Withdrawal of MEK1/2 inhibitor reverses acquired resistance driven by BRAF amplification but drives EMT and chemoresistance in cells with amplified KRAS
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ABSTRACT:
PROVIDER: PRJNA495324 | ENA |
REPOSITORIES: ENA
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Project description:Acquired resistance to MEK1/2 inhibitors can arise through amplification of BRAFV600E or KRASG13D to reinstate ERK1/2 signalling. Here we show that BRAFV600E amplification and selumetinib resistance are fully reversible following drug withdrawal. Resistant cells with BRAFV600E amplification become addicted to selumetinib to maintain a precise level of ERK1/2 signalling (2-3% of total ERK1/2 active, here quantified by mass spectrometry), that is optimal for cell survival and proliferation. The magnitude of ERK1/2 activation following selumetinib withdrawal (~20% active) drives a p57KIP2-dependent G1 cell cycle arrest and senescence or expression of NOXA and cell death, which selects against those cells with amplified BRAFV600E. ERK1/2-dependent p57KIP2 expression is required for loss of BRAFV600E amplification and determines the rate of reversal of selumetinib resistance. Furthermore, growth of selumetinib-resistant cells with BRAFV600E amplification as tumour xenografts is inhibited in mice that do not receive selumetinib. Thus, BRAFV600E amplification confers a selective disadvantage during drug withdrawal, providing a rationale for intermittent dosing to forestall resistance. In striking contrast, selumetinib resistance driven by KRASG13D amplification is not reversible. In these cells ERK1/2 reactivation does not inhibit proliferation but drives a ZEB1-dependent epithelial-to-mesenchymal transition that increases cell motility and promotes resistance to traditional chemotherapy agents arguing strongly against the use of ‘drug holidays’ in cases of KRASG13D amplification.
2019-03-11 | GSE120993 | GEO
Project description:Acquired resistance to MEK1/2 inhibitors (MEKi) arises through amplification of BRAFV600E or KRASG13D to reinstate ERK1/2 signalling. Here we show that BRAFV600E amplification and MEKi resistance are reversible following drug withdrawal. Cells with BRAFV600E amplification are addicted to MEKi to maintain a precise level of ERK1/2 signalling that is optimal for cell proliferation and survival, and tumour growth in vivo. Robust ERK1/2 activation following MEKi withdrawal drives a p57KIP2-dependent G1 cell cycle arrest and senescence or expression of NOXA and cell death, selecting against those cells with amplified BRAFV600E. p57KIP2 expression is required for loss of BRAFV600E amplification and reversal of MEKi resistance. Thus, BRAFV600E amplification confers a selective disadvantage during drug withdrawal, validating intermittent dosing to forestall resistance. In contrast, resistance driven by KRASG13D amplification is not reversible; rather ERK1/2 hyperactivation drives ZEB1-dependent epithelial-to-mesenchymal transition and chemoresistance, arguing strongly against the use of drug holidays in cases of KRASG13D amplification.
| S-EPMC6497655 | biostudies-literature
Project description:Overexpression of miR-155 in hematological tissue leads to the onset of lymphoma, and Tet-off shutdown of this overexpression reverses the disease phenotype in mir-155LSLtTA mice. This study compares the gene expression profiles of tumors with miR-155 overexpression and withdrawal.
2015-01-30 | GSE61851 | GEO
Project description:Saccharomyces cerevisiae Mek1 is a CHK2/Rad53-family kinase that regulates meiotic recombination and progression upon its activation in response to DNA double-strand breaks (DSBs). The full catalog of direct Mek1 phosphorylation targets remains unknown. Here, we show that phosphorylation of histone H3 on threonine 11 (H3 T11ph) is induced by meiotic DSBs in S. cerevisiae and Schizosaccharomyces pombe. Molecular genetic experiments in S. cerevisiae confirmed that Mek1 is required for H3 T11ph and revealed that phosphorylation is rapidly reversed when Mek1 kinase is no longer active. Reconstituting histone phosphorylation in vitro with recombinant proteins demonstrated that Mek1 directly catalyzes H3 T11 phosphorylation. Mutating H3 T11 to nonphosphorylatable residues conferred no detectable meiotic defects, indicating that H3 T11ph is dispensable for Mek1 functions in controlling recombination. However, H3 T11ph provides an excellent marker of ongoing Mek1 kinase activity in vivo. Anti-H3 T11ph chromatin immunoprecipitation followed by deep sequencing demonstrated that H3 T11ph was highly enriched at presumed sites of attachment of chromatin to chromosome axes, gave a more modest signal along chromatin loops, and was present at still lower levels immediately adjacent to DSB hotspots. These localization patterns closely tracked the distribution of Red1 and Hop1, axis proteins required for Mek1 activation. These findings provide insight into the spatial disposition of Mek1 kinase activity and the higher order organization of recombining meiotic chromosomes.
