing on a patient with successive stages of acquired resistance, first to an EGFR inhibitor with MET gene amplification and then subsequently to combination EGFR and MET targeted therapies. A patient-derived cell line obtained at the time of disease progression was used to identify NRAS gene amplification as an additional driver of drug resistance to combination EGFR/MET therapies. Analysis of downstream signaling revealed ERK activation that could only be eliminated by trametinib treatment, while Akt activation could be modulated by various combinations of MET, EGFR and PI3K inhibitors. Combination of an EGFR inhibitor with a MEK inhibitor was identified as a possible treatment option to overcome drug resistance related to NRAS gene amplification.
2021-07-28 | GSE180894 | GEO
Project description:Inhibition of the HSP90 chaperone results in depletion of many signaling proteins that drive tumorigenesis, such as downstream effectors of KRAS, the most commonly mutated human oncogene. As a consequence, several small-molecule HSP90 inhibitors are being evaluated in clinical trials as anticancer agents. To prospectively identify mechanisms through which HSP90-dependent cancer cells evade pharmacologic HSP90 blockade, we generated multiple mutant KRAS-driven cancer cell lines with acquired resistance to the purine-scaffold HSP90 inhibitor PU-H71. All cell lines retained dependence on HSP90 function, as evidenced by sensitivity to short hairpin RNA-mediated suppression of HSP90AA1 or HSP90AB1 (also called HSP90α and HSP90β, respectively), and exhibited two types of genomic alterations that interfere with the effects of PU-H71 on cell viability and proliferation: (i) a Y142N missense mutation in the ATP-binding domain of HSP90α that co-occurred with amplification of the HSP90AA1 locus, (ii) genomic amplification and overexpression of the ABCB1 gene encoding the MDR1 drug efflux pump. In support of a functional role for these alterations, exogenous expression of HSP90α Y142N conferred PU-H71 resistance to HSP90-dependent cells, and pharmacologic MDR1 inhibition with tariquidar or lowering ABCB1 expression restored sensitivity to PU-H71 in ABCB1-amplified cells. Finally, comparison with structurally distinct HSP90 inhibitors currently in clinical development revealed that PU-H71 resistance could be overcome, in part, by ganetespib (also known as STA9090) but not tanespimycin (also known as 17-AAG). Together, these data identify potential mechanisms of acquired resistance to small molecules targeting HSP90 that may warrant proactive screening for additional HSP90 inhibitors or rational combination therapies.
2016-12-31 | GSE85732 | GEO
Project description:Inhibition of the HSP90 chaperone results in depletion of many signaling proteins that drive tumorigenesis, such as downstream effectors of KRAS, the most commonly mutated human oncogene. As a consequence, several small-molecule HSP90 inhibitors are being evaluated in clinical trials as anticancer agents. To prospectively identify mechanisms through which HSP90-dependent cancer cells evade pharmacologic HSP90 blockade, we generated multiple mutant KRAS-driven cancer cell lines with acquired resistance to the purine-scaffold HSP90 inhibitor PU-H71. All cell lines retained dependence on HSP90 function, as evidenced by sensitivity to short hairpin RNA-mediated suppression of HSP90AA1 or HSP90AB1 (also called HSP90α and HSP90β, respectively), and exhibited two types of genomic alterations that interfere with the effects of PU-H71 on cell viability and proliferation: (i) a Y142N missense mutation in the ATP-binding domain of HSP90α that co-occurred with amplification of the HSP90AA1 locus, (ii) genomic amplification and overexpression of the ABCB1 gene encoding the MDR1 drug efflux pump. In support of a functional role for these alterations, exogenous expression of HSP90α Y142N conferred PU-H71 resistance to HSP90-dependent cells, and pharmacologic MDR1 inhibition with tariquidar or lowering ABCB1 expression restored sensitivity to PU-H71 in ABCB1-amplified cells. Finally, comparison with structurally distinct HSP90 inhibitors currently in clinical development revealed that PU-H71 resistance could be overcome, in part, by ganetespib (also known as STA9090) but not tanespimycin (also known as 17-AAG). Together, these data identify potential mechanisms of acquired resistance to small molecules targeting HSP90 that may warrant proactive screening for additional HSP90 inhibitors or rational combination therapies.
2016-12-31 | GSE85733 | GEO