Project description:Whole exome sequencing was performed on set of 48 DNA samples obtained from 16 EGFR mutated NSCLC patients whose tumors progressed following EGFR-TKI treatment. The DNA samples included baseline biopsy, rebiopsy and blood from the same patient. By comparing the variants in rebiopsy tumors and baseline tumors we aim to understand the genomic alterations responsible for the development of EGFR-TKI resistance in NSCLC patients.
Project description:In this study, we explored the mechanisms of hypoxia-induced EGFR TKI resistance in non-small cell lung cancer (NSCLC) harbored activating EGFR mutation. The NSCLC cell lines were exposed to normorxia or 1% oxygen for 4 weeks, and then we tested EGFR TKI sensitivity in normoxic and hypoxic NSCLC cell lines. In this microarray experiment, we used normoxic HCC827 and hypoxia-induced gefitinib resistant clones, C2-3 and C2-10. Those clones were selected with gefitinib treatment after the HCC827 were exposed to 1% oxygen for 4 weeks, and the HCC827 C2-3 and C2-10 clones were selected at random for this study.
Project description:Activating mutations of EGFR have been characterized as important mechanisms for carcinogenesis in a subset of EGFR-dependent non-small cell lung cancers (NSCLC). EGFR tyrosine kinase inhibitors (TKI), such as erlotinib and gefitinib, have dramatic clinical effects on EGFR-addicted lung cancers and are used as first-line therapy for EGFR-mutant tumors. However, eventually all tumors acquire secondary resistance to the drugs and progress. We established a model to better understand mechanisms of acquired resistance. NCI- HCC827 cells are EGFR-mutant and highly erlotinib-sensitive. In this study we exposed HCC827 cells to increasing concentrations of erlotinib and two highly erlotinib-resistant subclones were developed (ER3 and T15-2). In these subclones no acquired alterations of EGFR or MET were found. We hereby performed a gene expression microarray studies to understand changes that might explain mechanisms of resistance. Through these studies we demonstrated in one resistant clone (ER3) overexpression of AXL, a tyrosine kinase implicated in imatinib and lapatinib resistance. Gene expression profilings were measured in NSCLC cell line HCC827 and two erlotinib-resistant HCC827-originated sublines ER3 and T15-2.
Project description:Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been recommended as the first line therapy for non-small cell lung cancer (NSCLC) with EGFR mutations. However, acquired resistance to EGFR-TKIs is inevitable. Although anti- programmed cell death 1 (PD-1)/PD-ligand (PD-L1) immunotherapies have achieved great clinical success as second-line treatment for many cancer types, the clinical efficacy of anti-PD-1/PD-L1 blockades in EGFR mutated NSCLC patients has been demonstrated to be obviously lower than those without EGFR mutations. Here, we reported an advanced NSCLC patient with exon 19 deletion and T790M EGFR mutation benefitting from anti-PD-1 blockade therapy after acquiring resistance to EGFR-TKI. We characterized the mutational landscape of the patient with next-generation sequencing (NGS), and successfully identified neoantigen-specific T cell clones derived from EGFR exon 19 deletion, TP53 A116T and DENND6B R398Q mutations. Our findings support the potential application of immune checkpoint blockades in NSCLC patients with acquired resistance to EGFR-TKIs in the context of specific clonal neoantigens with high immunogenicity. Personalized immunomodulatory therapy targeting these neoantigens should be explored for better clinical outcomes in EGFR mutant NSCLC patients.
Project description:Osimertinib, as a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has been approved as a first-line therapy in advanced non–small-cell lung cancer (NSCLC) patients with EGFR-activating or T790M resistance mutations. However, the efficacy of osimertinib is limited due to acquired resistance. In order to search for the mechanism of resistance to osimertinib, we screened on significantly upregulated genes encoding protein kinases in osimertinib-resistant NSCLC cells via RNA-sequence.In summary, our data elucidate the alterations in gene expression within lung cancer cells before and after resistance to osimertinib, aiding in the analysis and identification of key molecules influencing osimertinib resistance.
Project description:Epidermal growth factor receptor (EGFR) harboring active mutations, Del19 and L858R, are most common oncogenic mutations in in non-small cell lung cancer (NSCLC) patients. The preferred treatment at first line is tyrosine kinase inhibitor (TKI) administration while the TKI-resistance usually develops because of acquiring the secondary EGFR T790M mutant. Protein-protein interactions (PPIs) constitute the signaling scaffold and thus aberrant PPIs ascribed to mutations often results in dysregulations of downstream signaling cascades. Affinity purification coupled mass spectrometry (AP-MS) was utilized to characterize the EGFR PPIs in four NSCLC cells which carry different EGFR subtypes representing as TKI-sensitive and -resistant models in this study. The EGFR interactomes of TKI-resistant NSCLC cells presented higher diversity of subcellular distribution as well as the hyperactive EGFR trafficking. Furthermore, gefitinib perturbation activated autophagy-mediated EGFR degradation in TKI-resistant NSCLC models and inhibiting autophagy process indeed reduced the TKI-resistance against gefitinib as cytotoxicity was significantly improved. Alternatively, gefitinib induced EGFR translocation toward cell periphery through Rab7 ubiquitination in TKI-sensitive models which may confer TKIs more chance to suppress EGFR activity. In brief, acquired T790M EGFR mutation rewired the EGFR inherent interactomes and thus guided EGFR moving toward distinct trafficking routes, EGFR recycling or autophagy-mediated degradation, in response to TKI insult in TKI-sensitive and -resistant NSCLC cells. These finding suggest that manipulation or combined autophagy inhibition may provide us a novel therapeutic strategy to manage TKI-resistance and tumor relapse in NSCLC.
