Fragmentation of chromatin with 125I radioactive disintegrations

Radiolabeled 5-iodo-3'-O-(17beta-succinyl-5alpha-androstan-3-one)-2'-deoxyuridine and its 5'-monophosphate for imaging and therapy of androgen receptor-positive cancers: synthesis and biological evaluation

High levels of androgen receptor (AR) are often indicative of recurrent, advanced, or metastatic cancers. These conditions are also characterized by a high proliferative fraction. 5-Radioiodo-3'-O-(17beta-succinyl-5alpha-androstan-3-one)-2'-deoxyuridine 8 and 5-radioiodo-3'-O-(17beta-succinyl-5alpha-androstan-3-one)-2'-deoxyuridin-5'-yl monophosphate 13 target AR. They are also degraded intracellularly to 5-radioiodo-2'-deoxyuridine 1 and its monophosphate 20, respectively, which can participate in the DNA synthesis. Both drugs were prepared at the no-carrier-added level. Precursors and methods are readily adaptable to radiolabeling with various radiohalides suitable for SPECT and PET imaging, as well as endoradiotherapy. In vitro and in vivo studies confirm the AR-dependent interactions. Both drugs bind to sex hormone binding globulin. This binding significantly improves their stability in serum. Biodistribution and imaging studies show preferential uptake and retention of 8 and 13 in ip xenografts of human ovarian adenocarcinoma cells NIH:OVCAR-3, which overexpress AR. When these drugs are administered at therapeutic dose levels, a significant tumor growth arrest is observed.

Iodine-125 induced micronuclei and sperm head abnormalities in mice

Swiss albino mice were injected with 0 (controls) 5, 10 or 15 microCi of iodine-125 (125I) and a high incidence of micronuclei in young bone marrow erythrocytes and of sperm head abnormalities was observed. The percentage of polychromatic erythrocytes containing micronuclei in mice treated with 0, 2.5, 5 and 7.5 microCi of 125I administered twice (at 30 and 6 h before sampling) was 0.23, 0.44, 0.56 and 0.72, respectively. The percentage (mean) of abnormal sperm recorded in controls during 1-3, 4-5 and 6-8 weeks was 3.3, 3.7 and 3.7 respectively, whereas the values for the same periods in the 5 microCi (5.5, 6.4 and 7.3), 10 microCi (7.7, 8.4 and 10.0) and 15 microCi (10.3, 9.9 and 10.2) groups were significantly higher. These results suggest that 125I can induce genetic damage in both somatic and germ cells.

125I-UDR induced division delay

Mitotic selection for cell cycle analysis was used to investigate the effects of (3)H and (125)I, incorporated into DNA, on the cell cycle progression of Chinese hamster ovary (CHO) cells. The results indicate that S-phase cells were delayed and G(2) cells were not.