The Expression of Matrix Metalloproteinase-9 and Tumor Angiogenesis in Human Osteosarcoma

Yoo, Jinyoung; Jung, Ji Han; Choi, Hyun Joo; Kang, Seok Jin; Lee, Anhi; Seo, Eun Joo; Shim, Sang In; Kang, Chang Suk

Abstract

BACKGROUND: Matrix metalloproteinase-9 (MMP-9) is a matrix-degrading enzyme that's believed to play a crucial role not only for tumor invasion and metastasis, but also for a variety of stromal reactions, including neovascularization. The aim of this study was to investigate the expression of MMP-9 and to compare its expression with the angiogenesis activity in human osteosarcoma.
METHODS
Archival tumor tissue samples from 20 patients with osteosarcoma were analyzed by performing immunohistochemistry for the expression of MMP-9 and CD34. The vascularity was measured as the average microvascular density (MVD) of the CD34-positive vessels. The clinical information was obtained through searching the computerized retrospective database from the tumor registry.
RESULTS
MMP-9 was expressed in 90% (18/20) of the tumors we examined. The MVD ranged from 10.5 to 179.7 with a mean of 64.9. There was no significant correlation between the MMP-9 expression and the MVD (p=.613). The MMP-9 expression was not associated with any of the clinicopathologic variables, whereas the MVD showed an increasing tendency according to the metastasis status (p=.073).
CONCLUSIONS
We demonstrated that MMP-9 activation is likely to occur in human osteosarcoma. However, there was no direct involvement of MMP-9 with tumor angiogenesis. It is noteworthy that MVD may aid physicians to predict the presence of distant metastasis in osteosarcoma patients.