Study of radioisotope labeled cobalt-bleomycins

已知^<57> co -bleomycin对恶性肿瘤有很强的亲和力。由于^<57>Co的半衰期较长（270天），^<57>Co-bleomycin尚未用于临床诊断。非放射性钴结合博来霉素（co -bleomycin）天然对恶性肿瘤也有很强的亲和力。我们打算用放射性同位素（RI）标记科博莱霉素，用于临床诊断和治疗。以博来霉素和氯化钴为原料制备复方博来霉素很容易。作为标记的放射性试剂，我们选择了Na^<131>I,^<125>I- bolton - hunter试剂和^<125>I- pib试剂。取少量标记为^<125>I-Bolton-Hunter的Co-bleomycin，用Ehrlich带瘤小鼠检测其对肿瘤的亲和力。不幸的是，标记的科博莱霉素对恶性肿瘤没有亲和力。标记为^<125>I- pib的科博莱霉素没有获得足够的动物研究量，Na^<131>I…More不能与科博莱霉素结合。此外，我们打算分别用Na^<131>I,^<125>I- bolton - hunter试剂和^<125>I- pib试剂标记博来霉素。这三种标记试剂分别与博来霉素高收率结合。采用上述方法检测bleomycin-^<131>I、bleomycin-^<125>I- bolton - hunter和bleomycin-^<125>I- pib的肿瘤亲和性。这些标记的博来霉素对恶性肿瘤没有亲和力。为了使肿瘤对标记的博来霉素具有亲和力，我们尝试将钴与这三种标记的博来霉素结合。但钴不能与标记的博来霉素结合。从以上结果可以看出，复方博莱霉素的RI标记是非常困难的。如果RI标记试剂与科博莱霉素侧链胺结合，则科博莱霉素的生物学特性不会引起试剂结合的退化。我们承诺在下一个项目中将RI标记试剂与科博莱霉素侧链胺结合。少

It is known that ^<57>Co-bleomycins have the strong affinity for the malignant tumor. Owing to the long-half life (270 days) of ^<57>Co, ^<57>Co-bleomycins have not been used for the clinical diagnosis. Non-radioactive cobalt binding bleomycins (Co-bleomycins) naturally have the strong affinity for the malignant tumor, too.We intended to label Co-bleomycins with radioisotope (RI) to use for the clinical diagnosis and therapy. Co-bleomycin was easily prepared from bleomycin and cobaltous chloride. As the radioactive reagent for the label, we chose Na^<131>I,^<125>I-Bolton-Hunter reagent and ^<125>I-PIB reagent.A small quantity of Co-bleomycin labeled with ^<125>I-Bolton-Hunter was obtained, and the tumor affinity of this labeled Co-bleomycin was examined by using Ehrlich tumor bearing mice. Unfortunately, the labeled Co-bleomycin had not the affinity for the malignant tumor.An adequate quantity for the animal study of Co-bleomycin labeled with ^<125>I-PIB was not obtained and Na^<131>I … More did not bind to Co-bleomycin.In addition, we intented to label bleomycin with Na^<131>I,^<125>I-Bolton-Hunter reagent and ^<125>I-PIB reagent, respectively. These three lableling reagents were bound to bleomycin with high yield, respectively. The tumor affinity of bleomycin-^<131>I,bleomycin-^<125>I-Bolton-Hunter and bleomycin-^<125>I-PIB was examined by the method described above. These labeled bleomycin had not the affinity for the malignant tumor. To give the tumor affinity to the labeled bleomycin, we attempted to bind cobalt to these three labeled bleomycin. But cobalt did not bind to the labeled bleomycin.From the results mentioned above, it was clarified that RI labeling for Co-bleomycin was very difficult. If RI labeling reagent was bound to the amine of side chain of Co-bleomycin, the biological property of Co-bleomycin would not originate the degeneration in binding the reagent. We undertake to bind RI labeling reagent to the amine of side chain of Co-bleomycin in the next project. Less