The spreading of human normal glial and malignant glioma cells in culture. Studies on standard culture conditions.

Abstract

Using three lines of human normal glial cells and four established lines of human malignant glioma cells we have studied cell spreading following seeding onto glass and plastic substrata. The cells were detached with EDTA and trypsin, suspended in EMEM with 10% calf serum and studied with time-lapse, phase-contrast cinematography in suspension and during attachment and spreading. Cells were fixed and prepared for light microscopy while in suspension and during the spreading process. They were also prepared for scanning and transmission electron microscopy at different times during spreading. The projected areas of stained cells, in suspension and at different stages of spreading, were measured morphometrically and the results compared statistically. The glial cells in suspension were often found to retain somewhat their shape from the previous monolayer. They spread radially outwards with even lamellar cytoplasm and peripheral ruffling, as a group more quickly than the malignant glioma cells. They also became polarized and started to translocate in a shorter time. The glioma cells were spherical in suspension and characterized by pronounced blebbing of the cell surface. Blebbing continued during spreading and was finally replaced by ruffling at the edge. The cells spread like the glial cells radially outwards but the lamellar cytoplasm was occasionally somewhat irregular. Cells from the glioma lines spread as groups slower than the glial cells but with individual rates for the different lines. One of the glioma lines appeared to spread more thinly than the glial cells. Cells which sedimented on top of other cells could not spread. Aggregations of cells spread and became polarized more quickly than single cells in all cases.