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.
Chantrain
Christophe F
CF
Department of Pediatrics and Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Shimada
Hiroyuki
H
Jodele
Sonata
S
Groshen
Susan
S
Ye
Wei
W
Shalinsky
David R
DR
Werb
Zena
Z
Coussens
Lisa M
LM
DeClerck
Yves A
YA
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