Nitroreductase enzymes catalyze the conversion of the nitro group of prodrug compounds via hydroxylamine to amine group and the active drug inhibits tumor formation by binding to DNA. E. coli NTR/CB1954 (5-aziridinyl-2,4- dinitrobenzamide) is the best known combination that have studied phase I/II trial for different cancer types. So more effective NTR/drug combination should be investigated for cancer therapies. In this study, first of all, we explored and characterized two novel nitroreductases (Ssap-NtrB-cloned from a mesophilic microorganism and Gk-Ntr-cloned from a thermophilic microorganism) with enhanced activity-selectivity and implemented various applications. And nitro group containing two potential prodrugs (isoxazole derivatives and 3,5-difluorophenyl derivatives) were synthesized and were investigated the interaction of these potential pro-drugs with NTR enzymes by spectroscopic techniques and HPLC analysis. Michaelis-Menten kinetic parameters were calculated for reduction reactions of prodrugs and compared common known prodrugs like as CB1954 and SN23862. The prodrugs were evaluated by MTT and SRB assay in three different cancer cell lines, Human Hepatoma Cancer (Hep3B), Human Colon Cancer (HT-29) and Human Prostate Cancer (PC3) in addition to non-cancer cell, HUVEC. According to our results, proposed enzyme/prodrug combinations may use NTR based cancer therapy.
•Learn the importance of nitroreductase to drug design and other applications,
•Synthesis of new prodrug candidates,
•Design new projects with collaboration for cancer therapy.