A Fusion Protein of RGD4C and β-Lactamase Has a Favorable Targeting Effect in Its Use in Antibody Directed Enzyme Prodrug Therapy

Int J Mol Sci. 2015 Apr 28;16(5):9625-34. doi: 10.3390/ijms16059625.

Abstract

Antibody directed enzyme prodrug therapy (ADEPT) utilizing β-lactamase is a promising treatment strategy to enhance the therapeutic effect and safety of cytotoxic agents. In this method, a conjugate (antibody-β-lactamase fusion protein) is employed to precisely activate nontoxic cephalosporin prodrugs at the tumor site. A major obstacle to the clinical translation of this method, however, is the low catalytic activity and high immunogenicity of the wild-type enzymes. To overcome this challenge, we fused a cyclic decapeptide (RGD4C) targeting to the integrin with a β-lactamase variant with reduced immunogenicity which retains acceptable catalytic activity for prodrug hydrolysis. Here, we made a further investigation on its targeting effect and pharmacokinetic properties, the results demonstrated that the fusion protein retains a targeting effect on integrin positive cells and has acceptable pharmacokinetic characteristics, which benefits its use in ADEPT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / metabolism*
  • Cell Line, Tumor
  • Fluorescent Antibody Technique
  • Microscopy, Fluorescence
  • Oligopeptides / therapeutic use*
  • Prodrugs / therapeutic use*
  • Rats, Wistar
  • Recombinant Fusion Proteins / blood
  • Recombinant Fusion Proteins / pharmacokinetics
  • Recombinant Fusion Proteins / therapeutic use*
  • Technetium
  • Tissue Distribution
  • Xenograft Model Antitumor Assays
  • beta-Lactamases / therapeutic use*

Substances

  • Antibodies
  • Oligopeptides
  • Prodrugs
  • Recombinant Fusion Proteins
  • Technetium
  • beta-Lactamases