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:Tyrosine kinase inhibitors (TKIs) targeting Anaplastic Lymphoma Kinase (ALK) have transformed the treatment landscape of ALK fusion-positive non-small cell lung carcinoma (NSCLC), but limited options for patients who progress on approved TKIs highlight a continued need for an orthogonal therapeutic approach. TRI-611 is a potent, brain-penetrant molecular glue degrader (MGD) of ALK fusion proteins with the potential to address this need . TRI-611 promotes the proximity of the ALK kinase domain and CRBN via a unique degron interface distal from the kinase active site. The unique binding interface of TRI-611 leads to selectivity across the proteome including known CRBN neo-substrates and other kinases. TRI-611 treatment induces degradation of all forms of oncogenic ALK fusion proteins, including TKI-resistant mutated versions of ALK, leading to regression of cell line and patient-derived subcutaneous and intracranial tumour models of ALK-positive NSCLC. TRI-611 can be combined with orthosteric ALK TKIs, achieving synergistic and durable tumour regressions. TRI-611 represents the first example of a clinical stage MGD targeting an oncogenic gene fusion and has the potential to expand the arsenal of therapeutic options for ALK-positive NSCLC patients.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:The rearrangement of anaplastic lymphoma kinase (ALK) occurs in 3%-5% of patients with non-small cell lung cancer (NSCLC) and confers sensitivity to ALK-tyrosine kinase inhibitors (TKIs). For the treatment of patients with ALK-rearranged NSCLC, various additional ALK-TKIs have been developed. Ceritinib is a second-generation ALK-TKI and has shown great efficacy in the treatment of patients with both newly diagnosed and crizotinib, a first-generation ALK-TKI, refractory ALK-rearranged NSCLC. However, tumors can also develop ceritinib resistance. This may result from secondary ALK mutations, but other mechanisms responsible for this have not been fully elucidated. In this study, we explored the mechanisms of ceritinib resistance by establishing ceritinib-resistant, echinoderm microtubule-associated protein-like 4 (EML4)-ALK-positive H3122 cells and ceritinib-resistant patient-derived cells. We identified a mechanism of ceritinib resistance induced by bypass signals that is mediated by the overexpression and activation of fibroblast growth factor receptor 3 (FGFR3). FGFR3 knockdown by small hairpin RNA or treatment with FGFR inhibitors was found to resensitize the resistant cells to ceritinib in vitro and in vivo. FGFR ligands from either human serum or fetal bovine serum were able to activate FGFR3 and induce ceritinib resistance. A detailed analysis of ceritinib-resistant patient-derived specimens confirmed that tyrosine-protein kinase Met (cMET) amplification induces ceritinib resistance. Amplified cMET counter-activated EGFR and/or Her3, and induced ceritinib resistance. These results reveal multiple ceritinib resistance mechanisms and suggest that ceritinib resistance might be able to overcome by identifying precise resistance mechanisms.