Integrin-Targeting Knottin Peptide-Drug Conjugates Are Potent Inhibitors of Tumor Cell Proliferation

  • Angew Chem Int Ed Engl. 2016 Aug 16;55(34):9894-7. doi: 10.1002/anie.201603488.
Nick Cox  1 James R Kintzing  2 Mark Smith  1 Gerald A Grant  3 Jennifer R Cochran  4
Affiliations
  • 1. Stanford ChEM-H Medicinal Chemistry Knowledge Center, Stanford University, Stanford, CA, 94305, USA.
  • 2. Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.
  • 3. Department of Neurosurgery, Stanford University, Stanford, CA, 94305, USA.
  • 4. Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA. [email protected].
Abstract

Antibody-drug conjugates (ADCs) offer increased efficacy and reduced toxicity compared to systemic chemotherapy. Less attention has been paid to peptide-drug delivery, which has the potential for increased tumor penetration and facile synthesis. We report a knottin peptide-drug conjugate (KDC) and demonstrate that it can selectively deliver gemcitabine to malignant cells expressing tumor-associated integrins. This KDC binds to tumor cells with low-nanomolar affinity, is internalized by an integrin-mediated process, releases its payload intracellularly, and is a highly potent inhibitor of brain, breast, ovarian, and pancreatic Cancer cell lines. Notably, these features enable this KDC to bypass a gemcitabine-resistance mechanism found in pancreatic Cancer cells. This work expands the therapeutic relevance of knottin peptides to include targeted drug delivery, and further motivates efforts to expand the drug-conjugate toolkit to include non-antibody protein scaffolds.

Keywords
antitumor agents; drug delivery; integrins; knottins; peptides.
Products