Epidermal growth factor-induced cell rounding is sensitive to simulated microgravity.

Epidermal growth factor (EGF) induces rapid rounding of A431 human epidermoid carcinoma cells. This process is dependent upon temperature and EGF concentration. To investigate the possible influence of gravity variations on EGF-induced cell rounding of A431 cells, experiments were performed using a fast-rotating clinostat and centrifuge, thereby simulating microgravity and higher gravity values, respectively. We demonstrated that simulated microgravity conditions enhance EGF-induced cell rounding significantly, whereas hypergravity values do not show significant effects on this process. These results suggest that simulated microgravity modulates growth factor-induced signal transduction.