Project description:Third-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs), including osimertinib, an irreversible EGFR-TKI, are important treatments for non-small cell lung cancer with EGFR-TKI sensitizing or EGFR T790M resistance mutations. Whilst patients treated with osimertinib show clinical benefit, disease progression and drug resistance are common. Emergence of de novo acquired resistance from a drug tolerant persister (DTP) cell population is one mechanism proposed to explain progression on osimertinib and other targeted cancer therapies. Here we profiled osimertinib DTPs using RNA-seq, ChIP-seq, and ATAC-seq to characterize the features of these cells and performed drug screens to identify therapeutic opportunities.
Project description:Third-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs), including osimertinib, an irreversible EGFR-TKI, are important treatments for non-small cell lung cancer with EGFR-TKI sensitizing or EGFR T790M resistance mutations. Whilst patients treated with osimertinib show clinical benefit, disease progression and drug resistance are common. Emergence of de novo acquired resistance from a drug tolerant persister (DTP) cell population is one mechanism proposed to explain progression on osimertinib and other targeted cancer therapies. Here we profiled osimertinib DTPs using RNA-seq, ChIP-seq, and ATAC-seq to characterize the features of these cells and performed drug screens to identify therapeutic opportunities.
Project description:Third-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs), including osimertinib, an irreversible EGFR-TKI, are important treatments for non-small cell lung cancer with EGFR-TKI sensitizing or EGFR T790M resistance mutations. Whilst patients treated with osimertinib show clinical benefit, disease progression and drug resistance are common. Emergence of de novo acquired resistance from a drug tolerant persister (DTP) cell population is one mechanism proposed to explain progression on osimertinib and other targeted cancer therapies. Here we profiled osimertinib DTPs using RNA-seq, ChIP-seq, and ATAC-seq to characterize the features of these cells and performed drug screens to identify therapeutic opportunities.
Project description:Exosomal miRNAs involved in resistance to osimertinib in EGFR-mutant NSCLC cells were successfully identified through the microoarray analysis.
Project description:Human EGFR-mutant lung cancer cells lines were investigated for their dynamic transcriptional response upon treatment with EGFR-inhibitor osimertinib in a time-series experiment
Project description:Background: Although TP53 gain-of-function (GOF) mutations promote cancer survival, its effect on EGFR-TKI efficacy remains unclear. We established EGFR-mutant lung cancer cell lines expressing various TP53 genotypes using CRISPR-Cas9 technology and found that TP53-GOF mutant cells develop an early resistance to EGFR-TKI osimertinib.The goal of this study is to elucidate the mechanisms underlying resistance to osimertinib treatment in TP53 GOF mutations through comprehensive gene analysis using ChIP-seq.
Project description:Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective in non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. However, due to the acquired resistance to EGFR-TKIs, even third generation Osimertinib, the patients suffer poor prognosis. The resistance mechanisms are still not fully understood. Here, we demonstrate that increased expression of MUSASHI-2 (MSI2), an RNA binding protein, is novel mechanisms for resistance to EGFR-TKIs. We found that after long-exposure of gefitinib, the first generation EGFR-TKI, lung cancer cells harboring the EGFR-TKI-sensitive mutations became resistant to not only gefitinib but also Osimertinib. Although other mutations in EGFR were not found, expression levels of Nanog, a stemness core protein, and activities of aldehyde dehydrogenase (ALDH) were increased, suggesting that cancer stem-like properties were increased. Transcriptome analysis revealed that MSI2 was among the top list of the stemness-related genes upregulated in the EGFR-TKI-resistant cells. Knockdown of MSI2 reduced cancer stem-like properties, including expression levels of Nanog a core stemness factor. We demonstrate that knockdown of MSI2 restored sensitivity to Osimertinib or gefitinib in the EGFR-TKI-resistant cells to the similar levels of the parental cells in vitro. RNA immunoprecipitation (RIP) assay revealed that antibodies against MSI2 bound to Nanog mRNA, suggesting that MSI2 increases Nanog expression by binding to Nanog mRNA. Moreover, overexpression of MSI2 or Nanog conferred resistance to Osimertinib or gefitinib in parental cells. Finally, knockdown of MSI2 greatly increased sensitivity to Osimertinib in vivo. Collectively, our findings provide proof-of-principle that targeting MSI2-Nanog axis in combination with EGFR-TKIs would effectively prevent emergence of acquired resistance.
Project description:Osimertinib, as a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has been approved as a first-line therapy in advanced non–small-cell lung cancer (NSCLC) patients with EGFR-activating or T790M resistance mutations. However, the efficacy of osimertinib is limited due to acquired resistance. In order to search for the mechanism of resistance to osimertinib, we screened on significantly upregulated genes encoding protein kinases in osimertinib-resistant NSCLC cells via RNA-sequence.In summary, our data elucidate the alterations in gene expression within lung cancer cells before and after resistance to osimertinib, aiding in the analysis and identification of key molecules influencing osimertinib resistance.