Normal and benzo(a)pyrene-transformed fetal mouse brain cell. I. Tumorigenicity and immunochemical detection of glial fibrillary acidic protein.

Primary cultures of whole brain and cortex cells origination from 14-day-old A/Jax or C3H mouse fetuses were treated with benzo(a)pyrene (B(a)P) for 24 h. After 7 to 8 passages a malignant transformation was observed in the chemically treated whole brain and cortex cultures. Control cultures of cortex remained non-transplantable during the whole experiment (up to 14 passages) whereas in the control cultures originating from whole brain a spontaneous transformation appeared after 11 passages. With horseradish peroxidase-labelled antibody, the specific glial fibrillary acidic protein (GFAP) was detected in both control and transformed total brain and cortex cultures, and in the tumors initiated by the in vitro transformed cells. This finding shows that glialike cells persisted after a long in vitro maintanance and transformation.