Project description:The transcriptomic effects of EGFR-inhibition by osimertinib on murine EGFR-mutant lung cancer transplants in a syngenic model were assessed.
Project description:To determine the roles of oncogenic EGFR signaling in gliomagenesis and tumor maintenance, we generated a novel glioma mouse model driven by inducible expression of a mutant EGFR (EGFR*). Genetic suppression of EGFR* induction led to significant tumor regression and prolonged survival. But in spite of the initial response, the tumors relapsed invariably and propagated independent of EGFR*. We used microarrys to directly compare geen expression of control and relapse tumors and identified gene sets specifically activated in relapse tumors. Control and relasped glioma samples upon mutant EGFR extinction were selected for RNA extraction and hybridization on Affymetrix microarrays.
Project description:To determine the roles of oncogenic EGFR signaling in gliomagenesis and tumor maintenance, we generated a novel glioma mouse model driven by inducible expression of a mutant EGFR (EGFR*). Genetic suppression of EGFR* induction led to significant tumor regression and prolonged survival. But in spite of the initial response, the tumors relapsed invariably and propagated independent of EGFR*. We used microarrys to directly compare geen expression of control and relapse tumors and identified gene sets specifically activated in relapse tumors.
Project description:Human EGFR-mutant lung cancer cells lines were investigated for their dynamic transcriptional response upon treatment with EGFR-inhibitor osimertinib in a time-series experiment
Project description:Oncogene-driven lung cancers such as those with activating mutations in the epidermal growth factor receptor (EGFR) often harbor additional co-occurring genetic alterations. The significance of most alterations co-occurring with mutant EGFR remains unclear. We report the impact of loss of the mRNA splicing factor RBM10 in human EGFR mutant lung cancer. RBM10 loss decreased EGFR inhibitor efficacy in patient-derived EGFR mutant tumor models. RBM10 regulated mRNA splicing of the mitochondrial apoptotic regulator Bcl-x. Genetic inactivation of RBM10 diminished EGFR inhibitor-mediated apoptosis by altering Bcl-x splicing, decreasing Bcl-xS (pro-apoptotic) and increasing Bcl-xL (anti-apoptotic) levels. Co-inhibition of Bcl-xL and mutant EGFR overcomes resistance induced by RBM10 loss. RBM10 loss was a biomarker of poor response to EGFR inhibitor treatment in clinical samples. Inactivation of the splicing factor RBM10 is a key co-occurring genetic alteration in EGFR mutant tumors that limits EGFR inhibitor efficacy and a potential biomarker of Bcl-xL inhibitor response.
Project description:EGFR-mutant lung adenocarcnioma cell line PC9 pools were treated with different compounds until resistant cells regrew. Resistant and parental cells were then sequenced to study transcriptional changes.
Project description:EGFR tyrosine kinase inhibitors cause dramatic responses in EGFR-mutant lung cancer, but resistance universally develops. The involvement of β-catenin in EGFR TKI resistance has been previously reported however the precise mechanism by which β-catenin activation contributes to EGFR TKI resistance is not clear. Here, we show that EGFR inhibition results in the activation of β-catenin signaling in a Notch3-dependent manner, which facilitates the survival of a subset of cells that we call “adaptive persisters”. We previously reported that EGFR-TKI treatment rapidly activates Notch3, and here describe the physical association of Notch3 with β-catenin, leading to increased stability and activation of β-catenin. We demonstrate that the combination of EGFR-TKI and a β-catenin inhibitor inhibits the development of these adaptive persisters, decreases tumor burden, improves recurrence free survival, and overall survival in xenograft models. These results supports combined EGFR-TKI and β-catenin inhibition in patients with EGFR mutant lung cancer.
Project description:Drug tolerant persister cells of EGFR-mutant PC9 cell lines surviving treatment with kinase inhibitor combination. Cells were treated with combination of erlotinib, osimertinib, trametinib and dasatinib and surviving cells were harvested for RNA extraction. 3' UTR RNA-seq profiles were compared to parental control cells and to outgrowing cells after treatment had been removed
Project description:3' UTR RNA-sequencing of human EGFR-mutant PC9 cells that were CRISPR engineered to additionally contain EGFR-mutations T790M and C797S