Expression data from EGFR WT or EGFR mutant NSCLC with or without erlotinib
ABSTRACT: Non-small cell lung cancers (NSCLCs) harboring activating EGFR mutants show dramatic responses to EGFR TKIs, such as erlotinib and geffitinib. However, nearly all patients show relapse within 1 year after initial treatment. We used microarrays to detail global gene expression changes in EGFR mutant cells vs. WT cells responding to erlotinib. 4 EGFR mutant and 4 WT NSCLC cells were treated with or without erlotinib for 24 hr, followed by RNA extraction and hybridization on Affymetrix microarrays.
Project description:The receptor tyrosine kinase (RTK) EGFR is overexpressed and mutated in NSCLC. These mutations can be targeted by RTK inhibitors (TKIs), such as erlotinib. Chromatin-modifying agents offer a novel therapy approach by sensitizing tumor cells to TKIs. The NSCLC cell lines HCC827 (EGFR mutant, adenocarcinoma), A549 (EGFR wt, adenocarcinoma) and NCI-H460 (EGFR wt, large cell carcinoma) were analyzed by SNP6.0 array. Changes in proliferation were quantified by WST-1 assay, apoptosis by Annexin V/7-AAD flow cytometry and histone marks (acH3, H3K4me1,-2,-3) by immunoblotting. Expectedly, the EGFR wt cell lines A549 and NCI-H460 were insensitive to the growth-inhibiting effect of single-agent erlotinib (IC50 70-100µM), compared to HCC827 (IC50 <0.02μM). Treatment with panobinostat diminished growth to <50% in both EGFR wt and <30% in HCC827 cells. The combination of both drugs significantly reduced proliferation by ≥70% in A549, >95% in HCC827, but not further in NCI-H460. Panobinostat alone induced differentiation and expression of p21WAF1/CIP1 and p53 in all three cell lines, with almost no further increase when combined with erlotinib. In contrast, combination treatment additively decreased pERK, pAKT and pEGFR in A549, and synergistically induced acH3 in both adenocarcinoma lines. Surprisingly, we also saw an induction of H3K4 methylation marks in all three cell lines. In conclusion, panobinostat synergistically sensitized lung adenocarcinoma cells to the antiproliferative effects of erlotinib. Since single-agent erlotinib has only modest clinical effects in adenocarcinoma EGFR wt patients, combination therapy with an HDACi might offer a promising therapy approach to extend this activity. Copy-number analysis of three NSCLC cell lines HCC827, A549 and NCI-H460 (in unicates) was performed according to protocol by Affymetrix Genome-Wide Human SNP-Array 6.0.
Project description:Elevated expression and activity of the epidermal growth factor receptor (EGFR) is associated with development and progression of head and neck cancer (HNC) and a poor prognosis. Clinical trials with EGFR tyrosine kinase inhibitors (TKIs; eg. erlotinib) have been disappointing in HNC. To investigate the mechanisms mediating resistance to these agents, we developed a HNC cell line (HN5-ER) with acquired erlotinib resistance. In contrast to parental HN5 HNC cells, HN5-ER cells exhibited an epithelial-mesenchymal (EMT) phenotype with increased migratory potential, reduced E-cadherin and epithelial-associated miRNAs, and elevated vimentin expression. Phosphorylated RTK profiling identified Axl activation in HN5-ER cells. Growth and migration of HN5-ER cells was blocked with a specific Axl inhibitor, R428, and R428 re-sensitized HN5-ER cells to erlotinib. Microarray analysis of HN5-ER cells confirmed the EMT phenotype associated with acquired erlotinib resistance, and identified activation of gene expression associated with cell migration and inflammation pathways. Moreover, increased expression and secretion of interleukin (IL)-6 and IL-8 in HN5-ER cells suggested a role for inflammatory cytokine signaling in EMT and erlotinib resistance. Expression of the tumor suppressor miR-34a was reduced in HN5-ER cells and increasing its expression abrogated Axl expression and reversed erlotinib resistance. Finally, analysis of 302 HNC patients revealed that high tumor Axl mRNA expression was associated with poorer survival (HR 1.66, p=0.007). In summary, our results identify Axl as a key mediator of acquired erlotinib resistance in HNC and suggest that therapeutic inhibition of Axl by small molecule drugs or specific miRNAs might overcome anti-EGFR therapy resistance. Differential gene expression between parental and acquired erlotinib resistant head and neck cancer cell lines of HN5.
