Dissecting the Inter-Substrate Navigation of Migrating Glioblastoma Cells with the Stripe Assay Reveals a Causative Role of ROCK

Abstract A hallmark of gliomas is the growth and migration of cells over long distances within the brain and proliferation within selected niches, indicating that the migrating cells navigate between complex substrates. We demonstrate in the present study a differential preference for migration that de-pends on Rho-associated coil kinase (ROCK) signaling, using the alternating Bonhoeffer stripe assay. Membrane fractions from nonmyelinated and myelinated brain areas from female rats, purified myelin also from female rats, and commercial extracellular matrix were used as substrates, with each sub-strate being tested against the others. The human tumor cell lines exhibited a clear preference for extracellular matrix over all other substrates and for myelinated over nonmyelinated tissue. ROCK signaling was different when cells were cul-tured on either substrate. The ROCK inhibitor Y27632 signif-icantly attenuated and neutralized the preference for extracellular matrix and myelin, indicating that ROCK con-trols the substrate selectivity. The findings of this study pave the way for navigation-targeted therapeutics. Keywords Stripe assay. Glioblastoma cells. In vitro. Cel