Behavior of enzymes involved in purine nucleotide metabolism in tumors.

Abstract

Alterations in nucleotide metabolism have been observed in all experimental tumors. The “biosynthetic enzymes” and, specifically, phosphoribosylamidotransferase, which is the “key biosynthetic enzyme”, are clearly enhanced in experimental tumors, whereas “catabolic enzymes”-adenylate deaminase, S’-nucleotidase, purine nucleoside-phosphorylase and, specifically, xanthine oxidase (the “key catabolic enzyme”) — are decreased. The phosphoribosylamidotransferase/xanthine oxidase ratio increases with a characteristic pattern and is related to the aggressivity and invasiveness of the tumor1, 2.