Quantitative Analysis of Complex Glioma Cell Migration on Electrospun Polycaprolactone Using Time-Lapse Microscopy

Abstract

Malignant gliomas are the most common tumors originating within the central nervous system and account for over 15,000 deaths annually in the United States. The median survival for glioblastoma, the most common and aggressive of these tumors, is only 14 months. Therapeutic strategies targeting glioma cells migrating away from the tumor core are currently hampered by the difficulty of reproducing migration in the neural parenchyma in vitro. We utilized a tissue engineering approach to develop a physiologically relevant model of glioma cell migration. This revealed that glioma cells display dramatic differences in migration when challenged by random versus aligned electrospun poly-epsilon-caprolactone nanofibers. Cells on aligned fibers migrated at an effective velocity of 4.2 +/- 0.39 microm/h compared to 0.8 +/- 0.08 microm/h on random fibers, closely matching in vivo models and prior observations of glioma spread in white versus gray matter. Cells on random fibers exhibited extension along multiple fiber axes that prevented net motion; aligned fibers promoted a fusiform morphology better suited to infiltration. Time-lapse microscopy revealed that the motion of individual cells was complex and was influenced by cell cycle and local topography. Glioma stem cell-containing neurospheres seeded on random fibers did not show cell detachment and retained their original shape; on aligned fibers, cells detached and migrated in the fiber direction over a distance sixfold greater than the perpendicular direction. This chemically and physically flexible model allows time-lapse analysis of glioma cell migration while recapitulating in vivo cell morphology, potentially allowing identification of physiological mediators and pharmacological inhibitors of invasion.

How cells respond to environmental cues – insights from bio-functionalized substrates

“…Formins play a crucial role in generating and organizing the long actin cables that are necessary to support the elongated shape of the cells during 1D migration (Monzo et al, 2016;Vargas et al, 2016;Wilson et al, 2013), whereas Arp2/3 is more crucial for migration in 2D. Furthermore, if cell migration takes place on suspended electrospun nanofibers coated with ECM (Johnson et al, 2009), free actin waves propagate from the cell body to the tip of the cellular protrusion. This occurs in an asymmetric manner to polarize the movement of long spindle-shaped cells (Guetta-Terrier et al, 2015).…”

Interstitial Flow in a 3D Microenvironment Increases Glioma Invasion by a CXCR4-Dependent Mechanism

“…Glioma cell invasion into the brain shows distinctive patterns known as Scherer's structures that include white matter tract, perivascular, and parenchymal spread (1,2). Mechanisms underlying these patterns are unclear, although hypotheses exist including following tissue paths of least resistance (1), fluid flow (3), structural cues (4), and protein interactions (5).…”

Biomimetic Strategies for the Glioblastoma Microenvironment

“…Techniques to fabricate nanofibers, such as electrospinning, have been used to mimic the delicate fibrous structures of the white matter tracts (Johnson et al, 2009;Agudelo-Garcia et al, 2011;Rao et al, 2013b;Sharma et al, 2013;Beliveau et al, 2016;Cha et al, 2016). The behavior of glioma cells on nanofibers was observed to be a function of substrate topography, as GBM cells migrated much faster on aligned fibers than on random fibers (Johnson et al, 2009;Beliveau et al, 2016).…”

“…The behavior of glioma cells on nanofibers was observed to be a function of substrate topography, as GBM cells migrated much faster on aligned fibers than on random fibers (Johnson et al, 2009;Beliveau et al, 2016). This in vivo-like behaviors of glioma cells is associated with STAT3 signaling, a driver of malignancy during GBM progression (Agudelo-Garcia et al, 2011).…”