Enhancement of Viral Oncogenicity by the Prior Administration of Dimethyl Sulfoxide1

The i.m. injection of dimethyl sulfoxide prior to the infection of quail with Rous sarcoma virus strain 0 and of mice with Moloney sarcoma virus resulted in increased virus titers, decreased incubation time to tumors and, in the case of Moloney sarcoma virus, decreased spontaneous regressions. Dimethyl sulfoxide administered at the time of or after infection was without effect. This compound also increased focus formation by strain 0-Rous sarcoma virus in monolayer cultures of quail embryo fibroblasts. The basis for the promoting action of dimethyl sulfoxide is unknown, but increased cell permeation could be involved.