Construction and Evaluation of the Tumor-Targeting, Cell-Penetrating Multifunctional Molecular Probe iCREKA

Contrast Media Mol Imaging. 2018 Mar 4:2018:7929617. doi: 10.1155/2018/7929617. eCollection 2018.

Abstract

A novel tumor stroma targeting and membrane-penetrating cyclic peptide, named iCREKA, was designed and labeled by fluorescein isothiocyanate (FITC) and positron emitter 18F to build the tumor-targeting tracers. The FITC-iCREKA was proved to have significantly higher cellular uptake in the glioma U87 cells in the presence of activated MMP-2 than that in absence of activated MMP-2 by cells fluorescence test in vitro. The tumor tissue fluorescence microscope imaging demonstrated that FITC-iCREKA accumulated in the walls of the blood vessels and the surrounding stroma in the glioma tumor at 1 h after intravenous injection. While at 3 h after injection, FITC-iCREKA was found to be uptaken in the tumor cells. However, the control FITC-CREKA can only be found in the tumor stroma, not in the tumor cells, no matter at 1 h or 3 h after injection. The whole-animal fluorescence imaging showed that the glioma tumor could be visualized clearly with high fluorescence signal. The microPET/CT imaging further demonstrated that 18F-iCREKA could target U87MG tumor in vivo from 30 min to 2 h after injection. The present study indicated the iCREKA had the capacity of tumor stroma targeting and the membrane-penetrating. It was potential to be developed as the fluorescent and PET tracers for tumor imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell-Penetrating Peptides* / chemistry
  • Fluorescein-5-isothiocyanate* / chemistry
  • Fluorine Radioisotopes
  • Glioma / diagnostic imaging
  • Humans
  • Molecular Probes / chemistry*
  • Molecular Probes / pharmacokinetics
  • Neoplasms / diagnostic imaging*
  • Oligopeptides / chemistry
  • Optical Imaging / methods
  • Positron-Emission Tomography / methods*

Substances

  • Cell-Penetrating Peptides
  • Fluorine Radioisotopes
  • Molecular Probes
  • Oligopeptides
  • cysteinyl-arginyl-glutamyl-lysyl-alanyl
  • Fluorine-18
  • Fluorescein-5-isothiocyanate