Glioma stem cells invasive phenotype at optimal stiffness is driven by MGAT5 dependent mechanosensing

Abstract

AbstractGlioblastomas stem-like cells (GSCs) by invading the brain parenchyma escape resection and radiotherapy. GSC invasion is associated with altered N-glycosylation pattern of integrins and other transmembrane proteins resulting in changed mechanosensing but details are elusive. Because the tumour microenvironment has an increased stiffness we studied the interaction between matrix stiffness, N-glycosylation and GSC migration. To mimic the fibrillar microenvironments, we designed 3D-ex-polyacrylonitrile nanofibers scaffolds (NFS) with adjustable stiffnesses by loading multiwall carbon nanotubes (MWCNT). We found that migration of GSCs was maximum at 166 kPa. Migration rate was correlated with cell shape, expression of focal adhesion (FA), Epithelial to Mesenchymal Transition (EMT) proteins and (β1,6) branched N-glycan binding, galectin-3. Mutation of MGAT5 in GSC inhibited N-glycans (β1–6) branching, suppressed the stiffness dependence of FA and EMT protein expression as well as migration on 166kPa NFS; underpinning the role of multibranched N-glycans as a critical regulator of mechanotransduction by GSC.Significance StatementDuring pathological processes in which cell migration is involved, cells undergo important functional changes in protein glycosylation and are responsive to environmental mechanical modifications. We addressed the question of the glycosylation role in mechanotransduction regulation of glioma stem cells. We created a bio-inspired 3D nanofiber scaffold (NFS) loaded with multiwall carbon nanotubes to obtain NFS of adjustable stiffness in physiological and pathological ranges. We highlighted and described a mechanism of fine mechanotransduction leading to a nonlinear migration response regarding to 3D microenvironment stiffness values. We show the importance to develop mechano-pharmacology as new therapeutic target by demonstrating the relationship existing between environmental stiffness and multibranched N-glycans catalysed by the MGAT5 enzyme to optimize directed migration.