Chapter 17 Flow-Cytometric Identification and Characterization of Neural Brain Tumor-Initiating Cells for Pathophysiological Study and Biomedical Applications

Flow cytometry has garnered wide acceptance as an efficient tool for the isolation and enrichment of specific subpopulations of cells. Its utility in identifying brain tumor-initiating cells (BTICs) through their unique surface antigen expression is of particular interest in the fields of stem cell and cancer stem cell biology. Here, we review key cell-surface markers, like CD133, that are commonly used for isolating neural BTICs associated with primary brain tumors such as glioblastoma and medulloblastoma. Since CD133 was identified as a potentially universal marker of BTICs, it has gained much attention in terms of its exclusivity. However, inconsistencies between flow-cytometric analyses have created challenges in data interpretation and have consequently led to conflicting results. As such, the need for standardized in vitro methods, complemented with in vivo assays, could significantly improve reproducibility and resolve existing controversies within the field.