ABSTRACT
In this study we report serum sialyltransferase and nucleoside diphosphatase activities of patients with malignant tumors of various primary sites and extent, prior to and during chemotherapy. Enzyme levels were compared to clinical and laboratory parameters. The sialyltransferase and uridine diphosphatase (UDPase) activities in samples of 43 patients with advanced ovarian cancer was four to ten fold above the normal mean value (sialyltransferase 85.1 +/- 58 pmol/hr/ml and UDPase 26.6 +/- 7.2 nmol/hr/ml). After effective chemotherapy with adriamycin and cisplatin, the enzyme activity decreased markedly. In cases of complete remission, enzyme activity decreased to the normal range. In three cases after initial response for several months a rise of both enzymes was observed before any other biochemical finding of the forthcoming relapse. Similar patterns were observed in testicular cancer (6 cases). Clinical correlation is also obvious in other tumors except malignant lymphomas. Our findings show that the activities of these enzymes correlated with the clinical course, and therefore they can be the basis for clinical application for tumor monitoring, especially during chemotherapy.
Subject(s)
Acid Anhydride Hydrolases , Neoplasms/enzymology , Phosphoric Monoester Hydrolases/analysis , Sialyltransferases/analysis , Transferases/analysis , Female , Humans , Male , Monitoring, Physiologic , Neoplasms/drug therapy , Ovarian Neoplasms/enzymology , Testicular Neoplasms/enzymologyABSTRACT
The adenine nucleotides, 5'-AMP and 3',5'-cyclic AMP block L cells in the S-phase of the cell cycle. The intracellular level of cyclic AMP is reduced after incubation of cells with 5'-AMP, and rates of uridine transport are increased after incubation with either 5'-AMP or cyclic AMP. On the contrary, cyclic AMP levels are increased and uridine transport decreased in cells treated with an inhibitor of the cyclic AMP phosphodiesterase. This inhibitor partially reverses the growth-inhibitory effect of cyclic AMP, indicating that a breakdown product is the effective inhibitor of growth. The inhibition of cell growth induced by the adenine nucleotides is prevented by uridine, suggesting that the block in S is due to a lack of availability of pyrimidines.
