Rappaport Faculty of Medicine

About: Rappaport Faculty of Medicine is a based out in . It is known for research contribution in the topics: Population & Heparanase. The organization has 3205 authors who have published 3915 publications receiving 114533 citations.

The impact of heparanese and heparin on cancer metastasis and angiogenesis.

Abstract: Heparan sulfate (HS) proteoglycans play a key role in the self-assembly, insolubility and barrier properties of the extracellular matrix (ECM). Cleavage of HS therefore affects the integrity of tissues and hence normal and pathological phenomena involving cell migration and response to changes in the ECM. Mammalian heparanase, HS-degrading endoglycosidase,is synthesized as a latent 65 kDa precursor that undergoes proteolytic cleavage, yielding 8 kDa and 50 kDa subunits that heterodimerize to form a highly active enzyme. Heparanase is preferentially expressed in human tumors and its over-expression in tumor cells confers an invasive phenotype in experimental animals. Heparanase also releases angiogenic factors from the ECM and tumor micro environment and thereby induces an angiogenic response in vivo. Enhanced heparanase expression correlates with metastatic potential, tumor vascularity and reduced postoperative survival of cancer patients. Heparanase also promotes cell adhesion, survival and signaling events, independent of its enzymatic activity. These observations, the anti-cancerous effect of heparanase gene silencing and of heparanase inhibiting molecules as well as the unexpected identification of a predominant functional heparanase, suggest that the enzyme is a promising target for anti-cancer drug development. Here, we summarize recent progress in molecular and cellular aspects of heparanase, emphasizing its causal involvement in cancer metastasis and angiogenesis, and discuss the development of heparin-like heparanase inhibitors.

Müller cells separate between wavelengths to improve day vision with minimal effect upon night vision

Abstract: Vision starts with the absorption of light by the retinal photoreceptors-cones and rods. However, due to the 'inverted' structure of the retina, the incident light must propagate through reflecting and scattering cellular layers before reaching the photoreceptors. It has been recently suggested that Muller cells function as optical fibres in the retina, transferring light illuminating the retinal surface onto the cone photoreceptors. Here we show that Muller cells are wavelength-dependent wave-guides, concentrating the green-red part of the visible spectrum onto cones and allowing the blue-purple part to leak onto nearby rods. This phenomenon is observed in the isolated retina and explained by a computational model, for the guinea pig and the human parafoveal retina. Therefore, light propagation by Muller cells through the retina can be considered as an integral part of the first step in the visual process, increasing photon absorption by cones while minimally affecting rod-mediated vision.

Traumatic Ulcerative Granuloma With Stromal Eosinophilia A Reactive Lesion of the Oral Mucosa

Abstract: Traumatic ulcerative granuloma with stromal eosinophilia (TUGSE) is a benign lesion of the oral mucosa of an unclear pathogenesis. We analyzed the profile of the inflammatory infiltrate in 12 cases of TUGSE by using immunohistochemical analysis and polymerase chain reaction-based repertoire analysis to detect T- and B-cell receptor gene rearrangements. The inflammatory infiltrate consisted in most cases of B and T lymphocytes, macrophages, abundant eosinophils, and large atypical cells. In 5 cases, CD30+ cells were found. Spectratyping analysis displayed a polyclonal rearrangement of the T-cell receptor g gene in 6 cases and oligoclonality in 5 cases. Monoclonality was observed in 1 case that also fulfilled histologic criteria for lymphoma. Healing was uneventful in all cases, including the one suspected of being lymphoma, with no recurrences in more than 2 years'follow-up. TUGSE can be regarded reactive. Some cases, however, may harbor a dominant clonal T-cell population; in these cases, long-term follow-up is mandatory.

Mutations in STN1 cause Coats plus syndrome and are associated with genomic and telomere defects.

Abstract: The analysis of individuals with telomere defects may shed light on the delicate interplay of factors controlling genome stability, premature aging, and cancer. We herein describe two Coats plus patients with telomere and genomic defects; both harbor distinct, novel mutations in STN1 , a member of the human CTC1–STN1–TEN1 (CST) complex, thus linking this gene for the first time to a human telomeropathy. We characterized the patients’ phenotype, recapitulated it in a zebrafish model and rescued cellular and clinical aspects by the ectopic expression of wild-type STN1 or by thalidomide treatment. Interestingly, a significant lengthy control of the gastrointestinal bleeding in one of our patients was achieved by thalidomide treatment, exemplifying a successful bed-to-bench-and-back approach.

Heparanase: One Molecule with Multiple Functions in Cancer Progression

Abstract: Mammalian heparanase, an endoglycosidase-degrading heparan sulfate, is synthesized as a latent 65 kDa precursor that undergoes proteolytic processing, primarily by cathepsin-L, yielding 8 kDa and 50 kDa subunits that heterodimerize to form a highly active enzyme. Enhanced heparanase expression in human tumors correlates with metastatic potential, tumor vascularity, and reduced postoperative survival of cancer patients, attributed to enzymatic and nonenzymatic activities of the heparanase protein. Urinary and plasma levels of heparanase are elevated in cancer patients and suppressed in response to effective anticancer treatments. These observations and the anticancerous effect of heparanase gene silencing and of heparanase-inhibiting molecules suggest that the enzyme is a promising target for anticancer drug development.