EGAS00001001778-sc-20160427 - samples
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ABSTRACT:
PROVIDER: EGAD00001002066 | EGA |
REPOSITORIES: EGA
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Project description:KRAS mutant CRC is currently in clinical trial with a combination of a MEK and Akt inhibitor. These patients will likely develop resistance to this combination. We aim to identify the mechanisms of resistance via ENU mutagenesis, with a view to identifying additional therapeutics which have the ability to overcome this resistance.
| EGAS00001001778 | EGA
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:Purpose: The clinical use of MEK inhibitors in uveal melanoma is limited by the rapid acquisition of resistance. The current study has used multi-omics approaches and drug screens to identify the pan-HDAC inhibitor panobinostat as an effective strategy to limit MEK inhibitor resistance. Experimental Design: Mass spectrometry-based proteomics and RNA-Seq was used to identify the signaling pathways involved in the escape of uveal melanoma cells from MEK inhibitor therapy. Mechanistic studies were performed to evaluate the escape pathways identified and the efficacy of the MEK-HDAC inhibitor combination was demonstrated in multiple in vivo xenograft models of uveal melanoma. Results: We identified a number of putative escape pathways that were upregulated following MEK inhibition including the PI3K/AKT pathway, ROR1/2 and IGF1R signaling. MEK inhibition was also associated with a widespread increase in GPCR expression, particularly the Endothelin B receptor and that this contributed to therapeutic escape through YAP signaling. A screen of 289 clinical grade compounds identified HDAC inhibitors as potential candidates that suppressed the adaptive YAP and AKT signaling that followed MEK inhibition. In vivo xenograft studies revealed the MEK-HDAC inhibitor combination to outperform either agent alone, leading to a long-term decrease of tumor growth and the suppression of adaptive PI3K/AKT and YAP signaling. Conclusions Together our studies have identified GPCR-mediated YAP activation and RTK-driven AKT signaling as key pathways involved in the escape of uveal melanoma cells from MEK inhibition. We further demonstrate that HDAC inhibition is a promising combination partner for MEK inhibitors in uveal melanoma.
2020-05-26 | PXD013988 | Pride
Project description:Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signaling pathway and attractive targets for cancer therapy. However, PIK3CA mutation, which commonly co-occurs with KRAS mutation, offered resistance to MEK inhibitor through activation of PI3K-AKT signaling. We identified a gene that cooperates with MEK inhibitors to forcefully treat PIK3CA mutant colon cancer cells. -catenin, a key molecule of the WNT pathway, emerged as a candidate by protein/Ab Chip array. MEK inhibitor treatment led to a decrease in -catenin in PIK3CA wild-type colon cancer cells but not in PIK3CA mutant colon cancer cells. Tumor regression was promoted by a combination of MEK inhibitor and NVP-TNS656, which targets the WNT pathway. Furthermore, combined inhibition of MEK and -catenin by NVP-TNS656 promoted tumor regression in colon cancer patient-derived xenograft (PDX) models expressing mutant PIK3CA. Taken together, we propose that inhibition of the WNT pathway, particularly -catenin, may bypass resistance to MEK inhibitor in human PIK3CA mutant colon cancer. Additionally, -catenin is a potential PD marker of MEK inhibitor resistance. In the study, we identified and evaluated biomarker for response to MEK inhibitor on colon cancer cells.
2015-08-13 | E-GEOD-71981 | 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.
2012-02-01 | GSE35230 | GEO
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:Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft-tissue sarcomas which lack effective drugs. Previous studies support the usefulness of MEK inhibitors (MEKis) for treating RAS-driven tumors, however, the lack of preclinical assessment of MEK inhibitors in MPNSTs limit the clinical application as well as the development of combination therapy. In this study, we comprehensively evaluated 8 MEK inhibitors in terms of efficiency, safety and mechanisms of resistance for treating MPNSTs. We identified the most promising MEK inhibitor, trametinib, for the treatment of MPNSTs. Through high-throughput transcriptomic sequencing and drug screening, we discovered the upregulation of integrin signaling contributing to MEK inhibitor resistance, termed as cell adhesion-mediated drug resistance (CAM-DR). We also confirmed MET overactivation in MEKi-resistant MPNST cells. These targets are potential solutions to overcome MEKi- resistance in clinical applications.
