Project description:Bulk RNA-Seq of PC9 xenograft tumors in different stages of response and resistance to Erlotinib treatment. A combination treatment is proposed in order to overcome Erlotinib drug resistance.
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: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:The non-small cell lung carcinoma (NSCLC) PC9 cell line is an established preclinical model for tyrosine kinase inhibitors. To better understand gene expression changes in cells that survived the inhibitor treatment, we treated the EGFR-mutant PC9 cells with erlotinib, isolated RNA, and performed RNA-seq analysis. We were able to identify genes that are differentially expressed in erlotinib-treated cells compared to untreated. The results of this study will be integrated with single cell RNA-seq to address the utility of bulk RNA versus single cell RNA strategies in identifying biomarkers of drug resistance.
Project description:The non-small cell lung carcinoma (NSCLC) PC9 cell line is an established preclinical model for tyrosine kinase inhibitors. Using PC9 cells, we generated EGFR-mutant lung cancer xenografts to study the differences in response between individual cells and cell populations. We performed treatment of PC9 xenograft tumors with the combination of osimertinib and crizotinib as well as single drugs, followed by Drop-seq. The addition of crizotinib was guided by our previous data in PC9 grown in cell culture that identified an erlotinib-resistant drug population sensitive to crizotinib. The results of the xenograft study show that combination treatment targets specific osimertinib-tolerant cell populations but leaves a subset of the population that is tolerant to the combo. Each cell subpopulation is characterized by specific molecular signatures. The results of our study help to address emerging drug resistance that limits clinical usefulness of targeted strategies, particularly in NSCLC.
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 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:Given the recent reports on the role of AXL in mediating resistance to EGFR-targeted therapy, we generated cell line models of Erlotinib-resistance to investigate the effect of AXL inhibitors on EGFR TKI resistance. For this, EGFR-mutant PC9 cells were passed through a persister bottleneck by applying strong drug selection pressure to generate drug-tolerant erlotinib persister cells. We created four Erlotinib-resistant clones from one parental population; S1-34, S2-10, S2-17 and S2-30. Whole exome and RNA sequencing analyses were performed to probe the differences in Erlotinib-resistance mechanisms present in these persister-derived Erlotinib-resistant cells.
Project description:Gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), induces substantial clinical responses for non-small cell lung cancer (NSCLC) cells harboring EGFR activating mutations, but most of them invariably develop resistance. By generating a gefitinib resistance (PC9GR) from a human NSCLC-derived drug sensitive cell line (PC9), we studied differences of transcription dynamics between them by the aid of a computational decoupling of hidden regulatory signals from time course gene expression profiles. Given a collection of transcription factors (TFs) and their regulatory targets, the method captured temporally-synchronized shifts in evolving expression of target genes sharing each TF regulatory unit, and drew underlying regulatory signals. The analysis identified sterol regulatory element binding protein 1 (SREBP-1) as a key regulatory agent that facilitates the maintenance of drug tolerance, involving transcription controls of a G1-specific cyclin dependent kinase inhibitor whose expression was specifically elevated in PC9, but in turn, reduced in PC9GR Gefitinib-resistance cell line (PC9GR) was established derived from lung adenocarcinoma cell line PC9. PC9 cells and PC9GR cells were treated with the four different conditions, control (No treatment), EGF-treatment, gefitinib-treatment, and both gefitinib and EGF-treatment. In each condition, the gene expression was measured at 26 time points during 24 hrs.
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.