Ovarian Cancer Research Today is a free monthly online journal that collates and summarizes the latest research about Ovarian Cancer, including details on symptoms, causes, treatment, information.

Lysophosphatidic acid enhances epithelial ovarian carcinoma invasion through the increased expression of interleukin-8.

So J, Navari J, Wang FQ, Fishman DA

Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, New York University School of Medicine, New York, NY 10016, USA.

OBJECTIVE: We previously reported that lysophosphatidic acid (LPA) stimulates cellular invasion of ovarian cancer (OVCA) cells by enhancing membrane-type-1-matrix metalloproteinase (MT1-MMP)-mediated activation of MMP2. Here, we investigate a second mechanism in which LPA enhances cellular invasion through the increased expression of IL-8, independent of the expression or activation of MMP2. METHODS: Epithelial ovarian carcinoma cells (DOV 13) were exposed to LPA (80 microM) and IL-8 (100 ng/ml) for 24 h. IL-8 expression was quantified by enzyme-linked immunosorbent assay (ELISA). Cellular invasion (Matrigel invasion), migration (colloidal gold), and urinary-type plasminogen activator (uPA) activity (colorimetric assay) were quantified. Conditioned medium was also assayed for MMP activation and expression by SDS-PAGE gelatin zymography, ELISA, and Western blotting. In addition, IL-8 neutralizing antibody and MMP inhibitors were employed. RESULTS: Our results found LPA to increase IL-8 expression threefold. IL-8 did not affect cellular migration, MMP2 activation, or uPA expression. However, exposure to various concentrations of IL-8 increased cellular invasiveness. Using an IL-8 blocking antibody and various MMP inhibitors, we determined that the increase in invasion was IL-8-dependent, while independent of the activation of MMP2 or MMP9. We further determined IL-8 exposure increased the expression of matrilysin (MMP7). Cells exposed to LPA and IL-8 resulted in a synergistic effect on cellular invasion. Adding the IL-8 blocking antibody, slightly decreased cellular invasion, indicating LPA in part, increases cellular invasion through the increased expression of IL-8. CONCLUSION: We have identified a separate mechanism of enhanced cellular invasion, which is independent of MMP2 activation and involves the increased expression of IL-8 and subsequent increased expression of MMP7.

Published 19 October 2004 in Gynecol Oncol, 95(2): 314-22.
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