ABSTRACT
<p><b>OBJECTIVE</b>To study the expression of matrix metalloproteinase (MMP)-2, MMP-9 and vascular endothelial growth factor (VEGF)-C in breast cancer and their role in lymph node metastasis.</p><p><b>METHODS</b>Immunohistochemical staining was used to detect the expression of VEGF-C, MMP-2, MMP-9 and LYVE-1 in 84 cases of breast cancer, including 52 cases with and 32 cases without lymph node metastases. The recombinant vector (pSIREN-VEGF-C) was transfected into human breast cancer cell MCF-7 by liposome, and the RNA expression of MMP-2, MMP-9 and VEGF-C in MCF-7 cells after transfection was detected by PCR.</p><p><b>RESULTS</b>The expressions of MMP-2, MMP-9 and VEGF-C were 98.1% (51/52), 88.5% (46/52), and 94.2% (49/52) respectively for the metastatic group, and 75.0% (24/32), 53.1% (17/32), and 65.6% (21/32) respectively for the non metastatic group, and there was significant difference between these groups (P < 0.05). The lymphatic vessel density between these two groups was also significantly different (P < 0.05). Increased expression of MMP-2, MMP-9 and VEGF-C was also associated with increased number of lymphatic vessels had also increased (P < 0.05). The expression of MMP-2, MMP-9 and VEGF-C in MCF-7 cells after gene transfection decreased significantly (P < 0.05).</p><p><b>CONCLUSION</b>MMP-2 and MMP-9 in conjunction with VEGF-C, promote lymphangiogenesis and lymph node metastasis of breast cancer.</p>