Tubular network formation by adriamycin-resistant MCF-7 breast cancer cells is closely linked to MMP-9 and VEGFR-2/VEGFR-3 over-expressions.

We have previously demonstrated that matrix metalloproteinase-9 (MMP-9) is critical for breast cancer cell migration and is necessary but not sufficient for tubular network formation. Given the important angiogenic activity of vascular endothelial growth factor (VEGF), we investigate here its possible contribution in tubular network formation and its link with MMP-9. Exposure of resistant epithelial breast cancer cells (rMCF-7) to Avastin, a VEGF neutralising antibody, suppresses tubular network formation but not cell migration.

Matrix metalloproteinase-9 is required for tubular network formation and migration of resistant breast cancer cells MCF-7 through PKC and ERK1/2 signalling pathways.

Matrix metalloproteinase-9 (MMP-9) strongly influences tumor development and metastasis. Using resistant (rMCF-7) and sensitive (sMCF-7) breast cancer lines we investigated the role of MMP-9 in cell migration (CM) and tubular network (TN) formation, two processes implied in tumor growth and metastasis. Our data demonstrate that MMP-9 which is critical for CM is necessary but not sufficient for TN formation and suggest a link between MDR1/P-gp and constitutive MMP-9.