Expanded Circulating Tumor Cells from a Patient with ALK-Positive Lung Cancer Present with EML4-ALK Rearrangement Along with Resistance Mutation and Enable Drug Sensitivity Testing: A Case Study.

The emergence of liquid biopsy using circulating tumor cells (CTCs) as a resource to identify genomic alterations in cancer presents new opportunities for diagnosis, therapy, and surveillance. We identified EML4-ALK gene rearrangement in expanded CTCs from a patient with ALK-positive lung adenocarcinoma. At the time of radiographic progression, CTCs obtained from the patient revealed a drug resistance mutation (i.e., L1196M on the ALK gene). CTCs were expanded ex vivo and drug sensitivity testing was performed using two ALK inhibitors, crizotinib and ceritinib. The half maximal inhibitory concentration of ceritinib was 1664 nM compared with crizotinib (2268 nM), showing that ceritinib was a more potent ALK inhibitor. We show that it is feasible to detect serial genetic alterations in expanded CTCs and perform in vitro drug screening. These findings support the clinical utility of CTCs not only for diagnosis, but also a potential tool for drug sensitivity testing in distinct subsets of lung cancer and for personalized precision medicine

beta(1)-integrin mediates pressure-stimulated phagocytosis

BACKGROUND: Extracellular pressure alterations in infection, inflammation, or positive pressure ventilation May influence macrophage phagocytosis. We hypothesized that pressure modulates beta 1-integrins to stimulate phagocytosis. METHODS: We assayed fibroblast phagocytosis of fluorescent latex beads at ambient or 20 mm Hg increased pressure, and macrophage integrin phosphorylation by Western blot. RESULTS: Pressure did not alter phagocytosis in beta(1)-integrins null GD25 fibroblasts, but stimulate phagocytosis in fibroblasts expressing wild-type beta(1)-integrin. In phorbol myristate acetate-differentiated THP-1 macrophages, pressure stimulated beta(1)-integrin T788/789 phosphorylation, but not S785 phosphorylation. Furthermore, pressure stimulated phagocytosis in cells expressing an inactivating S785A point Mutation or a T788D substitution to mimic a constitutively phosphorylated threonine, but not in cells expressing an inactivating TT788/9AA mutation. CONCLUSIONS: The effects of pressure oil phagocytosis are not limited to macrophages but generalize to other phagocytic cells. These results suggest that pressure stimulates phagocytosis via increasing beta(1)-integrin T789 phosphorylation. Interventions that target beta(1)-integrin threonine 789 phosphorylation may modulate phagocytic function. Published by Elsevier Inc