2022-07-26 | GSE174100 | GEO
Project description:Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signaling pathway and attractive targets for cancer therapy. However, PIK3CA mutation, which commonly co-occurs with KRAS mutation, offered resistance to MEK inhibitor through activation of PI3K-AKT signaling. We identified a gene that cooperates with MEK inhibitors to forcefully treat PIK3CA mutant colon cancer cells. -catenin, a key molecule of the WNT pathway, emerged as a candidate by protein/Ab Chip array. MEK inhibitor treatment led to a decrease in -catenin in PIK3CA wild-type colon cancer cells but not in PIK3CA mutant colon cancer cells. Tumor regression was promoted by a combination of MEK inhibitor and NVP-TNS656, which targets the WNT pathway. Furthermore, combined inhibition of MEK and -catenin by NVP-TNS656 promoted tumor regression in colon cancer patient-derived xenograft (PDX) models expressing mutant PIK3CA. Taken together, we propose that inhibition of the WNT pathway, particularly -catenin, may bypass resistance to MEK inhibitor in human PIK3CA mutant colon cancer. Additionally, -catenin is a potential PD marker of MEK inhibitor resistance.
2015-08-13 | GSE71981 | GEO
Project description:Patients with BRAF-mutated colorectal cancer (BRAFV600E CRC) are currently treated by a combination of BRAF inhibitor and anti-EGFR antibody with or without MEK inhibitor. A fundamental problem in treating patients with BRAFV600E CRC is intrinsic and/or acquired resistance to this combination therapy. By screening 78 compounds, we identified tretinoin, a retinoid, as a compound that synergistically enhances the antiproliferative effect of a combination of BRAF inhibition and MEK inhibition with or without EGFR inhibition on BRAFV600E CRC cells. This synergistic effect was also exerted by other retinoids. Tretinoin, added to BRAF inhibitor and MEK inhibitor, upregulated PARP, BAK, and p-H2AX. When either RARα or RXRα was silenced, the increase in cleaved PARP expression by the addition of TRE to ENC/BIN or ENC/BIN/CET was canceled. Our results suggest that the mechanism of the synergistic antiproliferative effect involves modulation of the Bcl-2 family and the DNA damage response that affects apoptotic pathways, and this synergistic effect is induced by RARα- or RXRα-mediated apoptosis. Tretinoin also enhanced the antitumor effect of a combination of BRAF inhibitor and anti-EGFR antibody with or without MEK inhibitor in a BRAFV600E CRC xenograft mouse model. Our data provide a rationale for developing retinoids as a new combination agent to overcome resistance to the combination therapy for patients with BRAFV600E CRC.
2024-11-06 | GSE269881 | GEO
Project description:Patients with BRAF-mutated colorectal cancer (BRAFV600E CRC) are currently treated by a combination of BRAF inhibitor and anti-EGFR antibody with or without MEK inhibitor. A fundamental problem in treating patients with BRAFV600E CRC is intrinsic and/or acquired resistance to this combination therapy. By screening 78 compounds, we identified tretinoin, a retinoid, as a compound that synergistically enhances the antiproliferative effect of a combination of BRAF inhibition and MEK inhibition with or without EGFR inhibition on BRAFV600E CRC cells. This synergistic effect was also exerted by other retinoids. Tretinoin, added to BRAF inhibitor and MEK inhibitor, upregulated PARP, BAK, and p-H2AX. When either RARα or RXRα was silenced, the increase in cleaved PARP expression by the addition of TRE to ENC/BIN or ENC/BIN/CET was canceled. Our results suggest that the mechanism of the synergistic antiproliferative effect involves modulation of the Bcl-2 family and the DNA damage response that affects apoptotic pathways, and this synergistic effect is induced by RARα- or RXRα-mediated apoptosis. Tretinoin also enhanced the antitumor effect of a combination of BRAF inhibitor and anti-EGFR antibody with or without MEK inhibitor in a BRAFV600E CRC xenograft mouse model. Our data provide a rationale for developing retinoids as a new combination agent to overcome resistance to the combination therapy for patients with BRAFV600E CRC.
2024-11-06 | GSE269880 | GEO