Browsing by Subject "Claudin-3"

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    Claudin expression in breast cancer: High or low, what to expect?
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Ricardo, Sara; Gerhard, Renê; Cameselle-Teijeiro, Jorge F.; Schmitt, Fernando; Paredes, Joana
    . The evaluation of claudins (CLDNs) expression pattern in tumours can be important to understand breast carcinogenesis. The study of CLDNs became more appealing since it was found that CLDN3 and CLDN4 are putative therapeutic targets for Clostridium perfrigens enterotoxin (CPE), as well as for monoclonal antibody-based therapy. Moreover, the recently characterized CLDN-low molecular subgroup of breast tumours increased the interest in these molecules. Based on these facts, our aim was to explore the pattern of expression of CLDNs among a large series of invasive breast carcinomas. We also analysed the correlation between the combinatorial expression of CLDN3/CLDN4 and classical prognostic factors and biological markers. In addition, we also compared the characteristics of tumours with low expression of CLDN3, CLDN4 and CLDN7, assessed by immunohistochemistry (IHC), and the ones from CLDN-low subgroup of tumours previously defined by genomic assays. The combinatorial analysis of the expression of CLDN3/CLDN4 showed a significant association between high CLDN3/CLDN4 levels and triple-negative tumours, as well as with worse patient outcome. This combined analysis may provide useful information for breast carcinomas, since these two CLDN members are putative therapeutic targets. Comparing tumours with low expression of CLDN3, CLDN4 and CLDN7 with tumours previously referred to as CLDN-low by genomic assays, we demonstrated that the single IHC evaluation of these three specific CLDNs is insufficient to identify the CLDN-low molecular subtype of breast tumours. The analysis of several other molecular markers, such as EMT (epithelial-to-mesenchymal transition) and CSC (cancer stem cell) markers should probably be added to improve the identification of this subgroup of tumours by IHC, which probably are enriched in carcinomas with metaplastic differentiation
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    Distinct presence of the tight junction protein claudin-3 in olfactory bulb and fila olfactoria of the mouse
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Eppler, Elisabeth; Müller Gerbl, Magdalena; Maly, I. Piotr
    The tight junction protein claudin-3 is overexpressed in diverse epithelial tumours and is associated with increased survival, progression and motility of tumour cells. Claudin-3 expression profiles are being increasingly used for diagnostic and prognostic tumour classification. Claudin-3 has been identified as a receptor for Clostridium perfringens enterotoxin, which is under consideration for selective lysis of claudin-3- expressing tumours, particularly brain metastases, and other translational medicine uses. However, the localization of claudin-3 in the brain has not been completely elucidated. While claudin-3 in brain tissue adjacent to claudin-3-expressing metastases had been excluded and low or undetectable levels proposed in the CNS, under physiological conditions, in adult human, rat and mouse brains, claudin-3 was exclusively found in choroid plexus epithelium where it is considered an integral component of the blood-cerebrospinal-fluid barrier. We report here the pronounced presence of claudin-3 not only in the nasal region (as described for rat), but also in the mouse olfactory bulb and nerve using immunohistochemistry and Western blot. Claudin-3 was present in the fila olfactoria from the epithelium to the olfactory nerve and in the main and accessory olfactory bulb. We propose that the abundant presence of claudin3 in the olfactory system, particularly in nerve fibres and the olfactory bulb cone, which we present here, may play a role at the interface of the central and peripheral nervous system, both as barrier and for axonal growth and communication. Thus, claudin-3 should be considered and further explored with regards to treatment approaches addressing the olfactory bulb and nasal region.