Recombinant targeted toxin based on HER2-specific DARPin possesses a strong selective cytotoxic effect in vitro and a potent antitumor activity in vivo

J Control Release. 2016 Jul 10:233:48-56. doi: 10.1016/j.jconrel.2016.05.020. Epub 2016 May 10.

Abstract

DARPins fused with other proteins are promising non-immunoglobulin scaffolds for specific binding to target cells. In this study HER2-specific DARPin (DARPin_9-29) was used as a tumor-targeting moiety for the delivery of a cytotoxic agent - the fragment of Pseudomonas aeruginosa exotoxin A. It was determined that DARPin-PE40 possesses a considerable cytotoxic activity and induces apoptosis in HER2-positive cells. Cytotoxic effect of DARPin-PE40 strongly correlates with the HER2 expression level. The effect of intravenous administration of DARPin-PE40 was tested in the xenograft model of breast cancer. It was shown that treatment of animals with DARPin-PE40 caused strong and prolonged suppression of xenograft tumor growth.

Keywords: DARPin; HER2; PE40; Pseudomonas aeruginosa exotoxin A; Recombinant targeted toxin; Targeted therapy.

MeSH terms

  • ADP Ribose Transferases / administration & dosage*
  • ADP Ribose Transferases / therapeutic use
  • Animals
  • Antineoplastic Agents / administration & dosage*
  • Antineoplastic Agents / therapeutic use
  • Apoptosis / drug effects
  • Bacterial Toxins / administration & dosage*
  • Bacterial Toxins / therapeutic use
  • CHO Cells
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cricetulus
  • Exotoxins / administration & dosage*
  • Exotoxins / therapeutic use
  • Female
  • Humans
  • Immunotoxins / administration & dosage*
  • Immunotoxins / therapeutic use
  • Mammary Neoplasms, Experimental / drug therapy*
  • Mammary Neoplasms, Experimental / metabolism
  • Mammary Neoplasms, Experimental / pathology
  • Mice, Nude
  • Pseudomonas aeruginosa Exotoxin A
  • Receptor, ErbB-2 / metabolism*
  • Recombinant Fusion Proteins / administration & dosage*
  • Recombinant Fusion Proteins / therapeutic use
  • Tumor Burden / drug effects
  • Virulence Factors / administration & dosage*
  • Virulence Factors / therapeutic use

Substances

  • Antineoplastic Agents
  • Bacterial Toxins
  • Exotoxins
  • Immunotoxins
  • Recombinant Fusion Proteins
  • Virulence Factors
  • ADP Ribose Transferases
  • ERBB2 protein, human
  • Receptor, ErbB-2