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:Methylation profiling study by MBD-seq for identifying genes associated with epithelial-mesenchymal transition and acquired resistance to ALK inhibitors
Project description:Gene expression profiling study by RNA-seq for identifying genes associated with epithelial-mesenchymal transition and acquired resistance to ALK inhibitors.
Project description:Gene expression profiling study by RNA-seq for identifying genes associated with epithelial-mesenchymal transition and acquired resistance to 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 ChIP-seq analysis.
Project description:The purpose of this study was to assess the preliminary antitumor activity, safety and tolerability of tepotinib in combination with cetuximab in participants with RAS/BRAF wild-type left-sided Metastatic Colorectal Cancer (mCRC) having acquired resistance to anti-epidermal growth factor receptor (EGFR) antibody targeted therapy due to mesenchymal epithelial transition (MET) amplification.
Project description:The crizotinibâresistant ALKF1174L mutation arises de novo in neuroblastoma (NB) and is acquired in ALK translocation-driven cancers, lending impetus to the development of novel ALK inhibitors with different modes of action. The diaminopyrimidine TAE684 and its derivative ceritinib (LDK378), which are structurally distinct from crizotinib, are active against NB cells expressing ALKF1174L. Here we demonstrate acquired resistance to TAE684 and LDK378 in ALKF1174L-driven human NB cells that is linked to overexpression and activation of the AXL tyrosine kinase and epithelial-to-mesenchymal transition (EMT). AXL phosphorylation conferred TAE684 resistance to NB cells through upregulated ERK signaling. Inhibition of AXL partly rescued TAE684 resistance, resensitizing these cells to this compound. AXL activation in resistant cells was mediated through increased expression of the active form of its ligand, GAS6, which also served to stabilize the AXL protein. Although ectopic expression of AXL and TWIST2 individually in TAE684-sensitive parental cells led to the elevated expression of mesenchymal markers and invasive capacity, only AXL overexpression induced resistance to TAE684 as well. TAE684-resistant cells showed greater sensitivity to HSP90 inhibition than did their parental counterparts, with downregulation of AXL and AXL-mediated ERK signaling. Our studies indicate that aberrant AXL signaling and development of an EMT phenotype underlie resistance of ALKF1174L-driven NB cells to TAE684 and its derivatives. We suggest that the combination of ALK and AXL or HSP90 inhibitors be considered to delay the emergence of such resistance. In order to understand the molecular mechanisms driving resistance to ALK inhibition in ALK-mutated neuroblatoma, we established cell line models of resistance to TAE684, an ALK inhibitor, by treating SH-SY5Y cells (bearing the ALKF1174L mutation) with increasing concentration of this compound over time. We then performed an analysis of gene expression changes genome wide using Affymetrix U133 Plus 2 arrays, by comparing the TAE684-sensitive parental SH-SY5Y cells to the TAE684-resistant SH-SY5Y cells (named SY5Y-TR1). For that experiment, we analyzed gene expression variations by comparing the parental SH-SY5Y (control sample) to the resistant SY5Y-TR1 cells. So 2 samples were analyzed, with 3 replicates run for each.