Lineage relationships connecting germinal regions to brain tumors

Abstract

Gliomas are a primary cancer of the brain and one of the most lethal cancers known to man. Historically, the neoplastic transformation of fully differentiated glia was widely assumed to be the only mechanism for gliomagenesis. Astrocytes and oligodendrocytes, once thought to be the sole dividing cells in the postnatal brain, were assumed to represent the cellular compartment most susceptible to transformation. More recently, however, this hypothesis has been challenged by the discovery of stem cell and progenitor populations residing in the postnatal brain, which may themselves serve as an origin of brain tumors. Phenotypic and behavioral similarities between gliomas and adult neural stem cells raise the possibility that stem or progenitor cells can give rise to gliomas. Possible candidate cells-of-origin include neuroepithelial cells, radial glia, astrocytic neural stem cells ('B cells'), transient amplifying precursors ('C cells') of the adult subventricular zone (SVZ), or oligodendrocyte progenitor cells of the white matter. While a direct link has yet to be established between any one of these cell types and tumor formation, the different cell lineages arising from the ventricular and subventricular zone during development in the adult may offer clues in deciphering the origin of various tumor subtypes, including gliomas. © Springer Science+Business Media, LLC 2009. All rights reserved.