The fine structure of growing human glia and glioma cells. Whole cell preparations

Three lines of normal human glia cells and eight established lines of malignant glioma cells have been studied in the electron microscope (E.M.), using preparations of critical-point dried whole cells, sparsely grown on formvar-coated, E. M., gold grids. The malignant cell lines showed a very varied morphology, almost every line having its peculiarities as compared to the essentially identical normal glia lines. The major differences noted concerned the form of the leading lamellae, number of microspikes and the distribution of organelles such as secondary lysosomes and mitochondria. No single consistent finding made it possible to differentiate the glioma cells as a group from the glia cells in sparse cultures. The findings of this study show some of the individual glioma cell lines to have characteristic cell-surface structures. They were found to be identical with the findings in previous SEM studies, suggesting the peculiarities of the individual malignant glioma lines to be stable and retained, despite continual passage.