ABSTRACT
Brain metastasis is a highly complex process, and some cancer cells enter a dormant state after extravasation into the brain. The molecular mechanism of dormancy remains largely unknown and is still under intense investigation. Here, we outline a basic approach to generating and analyzing experimental mouse models to study dormant cancer cells in the brain. Cancer cells stably expressing EGFP and firefly luciferase are injected into the left ventricle of athymic nude mice. After confirmation of brain metastasis by bioluminescence imaging, brain slices are prepared and subjected to Ki67 staining. In addition, a methodology for recovering brain metastatic cancer cells from the mouse brain is described, providing technical tips for unraveling the mysteries of cancer cell dormancy in brain metastasis.
Subject(s)
Brain Neoplasms , Disease Models, Animal , Mice, Nude , Animals , Brain Neoplasms/secondary , Brain Neoplasms/pathology , Mice , Humans , Cell Line, Tumor , Green Fluorescent Proteins/metabolism , Green Fluorescent Proteins/genetics , Luminescent Measurements/methods , Brain/pathology , Brain/metabolismABSTRACT
There are limited methods to stably analyze the interactions between cancer cells and glial cells in vitro, which hinders our molecular understanding. Here, we develop a simple and stable culture method of mouse glial cells, termed mixed-glial culture on/in soft substrate (MGS), which serves well as a platform to study cancer-glia interactions. Using this method, we find that human lung cancer cells become overly dependent on metabotropic glutamate receptor 1 (mGluR1) signaling in the brain microenvironment. Mechanistically, interactions with astrocytes induce mGluR1 in cancer cells through the Wnt-5a/prickle planar cell polarity protein 1 (PRICKLE1)/RE1 silencing transcription factor (REST) axis. Induced mGluR1 directly interacts with and stabilizes the epidermal growth factor receptor (EGFR) in a glutamate-dependent manner, and these cells then become responsive to mGluR1 inhibition. Our results highlight increased dependence on mGluR1 signaling as an adaptive strategy and vulnerability of human lung cancer brain metastasis.
Subject(s)
Brain Neoplasms , Lung Neoplasms , Receptors, Metabotropic Glutamate , Mice , Animals , Humans , Glutamic Acid , Astrocytes/metabolism , Receptors, Metabotropic Glutamate/metabolism , ErbB Receptors , Tumor MicroenvironmentABSTRACT
There are few cases describing the association of eosinophilia with hypercalcemia, and drug-induced eosinophilia with hypercalcemia has not been reported. A 74-year-old man had been diagnosed with asthma 4 months earlier. He was admitted due to eosinophilia with hypercalcemia. Chest computed tomography showed a nodule in the left lung and mediastinal lymphadenopathy. By obtaining a detailed medical history, clopidogrel was suspected as the prime cause of eosinophilia. After the discontinuation of clopidogrel, the eosinophilia with hypercalcemia, lung nodule and mediastinal lymphadenopathy improved. Clopidogrel-induced eosinophilia can potentially cause hypercalcemia. Obtaining a detailed clinical history is important in diagnosing the cause of eosinophilia.
Subject(s)
Eosinophilia , Hypercalcemia , Lymphadenopathy , Mediastinal Diseases , Aged , Clopidogrel/adverse effects , Eosinophilia/complications , Humans , Hypercalcemia/chemically induced , Hypercalcemia/complications , Lymphadenopathy/complications , MaleABSTRACT
A novel methodology for the sensing of formaldehyde that displays a response using distinct and diverse color changes is reported. Through copolymerization of a primary amine monomer with additional co-monomers on a pattern-printed microscope slide, primary amine-containing thin films were obtained. After the absorption of a range of colors of anionic dyes, the thin films were immersed in aqueous formaldehyde solutions. It was demonstrated that the color of the thin films changed depending on the formaldehyde concentration in the solution. As the anionic dyes were released from the thin films at varying formaldehyde concentrations, a set of thin films exhibiting a range of color-change patterns was observed. The response selectivity of the thin films towards carbonyl compounds was examined, and sensitivity in the order of formaldehyde¼acetaldehyde>acetone was observed. In addition, the effect of amine structure was examined, and it was found that thin films bearing tertiary amino groups show virtually no formaldehyde response. These observations clearly indicate that the existence of primary amino groups is essential for color changes to be observed, and that the formation of an imine is the crucial step in generating a response against formaldehyde. The formaldehyde-responsive system presented herein is advantageous, as its preparation is relatively simple and does not require complex organic synthesis. In addition, a wide range of anionic dyes is compatible with the system, and can be selected in terms of color, charge, toxicology profile, and cost, for example.
Subject(s)
Chemistry Techniques, Analytical/instrumentation , Coloring Agents/chemistry , Formaldehyde/analysis , Formaldehyde/chemistry , Amines/chemistry , Color , PolymerizationABSTRACT
Ten vitamin K(3) derivatives were synthesized and screened for anti-angiogenic activity. Results indicated that amine derivatives (1a-d) exerted a stronger inhibition effect on angiogenesis compared to alkyl derivatives (2a-d). In addition to being the most potent inhibitor, 1b also suppressed human umbilical vein endothelial cell tube formation and proliferation. These results suggest that vitamin K(3) amine derivatives with shorter alkyl chains, such as 1b, could be useful for developing anti-angiogenic agents.