Project description:Human non-small-cell lung cancers (NSCLCs) harboring activating mutations in epidermal growth factor receptor (EGFR) frequently respond to EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib and gefitinib. However, the responses are not durable, and the magnitude of tumor regression is variable, suggesting the existence of genetic modifiers of EGFR dependency in EGFR-mutant NSCLCs. Here, we applied a genome-wide CRISPR-Cas9 screening to identify genetic determinants of EGFR TKI sensitivity and uncovered both known and putative candidates. Specifically, we show that knockout of RIC8A, a guanine nucleotide exchange factor (GEF) essential for G-alpha protein activation, enhanced EGFR TKI-induced cell death and prevented acquired resistance. Mechanistically, we demonstrate that RIC8A is a potent positive regulator of the pro-survival YAP signaling pathway, activation of which rescued the EGFR TKI sensitizing phenotype resulting from RIC8A knockout. We also show that knockout of ARIH2, or other components in the Cullin-5 E3 ubiquitin ligase complex, conferred resistance to EGFR inhibition, in part by promoting nascent protein synthesis through METAP2. Together, these data uncover a spectrum of previously unidentified regulators of EGFR TKI sensitivity in EGFR-mutant NSCLC cells, providing insights into the heterogeneity of EGFR TKI treatment responses in EGFR-mutant NSCLCs.
Project description:The Epidermal Growth Factor Receptor (EGFR) regulates a diverse set of biological processes including cell growth, proliferation, and differentiation. Deregulation of the EGFR pathway has been implicated in a variety of human diseases including cancer. Gefitinib and erlotinib are tyrosine kinase inhibitors (TKIs) that have demonstrated clinical benefit for patients with Non-small cell lung cancer (NSCLC) and EGFR activating mutations. However, patients invariably acquire resistance to TKI treatment through a number of mechanisms. We utilized in vitro models of NSCLC with EGFR activating mutations and derived three isogenic cell lines with acquired resistance to gefitinib. We next studied genomewide mRNA expression in resistance and wild type cells and their effect in the reprogramming of pathways in lung cancer cell line models..
Project description:The Epidermal Growth Factor Receptor (EGFR) regulates a diverse set of biological processes including cell growth, proliferation, and differentiation. Deregulation of the EGFR pathway has been implicated in a variety of human diseases including cancer. Gefitinib and erlotinib are tyrosine kinase inhibitors (TKIs) that have demonstrated clinical benefit for patients with Non-small cell lung cancer (NSCLC) and EGFR activating mutations. However, patients invariably acquire resistance to TKI treatment through a number of mechanisms. We utilized in vitro models of NSCLC with EGFR activating mutations and derived three isogenic cell lines with acquired resistance to gefitinib. We next studied genomewide mRNA expression in resistance and wild type cells and their effect in the reprogramming of pathways in lung cancer cell line models..
Project description:Introduction: The clinical benefit of EGFR tyrosine kinase inhibitor (TKI) treatment in non-small cell lung cancer (NSCLC) patients with activating EGFR mutations is temporary, as virtually all patients develop acquired EGFR TKI resistance that occurs via diverse mechanisms. Here, we identified increased FGFR1 expression as such a resistance mechanism and using pathways analysis and drug combination testing we identified a novel combination treatment to control growth of these resistant tumors. Methods: Novel erlotinib-resistant NSCLC cell lines were generated and analyzed by mass spectrometry-based proteomics to identify altered pathways associated with erlotinib resistance. The altered pathways were further analyzed in gefitinib and osibenib resistant cell lines. Small molecule inhibitor combinations were used to block the altered pathways and investigate growth reduction in vitro and in two xenograft mouse models. FGFR1 mRNA levels were examined in pre- and (post?)- EGFR TKI treatment clinical tumor samples. Results: Proteomic analysis revealed increased expression of FGFR1 and AXL as well as increased Akt and ERK1/2 activation in a panel of novel erlotinib-resistant HCC827 cell lines. Combined treatment with erlotinib or osimertinib and a panel of small molecule inhibitors targeting AXL/MET, FGFRs, Akt, PI3K/mTOR, MEK or ERK1/2 showed that the most prominent re-sensitization to EGFR TKI occurred with the pan-FGFR inhibitor, PD173074. Interestingly, simultaneous blockade of components of the Akt pathway using specific Akt or dual PI3K-mTOR inhibitors combined with inhibitors targeting the FGFR family exhibited the most efficient growth inhibition of FGFR1 overexpressing EGFR TKI-resistant cell lines. Phosphorylation of proteins downstream of Akt, including PRAS40, FOXO and S6 ribosomal protein, were completely abrogated by PD173074 combined with the Akt inhibitor GSK2141795 . Combination treatment with PD173074 and an Akt inhibitor exhibited synergistic growth inhibition in vivo in two FGFR1 overexpressing NSCLC EGFR TKI-resistant animal models. Conclusion: The significant growth inhibition in vitro and in vivo observed with PD173074 combined with Akt compared to either drug alone imply that inhibition of several key targets may be beneficial in controlling erlotinib-resistant NSCLC. The complete abrogation of PRAS40, FOXO and S6 phosphorylations by PD173074 combined with an Akt inhibitor indicates that the Akt pathway is no longer active.