Purine Enzymology of Human Colon Carcinomas

摘要: The purpose of this study was to elucidate the purine enzymic programs human primary colorectal carcinomas. Marked alteration in enzymology colon neoplasm clearly distinguished it from that normal mucosa. In mucosa, activities ribonucleotide reductase, inosine phosphate dehydrogenase, formylglycinamidine synthetase, guanosine and amidophosphoribosyltransferase were 0.042, 5.2, 5.6, 8.2 36.0 nmol/h/mg protein, respectively, carcinomas increased 755, 575, 295, 280, 294% values. salvage enzymes, adenine hypoxanthine-guanine phosphoribosyltransferases, 310, 249, 602 whereas tumors, only activity phosphoribosyltransferase (2-fold). markedly higher absolute capacity for tumors accounts, part at least, lack chemotherapeutic success inhibitors enzymes de novo synthesis have been used clinical treatment Combinations biosynthesis blockers or transport ( e.g. , dipyridamole) should improve chemotherapy neoplasms. Since carcinoma glutamine-utilizing (guanosine synthetase amidophosphoribosyltransferase) increased, glutamine concentration decreased (50%), with an antiglutamine agent acivicin) be relevance. rate-limiting enzyme nucleic acid biosynthesis, neoplasms, combination might include drugs against enzyme.