Targeted radiopharmaceutical is an effective treatment for solid tumors. By labeling with radionuclides, targeting peptide could achieve both noninvasive diagnosis and targeted radionuclide therapy. In order to evaluate the potential applicability of GEBP11 peptides in diagnosis and radiotherapy of gastric cancer, in this study, iodine 131 labeled GEBP11 peptides, including a novel bifid PEGlylated GEBP11 trimer and its corresponding monomer, were developed. The clinical potential of GEBP11 peptides, such as tumor binding affinity and antitumor efficacy was demonstrated and assessed with multimodality imaging methods. Cerenkov and SPECT imaging showed higher tumor uptake for (131)I-2PEG-(GEBP11)3 (P<0.05, day 1; P<0.01, day 2; vs. monomer). Biodistribution studies indicated higher tumor accumulation and better T/NT of (131)I-2PEG-(GEBP11)3. Bioluminescence imaging exhibited a significant tumor growth suppression in (131)I-2PEG-(GEBP11)3 treated group (P<0.001 vs. control; P<0.01 vs. monomer). After treatment with (131)I-2PEG-(GEBP11)3, the tumor volume and vasculature decreased significantly, and the survival time was prolonged to 75.5days. Meanwhile, no significant hepatic or renal toxicity was observed with (131)I-2PEG-(GEBP11)3 administered. In conclusion, (131)I-2PEG-(GEBP11)3 could be a promising candidate for peptide-based targeting therapy of gastric cancer. 2PEG-(GEBP11)3 might be a potential drug delivery vehicle for the antiangiogenic therapy of gastric cancer.
Keywords: Gastric cancer; Multimodality imaging; Targeted radionuclide therapy; Trimeric GEBP11 peptide; Tumor vasculature targeting.
© 2013. Published by Elsevier B.V. All rights reserved.