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- Belting, Mattias, et al.
(författare)
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Regulation of angiogenesis by tissue factor cytoplasmic domain signaling
- 2004
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 10:5, s. 502-509
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Tidskriftsartikel (refereegranskat)abstract
- Hemostasis initiates angiogenesis-dependent wound healing, and thrombosis is frequently associated with advanced cancer. Although activation of coagulation generates potent regulators of angiogenesis, little is known about how this pathway supports angiogenesis in vivo. Here we show that the tissue factor (TF)-VIIa protease complex, independent of triggering coagulation, can promote tumor and developmental angiogenesis through protease-activated receptor-2 (PAR-2) signaling. In this context, the TF cytoplasmic domain negatively regulates PAR-2 signaling. Mice from which the TF cytoplasmic domain has been deleted (TFDeltaCT mice) show enhanced PAR-2-dependent angiogenesis, in synergy with platelet-derived growth factor BB (PDGF-BB). Ocular tissue from diabetic patients shows PAR-2 colocalization with phosphorylated TF specifically on neovasculature, suggesting that phosphorylation of the TF cytoplasmic domain releases its negative regulatory control of PAR-2 signaling in angiogenesis. Targeting the TF-VIIa signaling pathway may thus enhance the efficacy of angiostatic treatments for cancer and neovascular eye diseases.
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| 2. |
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| 3. |
- Rydén, Lisa, et al.
(författare)
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Evidence for tissue factor phosphorylation and its correlation with protease activated receptor expression and the prognosis of primary breast cancer.
- 2010
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 126:10, s. 2330-2340
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Tidskriftsartikel (refereegranskat)abstract
- Tissue factor (TF)-mediated protease activated receptor (PAR)-2 signaling is associated with a pro-migratory, invasive and pro-angiogenic phenotype in experimental models of breast cancer, and has been mechanistically coupled to phosphorylation of the TF cytoplasmic domain (pTF). However, the clinical relevance of these findings are unknown. Here, we provide first in vivo evidence of TF phosphorylation in experimental as well as clinical breast cancer tumors. pTF was demonstrated in MDA-MB-231 xenografts and in tumors from the MMTV-PyMT transgene model of spontaneous murine breast adenocarcinoma. Tumors from PAR-2-deficient transgenic mice were negative for pTF, thus linking pTF to PAR-2 signaling. The clinical correlation between TF, pTF, PAR-1, PAR-2, and VEGF-A was determined by IHC on tumors from a cohort of 172 consecutive primary breast cancer patients with a median follow-up time of 50 months. In 160 evaluable patient tumors, pTF was associated with TF (p=0.01) and cancer cell expression of PAR-1 (p=0.001), PAR-2 (p=0.014) and VEGF-A (p=0.003) using chi(2) test. PAR-2 and VEGF-A were co-expressed (p=0.013) and associated with a more aggressive phenotype. Interestingly, all patients experiencing recurrences had tumors expressing pTF and PAR-2, and pTF alone as well as co-expression of pTF and PAR-2 were significantly correlated with shorter recurrence-free survival (log rank test, p=0.04 and p=0.02, respectively). This study provides first evidence to link PAR-2 expression and TF phosphorylation to clinical data in human breast cancer. In conjunction with experimental tumor models, these data support an important role of TF-PAR-2 signaling in breast cancer recurrence. (c) 2009 UICC.
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| 4. |
- Svensson, Katrin, et al.
(författare)
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Hypoxia triggers a proangiogenic pathway involving cancer cell microvesicles and PAR-2-mediated heparin-binding EGF signaling in endothelial cells.
- 2011
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 108:32, s. 13147-13152
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Tidskriftsartikel (refereegranskat)abstract
- Highly malignant tumors, such as glioblastomas, are characterized by hypoxia, endothelial cell (EC) hyperplasia, and hypercoagulation. However, how these phenomena of the tumor microenvironment may be linked at the molecular level during tumor development remains ill-defined. Here, we provide evidence that hypoxia up-regulates protease-activated receptor 2 (PAR-2), i.e., a G-protein-coupled receptor of coagulation-dependent signaling, in ECs. Hypoxic induction of PAR-2 was found to elicit an angiogenic EC phenotype and to specifically up-regulate heparin-binding EGF-like growth factor (HB-EGF). Inhibition of HB-EGF by antibody neutralization or heparin treatment efficiently counteracted PAR-2-mediated activation of hypoxic ECs. We show that PAR-2-dependent HB-EGF induction was associated with increased phosphorylation of ERK1/2, and inhibition of ERK1/2 phosphorylation attenuated PAR-2-dependent HB-EGF induction as well as EC activation. Tissue factor (TF), i.e., the major initiator of coagulation-dependent PAR signaling, was substantially induced by hypoxia in several types of cancer cells, including glioblastoma; however, TF was undetectable in ECs even at prolonged hypoxia, which precludes cell-autonomous PAR-2 activation through TF. Interestingly, hypoxic cancer cells were shown to release substantial amounts of TF that was mainly associated with secreted microvesicles with exosome-like characteristics. Vesicles derived from glioblastoma cells were found to trigger TF/VIIa-dependent activation of hypoxic ECs in a paracrine manner. We provide evidence of a hypoxia-induced signaling axis that links coagulation activation in cancer cells to PAR-2-mediated activation of ECs. The identified pathway may constitute an interesting target for the development of additional strategies to treat aggressive brain tumors.
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