1. |
- Alvarez, Yolanda, et al.
(author)
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Selective inhibition of retinal angiogenesis by targeting PI3 kinase
- 2009
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 4:11, s. e7867-
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Journal article (peer-reviewed)abstract
- Ocular neovascularisation is a pathological hallmark of some forms of debilitating blindness including diabetic retinopathy, age related macular degeneration and retinopathy of prematurity. Current therapies for delaying unwanted ocular angiogenesis include laser surgery or molecular inhibition of the pro-angiogenic factor VEGF. However, targeting of angiogenic pathways other than, or in combination to VEGF, may lead to more effective and safer inhibitors of intraocular angiogenesis. In a small chemical screen using zebrafish, we identify LY294002 as an effective and selective inhibitor of both developmental and ectopic hyaloid angiogenesis in the eye. LY294002, a PI3 kinase inhibitor, exerts its anti-angiogenic effect in a dose-dependent manner, without perturbing existing vessels. Significantly, LY294002 delivered by intraocular injection, significantly inhibits ocular angiogenesis without systemic side-effects and without diminishing visual function. Thus, targeting of PI3 kinase pathways has the potential to effectively and safely treat neovascularisation in eye disease.
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2. |
- Jensen, Lasse Dahl, et al.
(author)
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In vivo angiogenesis and lymphangiogenesis models
- 2009
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In: Current molecular medicine. - : Bentham Science Publishers. - 1566-5240 .- 1875-5666. ; 9:8, s. 982-991
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Journal article (peer-reviewed)abstract
- Angiogenesis research has become one of the most important areas in biomedical research. At the time of writing this review, there were approximately 3536 articles published in the year of 2008 alone on the topic of angiogenesis. The fast expansion of this research field demands development of rigorous, reliable, stable, convenient, and clinically relevant assay systems for disease diagnosis, prognosis, therapeutic evaluation, drug discovery, and mechanistic studies at the molecular level. Here, we discuss several commonly used in vivo angiogenesis models by systematically analyzing and pointing out pitfalls of each assay. Owing to existence of numerous assays and the limitation of text, it is impossible to discuss all these assays in this article. Here we select several most commonly used angiogenesis assays performed in various species including mice, chicks and zebrafish for further in-depth discussion. We hope this information will be valuable for improving current angiogenesis research.
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3. |
- Jensen, Lasse Dahl, et al.
(author)
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Nitric oxide permits hypoxia-induced lymphatic perfusion by controlling arterial-lymphatic conduits in zebrafish and glass catfish
- 2009
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In: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:43, s. 18408-18413
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Journal article (peer-reviewed)abstract
- The blood and lymphatic vasculatures are structurally and functionally coupled in controlling tissue perfusion, extracellular interstitial fluids, and immune surveillance. Little is known, however, about the molecular mechanisms that underlie the regulation of bloodlymphatic vessel connections and lymphatic perfusion. Here we show in the adult zebrafish and glass catfish (Kryptopterus bicirrhis) that blood-lymphatic conduits directly connect arterial vessels to the lymphatic system. Under hypoxic conditions, arterial-lymphatic conduits (ALCs) became highly dilated and linearized by NO-induced vascular relaxation, which led to blood perfusion into the lymphatic system. NO blockage almost completely abrogated hypoxia-induced ALC relaxation and lymphatic perfusion. These findings uncover mechanisms underlying hypoxia-induced oxygen compensation by perfusion of existing lymphatics in fish. Our results might also imply that the hypoxia-induced NO pathway contributes to development of progression of pathologies, including promotion of lymphatic metastasis by modulating arterial-lymphatic conduits, in the mammalian system.
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4. |
- Lee, Samantha Lin Chiou, et al.
(author)
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Hypoxia-induced pathological angiogenesis mediates tumor cell dissemination, invasion, and metastasis in a zebrafish tumor model
- 2009
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:46, s. 19485-19490
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Journal article (peer-reviewed)abstract
- Mechanisms underlying pathological angiogenesis in relation to hypoxia in tumor invasion and metastasis remain elusive. Here, we have developed a zebrafish tumor model that allows us to study the role of pathological angiogenesis under normoxia and hypoxia in arbitrating early events of the metastatic cascade at the single cell level. Under normoxia, implantation of a murine T241 fibrosarcoma into the perivitelline cavity of developing embryos of transgenic fli1:EGFP zebrafish did not result in significant dissemination, invasion, and metastasis. In marked contrast, under hypoxia substantial tumor cells disseminated from primary sites, invaded into neighboring tissues, and metastasized to distal parts of the fish body. Similarly, expression of the hypoxia-regulated angiogenic factor, vascular endothelial growth factor (VEGF) to a high level resulted in tumor cell dissemination and metastasis, which correlated with increased tumor neovascularization. Inhibition of VEGF receptor signaling pathways by sunitinib or VEGFR2 morpholinos virtually completely ablated VEGF-induced tumor cell dissemination and metastasis. To the best of our knowledge, hypoxia- and VEGF-induced pathological angiogenesis in promoting tumor dissemination, invasion, and metastasis has not been described perviously at the single cell level. Our findings also shed light on molecular mechanisms of beneficial effects of clinically available anti-VEGF drugs for cancer therapy.
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