Biological and Karyotypic Characterization of a New Cell Line Derived from Human Gliosarcoma¹

A cell line (NCE-G28) was established from the biopsy material of a human gliosarcoma of low histological differentiation. The initial cultures showed a mixed population of cells which in later stages became more uniform due to loss of slower growing constituents. The cells have been growing steadily for 20 months. A suspension of NCE-G28 cells injected s.c. as well as i.p. into nude mice produced solid tumors in all cases. Histologically these tumors closely resembled the original tumor. The original tumor, the nude mouse tumor, and NCE-G28 cells were immunochemically positive for glial fibrillary acidic protein as well as for neural plasma membrane antigen A2B5 expression. Two cell strains, 9B2C and 9B2E, were obtained by cloning of the initial cultures and another strain, NCE-G28T, was derived after explantation of a mouse heterotransplant. The two subclones were negative for glial fibrillary acidic protein expression but stained for cell surface fibronectin. NCE-G28T cells initially were positive for glial fibrillary acidic protein but lost this property within 8 months of cultivation. Karyotype analysis of NCE-G28 and the three strains revealed hyperdiploidy and six structurally altered marker chromosomes five of which were shared by nearly all cells. Receptors for epidermal growth factor were detected in all cell lines with the highest levels (about 300,000 receptors/cell) in the parental cell line. The epidermal growth factor receptors had an affinity of 2.5 nm (K_d) and by affinity cross-linking analysis a molecular weight of 170,000 was found. Initially, NCE-G28 cells responded to epidermal growth factor as well as fibroblast growth factor with increased rates of proliferation, while platelet derived growth factor had no effect. In higher passages the growth factor sensitivity was reduced. Using antibodies directed against synthetic protooncogene peptides the production of c-sis immunoreactive material was detected. NCE-G28 cells produce an autocrine factor which stimulated proliferation. This factor is present in conditioned medium and is active on cultured meningiomas and other glioma cell lines. NCE-G28 cells can be maintained in serum-free defined medium on plastic coated with fibronectin or an extracellular matrix from bovine corneal endothelial cells. The NCE-G28 cell line with its strains provide an in vitro model system in which the complexity of gliosarcoma cell populations and the interaction of the cloned cellular constituents can be studied.