Scanning electron microscopy of neoplastic neurogenic rat cell lines in culture

The surface structure of a series of malignant neurogenic rat cell lines in culture has been investigated by scanning electron microscopy. Neoplastic transformation was induced by a single transplacental administration of the carcinogen ethylnitrosourea (ENU) to BD-IX rats on the 18th day of gestation. The malignant cell lines were established either by explantation into culture of cells from solid gliomas or neurinomas developed in the offspring, or by transfer of fetal brain cells to culture where they subsequently underwent malignant transformation. A high degree of surface activity was observed, as evidenced by microvilli, filopodia, ruffling membranes and zeiotic blebs. Surface activity was highest in cell cultures giving rise to glioma-like tumours upon re-implantation into syngeneic hosts, and low in those giving rise to neurinoma-like tumours, with one exception. The lowest surface activity was seen in a cell line which was not tumourigenic. High surface activity was mostly correlated with a high degree of aneuploidy. No correlation was apparent with other properties of the neoplastic cell lines, e.g., stem line ploidy and population doubling time in cell culture.