Investigation of radiopharmaceutical potential of Bleomycin and Bleomycin-Glucuronide labeled with iodine-131

Bleomycin, a group of glycopeptide antibiotics, was isolated from Streptomyces verticillus by Dr. Hamao UMEZAWA et al in 1962. Bleomycin is widely used as an anti-tumor agent in the treatment of lung cancer, lymphoma, carcinoma, testicle, head, neck and other tumors.Aim of this study is to label BLM and enzymatically synthesized BLMG with 131I and to investigate radiopharmaceutical potentials of these radiolabeled compounds using nuclear methods. For this, first of all BLMG was enzymatically synthesized using microsom preparations containing UDP-glycoronil transferase enzyme isolated from rat liver and UDP-glucuronic acid and then related compounds were labeled with 127I (KI) using stochiometrically (1:2:1) ratios of BLM, BLMG, KI and it was determined to see whether they were successfully labeled or not using HPLC and LC/MS/MS chromatographic techniques. In the next step radiochromotographic studies of BLM and BLMG were carried out. In this scope, labeling yields of 131I-BLM and 131I-BLMG was obtained as 90% and 60%, respectively. At the same time it was obtained that both of them were stable in blood serum for 24 hours. Finally, biodistribution and scintigraphic studies were carried out on test animals and it was obtained that similar metabolic behavior was observed for both compounds and the high accumulation of the radioiodinated compounds was observed in main organs such as stomach, bladder, prostate, testicle and spinal cord in the result of this studies and it was observed that scintigraphic studies are agreed with biodistributional studies. In addition to these, all experimental data of the biodistributional studies were evaluated using SPSS 13 statistical software.As a conclusion, both BLM and BLMG were successfully labeled using iodogen method and they may have diagnostic and therapeutic applications for the tumor of the testicle and the prostate. On the other hand, the selective incorporation of 131I-BLM and 131I-BLMG into the testicle and the prostate cancer cells should be examined using tumor bearing laboratory animals or cultured human cancer cell lines.