Expression of multiple matrix metalloproteinases and urokinase type plasminogen activator in cultured Kaposi sarcoma cells

Linda C. Meade-Tollin, Dennis Way, Marlys H. Witte

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


Kaposi's sarcoma (KS) cells are considered to be of endothelial origin. KS lesions are characterized by hyperproliferation and an invasive phenotype. We have determined that KS cell cultures constitutively secrete multiple forms of several matrix metalloproteinases (MMPs) and an altered form of urokinase plasminogen activator (uPA) by zymogram and Western analysis of the culture media. MMPs are a family of secreted endoproteinases which degrade components of the extracellular matrix. Their enhanced expression and activity are strongly correlated with cellular processes involving tissue remodeling and invasion. The KS cells secrete increased levels of gelatinase A and B and a high molecular weight uPA in vitro when compared with non-KS endothelial or epithelial cells. Multiple forms of gelatinases A and B were observed on gelatin zymograms. Caseinolytic bands observed were confirmed by Western blot analysis to be due to stromelysin activity, whereas matrilysin was not detected by casein zymography. Western blot analysis also detected secretion of interstitial collagenase and high molecular weight uPA. Gelatinolytic activity with the mobility of gelatinase B was detected on gelatin zymograms, but not by Western analysis. This unusual constitutive expression pattern of MMPs and uPA by KS cells in vitro is characterized by elevated levels of gelatinase A, gelatinase B, interstitial collagenase, stromelysin and a high molecular weight form of uPA, and the lack of expression of matrilysin. These secreted MMPs, taken together, are capable of digesting a broad range of components of the extracellular matrix. This unusual pattern is likely to contribute to the characteristic hyperproliferative and invasive phenotype of KS lesions.

Original languageEnglish (US)
Pages (from-to)305-316
Number of pages12
JournalActa Histochemica
Issue number3
StatePublished - Jul 1999


  • Gelatinase A
  • Kaposi's sarcoma
  • Matrix metalloproteinases
  • Stromelysin
  • Urokinase plasminogen activator

ASJC Scopus subject areas

  • Histology
  • Cell Biology


Dive into the research topics of 'Expression of multiple matrix metalloproteinases and urokinase type plasminogen activator in cultured Kaposi sarcoma cells'. Together they form a unique fingerprint.

Cite this