VEGF induces ascites in ovarian cancer patients via increasing peritoneal permeability by downregulation of Claudin 5
ABSTRACT To evaluate the role of VEGF-dependent Claudin 5 production for the development of ascites via influencing endothelial permeability in peritoneal tissue of ovarian cancer patients.
This study investigates the mechanisms of formation of ascites in ovarian cancer patients, performing RT-PCR, VEGF-ELISA and immunohistochemical dual staining for CD31 and Claudin 5. In addition, in order to analyze the connectivity of VEGF, Claudin 5, and endothelial permeability, an endothelial cell/ovarian cancer cell-co-culture-system was established and evaluated performing Western blot analysis and a permeability assay.
Firstly, VEGF-gene expression was demonstrated for all ovarian cancer and peritoneal biopsies. In addition, quantification of VEGF in the serum and ascites of ovarian cancer patients revealed significantly increased values. We subsequently demonstrated Claudin 5 production in the peritoneal vessels, which was weaker than in the vessels of the controls. Evaluation of endothelial permeability finally showed a VEGF-dependent regulation via Claudin 5 suggesting a mechanism for the development of ascites in ovarian cancer patients.
VEGF induces ascites in ovarian cancer patients. This instance happens due to increased peritoneal permeability, caused by downregulation of the tight junction protein Claudin 5 in the peritoneal endothelium.
SourceAvailable from: Gerasimos Aravantinos[Show abstract] [Hide abstract]
ABSTRACT: As increased angiogenesis has been linked with the progression of ovarian cancer, a number of anti-angiogenic agents have been investigated, or are currently in development, as potential treatment options for patients with advanced disease. Bevacizumab, a recombinant monoclonal antibody against vascular endothelial growth factor, has gained European Medicines Agency approval for the front-line treatment of advanced epithelial ovarian cancer, fallopian tube cancer or primary peritoneal cancer in combination with carboplatin and paclitaxel, and for the treatment of first recurrence of platinum-sensitive ovarian cancer in combination with carboplatin and gemcitabine. We conducted a systematic literature review to identify available efficacy and safety data for bevacizumab in ovarian cancer as well as for newer anti-angiogenic agents in development. We analyzed published data from randomized, controlled phase II/III clinical trials enrolling women with ovarian cancer to receive treatment with bevacizumab. We also reviewed available data for emerging anti-angiogenic agents currently in phase II/III development, including trebananib, aflibercept, nintedanib, cediranib, imatinib, pazopanib, sorafenib and sunitinib. Significant efficacy gains were achieved with the addition of bevacizumab to standard chemotherapy in four randomized, double-blind, phase III trials, both as front-line treatment (GOG-0218 and ICON7) and in patients with recurrent disease (OCEANS and AURELIA). The type and frequency of bevacizumab-related adverse events was as expected in these studies based on published data. Promising efficacy data have been published for a number of emerging anti-angiogenic agents in phase III development for advanced ovarian cancer. Further research is needed to identify predictive or prognostic markers of response to bevacizumab in order to optimize patient selection and treatment benefit. Data from phase III trials of newer anti-angiogenic agents in ovarian cancer are awaited.Journal of Ovarian Research 05/2014; 7:57. DOI:10.1186/1757-2215-7-57 · 2.03 Impact Factor
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ABSTRACT: Developing human corpus luteum contains a closely regulated cellular communication system, between luteal steroidogenic cells and endothelial cells. This system guaranties the vascularization process during luteal formation. The process is combined with rapid release of large amounts of progesterone into the bloodstream. The regulation of endothelial proliferation and permeability by LH and human chorionic gonadotropin (hCG) is integral to this process. On the cellular level, endothelial permeability is regulated by intercellular junctions, such as: adherens junctions (AJ), and tight junctions (TJ), which act as zipper-like structures between interacting endothelial cells. Several cell junctional proteins are localized to the corpus luteum, including: Occludin, Nectin 2, Claudin 1 and Claudin 5, as well as, VE-Cadherin. It has been assumed that regulation of AJ- and TJ-proteins is of particular importance for permeability, and accordingly, for the functionality of the corpus luteum in early pregnancy - since treatment with hCG induces down regulation of juntional proteins in the luteal vessels. The effect of hCG on the adhesive molecules is mediated by vascular endothelial growth factor (VEGF). On a functional level, the hCG-dependent and VEGF-mediated decrease of junctional proteins cause a decrease in the density of cell-cell-closure, and accordingly, an increase in endothelial permeability. In doing so, the different junctional proteins are not only directly influenced by VEGF, but also interact among themselves and influence each other reciprocal. Disturbances of this strictly, regulated interactions may explain the development of pathologies with increased vascular permeability, such as the ovarian hyperstimulation syndrome (OHSS).Reproduction (Cambridge, England) 10/2014; DOI:10.1530/REP-13-0296 · 3.26 Impact Factor
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ABSTRACT: Over the last decade, it has become apparent that the tight junction (TJ) is a key component in tumour progression and metastasis. In addition to its role in the control of paracellular diffusion of ions and certain molecules, the TJ has a vital role in maintaining cell to cell adhesion and tissue integrity. Changes in the expression and/or distribution of TJ proteins can result in loss in cohesion of the TJ structure, which in turn results in the ability of cancer cells to become invasive and then ultimately lead to the metastasis of cancer cells. This review will discuss recent insights into how TJ are involved in the process of tumour metastasis.Seminars in Cell and Developmental Biology 09/2014; 36. DOI:10.1016/j.semcdb.2014.09.008 · 5.97 Impact Factor