Froehlich2022 - Model of Adaptive Resistance in Melanoma
Ontology highlight
ABSTRACT: This model provides a thermodynamically consistent description of the action of MEK, RAF and panRAF inhibitors on EGFR and ERK signaling in BRAF mutant cancers.
Project description:The clinical efficacy of EGFR kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here we show that in multiple complementary models harboring EGFR T790M, resistance to WZ4002 develops through aberrant activation of ERK signaling caused by either an amplification of MAPK1 or by downregulation of negative regulators of ERK signaling. Inhibition of MEK or ERK restores sensitivity to WZ4002, and the combination of WZ4002 and a MEK inhibitor prevents the emergence of drug resistance. The WZ4002 resistant MAPK1 amplified cells also demonstrate an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy compared to the parental counterparts. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rational combination therapies that should be evaluated in clinical trials. Our study identifies ERK signaling as a mediator of resistance to irreversible pyrimidine EGFR inhibitors in EGFR T790M-bearing cancers. We further provide a therapeutic strategy to both treat and prevent the emergence of this resistance mechanism. To generate drug-resistant NCI-H1975 cell lines, non-small cell lung cancer (NSCLC) cells were exposed to increasing concentrations of WZ4002 similar to previously described methods. Individual clones from WZ4002-resistant (WZR) cells were isolated and confirmed to be drug resistant. Clone #6, designated as WZR6, was used in this study. For expression analysis, samples were prepared in triplicate from parental NCI-H1975 and NCI-H1975 WZR6 cells.
Project description:The clinical efficacy of EGFR kinase inhibitors gefitinib and erlotinib is limited by the development of drug resistance. The most common mechanism of drug resistance is the secondary EGFR T790M mutation. Strategies to overcome EGFR T790M mediated drug resistance include the use of mutant selective EGFR inhibitors, including WZ4002, or by the use of high concentrations of irreversible quinazoline EGFR inhibitors such as PF299804. In the current study we develop drug resistant versions of the EGFR mutant PC9 cell line which reproducibly develops EGFR T790M as a mechanism of drug resistance to gefitinib. Neither PF299804 resistant (PFR) or WZ4002 resistant (WZR) clones of PC9 harbor EGFR T790M. Instead, they demonstrate activated IGF1R signaling as a result of loss of expression of IGFBP3 and the IGF1R inhibitor, BMS 536924, restores EGFR inhibitor sensitivity. Intriguingly, prolonged exposure to either PF299804 or WZ4002 results in the emergence of a more drug resistant subclone which contains ERK activation. A MEK inhibitor, CI-1040, partially restores sensitivity to EGFR/IGF1R inhibitor combination. Moreover, an IGF1R or MEK inhibitor used in combination with either PF299804 or WZ4002 completely prevents the emergence of drug resistant clones in this model system. Our studies suggest that more effective means of inhibiting EGFR T790M will prevent the emergence of this common drug resistance mechanism in EGFR mutant NSCLC. However, multiple drug resistance mechanisms can still emerge. Preventing the emergence of drug resistance, by targeting pathways activated in resistant cancers before they emerge, may be a more effective clinical strategy. Total of three samples with duplicate or triplicate each were analyzed.
Project description:The clinical efficacy of EGFR kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here we show that in multiple complementary models harboring EGFR T790M, resistance to WZ4002 develops through aberrant activation of ERK signaling caused by either an amplification of MAPK1 or by downregulation of negative regulators of ERK signaling. Inhibition of MEK or ERK restores sensitivity to WZ4002, and the combination of WZ4002 and a MEK inhibitor prevents the emergence of drug resistance. The WZ4002 resistant MAPK1 amplified cells also demonstrate an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy compared to the parental counterparts. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rational combination therapies that should be evaluated in clinical trials. Our study identifies ERK signaling as a mediator of resistance to irreversible pyrimidine EGFR inhibitors in EGFR T790M-bearing cancers. We further provide a therapeutic strategy to both treat and prevent the emergence of this resistance mechanism.
