The co-carcinogenic activity of 4-nitropyridine-1-oxide (4-npo) and prevention of transformation by type-specific anti-viral antibodies

Abstract

Fischer rat embryo cells chronically infected with Rauscher murine leukemia virus, and known to be sensitive to transformation by potent chemical carcinogens, were transformed by the weak carcinogen 4-nitropyridine-1-oxide. Transformed cells grew in semi-solid agar and produced tumors in newborn Fischer rats. Transformation was inhibited by antisera specific for the ecotropic Rauscher murine leukemia virus, but not by antisera of equal toxicity specific for xenotropic Swiss mouse AT-124 virus.

Leukemia induction by Friend virus in normally leukemia virus resistant mice after treatment with methyl methane sulfonate

“…The fact that our data show an effect as early as 3.5 to 5 hours would be in agreement with that. It has also been postulated (8,9) that virus enhancement by radiation and chemicals that mimic radiation damage to DNA might be accomplished during post replication repair of DNA damage. Whether the same is true in our system can be tested by the use of inhibitors of such repair, for example caffeine (9).…”