Clin Cancer Res
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Hepatocyte growth factor (HGF) induces resistance to reversible and irreversible epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) in EGFR mutant lung cancer cells by activating Met and the downstream phosphoinositide 3-kinase (PI3K)/Akt pathway. Moreover, continuous exposure to HGF accelerates the emergence of EGFR-TKI-resistant clones. We assayed whether a new Met kinase inhibitor, E7050, which is currently being evaluated in clinical trials, could overcome these three mechanisms of resistance to EGFR-TKIs. ⋯ A new Met kinase inhibitor, E7050, reverses the three HGF-induced mechanisms of gefitinib resistance, suggesting that E7050 may overcome HGF-induced resistance to gefitinib and next-generation EGFR-TKIs.
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Patients with anaplastic lymphoma kinase (ALK) gene rearrangements often manifest dramatic responses to crizotinib, a small-molecule ALK inhibitor. Unfortunately, not every patient responds and acquired drug resistance inevitably develops in those who do respond. This study aimed to define molecular mechanisms of resistance to crizotinib in patients with ALK(+) non-small cell lung cancer (NSCLC). ⋯ Crizotinib resistance in ALK(+) NSCLC occurs through somatic kinase domain mutations, ALK gene fusion CNG, and emergence of separate oncogenic drivers.
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Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor, often metastatic at presentation, for which current chemotherapeutic regimens are largely ineffective. As its pathogenesis is still unknown, we hypothesized that deregulation of signaling pathways commonly activated in cancer may contribute to MCC tumorigenesis and may provide insights into targeted therapy approaches for this malignancy. ⋯ PI3K pathway activation may drive tumorigenesis in a subset of MCC and screening these tumors for PIK3CA mutations could help identify patients who may respond to treatment with PI3K pathway inhibitors.
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Recent advances in tumor genetics and drug development have led to the generation of a wealth of anticancer targeted therapies. A few recent examples indicate that these drugs are mainly, if not exclusively, active against tumors of a particular genotype that can be identified by a diagnostic test, usually by detecting a somatic alteration in the tumor DNA. However, for the majority of targeted therapies in development, there are still no clinical tools to determine which patients are most likely to benefit or, alternatively, be resistant de novo to these novel agents or drug combinations.
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Comment Letter
Targeting proteasomal protein degradation in cancer-letter.