Project description:The clinical efficacy of EGFR kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here we show that in multiple complementary models harboring EGFR T790M, resistance to WZ4002 develops through aberrant activation of ERK signaling caused by either an amplification of MAPK1 or by downregulation of negative regulators of ERK signaling. Inhibition of MEK or ERK restores sensitivity to WZ4002, and the combination of WZ4002 and a MEK inhibitor prevents the emergence of drug resistance. The WZ4002 resistant MAPK1 amplified cells also demonstrate an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy compared to the parental counterparts. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rational combination therapies that should be evaluated in clinical trials. The EGFR mutant non-small cell lung cancer (NSCLC) cell line PC9 GR4 (delE746_A750/T790M) was exposed to increasing concentrations of WZ4002 similar to previously described methods. Individual clones from WZ4002-resistant (WZR) cells were isolated and confirmed to be drug resistant. Number of samples: 5. PC9GR4 as a control. 4 clones of WZ4002-resistant PC9GR4.
Project description:The clinical efficacy of EGFR kinase inhibitors gefitinib and erlotinib is limited by the development of drug resistance. The most common mechanism of drug resistance is the secondary EGFR T790M mutation. Strategies to overcome EGFR T790M mediated drug resistance include the use of mutant selective EGFR inhibitors, including WZ4002, or by the use of high concentrations of irreversible quinazoline EGFR inhibitors such as PF299804. In the current study we develop drug resistant versions of the EGFR mutant PC9 cell line which reproducibly develops EGFR T790M as a mechanism of drug resistance to gefitinib. Neither PF299804 resistant (PFR) or WZ4002 resistant (WZR) clones of PC9 harbor EGFR T790M. Instead, they demonstrate activated IGF1R signaling as a result of loss of expression of IGFBP3 and the IGF1R inhibitor, BMS 536924, restores EGFR inhibitor sensitivity. Intriguingly, prolonged exposure to either PF299804 or WZ4002 results in the emergence of a more drug resistant subclone which contains ERK activation. A MEK inhibitor, CI-1040, partially restores sensitivity to EGFR/IGF1R inhibitor combination. Moreover, an IGF1R or MEK inhibitor used in combination with either PF299804 or WZ4002 completely prevents the emergence of drug resistant clones in this model system. Our studies suggest that more effective means of inhibiting EGFR T790M will prevent the emergence of this common drug resistance mechanism in EGFR mutant NSCLC. However, multiple drug resistance mechanisms can still emerge. Preventing the emergence of drug resistance, by targeting pathways activated in resistant cancers before they emerge, may be a more effective clinical strategy.
Project description:The clinical efficacy of EGFR kinase inhibitors is limited by the development of drug resistance. The irreversible EGFR kinase inhibitor WZ4002 is effective against the most common mechanism of drug resistance mediated by the EGFR T790M mutation. Here we show that in multiple complementary models harboring EGFR T790M, resistance to WZ4002 develops through aberrant activation of ERK signaling caused by either an amplification of MAPK1 or by downregulation of negative regulators of ERK signaling. Inhibition of MEK or ERK restores sensitivity to WZ4002, and the combination of WZ4002 and a MEK inhibitor prevents the emergence of drug resistance. The WZ4002 resistant MAPK1 amplified cells also demonstrate an increase both in EGFR internalization and a decrease in sensitivity to cytotoxic chemotherapy compared to the parental counterparts. Our findings provide insights into mechanisms of drug resistance to EGFR kinase inhibitors and highlight rational combination therapies that should be evaluated in clinical trials.
