The Mechanism of Carcinogenesis by Avian Sarcoma Viruses. I. Cell Multiplication and Differentiation2

Abstract

Several types of cells were infected with different avian sarcoma viruses. The infected cells were then grown under diverse conditions, and the changes in their properties were compared to those of control uninfected cells. The viruses used were morph^r, morph^f, and h^D Rous sarcoma virus, Schmidt-Ruppin Rous sarcoma virus, morph^f and morph^r Fujinami virus, myeloblastosis virus, and leukosis virus. The cells used were chicken embryo fibroblasts and iris epithelial cells, and duck embryo fibroblasts. The properties studied were increase in cell number, cell protein, cell ribonucleic acid, and cell deoxyribonucleic acid and production of acid mucopolysaccharides (AMPS), collagen, and pigment. The cells were grown under a fluid or an agar-containing medium. It was concluded that; 1) Conversion of cell morphology and increased rate of AMPS production are associated; 2) conversion of cell morphology and increased rate of AMPS production are not necessarily associated with altered multiplication; 3) altered growth in converted cells depends on environmental conditions; 4) specific cell functions are not all altered in the same way by conversion.