Radiolabeling RGD peptide and preliminary biodistribution evaluation in mice bearing S180 tumors.
OBJECTIVE
To prepare the rhenium-188 (188Re)-arginine-glycine-aspartic acid (RGD) peptide in a convenient manner and to evaluate its potential as an agent for alphavbeta3 integrin receptor-positive tumors.


METHODS
Radiolabeled RGD was obtained by conjugating the His group at the end of peptide with fac-[188Re(H2O)3(CO)3]+. Chelating efficiency of fac-[188Re(H2O)3(CO)3]+ and radiolabeling efficiency of radiolabeled peptide were measured by thin-layer chromatography and high-performance liquid chromatography. In-vitro stability of the radio-complex was determined in phosphate-buffered saline (0.05 mol/l, pH 7.4), new-born calf serum, His or Cys solution at 37 degrees C or room temperature and analyzed by thin-layer chromatography. A biodistribution study was carried out in mice bearing S180 tumors.


RESULTS
188Re-RGD was obtained with a more than 95% of radiolabeling efficiency, and showed high stability in phosphate-buffered saline, new-born calf serum, His and Cys solution. Furthermore, this radio-complex was cleared rapidly from the blood and showed specific tumor uptake in mice bearing S180 tumors.


CONCLUSIONS
188Re-RGD was prepared by a simple method. Preliminary biodistribution results showed its potential as an agent for cancer therapy and encouraged further investigation.
Ma
Yufei
Y
Shanghai Institute of Applied Physics (SINAP), Chinese Academy of Sciences, PR China.
Yu
Junfeng
J
Han
Yanjiang
Y
Shen
Hua
H
Li
Zheng
Z
Zhou
Wei
W
Yin
Duanzhi
D
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics* / Q000627:therapeutic use; D055550:Protein Stability; D011868:Radioisotopes; D012211:Rhenium / Q000737:chemistry*; D014018:Tissue Distribution
D039302:Integrin alphaVbeta3; D009842:Oligopeptides; D011868:Radioisotopes; D012211:Rhenium; C047981:arginyl-glycyl-aspartic acid