Vascular infarction by subcutaneous application of tissue factor targeted to tumor vessels with NGR-peptides: Activity and toxicity profile

tTF-NGR consists of the extracellular domain of the (truncated) tissue factor (tTF), a central molecule for coagulation in vivo, and the peptide GNGRAHA (NGR), a ligand of the surface protein aminopeptidase N (CD13). After deamidation of the NGR-peptide moiety, the fusion protein is also a ligand fo...

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Published inInternational journal of oncology Vol. 37; no. 6; pp. 1389 - 1397
Main Authors DREISCHALÜCK, Johannes, SCHWÖPPE, Christian, MESTERS, Rolf M, BERDEL, Wolfgang E, SPIEKER, Tilmann, KESSLER, Torsten, TIEMANN, Klaus, LIERSCH, Ruediger, SCHLIEMANN, Christoph, KREUTER, Michael, KOLKMEYER, Astrid, HINTELMANN, Heike
Format Journal Article
LanguageEnglish
Published Athens Editorial Academy of the International Journal of Oncology 01.12.2010
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Summary:tTF-NGR consists of the extracellular domain of the (truncated) tissue factor (tTF), a central molecule for coagulation in vivo, and the peptide GNGRAHA (NGR), a ligand of the surface protein aminopeptidase N (CD13). After deamidation of the NGR-peptide moiety, the fusion protein is also a ligand for integrin αvβ3 (CD51/CD61). Both surface proteins are upregulated on endothelial cells of tumor vessels. tTF-NGR showed binding to specific binding sites on endothelial cells in vitro as shown by flow cytometry. Subcutaneous injection of tTF-NGR into athymic mice bearing human HT1080 fibrosarcoma tumors induced tumor growth retardation and delay. Contrast enhanced ultrasound detected a decrease in tumor blood flow in vivo after application of tTF-NGR. Histological analysis of the tumors revealed vascular disruption due to blood pooling and thrombotic occlusion of tumor vessels. Furthermore, a lack of resistance was shown by re-exposure of tumor-bearing mice to tTF-NGR after regrowth following a first cycle of treatment. However, after subcutaneous (s.c.) push injection with therapeutic doses (1-5 mg/kg bw) side effects have been observed, such as skin bleeding and reduced performance. Since lethality started within the therapeutic dose range (LD10 approximately 2 mg/kg bw) no safe therapeutic window could be found. Limiting toxicity was represented by thrombo-embolic events in major organ systems as demonstrated by histology. Thus, subcutaneous injection of tTF-NGR represents an active, but toxic application procedure and compares unfavourably to intravenous infusion.
ISSN:1019-6439
1791-2423
DOI:10.3892/ijo_00000790