Overexpression of Vascular Endothelial Growth Factor 189 in Breast Cancer Cells Leads to Delayed Tumor Uptake with Dilated Intratumoral Vessels

Marie-Astrid Hervé^*, Hélène Buteau-Lozano^*, Roger Vassy, Ivan Bieche, Guillaume Velasco^*, Marika Pla, Gérard Perret, Samia Mourah^¶ and Martine Perrot-Applanat^*

From INSERM U553,^*INSERM U718,and INSERM U716,^¶Institut Universitaire d’Hématologie, Hôpital Saint-Louis, University of Paris VII, Paris; the Centre National de la Recherche Scientifique UMR7033,Equipe de Pharmacologie, Bobigny; and INSERM U735,Centre René Huguenin, Saint Cloud, France

Vascular endothelial growth factor (VEGF) is essential for breastcancer progression and is a relevant target in anti-angiogenesis.Although VEGF121 and VEGF165, the fully or partially secretedisoforms, respectively, have been the focus of intense studies,the role of the cell-associated VEGF189 isoform is not understood.To clarify the contribution of VEGF189 to human mammary carcinogenesis,we established several clones of MDA-MB-231 cells stably overexpressingVEGF189 (V189) and VEGF165 (V165). V189 and V165 clones increasedtumor growth and angiogenesis in vivo. Remarkably, V165 inducedthe most rapid tumor uptake, whereas V189 increased vasodilation.In vitro overexpression of VEGF165 and VEGF189 increases theproliferation and chemokinesis of these cancer cells. Interestingly,overexpression of VEGF189 increased cell adhesion on fibronectin(1.9-fold) and vitronectin (1.6-fold), as compared to VEGF165,through ${alpha}$ 5β1 and ${alpha}$ vβ5 integrins. Using the BIACore systemwe demonstrated for the first time that VEGF189 binds directlyto neuropilin-1, which is strongly expressed in MDA-MB-231 cells.In contrast, VEGF-R2 was not significantly expressed and VEGF-R1was expressed at low level. Our in vitro results suggest anautocrine effect of VEGF189 on breast cancer cells, probablythrough neuropilin-1. In conclusion, our data indicate thatVEGF189 participates in mammary tumor growth through both angiogenesisand nonangiogenic functions. Whether VEGF189 overexpressionis correlated to prognosis in human breast tumors remains tobe established.