1326 A Zebrafish Model to Investigate the Invasiveness of Cancer Stem Cells From the Sub-Ventricular Zone of Glioblastoma Patients

INTRODUCTION: We have previously shown that cancer stem-like cells (CSCs) derived from the sub-ventricular zone (SVZ) are the unit responsible for tumor resistance and the emergence of recurrence in human glioblastoma (GBM). Here we present a zebrafish model to study the invasiveness of GBM CSCs from the SVZ and matched tumor mass and compare it with that from commercially available cell lines. METHODS: Fluorophore-labeled cells (50-100 cells) from the U87, U373 cell lines, and CSCs from tumor mass and SVZ from one GBM patient were injected into the rostral forebrain of anesthetized zebrafish embryos at day 2 post-fertilization and imaged at 1, 4, and 8 days post-injection (DPI). Cell counts and invasiveness were determined manually with Image J. T-test and one-way ANOVA were used to evaluate group differences. RESULTS: High-resolution images were obtained of U87 and U373-injected zebrafish embryos injected at 4 and 8 DPI. Compared to U87 cells, the U373 cell line demonstrated statistically significant invasive phenotype at 8 DPI. Similarly, at 4, and 8 DPI, SVZ-derived CSCs are significantly more invasive than CSCs from the tumor mass. However, no significant difference was observed compared to U87. CONCLUSIONS: Zebrafish embryos represent a cost-effective in vivo model to study GBM tumor growth and invasion. Our preliminary results show that SVZ-derived CSCs are more invasive than CSCs from the tumor mass, suggesting a unique propensity to invade and seed distal tumors. Our model provides a useful tool for the identification of SVZ-specific mechanisms of cell invasion with potential therapeutic implications.