Genome-wide analysis of gefitinib short-term resistance gene expression in the NSCLC cell line HCC827 in co-culture
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ABSTRACT: Analysis of gefitinib short-term resistance at gene expression level. The hyposthesis tested in the present study was that short-term resistance towards gefitinib in NSCLC cells influences pathways that associates with resistance towards EGFR-TKI treatment. Results provide important information of the response of EGFR mutant NSCLC cells to gefitinib and also to resistance towards gefitinib resistance, up-or down-regulated specific resistance pathways and cellular functions. Total RNA obtained from HCC827 cell line (n=3), co-cultured HCC827 (with MRC-5 cells)(n=3), gefitinib treated (0.5µM) HCC827 (n=3), and co-cultured (MRC-5) + gefitinib treated HCC827 cells (n=3) for 48h after gefitinib treatment
Project description:Analysis of gefitinib short-term resistance at gene expression level. The hyposthesis tested in the present study was that short-term resistance towards gefitinib in NSCLC cells influences pathways that associates with resistance towards EGFR-TKI treatment. Results provide important information of the response of EGFR mutant NSCLC cells to gefitinib and also to resistance towards gefitinib resistance, up-or down-regulated specific resistance pathways and cellular functions. Total RNA obtained from PC9 cell line (n=3), co-cultured PC9 (with MRC-5 cells)(n=3), gefitinib treated (0.5µM) PC9 (n=3), and co-cultured (MRC-5) + gefitinib treated PC9 cells (n=3) for 48h after gefitinib treatment
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:Analysis of gefitinib short-term resistance at gene expression level. The hyposthesis tested in the present study was that short-term resistance towards gefitinib in NSCLC cells influences pathways that associates with resistance towards EGFR-TKI treatment. Results provide important information of the response of EGFR mutant NSCLC cells to gefitinib and also to resistance towards gefitinib resistance, up-or down-regulated specific resistance pathways and cellular functions.
Project description:Analysis of gefitinib short-term resistance at gene expression level. The hyposthesis tested in the present study was that short-term resistance towards gefitinib in NSCLC cells influences pathways that associates with resistance towards EGFR-TKI treatment. Results provide important information of the response of EGFR mutant NSCLC cells to gefitinib and also to resistance towards gefitinib resistance, up-or down-regulated specific resistance pathways and cellular functions.
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:Lung adenocarcinoma cells harboring epidermal growth factor receptor (EGFR) mutations are sensitive to EGFR tyrosine kinase inhibitors (TKIs). Prolonged cancer treatment will induce the development of acquired resistance to EGFR TKI. To gain insight into the molecular mechanisms of EGFR-TKIs resistance, we generate EGFR-TKI-resistant HCC827-8-1 cells to be analyzed by microarray with their parental HCC827cells. gefitinib resistant HCC827-8-1 cells with three replications; gefitinib-sensitive HCC827 cells with three replications
Project description:Despite initial and often dramatic responses of epidermal growth factor receptor (EGFR)-addicted lung tumors to the EGFR-specific tyrosine kinase inhibitors (TKIs), gefitinib and erlotinib, nearly all develop resistance and relapse. To explore novel mechanisms mediating acquired resistance, we employed non-small-cell lung cancer (NSCLC) cell lines bearing activating mutations in EGFR and rendered them resistant to EGFR-specific TKIs through chronic adaptation in tissue culture. In addition to previously observed resistance mechanisms including EGFR-T790M 'gate-keeper' mutations and MET amplification, a subset of the seven chronically adapted NSCLC cell lines including HCC4006, HCC2279 and H1650 cells exhibited marked induction of fibroblast growth factor (FGF) 2 and FGF receptor 1 (FGFR1) mRNA and protein. Also, adaptation to EGFR-specific TKIs was accompanied by an epithelial to mesenchymal transition (EMT) as assessed by changes in CDH1, VIM, ZEB1 and ZEB2 expression and altered growth properties in Matrigel. In adapted cell lines exhibiting increased FGF2 and FGFR1 expression, measures of growth and signaling, but not EMT, were blocked by FGFR-specific TKIs, an FGF-ligand trap and FGFR1 silencing with RNAi. In parental HCC4006 cells, cell growth was strongly inhibited by gefitinib, although drug-resistant clones progress within 10 days. Combined treatment with gefitinib and AZD4547, an FGFR-specific TKI, prevented the outgrowth of drug-resistant clones. Thus, induction of FGF2 and FGFR1 following chronic adaptation to EGFR-specific TKIs provides a novel autocrine receptor tyrosine kinase-driven bypass pathway in a subset of lung cancer cell lines that are initially sensitive to EGFR-specific TKIs. The findings support FGFR-specific TKIs as potentially valuable additions to existing targeted therapeutic strategies with EGFR-specific TKIs to prevent or delay acquired resistance in EGFR-driven NSCLC. Examination of mRNA levels in DMSO and gefitinib-resistant cultures of HCC4006 and HCC827. Each group has two replicates.
Project description:The model is based on publication:
Mathematical analysis of gefitinib resistance of lung adenocarcinoma caused by MET amplification
Abstract:
Gefitinib, one of the tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR), is effective for treating lung adenocarcinoma harboring EGFR mutation; but later, most cases acquire a resistance to gefitinib. One of the mechanisms conferring gefitinib resistance to lung adenocarcinoma is the amplification of the MET gene, which is observed in 5–22% of gefitinib-resistant tumors. A previous study suggested that MET amplification could cause gefitinib resistance by driving ErbB3-dependent activation of the PI3K pathway. In this study, we built a mathematical model of gefitinib resistance caused by MET amplification using lung adenocarcinoma HCC827-GR (gefitinib resistant) cells. The molecular reactions involved in gefitinib resistance consisted of dimerization and phosphorylation of three molecules, EGFR, ErbB3, and MET were described by a series of ordinary differential equations. To perform a computer simulation, we quantified each molecule on the cell surface using flow cytometry and estimated unknown parameters by dimensional analysis. Our simulation showed that the number of active ErbB3 molecules is around a hundred-fold smaller than that of active MET molecules. Limited contribution of ErbB3 in gefitinib resistance by MET amplification is also demonstrated using HCC827-GR cells in culture experiments. Our mathematical model provides a quantitative understanding of the molecular reactions underlying drug resistance.
Project description:Previous study has demonstrated that HCC827/gef cells are resistant to gefitinib-induced aspoptosis. To investigate the regulators contributed to gefitinib resistance in lung cancer, we analyzed the gene expression profiles between HCC827 andHCC827/gef cells. Reduced IGFBP7 in TKI-resistant cells reversed resistance to EGFR-TKIs, and increased EGFR-TKI-induced apoptosis through up-regulation of BIM and activation of caspases. Suppression of IGFBP7 attenuated phosphorylation of IGF-IR and downstream AKT in TKI-resistant cells.
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.