Expression of claudin-1, -3, -4, -5 and -7 proteins in low grade colorectal carcinoma of canines

• Autores: Cs. Jakab, M. Rusvai, P. Gálfi, Z. Szabó, A. Szabára, J. Kulka
• Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 25, Nº. 1, 2010, págs. 55-62
• Idioma: inglés
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• Resumen

  • The aim of the present study was to characterise the expression pattern of claudin-1, -3, -4, -5 and -7 tight junction proteins in canine normal colorectum and in the low-grade, tubulopapillary colorectal carcinoma in canines. Methods and results: The biopsy samples included 10 canine normal colorectal tissues and 20 canine low grade colorectal carcinomas (CLGCCs). The canine normal colorectal mucosa was negative for claudin-1. Claudin-1 was detected as a non-diffuse intense membrane labelling of neoplastic epithelial cells in low grade colorectal cancer in canines. Fifty five per cent of all tumours showed a weak cytoplasmic pattern of staining for claudin-1 protein. The normal colorectal mucosa showed diffuse punctate positivity for claudin-3. Claudin-3 was detected as an intense lateral membrane labelling of tumour cells in CLGCCs. Claudin-4 expression in surface and crypt epithelial cells of the intact colorectal mucosa in canines was punctate. Claudin-4 molecule was detected as a lateral membrane labelling of neoplastic cells in CLGCCs. The epithelium of the CLGCCs and the low grade colorectal carcinoma were negative for claudin-5. The surface and crypt epithlial cells of the canine normal colorectal mucosa showed a diffuse lateral membranous pattern of staining for claudin-7. Claudin-7 molecule was detected as an intense membrane labelling of neoplastic cells in CLGCCs. Seventy per cent of all tumours showed weak cytoplasmic positivity for claudin-7. Conclusion: Consequently, we hypothesize that claudin-1 plays a role in the progression of CLGCCs. Further functional studies are needed to clarify the biological role of the mislocalization of the claudin-1 molecule from cell membrane to the cytoplasm in CLGCCs. Lower claudin-4 expression suggests that reduced expression of claudin-4 molecule may lead to cellular disorientation, detachment and invasion of CLGCCs. Further functional studies are needed to clarify the biological role of overexpression and mislocalisation of claudin-7 in CLGCCs.