The efficient elimination of solid tumor cells by EGFR-specific and HER2-specific scFv-SNAP fusion proteins conjugated to benzylguanine-modified auristatin F.

Abstract

Antibody-drug conjugates (ADCs) combine the potency of cytotoxic drugs with the specificity of monoclonal antibodies (mAbs). Most ADCs are currently generated by the nonspecific conjugation of drug-linker reagents to certain amino acid residues in mAbs, resulting in a heterogeneous product. To overcome this limitation and prepare ADCs with a defined stoichiometry, we use SNAP-tag technology as an alternative conjugation strategy. This allows the site-specific conjugation of O(6)-benzylguanine (BG)-modified small molecules to SNAP-tag fusion proteins. To demonstrate the suitability of this system for the preparation of novel recombinant ADCs, here we conjugated SNAP-tagged single chain antibody fragments (scFvs) to a BG-modified version of auristatin F (AURIF). We used two scFv-SNAP fusion proteins targeting members of the epidermal growth factor receptor (EGFR) family that are frequently overexpressed in breast cancer. The conjugation of BG-AURIF to EGFR-specific 425(scFv)-SNAP and HER2-specific αHER2(scFv)-SNAP resulted in two potent recombinant ADCs that specifically killed breast cancer cell lines by inducing apoptosis when applied at nanomolar concentrations. These data confirm that SNAP-tag technology is a promising tool for the generation of novel recombinant ADCs.

• Authors: Mira Woitok, Diana Klose, Judith Niesen, Wolfgang Richter, Muhammad Abbas, Christoph Stein, Rolf Fendel, Magdalena Bialon, Christiane Püttmann, Rainer Fischer, Stefan Barth, Katharina Kolberg
• Journal: Cancer letters (Cancer Lett) Vol. 381 Issue 2 Pg. 323-30 (10 28 2016) ISSN: 1872-7980 [Electronic] Ireland
• PMID: 27502168 (Publication Type: Journal Article)
• Copyright: Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Antineoplastic Agents
• Immunotoxins
• Oligopeptides
• Q-SNARE Proteins
• Recombinant Fusion Proteins
• Single-Chain Antibodies
• Guanine
• EGFR protein, human
• EGFR protein, mouse
• ERBB2 protein, human
• ErbB Receptors
• Erbb2 protein, mouse
• Receptor, ErbB-2

Topics

• Animals
• Antineoplastic Agents (pharmacology)
• Apoptosis (drug effects)
• Breast Neoplasms (drug therapy, immunology, metabolism, pathology)
• Cell Cycle Checkpoints (drug effects)
• Cell Line, Tumor
• Cell Survival (drug effects)
• Dose-Response Relationship, Drug
• Drug Stability
• ErbB Receptors (immunology, metabolism)
• Guanine (analogs & derivatives, pharmacology)
• Humans
• Immunotherapy (methods)
• Immunotoxins (immunology, pharmacology)
• Inhibitory Concentration 50
• Mice
• Oligopeptides (pharmacology)
• Q-SNARE Proteins (immunology, pharmacology)
• Receptor, ErbB-2 (immunology, metabolism)
• Recombinant Fusion Proteins (pharmacology)
• Signal Transduction (drug effects)
• Single-Chain Antibodies (immunology, pharmacology)