Elevated Fluid Shear Stress Decreases Ras Expression and Activation in Glioblastoma

Abstract

R-Ras, a small GTPase and member of the Ras superfamily, is involved in cellular signal transduction, migration, proliferation, and differentiation. R-Ras and FLNA (a cytoskeletal protein) form the R-Ras/FLNA complex, which is critical for maintaining the integrity of the endothelial barrier and promoting endothelial homeostasis. Cells that lack FLNA expression have impaired locomotion function, making them unable to migrate. The R-Ras/FLNA complex plays a prominent role in the blood-brain barrier (BBB). Glioblastoma (GBM), the most lethal primary brain tumor in adults, has a compromised BBB. We hypothesize that R-Ras activity affects GBM metabolic activity and migration. Ras activity in a cell line can be determined by performing an Active Ras Pull-Down Assay and running Western blots (WB) to probe them with an anti-Ras primary antibody. Ras activity monitors all Ras small GTPase activation, not just R-Ras. To emulate the fluid shear stress found in the BBB, we utilized cell spinpods at different shear stress levels. The results of this study will help us better understand how R-Ras and FLNA are involved in regulating the blood-brain barrier in infiltrative gliomas in future experiments.