Project description:We were interested in characterizing the transcriptional changes that occur on a genome-wide scale following treatment of EGFR-mutant lung cancer cells with targeted therapies. HCC827 human lung cancer cells harboring an amplified EGFR allele with an activating in frame deletion of 15 nucleotides in exon 19 were treated in triplicate with 1uM erlotinib (EGFR inhibitor), AZD-6244 (MEK inhibitor) or BEZ-235 (PI3-Kinase/mTOR inhibitor) for 6 hours, followed by total mRNA isolation and whole transcriptome analysis using Affymetrix U133 Plus 2.0 expression arrays.
Project description: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: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: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.
Project description:Analysis of human, adult, dermal fibroblasts following treatment with 100nM or 1 uM of erlotinib, a tryrosine kinase inhibitor (TKI) that targets the epidermal growth factor receptor (EGFR) inhibiting EGFR activation and signaling. Erlotinib is widely used to effectively treat patients with advanced non-small cell lung cancer but treatment with erlotinib and other EGFR TKIs are associated with a painful skin rash. Results identified significantly differentially expressed genes in fibroblasts treated with erlotinib providing insight into how the drug alters the transcriptome in ways that may contribute to the TKI-related rash.
Project description:Epidermal growth factor receptor (EGFR) inhibitors, as targeted therapies for non-small-cell lung cancer (NSCLC), have significantly enhanced patient survival and quality of life. However, despite these advancements, a significant proportion of patients exhibit resistance to EGFR inhibitors, limiting their overall treatment effectiveness. This study investigates the synergistic effects of combining Paeoniae Radix (PR) with the EGFR inhibitors erlotinib and gefitinib to overcome this resistance. The transcriptomic analysis of PR treatment revealed its potential to reverse the gene signature associated with resistance to EGFR inhibitors, as identified through analysis of a cell line database in EGFR mutant NSCLC. Combination treatment experiments validated that PR increased responsiveness to erlotinib and gefitinib in H1650 and H1975 NSCLC cells. By combining molecular experiments and transcriptome analysis, we found that PR may suppress resistance by modulating the Aurora B and apoptosis pathways. Notably, the combination therapy upregulated the apoptosis pathway and downregulated the Aurora B pathway more than single drug treatments. These results may contribute to the development of natural product-based combination therapeutic strategies to inhibit drug resistance in NSCLC.
Project description:Mutations in the epidermal growth factor receptor (EGFR) kinase domain occur in 10-30% of lung adenocarcinoma. Leucine to arginine substitution at amino acid position 858 (L858R) accounts for around 50% of EGFR-tyrosine kinase inhibitor (TKI) sensitizing mutations. A second site mutation in the gatekeeper residue (T790M) accounts for around 60% of acquired resistance to EGFR-TKIs. We sought to identify the immediate direct and indirect targets of these mutant EGFRs in lung adenocarcinoma and their modulation by erlotinib, the first generation, and most widely used EGFR-directed TKI. We undertook stable isotope labeling of amino acids in cell culture (SILAC), phosphopeptide enrichment, and quantitative mass spectrometry to identify dynamic changes of phosphorylation downstream of mutant EGFRs in lung adenocarcinoma cells harboring L858R or L858R/T790M mutations and their modulation by erlotinib inhibition. Phosphorylation at the majority of phosphosites identified exhibited no change upon either EGF stimulation or erlotinib inhibition. Only around 7% of phosphosites identified and quantified showed increased phosphorylation upon EGF stimulation in either cell line. However, while phosphorylation at 61% of these phosphosites decreased upon erlotinib inhibition in the TKI sensitive H3255 cells, only 24% of such sites exhibited decreased phosphorylation upon erlotinib inhibition in the TKI resistant H1975 cells. Top canonical pathways that were inhibited upon erlotinib treatment in sensitive cells, but not the resistant cells include EGFR, Insulin receptor, HGF, MAPK, mTOR, p70S6K and JAK/STAT signaling. We identified phosphosites in proteins of the autophagy network, such as ULK1 (S623) that is constitutive phosphorylated in these lung adenocarcinoma cells, but phosphorylation is inhibited upon erlotinib treatment in sensitive cells, but not resistant cells. Finally, kinase-substrate prediction analysis from our data indicated that substrates of basophilic kinase families, AGC, CAMK and STE were significantly enriched and those of proline directed kinase families, CMGC and CK were significantly depleted among substrates that exhibit increased phosphorylation upon EGF stimulation and reduced phosphorylation upon TKI inhibition. This is the first study to date to examine global phosphorylation changes upon erlotinib treatment of lung adenocarcinoma cells and results from this study provide new insights into signaling downstream of mutant EGFRs in lung adenocarcinoma.