Synthesis and preliminary biological studies of the novel conjugate 188Re-labeled meso-tetrakis(4-sulfophenyl)porphyrin in mice.
OBJECTIVE
The objective of this study was to evaluate the biological behaviors of a novel (188)Re-labeled meso-tetrakis(4-sulfophenyl)porphyrin (TPPS(4)) in normal mice and tumor-bearing mice.


METHODS
TPPS(4) was synthesized and labeled by (188)ReO(4)(-). Normal KM mice and BALB/c nude mice bearing melanoma or hepatoma were prepared for distribution studies.


RESULTS
The [(188)Re]TPPS(4) yield was >98% with a specific activity of 11.2 GBq/mol, and vitamin C could increase its stability in vitro. In normal KM mice, [(188)Re]TPPS(4) had a fast blood clearance ( approximately 90%, 24 h postinjection), low retention in vital organs and hepatotropic characteristics. In nude mice, uptakes of >4.1% and 6.5% ID/g tumor at 8 h postinjection were observed in melanoma and hepatoma, respectively; this remained at high levels of 4.7% and 5.7%, respectively, after 24 h. At 8 h, the tumor/blood and tumor/muscle ratios in melanoma-bearing and hepatoma-bearing mice were 6.2-15.2 and 6.1-24.2, respectively. Twenty-four hours later, these high ratios still continued at 8.6-22.1 and 12-26.1, respectively.


CONCLUSIONS
The results obtained in this study indicate that [(188)Re]TPPS(4) has a high tumor affinity and retainable accumulation characteristics in carcinoma, which can potentially be used for tumor-targeted therapy.
Jia
Zhiyun
Z
Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
Deng
Houfu
H
Pu
Manfei
M
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007553:Isotope Labeling; D008114:Liver Neoplasms, Experimental / Q000378:metabolism; D008546:Melanoma, Experimental / Q000378:metabolism; D008665:Metalloporphyrins / Q000138:chemical synthesis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011868:Radioisotopes; D019275:Radiopharmaceuticals / Q000138:chemical synthesis*; D012211:Rhenium; D014018:Tissue Distribution
D007202:Indicators and Reagents; D008665:Metalloporphyrins; D011868:Radioisotopes; D019275:Radiopharmaceuticals; C524176:rhenium tetrakis(4-sulfophenyl)porphyrin; D012211:Rhenium