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- Casslén, Vera, et al.
(författare)
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Ovarian cancer cells stimulate uPA gene expression in fibroblastic stromal cells via multiple paracrine and autocrine mechanisms.
- 2009
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Ingår i: Gynecologic Oncology. - : Elsevier BV. - 1095-6859 .- 0090-8258. ; 115, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Expression of uPA mRNA is massively up-regulated in the stroma of poorly differentiated ovarian tumors. We hypothesized that this expression was induced by paracrine signals from the epithelial tumor cells, and established an in vitro model of ovarian cancer microenvironment to study intercellular cross-talk. METHODS: ES-2 clear cell carcinoma cells were grown in tissue culture inserts in a double-chamber system with fibroblastic stromal LEP cells embedded in Matrigel. Binding-site directed antibodies were used to neutralize soluble cytokines in ES-2 conditioned medium (CM) before incubation with LEP cells. Real time PCR measured uPA mRNA in LEP cells, as well as mRNA for cytokines in both cell types. RESULTS: Co-culture with ES-2 cells as well as incubation with ES-2 CM induced uPA mRNA in LEP cells about two-fold. In short time (12 h) incubation of LEP cells with CM, antibodies to EGF and bFGF reduced induction of uPA mRNA, suggesting that these cytokines function as paracrine signals. EGF mRNA and bFGF mRNA were also found in ES-2 cells. At longer incubation (24 h) antibodies to bFGF, HB-EGF, HGF, IGF-1, and IL-1alpha reduced uPA mRNA induction, suggesting an autocrine function for these cytokines in LEP cells. In fact, expression of the same five cytokines was up-regulated in LEP cells exposed to CM. CONCLUSION: We identified two cytokines as paracrine signals, and five cytokines as autocrine signals in ovarian cancer cell induced up-regulation of uPA mRNA in stromal fibroblastic cells. It is crucial to understand intra-tumoral cross-talk, since it can offer new therapeutic approaches.
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| 2. |
- Henic, Emir, et al.
(författare)
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EGF-stimulated migration in ovarian cancer cells is associated with decreased internalization, increased surface expression, and increased shedding of the urokinase plasminogen activator receptor.
- 2006
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Ingår i: Gynecologic Oncology. - : Elsevier BV. - 1095-6859 .- 0090-8258. ; 101:1, s. 28-39
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. The EGFR is expressed in malignant ovarian tumor tissue, and tissue content of EGFR has been directly associated with poor prognosis in patients with ovarian cancer. The uPA system plays a role in pericellular proteolysis, cell migration, invasion, and is over-expressed in ovarian cancer. This study explored the effects of EGF on uPAR expression in the ovarian cancer cell line OVCAR-3. Methods. We used OVCAR-3 cells and the following methods: cell migration assay, time-lapse video microscopy, real-time PCR, assays for cellular binding of I-125-uPA and cellular degradation of I-125-uPA:PAI-1 complex, biosynthetic labeling using S-35-methionin, Western blot, Northern blot, and ELISAs for uPA, PAI-1, and uPAR. Results. EGF up-regulates both protein and mRNA not only for uPAR, but also for the ligand uPA and its inhibitor PAI-1. Cell surface uPAR, in control as well as EGF-stimulated cells, is present only in the intact, not the cleaved, form. Ligand binding experiments showed an increase of endogenously occupied uPAR, whereas non-occupied receptor sites were not increased. In addition, EGF treatment resulted in decreased degradation of radiolabeled uPA:PAI-1 complex. This suggests decreased internalization of uPAR, since the complex is internalized together with uPAR. Like EGF, colchicine, which inhibits endocytosis, increased cell surface expression of uPAR. In addition, we found an immediate increase of uPAR after exposing the cells to EGF and this was accompanied by a transient increase of cell migration. The increase of cell surface uPAR in response to EGF is accompanied by increased release of the soluble form of uPAR (suPAR) to the medium as well as by increased cell migration. Both uPAR and suPAR increased in cells treated with the endocytosis inhibitor colchicine even though cell migration was inhibited, suggesting that the mechanism of uPAR shedding is not related to cell migration. Conclusion. Increased cell surface uPAR in response to EGF stimulation results from mobilization of uPAR from detergent-resistant domains, increased expression of uPAR mRNA, and decreased internalization and degradation of uPAR. Both the anti-uPAR antibody R3, which inhibits binding of uPA, and the EGFR phosphorylation inhibitor Iressa inhibited cell migration in response to uPA as well as to EGF, suggesting that EGFR and uPAR are engaged in the same multiprotein assembly on the cell surface. (C) 2005 Elsevier Inc. All rights reserved.
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