SV-40 virus-induced neoplastic transformation of hamster brain cells in vitro. Studies with scanning and transmission electron microscopy

Neoplastic transformation of one-day-old hamster brain cells was produced by infection with SV-40 virus and verified by phase contrast microscopy, growth in semisolid media, and intracranial tumor production after inoculation of the cells into other one-day-old hamsters. Transformed cells were studied by transmission and scanning electron microscopy. The numerous alterations in cell surface structure and in nuclear and cytoplasmic organization suggest a marked increase in cell metabolism and in the rate of mitosis and cell division. Cilia with a nine-to-zero pattern of microtubule doublets were present in cells with intermediate size filaments which stained for glial fibrillary acidic protein. The findings indicate that infection of one-day-old hamster brain cells in culture by SV-40 virus results in their transformation to a neoplastic state and the transformed cells are differentiating neoplastic astrocytes.