RNA-seq analysis revealed that crizotinib-induced cardiomyocyte death, and cardiac dysfunctionapoptosis is related to autophagosome-lysosome fusion and mitochondrial injury
Ontology highlight
ABSTRACT: Crizotinib, a widely used dual ALK/MET/ROS1 inhibitor, have been seriously limited due to cardiac adverse effects. Here, we found that crizotinib caused left ventricular dysfunction, structural damage and pathological remodeling in mice and induced cardiomyocyte apoptosis and mitochondrial injury. Here, we demonstrated that crizotinib lead to aberrant accumulation of MET protein by interrupting autophagosome-lysosome fusion and knockdown of MET expression or re-activating autophagy flux rescued the cardiomyocytes death and mitochondrial injury caused by crizotinib. We identified that inhibition of the phosphorylation of AMPKSer485/491 reduced the transcriptional level of genes required for autophagosome-lysosome fusion by inhibiting the nuclear localization of FoxO1. Recovering the phosphorylation of AMPKSer485/491 by AAV-mediated overexpression of the AMPK (T485D) or metformin treatment rescued the cardiotoxicity caused by crizotinib.
Project description:MET amplification has been clinically credentialed as a therapeutic target in gastric cancer, but the molecular mechanisms underlying sensitivity and resistance to MET inhibitors are still not well understood. Using whole-genome mRNA expression profiling, we identified autophagy as a top molecular pathway that was activated by the MET inhibitor crizotinib in drug-sensitive human gastric cancer cells, and functional studies confirmed that crizotinib increased autophagy levels in the drug-sensitive cells in a concentration-dependent manner. We then used chemical and molecular approaches to inhibit autophagy in order to define its role in cell death. The clinically available inhibitor of autophagy, chloroquine, or RNAi-mediated knockdown of two obligate components of the autophagy pathway (ATG5 and ATG7) blocked cell death induced by crizotinib or RNAi-mediated knockdown of MET, and mechanistic studies localized the effects of autophagy to cytochrome c release from the mitochondria. Overall; the data reveal a novel relationship between autophagy and apoptosis in gastric cancer cells exposed to MET inhibitors. The observations suggest that autophagy inhibitors should not be used to enhance the effects of MET inhibitors in gastric cancer patients.
Project description:RNA-seq analysis revealed that crizotinib-induced cardiomyocyte death, and cardiac dysfunctionapoptosis is related to autophagosome-lysosome fusion and mitochondrial injury
Project description:MET amplification is present in 20% of gastric cancers and has been confirmed as a therapeutic target in clinical trials. The molecular mechanisms of response and resistance to MET inhibitors are not well understood. We investigated the determinants of MET dependency in human gastric cancer. MET inhibition inhibited proliferation and induced cell death only in MET-amplified gastric cancer cell lines. The effects on growth arrest were stronger than the effects on cell death. To identify possible resistance mechanisms, we performed whole-genome mRNA expression profiling. Molecular changes related to autophagy were among the top alterations observed. Consistent with these findings, autophagy levels increased in a concentration-dependent manner when MET-amplified cells were exposed to crizotinib. Autophagy inhibition caused a dramatic decrease in apoptosis in one of the MET-amplified cell lines (MKN45) but not in the other (SNU-5). Because autophagy may provide energy in cells subjected to growth factor deprivation, we explored the effects of MET or autophagy inhibition on cellular ATP levels. This revealed that autophagy-dependent ATP production was selectively required for apoptosis in the MKN45 cells and that chemical ATP depletion mimicked the effects of autophagy inhibition to block cell death. Overall, the data reveal a novel relationship between ATP depletion and resistance to MET inhibitor-induced cell death. Our observations suggest that autophagy inhibitors could have unintended consequences when they are combined with growth factor receptor inhibitors in tumors that require autophagy-dependent ATP production for apoptosis. 12 samples triplicate samples of SNU-5 and MKN45 +/- criztonib for 24 hours
Project description:The non-small cell lung cancer (NSCLC) cell line HCC827 harbors an activating EGFR mutation (exon 19 deletion) that confers sensitivity to the FDA-approved EGFR inhibitor erlotinib. By applying the ClonTracer barcoding system, we were able to show the presence of pre-existing sub-populations in HCC827 that contribute to erlotinib resistance. Prior studies implicated that MET amplification confers resistance to erlotinib in this cell line. Therefore we examined the effects of the c-Met inhibitor crizotinib on the barcoded HCC827 population when treated either sequentially or simultaneously with both inhibitors. Despite the significant reduction in barcode complexity, the erlotinib/crizotinib combination treatment failed to eradicate all of the resistant clones implying the presence of an erlotinib/crizotinib dual resistant subpopulation. We performed transcriptome profiling (RNA-seq) to elucidate the potential resistance mechanisms of the dual resistant subpopulation in comparison to vehicle-treated or single agent erlotinib-resistant HCC827 cell populations as controls. mRNA profiling of the subpopulations of human NSCLC cell line HCC827 that contribute to EGFR inhibitor erlotinib and MET inhibitor crizotinib resistance
