Mitogenic Lectin Receptors of Nervous System Tumors

Abstract

The effects of mitogenic lectins Phytohemagglutinin (PHA), and Concanavalin A (Con A) on the growth rate of cells derived from glial tumors (astrocytoma, ependymoma, glioblastoma, medulloblastoma, and C6 rat glioma), neural crest tumors (neuroblastoma and schwannoma), and meningiomas were studied. The cell lines were of human and animal origin. The specificity of lectin binding to mitogenic receptors was evaluated using complementary monosaccharides. In all glial- and some neural-crest tumor-derived cell lines, there was a lectin concentration-dependent and cell density-dependent, biphasic growth rate response with stimulation at low and inhibition at high lectin concentrations. This response did not depend on the type of glial tumor, species of origin, or passage level in vitro. Although, in meningioma-derived cell lines, lectins did not induce a growth rate response, they caused morphological changes ("whorling"). Lectin stimulation in glial tumor-derived cell lines resembles that occurring in peripheral blood lymphocytes. Lectin-induced mitogenesis may lay the groundwork for the establishment of a model of glial cell proliferation, and that permits the evaluation of cell surface effects, intracellular mechanisms, and epigenetic factors in studies of tumors, neural development, and neuroimmunology.