Abstract
4-Nitroquinoline-N-oxide was demonstrated to possess a very powerful carcinogenic action. Applied to the skin of normal mice three times a week this substance in 0.25 percent benzene solution produced papillomata in all the animals during the period between 80th to 140th day, and malignant tumors between 120th to 200th day. At 150th day, 100 percent of the mice bore tumors and in 36 percent the tumors were already malignant. The malignant tumors produced were histologically squamous cell carcinoma or fibrosarcoma. Metastases were found in a few cases. These tumors were found to show the glycolytic activity in vitro consistent with their malignant nature. One of the tumors was successfully transplanted to normal mice.
4-Nitroquinoline-N-oxide is the first bicyclic compound to be shown to have the carcinogenic activity of the magnitude approaching that of the most potent polycyclic hydrocarbons.