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: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:Chronic inflammation plays a significant role in tumor promotion, migration and invasion. Using microarray analysis, we observed a profound increase in genes involved in pro-inflammatory pathways in epidermal growth factor receptor inhibitor (EGFRI)-treated head and neck squamous cell carcinoma (HNSCC) cell lines compared to their respective vehicle-treated cell lines. We hypothesized that the efficacy of EGFRIs may be offset by the pro-inflammatory response that these drugs produce in HNSCC tumor cells. We found that clinical EGFRIs such as erlotinib, cetuximab, lapatinib and panitumumab induced the secretion of pro-inflammatory cytokines such as IL-2, IL-4, IL-6, IL-8, GM-CSF, TNFα and IFNγ. Focusing on IL-6, we found that erlotinib induced a time-dependent increase in IL-6 mRNA and protein expression and exogenous IL-6 was able to protect HNSCC cells from erlotinib-induced cytotoxicity. Conversely, an IL-6 receptor antagonist tocilizumab, sensitized HNSCC cells to erlotinib in vitro and in vivo. Inhibitors of NFκB, p38 and JNK suppressed erlotinib-induced IL-6 expression, suggesting an important role of NFκB and MAPK pathways in IL-6 expression. Furthermore, knockdown of NADPH oxidase 4 (NOX4) suppressed erlotinib-induced pro-inflammatory cytokines expression. Taken together, these results suggest that clinical EGFRIs induce the expression of pro-inflammatory cytokines via NOX4. Therefore, the anti-tumor activity of EGFRIs may be partially reduced by activation of NOX4-mediated pro-inflammatory pathways in HNSCC. Total RNA was isolated from Head and Neck Squamous Cell Carcinoma cell lines FADU, SQ20B and Cal 27 subjected to 48 hours of 0.01% DMSO or 5uM EGFR inhibitor, erlotinib treatment.
Project description:Despite the role of epidermal growth factor receptor (EGFR) signaling in head and neck squamous cell carcinoma (HNSCC) development and progression, clinical trials involving EGFR tyrosine kinase inhibitors (TKIs) have yielded poor results in HNSCC patients. Mechanisms of acquired resistance to the EGFR TKI erlotinib was investigated by developing erlotinib-resistant HNSCC cell lines (Cal-27, SCC-25, FaDu, and SQ20B) and comparing their gene expression profiles with their parental erlotinib-sensitive HNSCC cell lines using microarray analyses. Subsequent pathway and network analyses displayed a significant upregulation in immune response pathways. Role of immune/inflammatory signaling in acquired resistance to erlotinib in HNSCC was investigated. Overall design: Total RNA was isolated from erlotinib-resistant and erlotinib-sensitive head and neck squamous cell carcinoma cell lines Cal-27, SCC-25, FaDu, and SQ20B subjected to 48 hours of 0.01% DMSO (i.e., vehicle control).
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: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.. Overall design: Differntial expresssion profile of transcripts of parental (HCC827) and EGFR-TKI (HCC827 ZDR3) resistance cells
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.. Overall design: Genome wide study on the transcriptional binding profile with C-JUN in parental (HCC827) and EGFR-TKI (HCC827 ZDR3) resistance cells using a ChIP_seq.
Project description:Targeted therapies against EGFR show clinical benefit, but resistance to these agents invariably develops. Thus, there is a need for dynamic biomarkers - effect sensors - that reflect treatment with EGFR therapeutics during therapy. Making use of SILAC-labeling we aimed to discover plasma membrane proteins that become differentially expressed after treatment with EGFR inhibitor erlotinib in three erlotinib-sensitive breast cancer cell lines.