The in vitro transformation by an avian adenovirus (CELO). III. Human amnion cell cultures

SUMMARY-Chicken-embryo-Iethal-orphan (CELO) virus was shown to transForm hamster-embryo fibroblastic cells in vitro. The first signs of in-fection were at 24 hours when pyramidal or stellate cell forms were observ ed in a disorganiz:ed growth paHern. After 4 passages fibroblastic elem ents gave way to epithelioid-like cells. Virus production decreased as the number of transformed cells increased. A virus-speciFic intranuclear "T't antigen was observed in most cells by immunoHuorescent techniques. Cells from the seventh and twelfth passages induced fibrosarcomas when inoculated subcutaneously into hamsters 3-4 weeks old.-j Nat Cancer Inst 42: 1-7, 1969. A NUMBER of oncogenic DNA viruses induce in vitro transformation in a variety of cells. Hamster kidney (1-3) and human fibroblastic cells (4--6) have been transformed by simian virus 40 (SV40). The adeno-SV40 hybrid transformed hamste