A comparative study of the structural organization of spheres derived from the adult XXXX subventricular zone and glioblastoma biopsies.

@entity1 @entity5439 @entity1313 @entity5 @entity5824 @entity436
Sphere forming assays have been useful to enrich for stem like cells in a range of @entity5 . The robustness of this system contrasts the difficulties in defining a stem cell population based on cell surface markers. We have undertaken a study to describe the cellular and organizational composition of tumorspheres, directly comparing these to neurospheres derived from the adult @entity1 subventricular zone (SVZ). Primary cell cultures from @entity1313 were found to contain variable fractions of cells positive for @entity5 stem cell markers ( @entity5439 (2-93%)/ @entity5824 (3-15%)/ @entity436 (1-72%)). All cultures produced @entity5 upon xenografting. Tumorspheres contained a heterogeneous population of cells, but were structurally organized with stem cell markers present at the core of spheres, with markers of more mature glial progenitors and astrocytes at more peripheral location. Ultrastructural studies showed that tumorspheres contained a higher fraction of electron dense cells in the core than the periphery (36% and 19%, respectively). Neurospheres also contained a heterogeneous cell population, but did not have an organization similar to tumorspheres. Although tumorspheres clearly display irregular and neoplastic cells, they establish an organized structure with an outward gradient of differentiation. We suggest that this organization is central in maintaining the @entity5 stem cell pool.
