The role of drebrin in glioma migration and invasion.

Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite current advances in therapy consisting of surgery followed by chemotherapy and radiation, the overall survival rate still remains poor. Therapeutic failures are partly attributable to the highly infiltrative nature of tumor adjacent to normal brain parenchyma. Recently, evidence is mounting to suggest that actin cytoskeleton dynamics are critical components of the cell invasion process. Drebrin is an actin-binding protein involved in the regulation of actin filament organization, and plays a significant role in cell motility; however, the role of drebrin in glioma cell invasiveness has not yet been fully elucidated. Therefore, this study was aimed to clarify the role of drebrin in glioma cell morphology and cell motility. Here we show that drebrin is expressed in glioma cell lines and in operative specimens of GBM. We demonstrate that stable overexpression of drebrin in U87 cells leads to alterations in cell morphology, and induces increased invasiveness in vitro while knockdown of drebrin in U87 cells by small interfering RNA (siRNA) decreases invasion and migration. In addition, we show that depletion of drebrin by siRNA alters glioma cell morphology in A172 GBM cell line. Our results suggest that drebrin contributes to the maintenance of cell shape, and may play an important role in glioma cell motility.