Enhancement of the antiangiogenic activity of interleukin-12 by peptide targeted delivery of the cytokine to alphavbeta3 integrin.

Abstract

We engineered a fusion protein, mrIL-12vp [mouse recombinant interleukin (IL)-12 linked to vascular peptide], linking the vascular homing peptide CDCRGDCFC (RGD-4C), a ligand for alphavbeta3 integrin, to mrIL-12 to target IL-12 directly to tumor neovasculature. The fusion protein stimulated IFN-gamma production in vitro and in vivo, indicating its biological activity was consistent with mrIL-12. Immunofluorescence techniques showed mrIL-12vp specifically bound to alphavbeta3 integrin-positive cells but not to alphavbeta3 integrin-negative cells. In corneal angiogenesis assays using BALB/c mice treated with either 0.5 microg/mouse/d of mrIL-12vp or mrIL-12 delivered by subcutaneous continuous infusion, mrIL-12vp inhibited corneal neovascularization by 67% compared with only a slight reduction (13%) in angiogenesis in the mrIL-12-treated animals (P = 0.008). IL-12 receptor knockout mice given mrIL-12vp showed a marked decrease in the area of corneal neovascularization compared with mice treated with mrIL-12. These results indicate that mrIL-12vp inhibits angiogenesis through IL-12-dependent and IL-12-independent mechanisms, and its augmented antiangiogenic activity may be due to suppression of endothelial cell signaling pathways by the RGD-4C portion of the fusion protein. Mice injected with NXS2 neuroblastoma cells and treated with mrIL-12vp showed significant suppression of tumor growth compared with mice treated with mrIL-12 (P = 0.03). Mice did not show signs of IL-12 toxicity when treated with mrIL-12vp, although hepatic necrosis was present in mrIL-12-treated mice. Localization of IL-12 to neovasculature significantly enhances the antiangiogenic effect, augments antitumor activity, and decreases toxicity of IL-12, offering a promising strategy for expanding development of IL-12 for treatment of cancer patients.

• Authors: Erin B Dickerson, Nasim Akhtar, Howard Steinberg, Zun-Yi Wang, Mary J Lindstrom, Marcia L Padilla, Robert Auerbach, Stuart C Helfand
• Journal: Molecular cancer research : MCR (Mol Cancer Res) Vol. 2 Issue 12 Pg. 663-73 (Dec 2004) ISSN: 1541-7786 [Print] United States
• PMID: 15634755 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Angiogenesis Inhibitors
• Integrin alphaVbeta3
• Oligopeptides
• Peptides
• Protein Isoforms
• Receptors, Interleukin
• Receptors, Interleukin-12
• Recombinant Fusion Proteins
• Recombinant Proteins
• Interleukin-12
• arginyl-glycyl-aspartic acid
• Interferon-gamma

Topics

• Angiogenesis Inhibitors (pharmacology)
• Animals
• CHO Cells
• Cell Line, Tumor
• Cloning, Molecular
• Cricetinae
• Flow Cytometry
• Integrin alphaVbeta3 (metabolism)
• Interferon-gamma (genetics, metabolism)
• Interleukin-12 (administration & dosage, pharmacology)
• Mice
• Mice, Inbred BALB C
• Mice, Inbred DBA
• Mice, Knockout
• Mice, Transgenic
• Necrosis (pathology)
• Neoplasm Transplantation
• Neovascularization, Pathologic
• Oligopeptides (chemistry)
• Peptides (chemistry)
• Plasmids (metabolism)
• Protein Engineering
• Protein Isoforms
• Receptors, Interleukin (genetics)
• Receptors, Interleukin-12
• Recombinant Fusion Proteins (metabolism)
• Recombinant Proteins (chemistry)
• Signal Transduction
• Time Factors
• Transfection