Fig. 2

Characterization of glioblastoma stem cells from recurrent GBM. a–c Pre- and post-operative T1-weighted, contrast-enhanced MRI of three recurrent GBM with the corresponding sphere-, cellular- and xenograft morphology. The individual cultures displayed extensive tumor-to-tumor heterogeneity in their in vitro morphology (e.g. adherent growth in T1608, various differentiation morphology) and in their induced tumor phenotype (e.g. mainly bulk formation In T1534, mainly invasive in T1608). Arrow points to compressed lateral ventricle. Xenografts stained with hematoxylin & eosin. In the recGSC cultures the tumors were harvested after 15 weeks following xenografting. d Total cell yield following serial passages revealed intertumoral variability in their capacity for cell proliferation. Dashed lines represent tumors that could not be serially expanded. e Intertumoral heterogeneity in the expression of stem cell related markers evaluated by flow cytometry. f Upon differentiation all cultures evaluated increased their expression of glial lineage marker GFAP, and all but one (T1513) increased the expression of the neuronal lineage marker β3-tubulin. Scale bar in the light microscopy images: 100 µm. Scale bar in fluorescent images 20 µm. Scale bar in brain sections 1 mm. T tumor, CC corpus callosum