Infectious and Oncogenic Effect of DNA Extracted from Cells Infected with Polyoma Virus

Abstract

SummaryThirty-five newborn hamsters were injected subcutaneously (approx. 70 μg) or intracerebrally (15 μg) with DNA from polyoma-infected cultures of embryonal mouse cells. All animals showed circulating antibodies and 26 of them presented tumors, mostly of subcutaneous localization, after intervals of 2 to 3 months. Fully grown hamsters appeared to be less sensitive; of 17 animals, 11 developed antibodies and 5 developed tumors. The same DNA preparations were shown to be capable of infecting primary cultures of mouse kidney cells. All the control series, in which use was made of DNA treated with DNase or of DNA originating from non-infected cells, have given negative results both in vivo and in vitro.