Project description:Treatment with ALK tyrosine kinase inhibitors often elicits profound initial antitumor responses in ALK fusion-positive patients with lung adenocarcinoma. However, patients invariably develop acquired resistance to ALK inhibitors. In this study, we aimed to identify molecular events that limit the response to ALK inhibition using genetic and epigenetic approaches. To identify novel mechanisms of acquired resistance to ALK inhibitors, we established in vitro models of acquired resistance to ceritinib using H3122 cell. For in vitro model, H3122 parental cells, ceritinib-treated resistant cells, and non-resistant cells that combinely treated with certinib and panobinostat were used for small RNA-seq based miRNA expression profiling.
Project description:Anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs) induce a dramatic response in non–small cell lung cancer (NSCLC) patients with the ALK fusion gene. However, acquired resistance to ALK-TKIs in lung cancer cells remains an inevitable problem: ALK secondary mutations and bypass pathways have been reported as major resistance mechanisms. In this study, we aimed to discover a novel mechanism of acquired resistance to ALK-TKIs and a strategy to conquer ALK-positive lung cancer. We established three types of ALK-TKI (crizotinib, alectinib and ceritinib)–resistant H2228 non-small cell lung cancer cell lines by high exposure and stepwise methods. We found these cells showed a loss of ALK signaling, overexpressed AXL with epithelial–mesenchymal transition (EMT), and had cancer stem cell–like properties. Similarly, we demonstrated that TGF-β1 treated H2228 cells also showed AXL overexpression with EMT features and ALK-TKI–resistance. The AXL inhibitor, R428, or HSP90 inhibitor, ganetespib, were effective in reversing ALK-TKI–resistance and EMT changes in both ALK-TKI–resistant and TGF-β1–exposed H2228 cells. Progression-free survival of ALK-positive NSCLC patients with AXL overexpression was shorter than that of patients who underwent crizotinib therapy and showed low AXL expression. Thus, we found ALK signaling-independent AXL overexpression and EMT features were commonly involved in intrinsic and acquired resistance to first and second generation ALK-TKIs. This suggests AXL and HSP90 inhibitors may be promising therapeutic drugs to overcome tumor cells in ALK-positive NSCLC patients.
Project description:Expression profiling by small RNA-seq for identifying miRNA associated with epithelial-mesenchymal transition and acquired resistance to ALK inhibitors
Project description:A subset of lung adenocarcinomas is driven by the EML4-ALK translocation. Despite excellent initial responses in patients, acquired resistance to ALK inhibitors occurs. Exploring these mechanisms of resistance, we found that EML4-ALK cells resistant to ALK inhibitors are remarkably sensitive to THZ1, alvocidib or dinaciclib. These compounds robustly induce apoptosis through transcriptional inhibition and downregulation of anti-apoptotic genes. In conclusion, this study shows that THZ1, alvocidib or dinaciclib could be a therapeutic option for a subset of patients with acquired resistance to first, second and third-generation ALK inhibitors.
Project description:A subset of lung adenocarcinomas is driven by the EML4-ALK translocation. Despite excellent initial responses in patients, acquired resistance to ALK inhibitors occurs. Exploring these mechanisms of resistance, we found that EML4-ALK cells resistant to ALK inhibitors are remarkably sensitive to THZ1, alvocidib or dinaciclib. These compounds robustly induce apoptosis through transcriptional inhibition and downregulation of anti-apoptotic genes. In conclusion, this study shows that THZ1, alvocidib or dinaciclib could be a therapeutic option for a subset of patients with acquired resistance to first, second and third-generation ALK inhibitors.
Project description:Treatment with ALK tyrosine kinase inhibitors often elicits profound initial antitumor responses in ALK fusion-positive patients with lung adenocarcinoma. However, patients invariably develop acquired resistance to ALK inhibitors. In this study, we aimed to identify molecular events that limit the response to ALK inhibition using genetic and epigenetic approaches. To identify novel mechanisms of acquired resistance to ALK inhibitors, we established in vitro models of acquired resistance to ceritinib using H3122 cell. For in vitro model, H3122 parental cells, ceritinib-treated resistant cells, and non-resistant cells that combinely treated with certinib and panobinostat were used for MBD-seq based methylation profiling.
Project description:Treatment with ALK tyrosine kinase inhibitors often elicits profound initial antitumor responses in ALK fusion-positive patients with lung adenocarcinoma. However, patients invariably develop acquired resistance to ALK inhibitors. In this study, we aimed to identify molecular events that limit the response to ALK inhibition using genetic and epigenetic approaches. To identify novel mechanisms of acquired resistance to ALK inhibitors, we established in vitro models of acquired resistance to ceritinib using H3122 cell. For in vitro model, H3122 parental cells, ceritinib-treated resistant cells, and non-resistant cells that combinely treated with certinib and panobinostat were used for ChIP-seq analysis.
