Project description:Erlotinib is a tyrosine kinase inhibitor (TKI) that is approved as a second-line monotherapy in patients with advanced non-small cell lung cancer (NSCLC). In these patients, erlotinib prolongs survival but its benefit remains modest since overtime, many tumors develop resistance. To analyse the changes in the gene expression profile, that accompany resistance development, we treated the erlotinib sensitive non-small cell lung cancer cell line H358 with increasing concentrations of erlotinib (1-5µM) for several weeks (H358res). In parallel, we kept H358 with the same concentrations of the vehicle DMSO (H358co). After ten weeks of treatment, when the H358res stably grew under 5µM erlotinib, total RNA of both cell lines was harvested and hybridized.
Project description:Erlotinib is a tyrosine kinase inhibitor (TKI) that is approved as a second-line monotherapy in patients with advanced non-small cell lung cancer (NSCLC). In these patients, erlotinib prolongs survival but its benefit remains modest since overtime, many tumors develop resistance. To analyse the changes in the gene expression profile, that accompany resistance development, we treated the erlotinib sensitive non-small cell lung cancer cell line H358 with increasing concentrations of erlotinib (1-5µM) for several weeks (H358res). In parallel, we kept H358 with the same concentrations of the vehicle DMSO (H358co). After ten weeks of treatment, when the H358res stably grew under 5µM erlotinib, total RNA including microRNA of both cell lines was harvested and analyzed.
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:Standard and targeted therapies almost universally fail due to tumor heterogeneity/plasticity leading to intrinsic or acquired drug resistance. We used the telomerase substrate precursor 6-thio-2’-deoxyguanosine (6-thio-dG) to target telomerase-expressing targeted therapy and platin-doublet chemotherapy resistant cells. We observed that erlotinib, paclitaxel/carboplatin and gemcitabine/cisplatin resistant cells are sensitive to 6-thio-dG in xenograft, syngeneic immunocompetent and genetically engineered mouse models. We also show sensitivity to 6-thio-dG on a large panel of non-small cell lung cancer cell lines (73 of 77). The 4 resistant NSCLC lines clustered together, providing a molecular signature for patients that may not respond to 6-thio-dG. We find SLC43A3 as a top candidate in this molecular signature. Thus, 6-thio-dG may prolong disease control of therapy-resistant lung cancer patients.
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:The non-small cell lung carcinoma (NSCLC) PC9 cell line is an established preclinical model for tyrosine kinase inhibitors. To be able to better understand the differences in response between individual cells, we performed treatment of PC9 cells grown in cell culture with etoposide, erlotinib and its combination with crizotinib, followed by Drop-seq. The addition of crizotinib was guided by our previous data that an erlotinib-resistant drug population may be sensitive to crizotinib. To better understand the common events in drug resistance, we compared the resistant cell populations arising from the treatment with etoposide and from the treatment with erlotinib. The results of our study will address emerging drug resistance that limits clinical usefulness of conventional and targeted strategies, particularly in NSCLC.
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.
Project description:Drug-tolerance has emerged as one of the major non-genetic adaptive processes driving resistance to targeted therapy (TT) in non-small cell lung cancer (NSCLC). However, the kinetics and sequence of molecular events governing this adaptive response remain poorly understood. Here, we performed transcriptomic profiling by RNAseq in a panel of EGFR-mutant NSCLC cell lines (PC9, HCC4006, H3255 and HCC827) that were previously subcloned to minimize the presence of potential pre-existing resistant cells. Cells were treated by either erlotinib (1 µM) or osimertinib (1 µM) for a short period (24h), until drug-tolerance (between 7 and 21 days), and until development of fully resistant proliferative cells (RPC).
Project description:The expression profiles of miRNAs in drug-resistant non-small cell lung cancer (NSCLC) cell lines were identified via next generation sequencing and the common dysregulated miRNAs in drug-resistant NSCLC cell lines were picked up for further analysis.
Project description:We characterized the gene expression profile of Epithelial Growth Factor Receptor (EGFR) inhibitor (Erlotinib)-sensitive and resistant human NSCLC cell lines. Total RNA was extracted from the cell lines and expression profiles were studied by Agilent microarray analysis. Wide changes in gene expression profiles occur in the Erlotinib-resistant cell lines when compared with their parental cell lines (HCC827 and HCC4006).