Effect of lactate dehydrogenase virus on chemically induced mouse lung tumorigenesis.

Lactate dehydrogenase virus is the third in a series of viruses which have been examined for the capacity to alter chemically induced mouse lung tumorigenesis. This virus was given to strain A mice by i.p. injection either 4 weeks before, on the same days as, 4 weeks after, or 8 weeks after the s.c. injection of urethan (either 0.25 or 1.0 mg/g). The pulmonary adenoma response to urethan was suppressed in all of the lactate dehydrogenase-infected mice, with a maximum suppression of 30 to 40% when the virus was given simultaneously with or 4 weeks after urethan. As with murine sarcoma virus and reovirus, it is postulated that this suppression of chemically induced mouse lung tumorigenesis is due to virally induced alterations in the immune response of the mouse to chemically induced tumors.