NEOPLASTIC TRANSFORMATION OF NEWBORN RAT OLIGODENDROCYTES IN CULTURE

  • 1 January 1983
    • journal article
    • research article
    • Vol. 43  (2) , 709-715
Abstract
A model was developed to study the neoplastic transformation of rat oligodendrocytes in culture. Astrocyte and oligodendrocyte populations were prepared from 1- to 2-day-old rat cerebral cortices. Pregnant rats on the 19th day of gestation were given injections with either ethyl nitrosourea (10 .mu.g/g body weight) in phosphate-buffered saline or phosphate-buffered saline, and oligodendrocyte cultures were prepared. Oligodendrocytes appear to be unstable in culture since transformation was observed with cells derived from either pups from pregnant rats treated with nitrosourea or phosphate-buffered saline. Transformation required 78-108 days and 3-9 passages, at which time a marked increase in cellular proliferation was observed. The possibility that the transformed cells were derived from a nonoligodendroglial cell was excluded by light and scanning electron micrographs which revealed cytological features essentially similar to those of primary oligodendroglial cultures. Two biochemical oligodendroglial markers, the induction of lactate dehydrogenase by N6,O6-dibutyryl cAMP and the presence of 2'',3''-cyclic nucleotide 3'' phosphohydrolase, were also retained. Another oligodendroglial marker, the hydrocortisone induction of glycerol phosphate dehydrogenase, was not found in any of the cell lines. These transformed cells grew as tumors when injected intracranially into 21-day-old rats. Histologically, these tumors did not appear as classical oligodendrogliomas, but their oligodendroglial origin was confirmed since the tumor tissue contained 2'':3''-cyclic nucleotide 3''-phosphohydrolase activity, and the cells which grew from tumor explant cultures morphologically appeared similar to the parent cell line. The transformed cells were also characterized for in vitro properties which correlate with the expression of tumorigenicity. The transformed cells exhibited anchorage-independent growth and were agglutinated by concanavalin A treatment. Changes in fibrinolytic activity were not an exclusive property of transformed glial cells. This model should now allow the study of various mechanisms involved in the neoplastic transformation of oligodendrocytes.