The effects of antitumor drugs upon P32 incorporation into nucleic acids of mouse tumors.

The effect of various types of antitumor com pounds on nucleic acid metabolism has been in vestigated in order to determine more precisely the mechanism of drug action. This was effected through observations on the influence of the agents upon the incorporation of a labeled precursor into the nucleic acids of an experimental tumor. Simi lar investigations have been reported by others (4, 12, 13, 17, 22, 23, and 24). For the most part, these have indicated that effective antitumor com pounds depressed the incorporation of various nu cleic acid precursors into desoxypentosenucleic acid (DNA) in treated animals. The present report will give evidence to show that this is not a neces sary accompaniment of antitumor activity : certain drugs appear to have no primary effect upon the incorporation of P32 of inorganic phosphate into