Project description:Previous study has demonstrated that PC9/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 PC9 and PC9/gef cells. Our results showed that IL-8 contributes to gefitinib resistance and cancer stemness. In contrast, IL-8 knockdown decreased stem-like characteristics and increased gefitinib-induced apoptosis in PC9/gef cells. RNAs extracted from gefitinib-sensitive PC9 cells and gefitinib-resistant PC9/gef cells were hybridized on Affymetrix microarrays. We tried to compare the differential gene expression profiles between PC9 and PC9/gef cells to identify the possible regulators in gefitinib resistance.
Project description:Lung cancer is the leading cause of cancer death. Mutations in the kinase domain of EGFR, a predominant driver oncogene, such as L858R missense mutation and a series of deletions spanning the conserved sequence 747LREA750, are associated with sensitivity to tyrosine kinase inhibitors (TKIs). However, patients receiving EGFR-TKIs (gefitinib and erlotinib) develop drug-resistance due to a secondary mutation at the gatekeeper residue (T790M) in about 50-60% of cases, urging for new drug development. Afatinib, a FDA approved second-generation EGFR-TKI that was developed to circumvent T790M-mediated resistance, has not been very effective in clinical trials. In this study, we performed a global phosphoproteomic screen to identify targets that undergo mutant EGFR-dependent tyrosine phosphorylation and their modulation by erlotinib or afatinib. 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 and afatinib inhibition. We identified and quantified 397, 429, 223, and 594 phosphotyrosine sites in H3255, 11-18,PC9, and H1975 cell lines that were grown in presence of FBS and in presence/absence of TKIs, respectively. These account for a total of 907 unique phospho-tyrosine sites in 496 proteins. Among them, 187 phosphotyrosine sites were found to be in 89 kinases, which may serve as intermediary regulatory kinases in EGFR signalling pathway. Further analysis indicated that in TKI-sensitive H3255 and 11-18 cells, there were 58/111 and 65/101 tyrosine sites that were hypophosphorylated in presence of erlotinib and afatinib, respectively. However, in TKI-resistant H1975 cells, 189 and 264 tyrosine sites were hypophosphorylated in presence of erlotinib and afatinib respectively, indicating that the afatinib-specific additional sites could be validated for identifying potentially new drug targets to counter TKI-resistance. Ingenuity pathway analysis (IPA) of proteins with altered phosphorylation sites demonstrated that several canonical pathways including ephrin receptor signalling and integrin signalling pathways were enriched, which may play important roles in cell growth and proliferation. However, upon EGF stimulation of serum starved H3255 cells in presence or absence of TKIs, 99 tyrosine sites that were hyperphosphorylated upon EGF stimulation were inhibited in presence of erlotinib or afatinib. But in H1975 cells treated with erlotinib, 48 of the above sites were either unchanged or were hyperphosphorylated. These sites include EGFR (Y1197/869/998), JAK1 (Y1034), FRK (Y497), GAB1 (Y657/689), MAPK1 (Y187), MAPK3 (Y204), MET (Y1252/1253). Furthermore, a total of 112 sites that were observed to be hypophosphorylated upon EGF stimulation in H1975 cells, were found to be hyperphosphorylated upon erlotinib inhibition. This could possibly be due to the activation of downstream phosphatases with EGF stimulation. We are now performing in-depth bioinformatic analysis and validation experiments using functional genomics to understand the role of targets of mutant EGFR signalling in lung cancer.
Project description:Genome variation profiling of lung adenocarcinoma cells comparing untreated NCI-H1975 cells with CNX-2006-resistant untreated cells. Goal was to determine the potential mechanism of resistance to mutant EGFR-TKIs and rationally design novel strategies for the treatment of EGFR-mutant lung cancer patients. Two-condition experiment: NCI-H1975 parental cells vs CNX-2006-resistant cells. Pooled DNA from healthy volunteers was used as reference.
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:Immunocompromised mice were inoculated with human lung adenocarcinoma cell line PC9 and with human PBMCs. Tumors were treated with osimertinib/vehicle of RIG-I agonist IVT4/unspecific control IVT-GAC to assess response.
Project description:Purpose: Our previous clinical trials have been demonstrated that Anlotinib can inhibit tumor growth upon refractory advanced non-small cell lung cancer (NSCLC) patients with the possibility mechanism of anti-angiogenesis. The present study sought to reveal the underlying molecular mechanism of Anlotinib-induced anti-angiogenesis in advanced NSCLC. Experimental Design: Computed tomography (CT) was used to evaluate the treatment effect of Anlotinib upon refractory advanced NSCLC patients. Transcriptome profiling was performed to identify the key gene expression alteration in NCI-H1975 cells before and after Anlotinib treatment. NCI-H1975 derived xenograft model was applied to investigate treatment effect and verify anti-angiogenesis mechanism of Anlotinib. Results: Anlotinib induces tumor cytotoxicity on refractory advanced NSCLC patients, NCI-H1975 derived xenograft models and lung adenocarcinoma cell lines. Transcriptome profiling revealed CCL2 blockade could be responsible for Anlotinib-induced anti-angiogenesis. NCI-H1975 derived xenograft model demonstrated Anlotinib-induced CCL2 blockade play an important role in anti-angiogenesis. Conclusions: This study not only offered the first evidence that Anlotinib inhibits angiogenesis via blocking CCL2 expression, but also provided a novel theoretical basis for the application of Anlotinib in advanced NSCLC patients.
Project description:H1975 cells were treated with DMSO and erastin, respectively. Protein was extracted and separated using SDS-PAGE electrophoresis. MS analysis was performed and protein was identified and quantified using Proteome Discoverer™ 1.3 software using the SEQUEST® search engine.
Project description:Gene expression profile was analyzed after knockdown of PAEP in lung cancer cell lines 2106T and H1975 as well as in skin cancer cell line MeWo. The aim of the study was to investigate the role of PAEP and its protein product glycodelin in lung cancer cell lines. Cells were treated with a control siRNA or a siRNA pool of 4 siRNAs targeting PAEP. RNA of three biological replicates each was extracted and used for Affymetrix analyses.