Project description:This SuperSeries is composed of the following subset Series: GSE37698: Reactivation of ERK signaling causes resistance to EGFR kinase inhibitors (SNP array) GSE37699: Aberrant ERK signaling causes resistance to EGFR kinase inhibitors Refer to individual Series
Project description:Disruption of the MAPK pathway in cancer by kinase inhibition often fails due to pathway reactivation, causing clinical relapse. Among MAPK inhibitors, type I RAF inhibitors are only active against specific BRAF mutants; MEK inhibitor monotherapy is associated with limited clinical benefits but may serve as a foundation for combinatorial therapy. Here, we show that type II RAF plus allosteric MEK inhibitors durably blunt the development of acquired MEK inhibitor resistance among cancers with KRAS, NRAS, NF1, BRAFnon-V600 and BRAFV600 mutations, when compared to a combination of type II RAF plus ERK inhibitors. Type II RAF and MEK (versus ERK) inhibitors also display superior capacity to sequester MEK in RAF complexes and uncouple MEK and ERK interaction in acquired resistant tumor subpopulations. Systemically and intratumorally, type II RAF plus MEK inhibitors expand memory and activated/exhausted CD8+ T-cells. Whereas trametinib alone temporally reduces dominant intra-tumoral T-cell clones, type II RAF inhibitor co-treatment reverses this effect and promotes T-cell clonotypic expansion and convergence. Importantly, durably control of tumors by this combination requires CD8+ T-cells. Thus, the prolonged anti-tumor efficacy of type II RAF plus MEK inhibitors reveals exquisite MAPK addiction in common lethal cancer histologies, and the mechanisms include unexpected allosteric perturbation of the MAPK pathway and engagement of anti-tumor CD8+ T-cell immunity.
Project description:Disruption of the MAPK pathway in cancer by kinase inhibition often fails due to pathway reactivation, causing clinical relapse. Among MAPK inhibitors, type I RAF inhibitors are only active against specific BRAF mutants; MEK inhibitor monotherapy is associated with limited clinical benefits but may serve as a foundation for combinatorial therapy. Here, we show that type II RAF plus allosteric MEK inhibitors durably blunt the development of acquired MEK inhibitor resistance among cancers with KRAS, NRAS, NF1, BRAFnon-V600 and BRAFV600 mutations, when compared to a combination of type II RAF plus ERK inhibitors. Type II RAF and MEK (versus ERK) inhibitors also display superior capacity to sequester MEK in RAF complexes and uncouple MEK and ERK interaction in acquired resistant tumor subpopulations. Systemically and intratumorally, type II RAF plus MEK inhibitors expand memory and activated/exhausted CD8+ T-cells. Whereas trametinib alone temporally reduces dominant intra-tumoral T-cell clones, type II RAF inhibitor co-treatment reverses this effect and promotes T-cell clonotypic expansion and convergence. Importantly, durably control of tumors by this combination requires CD8+ T-cells. Thus, the prolonged anti-tumor efficacy of type II RAF plus MEK inhibitors reveals exquisite MAPK addiction in common lethal cancer histologies, and the mechanisms include unexpected allosteric perturbation of the MAPK pathway and engagement of anti-tumor CD8+ T-cell immunity.
Project description:Disruption of the MAPK pathway in cancer by kinase inhibition often fails due to pathway reactivation, causing clinical relapse. Among MAPK inhibitors, type I RAF inhibitors are only active against specific BRAF mutants; MEK inhibitor monotherapy is associated with limited clinical benefits but may serve as a foundation for combinatorial therapy. Here, we show that type II RAF plus allosteric MEK inhibitors durably blunt the development of acquired MEK inhibitor resistance among cancers with KRAS, NRAS, NF1, BRAFnon-V600 and BRAFV600 mutations, when compared to a combination of type II RAF plus ERK inhibitors. Type II RAF and MEK (versus ERK) inhibitors also display superior capacity to sequester MEK in RAF complexes and uncouple MEK and ERK interaction in acquired resistant tumor subpopulations. Systemically and intratumorally, type II RAF plus MEK inhibitors expand memory and activated/exhausted CD8+ T-cells. Whereas trametinib alone temporally reduces dominant intra-tumoral T-cell clones, type II RAF inhibitor co-treatment reverses this effect and promotes T-cell clonotypic expansion and convergence. Importantly, durably control of tumors by this combination requires CD8+ T-cells. Thus, the prolonged anti-tumor efficacy of type II RAF plus MEK inhibitors reveals exquisite MAPK addiction in common lethal cancer histologies, and the mechanisms include unexpected allosteric perturbation of the MAPK pathway and engagement of anti-tumor CD8+ T-cell immunity.