title: Overexpression of VEGF189 in breast cancer cells induces apoptosis via NRP1 under stress conditions.
abstract: The existence of multiple VEGF-A isoforms raised the possibility that they may have distinct functions in tumor growth. We have previously published that VEGF189 and VEGF165 contribute to breast cancer progression and angiogenesis, but VEGF165 induced the most rapid tumor uptake. Since VEGF165 has been described as a survival factor for breast tumor cells, we questioned here the effects of VEGF189 on the survival/apoptosis of MDA-MB-231 cells. We used clones which overexpress VEGF189 (V189) or VEGF165 (V165) isoforms and compared them to a control one (cV). Overexpression of VEGF189 resulted in increased cell apoptosis, as determined by Annexin-V apoptosis assay, under serum starvation and doxorubicin treatment, while VEGF 165 was confirmed to be a survival factor. Since MDA-MB-231 highly express NRP1 (a co-receptor for VEGF-A), we used short hairpin RNA (shRNA) to knockdown NRP1 expression. V189shNRP1 clones were characterized by reduced apoptosis and higher necrosis, as compared to V189shCtl, under stress conditions. Unexpectedly, NRP1 knock-down had no effect on the survival or apoptosis of V165 cells. VEGF189 showed greater affinity towards NRP1 than VEGF165 using a BIAcore binding assay. Finally, since endogenously produced urokinase-type plasminogen (uPA) has been found to prevent apoptosis in breast cancers, we analyzed the level of uPA activity in our clones. An inhibition of uPA activity was observed in V189shNRP1 clones. Altogether, these results suggest a major role of NRP1 in apoptosis induced by VEGF189 in stress conditions and confirm VEGF165 as a survival factor.
authors: INSERM U65, Hôpital Lariboisière-Saint Louis, Paris, France.
authors: Nadejda
authors: N
authors: Vintonenko
authors: Irma
authors: I
authors: Pelaez-Garavito
authors: Hélène
authors: H
authors: Buteau-Lozano
authors: Aurore
authors: A
authors: Toullec
authors: Rosette
authors: R
authors: Lidereau
authors: Gérard Yves
authors: GY
authors: Perret
authors: Ivan
authors: I
authors: Bieche
authors: Martine
authors: M
authors: Perrot-Applanat
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D045744:Cell Line, Tumor; D004317:Doxorubicin / Q000494:pharmacology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D039942:Neuropilin-1 / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D020349:Surface Plasmon Resonance; D014162:Transfection; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D017304:Annexin A5; D020033:Protein Isoforms; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D039942:Neuropilin-1; D004317:Doxorubicin; D007770:L-Lactate Dehydrogenase; D014568:Urokinase-Type Plasminogen Activator