Heterotransplantation of a human oligoastrocytoma into nude mice: difference in tumour growth between males and females

A human oligodendroglial tumour cell line was established in the nude mouse from a mixed oligoastrocytoma. This cell line was identified by immunoperoxidase screening for glial fibrillary acid protein (GFAP) and Leu‐7, by electron microscopy, by its growth behaviour, and by radioreceptor assays for oestrogen, progestogen and androgen. At the first heterotransplantation, the tumour grew in the female but not in the male mice. GFAP‐positive cells were much less abundant than in the initial tumour, although Leu‐7 positive cells were plentiful. Growth curves were biphasic, and the tumours contained both oestrogen and androgen receptors. After three successive hetero transplantations in female mice, GFAP‐negative, Leu‐7‐positive tumours with the cytological features of an oligodendroglioma were obtained. In contrast to those of the first heterotransplantation, the growth curves showed a longer latency and a single growth phase. The tumours contained both progestogen and androgen receptors but lacked oestrogen receptor. The 5th heterotransplantation in male mice exhibited rapid growth, similar to the three previous heterotransplantations in the female mice. The growth observed solely in the female mice at the first heterotransplantation was thought to derive from the hormonal status of the host. The presence of hormone receptors in the tumours at the first heterotranspiantation lent support to this idea. There was no further influence of the sex of the host on tumour growth once the oligodendroglial line was established. The establishment and the development of oligodendrocytes may result from differentiation of transitory cells intermediate between astrocytes and oligodendrocytes. The effect of host‐sex on the development of oligodendrocytes points to a new facet of the differentiation of CNS glial cells.