Browsing by Subject "Tight junctions"

Now showing 1 - 4 of 4
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    Expression of claudin-1 in laryngeal squamous cell carcinomas (LSCCs) and its significance
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Ouban, Abderrahman
    . Background. A large body of scientific evidence points to the important roles of tight junction proteins in tumor development, progression and dissemination. The larynx has only a few studies, analyzing the role of this group of junctional proteins in its oncogenesis. In this study, the author sheds some light on the expression and possible role of claudin-1 in laryngeal squamous cell carcinomas. Materials and methods. This study analyzed the expression of claudin-1, using immunohistochemistry, in a tissue microarray of 80 cases of laryngeal squamous cell cancers. Clinicopathological parameters were analyzed according to claudin-1 expression in the tissue microarray. Furthermore, the expression of slug/snail1, an Epithelial-Mesenchymal Transition (EMT) linked protein, was analyzed by immunohistochemistry in the same microarray, and the expressions of the two proteins were assessed for correlation. Results. A significant majority of laryngeal squamous cell cancers exhibited positive expression of claudin-1 proteins. The majority of those tumors expressed claudin-1 in their cytoplasm. The overall majority of those same tumors also exhibited a cytoplasmic shift of the slug-snail-1 protein from the nuclei to the cytoplasm. There was also evidence of correlation of the two proteins' expressions in the cytoplasm of laryngeal tumors. Conclusion. The above may suggest a role for claudin-1 in the development and progression of laryngeal squamous cell carcinoma. Overall, claudin-1's aberrant expression in laryngeal cancer is in line with evidence seen in other head and neck cancers. Its co-expression with slug/snail-1 in LSCC patients should be investigated further to understand the nature of the relationship of the two proteins in LSCC and their possible contribution to its development and progression.
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    HAVcR-1 involvement in cancer progression
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Telford, Emily J.A.; Jiang, Wen G.; Martin, Tracey A.
    Formerly known for its importance in the immune system and kidney regeneration, it is becoming more apparent that HAVcR-1 is an important protein in cancer biology. HAVcR-1 is overexpressed in numerous cancers and associates with critical molecules of tight junctions. Tight junctions are critical in homeostasis of cellular compartments via the maintenance of epithelia and endothelia however it has also be suggested that via the prevention of dissemination, intravasation and extravasation, tight junctions play a critical role in the prevention of cancer metastasis. HAVcR-1 shedding and the production of the HAVcR-1 ectodomain has been linked to increased IL-6 thus implicated it in the process of angiogenesis via the activation of the STAT3 pathway leading to increased HIF-1α. The HAVcR-1 ectodomain has also been shown to be a potential urinary biomarker in certain cancers. HAVcR-1 is potentially important molecule both for the detection of cancer and the treatment of cancer by being a novel target for anticancer therapeutics.
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    Polarity and the development of the outer blood-retinal barrier
    (Murcia : F. Hernández, 1997) Rizzolo, L.J.
    The retinal pigment epithelium (RPE) is a monolayer that separates the outer surface of the neural retina from the choriocapillaris. Because the choriocapillaris is fenestrated, it is the RPE that forms the outer blood-retina1 barrier and regulates the environment of the outer retina. Like al1 epithelia and endothelia, the ability of RPE to regulate transepithelial transport depends upon two properties: apical tight junctions to retard diffusion through the paracellular spaces of the monolayer, and an asymmetric distribution of proteins to regulate vectorial transport across the monolayer. During development, these properties form gradually. Initially, the tight junctions are leaky, and the RPE exhibits only partial polarity. As the neural retina and choriocapillaris develop, there are progressive changes in the composition of the apical junctional complexes, the expression of cell adhesion proteins, and the distribution of membrane and cytoskeletal proteins. Development can be used to dissect the multiple mechanisms that establish and maintain polarity and barrier function. These mechanisms are regulated by the interactions that develop between the RPE and its neighboring tissues. This review discusses the remodeling of the apical, lateral and basal plasma membranes of RPE that occurs during normal development, and establishes a framework to integrate the data obtained from multiple species. It examines the progress in understanding how environmental interactions regulate this development.
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    Tight junctions and their role in cancer metastasis
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Martin, T. A.; Jiang, W. G.
    Tight Junctions gove rn the permeabili ty of endothelial and epithelial cells and are the most topical structures of these cell types. Tight junctions create an intercell ular ba rri er and in tramembrane diffusion fe nce. An important step in the fo rmation of ca ncer metastases is int e rac ti on and pe netrat io n o f th e vasc ula r endothelium by dissociated ca ncer cells. Ea rly studies demonstrated a correlation between the reduction of tight junctions and tumour diffe rent iati on and experimental evidence has emerged to pl ace tight junctions in the frontline as the structure that ca ncer cells must overcome in order to metastasise. Changes in tight juncti on function are thu s an ea rl y and key aspect in cancer metastasis. Further work is requ ired to fully realise the potent ial that this structure has in cancer invasion and metastasis in ord er to deve lop new and nove l th erapi es in th e prevention of tumour metastasis.