Aspirin inhibits tumor cell invasiveness induced by Epstein-Barr virus latent membrane protein 1 through suppression of matrix metalloproteinase-9 expression.

Abstract

Matrix metalloproteinases (MMPs) are thought to play crucial roles in tumor invasion and metastasis. Because we have shown that EBV latent membrane protein 1 (LMP1) enhances MMP-9 expression by activation of nuclear factor (NF)-kappaB and activator protein (AP)-1 (T. Yoshizaki, et al., Proc. Natl. Acad. Sci. USA, 95: 3621-3626, 1998), we therefore tested whether up-regulation of MMP-9 by LMP1 could be correlated with enhanced invasiveness of tumor cells in vitro. Whether aspirin and sodium salicylate could reduce invasiveness and whether LMP1 could enhance MMP-9 expression in tumors grown in nude mice were also tested. C33A cells stably expressing LMP1 had increased expression of MMP-9 and showed greater invasion through reconstituted basement membrane compared with vector-transfected C33A cells (P < 0.02). Treatment with aspirin or sodium salicylate inhibited invasiveness of the LMP1-expressing C33A cells (P < 0.03) and suppressed both the LMP1-induced MMP-9 expression in zymographic analyses and LMP1-induced MMP-9 promoter activity in CAT reporter assays (P < 0.01). Endogenous MMP-2 levels were unaffected by either drug. Both drugs repressed the CAT activity of the truncated MMP-9 promoter construct, which only contained a binding site for AP-1, to the basal level (P < 0.05). Moreover, EMSA indicated that the effects of the salicylates were through the inhibition of not only NF-kappaB but also AP-1 binding activity. Inhibitory effect of salicylates could be reversed by p50/p65 subunits of NF-kappaB or c-Jun overexpression. The inhibitory effect of aspirin on NF-kappaB activity was attributable to the inhibition of IkappaB kinase activity. Finally, tumors derived from C33A cells stably expressing LMP1 grown in nude mice showed enhanced MMP-9 levels compared with tumors derived from vector-transfected C33A cells. This enhancement was inhibited by treatment of the mice with aspirin. These results suggest that aspirin may be able to suppress invasion and metastasis of EBV-associated tumors that express LMP1 by suppression of MMP-9.

• Authors: S Murono, T Yoshizaki, H Sato, H Takeshita, M Furukawa, J S Pagano
• Journal: Cancer research (Cancer Res) Vol. 60 Issue 9 Pg. 2555-61 (May 01 2000) ISSN: 0008-5472 [Print] United States
• PMID: 10811139 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• EBV-associated membrane antigen, Epstein-Barr virus
• Enzyme Inhibitors
• I-kappa B Proteins
• Matrix Metalloproteinase Inhibitors
• NF-kappa B
• Transcription Factor AP-1
• Viral Matrix Proteins
• Chloramphenicol O-Acetyltransferase
• Protein Serine-Threonine Kinases
• CHUK protein, human
• Chuk protein, mouse
• I-kappa B Kinase
• IKBKB protein, human
• IKBKE protein, human
• Ikbkb protein, mouse
• Ikbke protein, mouse
• Matrix Metalloproteinase 9
• Aspirin
• Sodium Salicylate

Topics

• Animals
• Aspirin (pharmacology)
• Blotting, Western
• Cell Nucleus (metabolism)
• Chloramphenicol O-Acetyltransferase (metabolism)
• Enzyme Inhibitors (pharmacology)
• Humans
• I-kappa B Kinase
• I-kappa B Proteins (metabolism)
• Matrix Metalloproteinase 9 (genetics)
• Matrix Metalloproteinase Inhibitors
• Mice
• Mice, Nude
• NF-kappa B (antagonists & inhibitors)
• Neoplasm Invasiveness
• Neoplasm Metastasis
• Plasmids
• Promoter Regions, Genetic
• Protein Binding
• Protein Serine-Threonine Kinases (metabolism)
• Sodium Salicylate (pharmacology)
• Transcription Factor AP-1 (antagonists & inhibitors)
• Transfection
• Tumor Cells, Cultured
• Viral Matrix Proteins (pharmacology)