2017-10-17 | GSE103823 | GEO
Project description:Overexpression of miR-155 in hematological tissue leads to the onset of lymphoma, and Tet-off shutdown of this overexpression reverses the disease phenotype in mir-155LSLtTA mice. This study compares the gene expression profiles of tumors with miR-155 overexpression and withdrawal. Examination of mRNA from 2 conditions: miR-155 overexpressing tumors and miR-155 overexpressing tumors from mice exposed to doxycycline (DOX) for 16hrs prior to harvest; samples in triplicate; tumors generated in flanks of nude mice by subcutaneous injection of splenic cells from diseased mir-155LSLtTA mice.
2015-01-30 | E-GEOD-61851 | biostudies-arrayexpress
Project description:Mitogen activated protein kinase (MAPK) inhibitors are important therapies for treating many cancers. However, the development of acquired resistance to most protein kinase inhibitors limit their ability to provide durable responses. Approximately 50% of malignant melanomas contain activating mutations in the BRAF kinase, which promote cancer cell survival by activating the extracellular signal-regulated kinase-1/2 (ERK1/2) pathway through direct phosphorylation of the MAPK/ERK kinase-1/2 (MEK1/2). Although combination treatment with BRAF and MEK1/2 inhibitors is a recommended approach to treat melanoma, the development of drug resistance remains a barrier to achieving long term patient benefits. Using high-resolution label-free mass spectrometry, the current studies compared relative protein changes in BRAF and MEK1/2 inhibitor resistant A375 melanoma cells grown as monolayers or 3D spheroids. While approximately 66% of proteins identified were common in both monolayer and spheroid cultures, only 6.2% or 3.6% of proteins that significantly increased or decreased, respectively, compared to drug sensitive cells were common between the drug-resistant monolayer and spheroid cells. Major changes in drug-resistant monolayers suggested upregulation of alternative kinase signaling pathways that promote growth and metastasis. In contrast, the major changes in drug-resistant spheroids indicated increased catabolic metabolism to support oxidative phosphorylation and energy requirements.
2022-02-17 | PXD026952 | Pride
Project description:Meiotic recombination starts with the formation of DNA double-strand breaks (DSBs) made by Spo11. In Saccharomyces cerevisiae, the nonrandom distribution of meiotic DSBs along the genome can be attributed to the combined influence of multiple factors on Spo11 cleavage. One factor is higher-order chromatin structure, particularly the loop-axis organization of meiotic chromosomes. Axial element proteins Red1 and Hop1 provide the basis for meiotic loop-axis organization and are implicated in diverse aspects of meiotic recombination. Mek1 is a meiotic-specific kinase associated with Red1 and Hop1. Red1, Hop1, and Mek1 are required for normal DSB levels, but their effects on the DSB distribution has not been examined, and exactly how these proteins influence DSB levels and distribution is unknown. Here, we examined the contributions of Red1, Hop1, and Mek1 to the DSB distribution by deep sequencing and mapping Spo11-associated oligonucleotides from red1, hop1, and mek1 mutant strains, thereby generating genome-wide meiotic DSB maps.
2018-09-01 | GSE84859 | GEO
Project description:Analysis of bone-marrow derived macrophages (BMDMs) stimulated with single or combinatorial TLR agonist and MEK1/2 inhibitor in wild-type and Irf1-/- macrophages. Results provide insights into the versatile but yet uncharacterized roles of IRF1 in TLR-MEK1/2-ERK MAPK signaling.
2018-12-28 | GSE123512 | GEO
Project description:Despite advances in the detection and management of colorectal cancers, resistance to anti-cancer therapies remains a significant challenge. Activating mutations in KRAS and BRAF are frequently observed in colorectal cancers and have been associated with aggressive tumors and poor survival after chemotherapy. In the present study, we demonstrate that mutations in KRAS/BRAF alter the enhancer landscape of tumor cells, which leads to the resistance of the cornerstone colorectal cancer chemotherapeutic agent 5-fluorouracil (5-FU) through activation of transcription factor GATA1. Targeted inhibition of GATA1 reverses epigenetic changes in KRAS mutant cells and restores sensitivity to 5-FU. These results indicate a novel therapeutic opportunity for tailoring individualized therapy in human colorectal cancer.
2019-10-01 | GSE115400 | GEO
Project description:Drug resistance poses a significant clinical challenge, and comprehending the mechanisms underlying this resistance can facilitate the design of novel inhibitors and advance cancer treatment. The REPLACE system was employed to examine resistance mutations in MEK1 during the administration of 3 allosteric inhibitors. To explore the accumulation of mutations in various RNAs during the MEK1 evolution experiment, we established a barcoded library and conducted lineage tracing of replicative RNAs carrying MEK1 throughout the drug resistance evolution process.
2024-09-30 | GSE271875 | GEO