Project description:Pancreatic ductal adenocarcinoma (PDAC) remains a major unsolved health problem. Most drugs that pass preclinical tests fail in these patients, emphasizing the need of appropriate preclinical models to test novel anticancer strategies. We developed four orthotopic mouse models employing primary human PDAC cells expressing Firefly and Gaussia luciferases, enabling bioluminescence monitoring of tumor growth and metastasis formation. Additional tumor characterization was performed using MR and high frequency ultrasound imaging. Genomic and immunohistochemical analysis revealed c-Met amplification and overexpression in one of four models. Analysis of c-Met inhibitors in vitro showed that crizotinib had the most potent effect. Moreover, we demonstrated synergistic effects between crizotinib and gemcitabine – the standard of care therapeutic in PDAC patients - in vitro and in vivo. Importantly, crizotinib reduced the cytidine deaminase activity in PDAC cells causing prolonged activity of gemcitabine due to diminished metabolic inactivation, as measured by LC-MS/MS. This might at least in part explain the observed prolonged survival of concomitantly treated mice with PDAC tumors and metastases. In conclusion, our orthotopic PDAC models enabled PDAC tumor imaging, and showed genetic, histopathological and metastatic features similar to their originator tumors. This allowed the identification of c-Met as a potential therapeutic target in PDAC, and revealed a cytidine deaminase-mediated synergistic mechanism between crizotinib and gemcitabine, a combination of drugs that warrants further investigation for the potential treatment of PDAC patients.
Project description:Autophagy is a conserved and tightly regulated intracellular quality control pathway. ULK is a key kinase in autophagy initiation, but whether ULK kinase activity also participates in late stages of autophagy remains unknown. Here, we found that the autophagosomal SNARE protein, STX17, is phosphorylated by ULK at residue S289, beyond which it localizes specifically to autophagosomes. Inhibition of STX17 phosphorylation prevents such autophagosome localization. FLNA was then identified as a linker between ATG8 family proteins (ATG8s) and STX17 with essential involvement in STX17 recruitment to autophagosomes. Phosphorylation of STX17 S289 promotes its interaction with FLNA, activating its recruitment to autophagosomes and facilitates autophagosome-lysosome fusion. Disease causative mutations around the ATG8s- and STX17-binding regions of FLNA disrupt its interactions with ATG8s and STX17, inhibiting STX17 recruitment and autophagosome-lysosome fusion. Cumulatively, our study reveals an unexpected role of ULK in autophagosome maturation, uncovers its regulatory mechanism in STX17 recruitment, and highlights a potential association between autophagy and FLNA.
Project description:The non-small cell lung cancer (NSCLC) cell line HCC827 harbors an activating EGFR mutation (exon 19 deletion) that confers sensitivity to the FDA-approved EGFR inhibitor erlotinib. By applying the ClonTracer barcoding system, we were able to show the presence of pre-existing sub-populations in HCC827 that contribute to erlotinib resistance. Prior studies implicated that MET amplification confers resistance to erlotinib in this cell line. Therefore we examined the effects of the c-Met inhibitor crizotinib on the barcoded HCC827 population when treated either sequentially or simultaneously with both inhibitors. Despite the significant reduction in barcode complexity, the erlotinib/crizotinib combination treatment failed to eradicate all of the resistant clones implying the presence of an erlotinib/crizotinib dual resistant subpopulation. We performed transcriptome profiling (RNA-seq) to elucidate the potential resistance mechanisms of the dual resistant subpopulation in comparison to vehicle-treated or single agent erlotinib-resistant HCC827 cell populations as controls.
Project description:The energy sensor AMP-activated protein kinase (AMPK) can activate autophagy when cellular energy production becomes compromised. However, the degree to which nutrient sensing impinges on the autophagosome closure remains unknown. Here, we provide the mechanism underlying a plant unique protein FREE1, upon autophagy-induced SnRK1α1-mediated phosphorylation, functions as a linkage between ATG conjugation system and ESCRT machinery to regulate the autophagosome closure upon nutrient deprivation. Using high-resolution microscopy, 3D-electron tomography, and protease protection assay, we showed that unclosed autophagosomes accumulated in free1 mutants. Proteomic, cellular and biochemical analysis revealed the mechanistic connection between FREE1 and the ATG conjugation system/ESCRT-III complex in regulating autophagosome closure. Mass spectrometry analysis showed that the evolutionary conserved plant energy sensor SnRK1α1 phosphorylates FREE1 and recruits it to the autophagosomes to promote closure. Mutagenesis of the phosphorylation site on FREE1 caused the autophagosome closure failure. Our findings unveil how cellular energy sensing pathways regulate autophagosome closure to maintain cellular homeostasis.
Project description:we generated patient-derived xenograft crizotinib-resistant mice and subjected them to phosphorylation profiling, together with crizotinib-resistant mice treated with ASP3026 or alectinib