Selective control of human glioma cell proliferation by specific cell interaction.

Cells cultured from anaplastic astrocytoma (Kernohan and Sayre, grades III and IV) will proliferate on confluent monolayers of normal glia, while cells cultured from normal brain will not. The growth of a cell line containing a high proportion of well-differentiated glioma cells (G-CCM) was partially inhibited, though not as much as normal glia, while the growth of a cell line made up of less differentiated cells (G-UVW) was enhanced by the normal glia. Although non-glial confluent monolayers also inhibited the growth of normal glia, this was less specific, as one normal glial line (N-DUT) grew on fibroblasts and intestinal epithelium, although it was unable to do so on normal glia. It is suggested that this may be a useful method for examining reduced density limitation of growth, discriminating between normal and malignant glia, and for separating glioma cells from contaminating normal cells.