Suppression of Aggrus/podoplanin-induced platelet aggregation and pulmonary metastasis by a single-chain antibody variable region fragment.

Abstract

Almost all highly metastatic tumor cells possess high platelet aggregating abilities, thereby form large tumor cell-platelet aggregates in the microvasculature. Embolization of tumor cells in the microvasculature is considered to be the first step in metastasis to distant organs. We previously identified the platelet aggregation-inducing factor expressed on the surfaces of highly metastatic tumor cells and named as Aggrus. Aggrus was observed to be identical to the marker protein podoplanin (alternative names, T1α, OTS-8, and others). Aggrus is frequently overexpressed in several types of tumors and enhances platelet aggregation by interacting with the platelet receptor C-type lectin-like receptor 2 (CLEC-2). Here, we generated a novel single-chain antibody variable region fragment (scFv) by linking the variable regions of heavy and light chains of the neutralizing anti-human Aggrus monoclonal antibody MS-1 with a flexible peptide linker. Unfortunately, the generated KM10 scFv failed to suppress Aggrus-induced platelet aggregation in vitro. Therefore, we performed phage display screening and finally obtained a high-affinity scFv, K-11. K-11 scFv was able to suppress Aggrus-induced platelet aggregation in vitro. Moreover, K-11 scFv prevented the formation of pulmonary metastasis in vivo. These results suggest that K-11 scFv may be useful as metastasis inhibitory scFv and is expected to aid in the development of preclinical and clinical examinations of Aggrus-targeted cancer therapies.

• Authors: Kenichi Miyata, Satoshi Takagi, Shigeo Sato, Hiroshi Morioka, Kiyotaka Shiba, Tamiko Minamisawa, Miho Takami, Naoya Fujita
• Journal: Cancer medicine (Cancer Med) Vol. 3 Issue 6 Pg. 1595-604 (Dec 2014) ISSN: 2045-7634 [Electronic] United States
• PMID: 25132683 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Chemical References

• Antibodies, Monoclonal, Murine-Derived
• Membrane Glycoproteins
• Membrane Proteins
• PDPN protein, human
• Single-Chain Antibodies

Topics

• Animals
• Antibodies, Monoclonal, Murine-Derived (immunology, pharmacology)
• CHO Cells
• Cell Line, Tumor
• Cricetinae
• Cricetulus
• Female
• Humans
• Lung Neoplasms (blood, pathology, secondary, therapy)
• Membrane Glycoproteins (antagonists & inhibitors, blood, immunology)
• Membrane Proteins (antagonists & inhibitors, blood, immunology)
• Mice, Inbred BALB C
• Mice, Nude
• Neoplasm Metastasis
• Platelet Aggregation (drug effects)
• Rabbits
• Single-Chain Antibodies (immunology, pharmacology)