Cytosolic beta-glycosidases for activation of glycoside prodrugs of daunorubicinPinedo, H. M., Quadir, R., Haisma, H. J. & Boven, E., 1-Jun-2003, In : Biochem.Pharmacol.. 65, 11, p. 1875-1881 7 p.
Research output: Contribution to journal › Article › Academic › peer-review
Human cytosolic beta-glycosidase is a small monomeric enzyme that is active under physiological conditions, which might be ideal for enzyme-prodrug therapy. We have previously reported the synthesis of a galactoside (DNR-GlA(3)) and a glucoside (DNR-GsA3) prodrug of daunorubicin. In the present study, we established that cellular uptake of DNR-GlA3 and DNR-GsA3 was low in contrast to that of daunorubicin. Recombinant human beta-glycosidase converted both prodrugs to daunorubicin as shown by liquid chromatography. The kinetics of the conversion of DNR-GlA3 and DNR-GsA3 by human beta-glycosidase, however, was unfavorable as the K-m values were, respectively, 3- and 6-fold higher than those of another mammalian beta-glycosidase of bovine origin. The V-max values were, respectively, 3.3 and 8.5 nmol/hr/mg as compared to 158.3 and 147.8 nmol/hr/mg of the bovine enzyme. Treatment of OVCAR-3 cells with human beta-glycosidase (0.5 U/mL) and 0.5 muM DNR-GlA3 or DNR-GsA3 resulted in, respectively, 86 and 81% cell growth inhibition, while the prodrugs alone inhibited growth to only 19 and 1%. Treatment of cells with the bovine enzyme and the prodrugs inhibited cell growth more efficiently. We conclude that the endogenous intracellular beta-glycosidase is not available for extracellular prodrug activation. Thus, the incorporation of the enzyme in enzyme-prodrug therapy might be an elegant approach to achieve tumor-specific prodrug conversion. The efficiency of glycoside prodrug conversion might be improved by design of a prodrug that is more readily activated by human beta-glycosidase or by evolution of the enzyme into a mutant form that displays high activity towards these prodrugs. (C) 2003 Elsevier Science Inc. All rights reserved.
|Number of pages||7|
|Publication status||Published - 1-Jun-2003|
- anthracyclines, cancer chemotherapy, cytosolic beta-glycosidase, galactoside, glucoside, prodrug, MONOCLONAL-ANTIBODY, GENE-THERAPY, GLUCURONIDASE CONJUGATE, SELECTIVE CHEMOTHERAPY, HUMAN-LIVER, CANCER, ENZYME, CARCINOMA, GLUCOSIDASE, DOXORUBICIN