Open AccessIodine 125‐labeled mesenchymal–epithelial transition factor binding peptide‐click‐cRGDyk heterodimer for glioma imaging
Author(s) -
Kim EunMi,
Jeong MinHee,
Kim Dong Wook,
Jeong HwanJeong,
Lim Seok Tae,
Sohn MyungHee
Publication year - 2011
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/j.1349-7006.2011.01983.x
Subject(s) - in vivo , click chemistry , biodistribution , chemistry , glioma , in vitro , peptide , microbiology and biotechnology , biophysics , cancer research , biochemistry , medicine , biology , combinatorial chemistry
In our previous study, mesenchymal–epithelial transition factor (c‐Met)‐binding peptides (cMBP) had been readily radiolabeled with radioactive iodide for glioma imaging because of five histidine amino acids. However, iodinated cMBP showed relatively unfavorable in vivo kinetics. For this reason, we tried to design dual peptide ligands that would be advantageous in recognizing both c‐Met receptor and integrin α v β 3 . A cMBP‐click‐cRGDyk (cyclic Arg‐Gly‐Asp‐Tyr‐Lys) heterodimer was synthesized from mini polyethylene glycol‐conjugated cMBP‐3 glycine (GGG)‐a single name of amino acids (SC) (Ser‐Cys) and cRGDyk through a click (1 + 3 cycloaddition), and then labeled with iodine 125 (I‐125) via histidine in the cMBP and tyrosine in the cRGDyk. The receptor‐binding characteristics and tumor‐targeting efficacy of cMBP‐click‐cRGDyk were tested in vitro and in vivo . A cMBP‐click‐cRGDyk had comparable integrin α v β 3 ‐binding affinity with cRGDyk. The results of the biodistribution of 125 I‐cMBP‐click‐cRGDyk at 4 h showed higher tumor‐to‐blood, tumor‐to‐liver, and tumor‐to‐muscle ratios: 10.07, 6.76, and 11.12, compared to 2.34, 1.99, and 5.18 of 125 I‐cMBP‐GGG‐SC, respectively. U87MG tumor xenografts could be visualized by single photon emission computed tomography (SPECT)/CT using 125 I‐cMBP‐click‐cRGDyk and also image contrast and overall quality were improved compared to 125 I‐cMBP‐GGG‐SC. As the results of in vivo inhibition using free cRGDyk or cMBP‐GGG‐SC indicated, the tumoral uptake of 125 I‐cMBP‐click‐cRGDyk decreased. This finding means that 125 I‐cMBP‐click‐cRGDyk was specifically uptaken by integrin α v β 3 and the c‐Met receptor. Although imaging quality was improved, additional experiments are needed to acquire significant image‐quality improvement. ( Cancer Sci 2011; 102: 1516–1521)