Stromal matrix metalloproteinase-9 regulates the vascular architecture in neuroblastoma by promoting pericyte recruitment.
Advanced stages of neuroblastoma show increased expression of matrix metalloproteinases MMP-2 and MMP-9, that have been implicated in many steps of tumor progression, suggesting that they play a contributory role. Using pharmacological and genetic approaches, we have examined the role of these MMPs in progression of SK-N-BE (2).10 human neuroblastoma tumors orthotopically xenotransplanted into immunodeficient mice. Mice treated with Prinomastat, a synthetic inhibitor of MMPs, showed an inhibition of tumor cell proliferation in implanted tumors and a prolonged survival (50 versus 39 days in control group, P < 0.035). Treatment with Prinomastat did not affect formation of liver metastases (P = 0.52) but inhibited intravascular colonization by the tumor cells in the lung by 73.8% (P = 0.03) and angiogenesis in both primary tumors and experimental liver metastases. The primary tumors from Prinomastat-treated mice showed a 39.3% reduction in endothelial area detected by PECAM/CD31 staining in tumor sections (P < 0.001), primarily due to the presence of smaller vessels (P = 0.004). MMP-2 is expressed by neuroblastoma tumor cells and stromal cells, whereas MMP-9 is exclusively expressed by stromal cells, particularly vascular cells. To examine the contribution of MMP-9 to tumor angiogenesis, we generated RAG1/MMP-9 double-deficient mice. We observed a significant inhibition of angiogenesis in the immunodeficient RAG1/MMP-9 double-deficient mice orthotopically implanted with tumor cells (P = 0.043) or implanted s.c. with a mixture of tumor cells and Matrigel (P < 0.001). Using an FITC-labeled lectin, we demonstrated an inhibition in the architecture of the tumor vasculature in MMP-9-deficient mice, resulting in fewer and smaller blood vessels. These changes were associated with a 48% decrease in pericytes present along microvessels. Taken together, the data demonstrate that in neuroblastoma, stromally derived MMP-9 contributes to angiogenesis by promoting blood vessel morphogenesis and pericyte recruitment.
Department of Pediatrics and Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Christophe F
CF
Chantrain
Hiroyuki
H
Shimada
Sonata
S
Jodele
Susan
S
Groshen
Wei
W
Ye
David R
DR
Shalinsky
Zena
Z
Werb
Lisa M
LM
Coussens
Yves A
YA
DeClerck
D002455:Cell Division; D045744:Cell Line, Tumor; D018450:Disease Progression; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000502:physiology; D020780:Matrix Metalloproteinase 9 / Q000502:physiology*; D061965:Matrix Metalloproteinase Inhibitors; D009389:Neovascularization, Pathologic / Q000209:etiology*; D009447:Neuroblastoma / Q000098:blood supply* / Q000473:pathology; D020286:Pericytes / Q000502:physiology*
D061965:Matrix Metalloproteinase Inhibitors; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9