Background: The authors analyzed the secretion of extracellular matrix-degrading proteinases, including urinary-type plasminogen activator (u-PA), matrix metalloproteinase-2 (MMP-2, gelatinase A), and MMP-9 (gelatinase B), by short term primary cultures of epithelial ovarian carcinoma cells derived from primary ovarian tumors, intraperitoneal metastases, or ascites. The presence of these enzymatic activities in samples of ascites was also evaluated. The effect of adhesive substratum on proteinase production was determined.
Methods: A coupled spectrophotometric assay was utilized to evaluate the initial rate of plasminogen activation by u-PA in conditioned medium; this involved monitoring the activity of generated plasmin with a colorimetric substrate. MMP activity was evaluated by gelatin zymography.
Results: Ascitic fluids from 18 patients contained u-PA, MMP-2, and MMP-9. However, short term primary cultures of cells derived from primary ovarian tumors (OVET), metastatic lesions (OVEM), or ascites (OVEA) produced very low levels of u-PA. Production of u-PA by OVET and OVEM cells was regulated by adhesive substratum. Conditioned media from OVET, OVEM, and OVEA cells contained high levels of both MMP-2 and MMP-9. MMP-9 levels decreased with increasing passage in culture, whereas MMP-2 activity was maintained. Production of neither MMP-2 nor MMP-9 was regulated by adhesive substratum.
Conclusions: These results demonstrate that primary cultures of epithelial ovarian carcinoma cells derived from three distinct anatomic locations produce MMP-2 and MMP-9, with low level secretion of u-PA. These data suggest that MMPs, particularly MMP-2, may play a significant role in the intraperitoneal invasion of ovarian carcinoma cells.