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CD36-mediated activation of endothelial cell apoptosis by an N-terminal recombinant fragment of thrombospondin-2 inhibits breast cancer growth and metastasis in vivo.
- Source :
-
Breast cancer research and treatment [Breast Cancer Res Treat] 2011 Jul; Vol. 128 (2), pp. 337-46. Date of Electronic Publication: 2010 Aug 17. - Publication Year :
- 2011
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Abstract
- Thus far the clinical benefits seen in breast cancer patients treated with drugs targeting the vascular endothelial growth factor (VEGF) pathway are only modest. Consequently, additional antiangiogenic approaches for treatment of breast cancer need to be investigated. Thrombospondin-2 (TSP-2) has been shown to inhibit tumor growth and angiogenesis with a greater potency than the related molecule TSP-1. The systemic effects of TSP-2 on tumor metastasis and the underlying molecular mechanisms of the antiangiogenic activity of TSP-2 have remained poorly understood. We generated a recombinant fusion protein consisting of the N-terminal region of TSP-2 and the IgG-Fc1 fragment (N-TSP2-Fc) and could demonstrate that the antiangiogenic activity of N-TSP2-Fc is dependent on the CD36 receptor. We found that N-TSP2-Fc inhibited VEGF-induced tube formation of human dermal microvascular endothelial cells (HDMEC) on matrigel in vitro and that concurrent incubation of anti-CD36 antibody with N-TSP2-Fc resulted in tube formation that was comparable to untreated control. N-TSP2-Fc potently induced apoptosis of HDMEC in vitro in a CD36-dependent manner. Moreover, we could demonstrate a CD36 receptor-mediated loss of mitochondrial membrane potential and activation of caspase-3 in HDMEC in vitro. Daily intraperitoneal injections of N-TSP2-Fc resulted in a significant inhibition of the growth of human MDA-MB-435 and MDA-MB-231 tumor cells grown in the mammary gland of immunodeficient nude mice and in reduced tumor vascularization. Finally, increased serum concentrations of N-TSP2-Fc significantly inhibited regional metastasis to lymph nodes and distant metastasis to lung as shown by quantitative real-time alu PCR. These results identify N-TSP2-Fc as a potent systemic inhibitor of tumor metastasis and provide strong evidence for an important role of the CD36 receptor in mediating the antiangiogenic activity of TSP-2.
- Subjects :
- Angiogenesis Inhibitors therapeutic use
Animals
Blotting, Western
Breast Neoplasms blood supply
Breast Neoplasms pathology
CD36 Antigens genetics
Caspase 3 metabolism
Cell Adhesion
Cell Movement
Cell Proliferation
Dermis cytology
Dermis metabolism
Endothelium, Vascular metabolism
Endothelium, Vascular pathology
Enzyme-Linked Immunosorbent Assay
Female
Humans
Lung Neoplasms blood supply
Lung Neoplasms secondary
Membrane Potential, Mitochondrial
Mice
Mice, Nude
Recombinant Fusion Proteins genetics
Thrombospondins genetics
Tumor Cells, Cultured
Vascular Endothelial Growth Factor A metabolism
Apoptosis
Breast Neoplasms prevention & control
CD36 Antigens metabolism
Lung Neoplasms prevention & control
Neovascularization, Pathologic prevention & control
Recombinant Fusion Proteins metabolism
Thrombospondins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1573-7217
- Volume :
- 128
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Breast cancer research and treatment
- Publication Type :
- Academic Journal
- Accession number :
- 20714802
- Full Text :
- https://doi.org/10.1007/s10549-010-1085-7