Malignant Transformation of Mouse Connective Tissue Grown in Diffusion Chambers

Summary

After 18 months of continuous cultivation in diffusion chambers, placed by laparotomy into isologous hosts, C3H connective-tissue fibroblasts did not produce tumors upon intraocular or intramuscular injection. After 23 months, however, similar injections resulted in the production of rapidly growing, transplantable sarcomas. Cells derived from the tissue grown in chambers for over a year, and then grown in vitro, produced tumors at the same or earlier times than the chamber-grown tissue. While some of the chamber-cultured tissue was transplanted into new chambers on the average of once a month during the entire period of culture, some tissue remained in the same chamber in the same host for periods from 260 to 378 days. Tissue from these latter chambers produced tumors with the same regularity as tissue that had undergone the stimulation of continuous transplantation. Thus fibroblasts cultured in chambers under widely differing physiological conditions underwent the malignant alteration at the same time.