1.
Sandberg, Tove, et al.
(författare)
Paracrine stimulation of capillary endothelial cell migration by endometrial tissue involves epidermal growth factor and is mediated via up-regulation of the urokinase plasminogen activator receptor
2001
Ingår i: Journal of Clinical Endocrinology and Metabolism. - 1945-7197. ; 86:4, s. 1724-1730
Tidskriftsartikel (refereegranskat) abstract
Endometrial angiogenesis is not well studied, but has potential as a model for studies of physiological angiogenesis. Migration as well as proliferation of vascular endothelial cells are modulated by other endometrial cells. This study analyzes the chemotactic signal released from endometrial tissue in a wound assay using human microvascular endothelial cells. Endometrial tissue explants stimulate migration, and this effect is significantly weaker with explants taken at midcycle than those obtained earlier or later in the cycle. Migration is inhibited more than 50% by either blocking antibodies to the urokinase plasminogen activator receptor (uPAR) or enzymatic removal of uPAR from the cell surface. Also, migration is inhibited more than 50% by antibodies to epidermal growth factor (EGF), but not by antibodies to vascular endothelial growth factor or basic fibroblast growth factor. The combination, of anti-EGF and anti-uPAR antibodies does not further reduce the response, suggesting that these antibodies target a common pathway. Conditioned medium from endometrial explants contains EGF, and EGF stimulates the migration of endothelial cells in a dose-dependent way. This effect is completely blocked by antibodies to uPAR. These data suggest up-regulation of the uPA system by EGF. Conditioned medium from EGF-treated cells contains less uPA than medium from control cells. In contrast, binding of radiolabeled uPA reveals an increased number of uPA-binding sites in EGF-treated cells. Increased expression of uPAR potentially increases the activation and assembly of focal adhesion sites, a prerequisite for cell migration. We conclude that the endometrial migratory signal has two components. The major part of the signal is blocked by antibodies to EGF, and the response is mediated via upregulation of uPAR in the endothelial cells. The other part of the signal is unknown, and the response does not involve uPAR. Decreased endometrial chemotactic signal at midcycle is probably related to decreased release of EGF, which is secondary to increased binding to endometrial cell membranes.
2.
Borgfeldt, Christer, et al.
(författare)
Dedifferentiation of serous ovarian cancer from cystic to solid tumors is associated with increased expression of mRNA for urokinase plasminogen activator (uPA), its receptor (uPAR) and its inhibitor (PAI-1)
2001
Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 92:4, s. 497-502
Tidskriftsartikel (refereegranskat) abstract
The plasminogen activating system is involved in tumor growth and metastasis by degradation of extracellular matrix, and modulation of cell adhesion and migration. Benign and well-differentiated malignant ovarian tumors present as cystic lesions with preserved glandular morphology, whereas poorly differentiated tumors and metastases are solid with characteristic absence of glandular morphology. We analyzed the mRNAs for urokinase plasminogen activator (uPA), its receptor (uPAR), and inhibitor (PAI-1) in serous ovarian tumors by in situ hybridization and by densitometric scanning of Northern blots prepared from tissue extracts. The mRNA expressing cells in the in situ hybridization sections were evaluated and counted by two different observers. The number of mRNA expressing cells for uPA, uPAR and PAI-1 were all significantly increased in solid as compared with cystic malignant tumors. The increased expression of all three mRNA species was mainly located in the stroma of poorly differentiated tumors and metastases. Apart from being expressed in the stroma of these tumors, uPAR mRNA was also expressed by tumor cells located along the stromal/epithelial boarder. In addition, the tumor tissue content of uPA, uPAR and PAI-1 mRNAs as measured by Northern blots were higher in the solid as compared with the cystic tumors. Increased expression of uPA, uPAR and PAI-1 genes in the solid tumors suggest a correlation with a more aggressive phenotype.
3.
Fredstorp-Lidebring, M, et al.
(författare)
Urokinase plasminogen activator and its inhibitor, PAI-1, in association with progression-free survival in early stage endometrial cancer
2001
Ingår i: European Journal of Cancer. - 1879-0852. ; 37:18, s. 2339-2348
Tidskriftsartikel (refereegranskat) abstract
Components of the urokinase plasminogen activator (u-PA) system are involved in the metastatic process, and have accordingly been associated with clinical outcome in a variety of malignant tumours. We investigated the prognostic importance of u-PA and plasminogen activator inhibitor type 1 (PAI-1) in endometrial cancer, analysed with luminometric immunoassay (LIA) and enzyme-linked immunosorbent assay (ELISA), respectively. Two different cut-off levels were used: the median and the 80th percentile-the latter because of the low progression rate for patients with early stage (I-II) endometrial cancer. After a median follow-up time of 6.8 years, univariate analysis of patients with stage I-II disease (n=188) showed that high u-PA and high PAI-1 content was associated with a shorter progression-free survival (PFS), but at different cut-off levels, uPA at the median (P=0.003), and PAI-1 at the 80th percentile (P<0.001). Among the other factors, DNA ploidy status was most strongly correlated to PFS, followed by age (continuous), International Federation of Gynaecology and Obstetrics (FIGO) grade of differentiation, S-phase fraction and progesterone receptor (PgR) status. Bivariate analyses, including ploidy and one of the factors u-PA or PAI-1, showed that both add significant prognostic information. We conclude that u-PA and PAI-1 are promising prognostic factors in early stage endometrial cancer.
