Abstract 1433: Analysis of tumor cell migration on electrospun nanofibers identifies STAT3 as a pro-migratory target in gliomas
Authors: De Jesus Jessica , Agudelo Paula A. , Williams Shante , Nowicki Michal O. , Li Pui K. , Chiocca Ennio A. , Johnson Jed , Lannutti John J. , Lawler Sean E. , Viapiano Mariano 
Published: June 2012

Abstract
A hallmark of malignant gliomas is their ability to disperse through neural tissue, leading to the long-term failure of all current therapies. Current assays to study glioma migration follow models developed for epithelial cancers. However, glioma cells disperse preferentially along unique anatomical pathways in the CNS, such as parallel white matter fibers, and do not exhibit the invasive behavior of epithelial tumors through basal laminae. Thus, the goal of this work was to devise a culture system reproducing the texture of neural tissue, to more accurately analyze and target mechanisms of migration of glioma cells. Biocompatible poly-∈-caprolactone was electrospun onto culture dishes to form nanofiber-based scaffolds composed of either randomly organized or tightly aligned submicron-diameter fibers, which were then coated with different ECM substrates. Human glioma cells were cultured in suspension to form aggregates, stained with membrane-permeant dyes, and analyzed for migration on nanofibers over a 24h-period. Cells cultured on random fibers exhibited morphology and migration similar to cells cultured on conventional plastic surfaces. In contrast, cells grown on aligned fibers retained an elongated morphology and moved along the fiber axis in a manner similar to glioma cells moving along white matter. Cell migration along fibers was sensitive to the myosin-II inhibitor blebbistatin, as previously described in neural tissue, but the same cells were not affected by blebbistatin when cultured on plastic or random fibers. Microarray analysis of cells migrating on aligned versus random fibers suggest an increase of STAT3 signaling with enhanced cell migration. Accordingly, phosphorylated STAT3 was increased in cells cultured on aligned compared to random fibers. Moreover, cell migration along the fiber axis was significantly inhibited by two STAT3 inhibitors, STATTIC and the OSU-produced inhibitor LLL12, at concentrations that did not affect cell viability over 48h. To test this assay in a clinically-relevant situation, glioma cells were implanted intracranially to form tumors for two weeks, followed by resection of tumors with adjacent normal tissue. Tissue pieces containing tumor masses were placed on the fibers at different days post-resection and analyzed for motility. Outward motility of tumor cells from the tissue was evident after 24h and was also inhibited by STATTIC. In sum, the nanofiber-based culture offers significant advantages of a well-defined in vitro system that reproduces morphology and migratory behavior observed in glioma cells in vivo. Migratory cells cultured in this model can be interrogated for gene and protein expression, and cells or tissue specimens can be tested to identify anti-migratory treatments not disclosed by other in vitro models.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1433. doi:10.1158/1538-7445.AM2011-1433