Spheroid formation of human thyroid cancer cells under simulated microgravity: a possible role of CTGF and CAV1

摘要

Background Multicellular tumor spheroids (MCTS) formed scaffold-free under microgravity are of high interest for research and medicine. Their formation mechanism can be studied in space in real microgravity or on Earth using ground-based facilities (GBF), which simulate microgravity. On Earth, these experiments are more cost-efficient and easily performable. However, each GBF might exert device-specific and altered superimposingly gravity-dependent effects on the cells. Results FTC-133 human thyroid cancer cells were cultivated on a 2D clinostat (CN) and a random positioning machine (RPM) and compared with corresponding 1?g control cells. Harvested cell samples were investigated by microscopy, quantitative realtime-PCR and Multi-Analyte Profiling. Spheroid formation and growth occurred during 72?h of cultivation on both devices. Cytokine secretion and gene activation patterns frequently altered in different ways, when the cells were cultured either on the RPM or the CN. A decreased expression of CAV1 and CTGF in MCTS compared to adherent cells was observed after cultivation on both machines. Conclusion The development of MCTS proceeds similarly on the RPM and the CN resembling the situation observed under real microgravity conditions, while no MCTS formation was observed at 1?g under identical experimental conditions. Simultaneously, changes in the regulation of CTGF and CAV1 appeared in a comparable manner on both machines. A relationship between these molecules and MCTS formation is discussed.