Endothelial Cell Culture of Intramuscular Venous Malformation and Its Invasive Behavior Related to Matrix Metalloproteinase-9

Background: Intramuscular venous malformation is characterized by abnormal morphology of blood vessels. In certain cases, it displays an invasion of surrounding tissues. The in vitro model of its endothelial cell culture has not been reported, and the pathogenesis of its development is not clear. Matrix metalloproteinase-9 is identified to facilitate cell migration and tumor progression. The aim of this study was to establish the primary cell culture from intramuscular venous malformation and explore its invasive mechanism related to matrix metalloproteinase-9. Methods: Explant culture was adopted to isolate endothelial cells from intramuscular venous malformation. In contrast, with human umbilical vein endothelial cells collected by collagenase digestion, the biological behavior of cell migration and invasion was explored. Western blot, reverse-transcription polymerase chain reaction, and immunohistochemical study were performed to measure matrix metalloproteinase-9 expression of endothelial cells or tissue sections. Results: The primary endothelial cell culture from intramuscular venous malformation was established successfully by using explant culture. Compared with human umbilical vein endothelial cells, the established endothelial cells indicated more powerful capability of migration and invasion and expressed more matrix metalloproteinase-9 at both mRNA and protein levels. Matrix metalloproteinase-9 mRNA expression in intramuscular venous malformation was significantly higher than in normal subcutaneous tissues. The intensity of matrix metalloproteinase-9 demonstrated no statistically significant differences with varying courses, locations, dimensions, and infiltration degrees. Conclusions: The positive expression of matrix metalloproteinase-9 of intramuscular venous malformation tissues and endothelial cells provided circumstantial evidence that it may be involved in the pathogenesis of invasive biological behavior of the lesions. (Plast. Reconstr. Surg. 123: 1419, 2009.)