Blebbing Dynamics, Single Cell Force Measurements, and the Influence of Cytochalasin D on Glioblastoma Multiforme Cells Using STEP Fibers

Classified as a grade IV tumor of the central nervous system, Glioblastoma multiforme (GBM) arises from the glia. A poor understanding of tumor metastasis and limited treatment options have led to increase in deaths of patients suffering from GBM. Studying glioma behavior using aligned structures that mimic native glioblastoma metastatic path is challenging. In this study, we utilize a previously described non-electrospinning platform to manufacture aligned 3D structures called STEP nanonets that not only allows the study of individual cell-nanofiber interaction, but also allows the calculation of migratory forces using beam mechanics. In particular, the blebbing dynamics, force generation, and the effect of an actin disruptor, Cytochalasin D have been investigated on a glioma cell line (DBTRG, Denver Based Tumor Research Group). It was observed that cell pulled onto the nanofibers causing measurable deflections when they were in spread and non-blebbing conditions. In non-spread configurations while attached to fibers, the cells acquired spherical configurations and resumed blebbing. The average migratory force generated by cells exposed to DMSO (control, 1:1000 dilution) using nanonets of 2μm by 400nm fibers was 0.58±0.06nN. Actin disruptor, Cytochalasin D severely compromised the ability of the glioma cells to migrate causing no deflection of the fibers. Forces exerted by tumor cells on their native microenvironment affects their ability to metastasize, invade and proliferate. While the result presents actin disruptor as a potential target to minimize metastasis, the influence of other cytoskeleton disruptors can also be studied using the platform. Moreover, the results obtained from the study can be utilized to better understand the individual cell – nanofibers interaction which can shed light on how cells interact with their native environment during metastasis.