Endostatin inhibits human tongue carcinoma cell invasion and intravasation and blocks the activation of matrix metalloprotease-2, -9, and -13.
Endostatin, a 20-kDa collagen XVIII fragment, inhibits angiogenesis and tumor growth in vivo, but the mechanisms are still unclear. Matrix metalloproteases (MMPs), a family of extracellular and membrane-associated endopeptidases, collectively digest almost all extracellular matrix and basement membrane components, and thus play an important role in tumor progression. We studied the effects of recombinant human endostatin on human MMP-2, -9, -8, and -13. We found that endostatin inhibited the activation and catalytic activity of pro-MMP-9 and -13 as well as recombinant pro-MMP-2. It prevented the fragmentation of pro-MMP-2 that was associated with reduction of catalytic activity. Endostatin had no effect on MMP-8 as shown by collagenase activity assays. An in vitro migration assay and an in vivo chicken chorioallantoic membrane intravasation assay with the human tongue squamous cell carcinoma cell line HSC-3 revealed the biphasic nature of endostatin; low endostatin concentrations inhibited intravasation and migration of these cells in a dose-dependent manner, but at increased concentrations, the inhibitory effect was far less efficient. The results show that endostatin blocks the activation and activities of certain tumor-associated pro-MMPs, such as pro-MMP-2, -9, and -13, which may explain, at least in part, the antitumor effect of endostatin. Our results also suggest that endostatin inhibits tumor progression by directly affecting the tumor cells and not just acting via endothelial cells and blockage of angiogenesis.
Nyberg
Pia
P
Department of Diagnostics and Oral Medicine, Institute of Dentistry, University of Oulu, FIN-90014 Oulu, Finland.
Heikkilä
Pia
P
Sorsa
Timo
T
Luostarinen
Jani
J
Heljasvaara
Ritva
R
Stenman
Ulf-Håkan
UH
Pihlajaniemi
Taina
T
Salo
Tuula
T
D000970:Antineoplastic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D003094:Collagen / Q000494:pharmacology*; D043170:Collagen Type XVIII; D043169:Endostatins; D004789:Enzyme Activation / Q000187:drug effects*; D018093:Gelatinases / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D053509:Matrix Metalloproteinase 13; D061965:Matrix Metalloproteinase Inhibitors; D009361:Neoplasm Invasiveness; D010446:Peptide Fragments / Q000494:pharmacology*; D010663:Phenylmercury Compounds / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D014062:Tongue Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D043170:Collagen Type XVIII; D043169:Endostatins; D061965:Matrix Metalloproteinase Inhibitors; D010446:Peptide Fragments; D010663:Phenylmercury Compounds; D011994:Recombinant Proteins; D003094:Collagen; D018093:Gelatinases; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13