Plasminogen-activator inhibitor type 1 is a potent natural inhibitor of extracellular matrix degradation by fibrosarcoma and colon carcinoma cells

J. F. Cajot, J. Bamat, G. E. Bergonzelli, E. K.O. Kruithof, R. L. Medcalf, J. Testuz, B. Sordat

Research output: Contribution to journalArticleResearchpeer-review

137 Citations (Scopus)


We have analyzed the role of plasminogen-activator inhibitor type 1 (PAI-1) in the regulation of tumor cell-mediated extracellular matrix degradation. Immunocytochemical analysis revealed PAI-1 associated with microgranular and fibrillar material of the extracellular matrix and demonstrated the presence of PAI-1 as a cell surface-associated antigen. Transforming growth factor β significantly reduced matrix degradation mediated by HT-1080 human fibrosarcoma cells. This inhibition was correlated with an increase in PAI-1 antigen expression, whereas urinary-type plasminogen activator (u-PA) secretion was unaffected. In this experimental system, PAM regulated extracellular matrix breakdown, as added PAI-1 inhibited matrix solubilization, whereas monoclonal antibodies to PAI-1 increased it. A cell line (LPAI) producing high levels of biologically active PAI-1 was established by transfection of a human PAI-1 cDNA clone into mouse L cells. Coculture experiments demonstrated that LPAI cells prevented matrix degradation by Lu-PA cells (L cells expressing high levels of u-PA) or Co-115 human colon carcinoma cells (expressing tissue-type plasminogen activator). These results indicate that PAI-1 may play a critical role in the regulation of extracellular matrix degradation during tumor cell invasion.

Original languageEnglish
Pages (from-to)6939-6943
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number18
Publication statusPublished - 1 Jan 1990
Externally publishedYes


  • Cancer invasion
  • cDNA transfection
  • Proteolysis

Cite this