Introduction: Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib are approved for advanced non-small-cell lung cancer (NSCLC) with ALK rearrangement. However, the mechanisms of resistance remain largely unclear.
Methods: This prospective multicenter study analyzed cell-free DNA (cfDNA) and/or cancer tissues of patients with NSCLC after progression on ALK TKI(s), using targeted next-generation sequencing.
Cell migration is a highly regulated event that is initiated by cell membrane protrusion and actin reorganization. Robo1, a single-pass transmembrane receptor, is crucial for neuronal guidance and cell migration. ADP-ribosylation factor (Arf)-like 4A (Arl4A), an Arf small GTPase, functions in cell morphology, cell migration, and actin cytoskeleton remodeling; however, the molecular mechanisms of Arl4A in cell migration are unclear.
View Article and Find Full Text PDFChanges in cell morphology and the physical forces that occur during migration are generated by a dynamic filamentous actin cytoskeleton. The ADP-ribosylation factor-like 4C (Arl4C) small GTPase acts as a molecular switch to regulate morphological changes and cell migration, although the mechanism by which this occurs remains unclear. Here we report that Arl4C functions with the actin regulator filamin-A (FLNa) to modulate filopodium formation and cell migration.
View Article and Find Full Text PDFSince clinical drugs need to be approved for their liver metabolism efficiency before commercialization, a powerful in vitro drug-screening platform is imperative and indispensable for the clinical medicine and pharmaceutical industries. An essential issue in the development of drug screening platforms is choosing cell candidates that mimic and perform cell/tissue functions of normal hepatic tissues in vivo. In this study, we developed a self-designed bioreactor system to provide and mimic an appropriate environment for systematic cell expansion, micro-tissue formation, and increased cellular cytochrome P450 (CYP) enzymatic activities.
View Article and Find Full Text PDFHuman hepatoma cell lines are commonly used as alternatives to primary hepatocytes for the study of drug metabolism in vitro. However, the phase I cytochrome P450 (CYP) enzyme activities in these cell lines occur at a much lower level than their corresponding activities in primary hepatocytes, and thus these cell lines may not accurately predict drug metabolism. In the present study, we selected hepatocyte nuclear factor-1 alpha (HNF1α) from six transcriptional regulators for lentiviral transfection into Hep G2 cells to optimally increase their expression of the CYP3A4 enzyme, which is the major CYP enzyme in the human body.
View Article and Find Full Text PDFA reliable, reproducible, and convenient in vitro platform for drug metabolism determination and toxicity prediction is of tremendous value but still lacking. In the present study, a collection of 24 hepatic transcription factors and nuclear receptors in different combinations were surveyed, and 10 among them were finally selected to induce the expression and enzyme activities of cytochrome P450 (CYP) 3A4, 1B1, and 2C9 in human dermal fibroblasts (HDFs). The expression and activities of these CYPs in the induced HDFs were higher than those in commonly used hepatoma cell lines.
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