Ex vivo Dynamics of Human Glioblastoma Cells in a Microvasculature-on-a-Chip System Correlates with Tumor Heterogeneity and Subtypes

The perivascular niche (PVN) plays an essential role in brain tumor stem-like cell (BTSC) fate control, tumor invasion, and therapeutic resistance. We use a microvasculature-on-a-chip system as a PVN model to evaluate the ex vivo dynamics of BTSCs from ten glioblastoma patients. BTSCs were found to preferentially localize in the perivascular zone, where they exhibited either the lowest motility, as in quiescent cells, or the highest motility, as in the invasive phenotype, with migration over long distance. The degree of co-localization between tumor cells and microvessels varied significantly across patients. To validate these results from the microvasculature-on-a-chip system, single-cell transcriptome sequencing (10 patients and 21,750 single cells in total) was performed to identify tumor cell subtypes. The co-localization coefficient was found to positively correlate with proneural (stem-like) or mesenchymal (invasive) but not classical (proliferative) tumor cells. Furthermore, a gene signature profile including PDGFRA correlated strongly with the “homing” of tumor cells to the PVN. These findings demonstrate that our BTSC-on-a-chip model can recapitulate in vivo tumor cell dynamics and heterogeneity, representing a new route to study patient-specific tumor cell functions. Overall design: Single cell RNA-seq of human glioblastoma cells from 10 patients.