Communication in tiny packages: Exosomes as means of tumor-stroma communication

Tumor-derived exosomes are nano-sized vesicles acting as multi-signal devices influencing tumor growth at local and distant sites. Exosomes are derived from the endolysosomal compartment and can shuttle diverse biomolecules like nucleic acids (microRNAs, DNA fragments), lipids, proteins and even pharmacological compounds from a donor cell to recipient cells. The transfer of cargo to recipient cells enables tumor-derived exosomes to influence diverse cellular functions like proliferation, cell survival and migration in recipient cells highlighting tumor-derived exosomes as important players in the communication within the tumor microenvironment and at distant sites. In this review, we will discuss mechanisms associated with exosome biogenesis and cargo sorting. In addition, we highlight the communication of tumor-derived exosomes in the tumor microenvironment during different phases of tumor development with a main focus on angiogenesis, immune escape mechanisms, drug resistance, and metastasis

Structural Alterations of MET Trigger Response to MET Kinase Inhibition in Lung Adenocarcinoma Patients

Purpose: We sought to investigate the clinical response to MET inhibition in patients diagnosed with structural MET alterations and to characterize their functional relevance in cellular models.Experimental Design: Patients were selected for treatment with crizotinib upon results of hybrid capture-based next-generation sequencing. To confirm the clinical observations, we analyzed cellular models that express these MET kinase alterations.Results: Three individual patients were identified to harbor alterations within the MET receptor. Two patients showed genomic rearrangements, leading to a gene fusion of KIF5B or STARD3NL and MET One patient diagnosed with an EML4-ALK rearrangement developed a MET kinase domain duplication as a resistance mechanism to ceritinib. All 3 patients showed a partial response to crizotinib that effectively inhibits MET and ALK among other kinases. The results were further confirmed using orthogonal cellular models.Conclusions: Crizotinib leads to a clinical response in patients with MET rearrangements. Our functional analyses together with the clinical data suggest that these structural alterations may represent actionable targets in lung cancer patients. Clin Cancer Res; 24(6); 1337-43. (c)2017 AACR

Structural Alterations of MET Trigger Response to MET Kinase Inhibition in Lung Adenocarcinoma Patients

Purpose: We sought to investigate the clinical response to MET inhibition in patients diagnosed with structural MET alterations and to characterize their functional relevance in cellular models. Experimental Design: Patients were selected for treatment with crizotinib upon results of hybrid capture-based next-generation sequencing. To confirm the clinical observations, we analyzed cellular models that express these MET kinase alterations. Results: Three individual patients were identified to harbor alterations within the MET receptor. Two patients showed genomic rearrangements, leading to a gene fusion of KIF5B or STARD3NL and MET. One patient diagnosed with an EML4-ALK rearrangement developed a MET kinase domain duplication as a resistance mechanism to ceritinib. All 3 patients showed a partial response to crizotinib that effectively inhibits MET and ALK among other kinases. The results were further confirmed using orthogonal cellular models. Conclusions: Crizotinib leads to a clinical response in patients with MET rearrangements. Our functional analyses together with the clinical data suggest that these structural alterations may represent actionable targets in lung cancer patients. (C) 2017 AACR