Kategorie: Onkologická diagnostika
Číslo abstraktu: p003
Claudins are a family of proteins integral to the structure and function of TJ and their altered expression has been detected in several types of cancer.
Aim: The aim of the study was to determine the role of Claudin-1 expression in carcinomas and adenomas of the colon.
Material and Methods: Altogether 40 cases including adenocarcinomas and adenomas with various degrees of dysplasia were analyzed by indirect immunohistochemistry on formalin-fixed, paraffin-embedded tissue sections using mouse monoclonal anti-Claudin-1 primary antibody, sc-81796 diluted 1:500 (Santa Cruz Biotechnology, INC.). Protein detection was performed in the staining automaton Ventana Benchmark. Evaluation was done by H-score (percent of positive cell x intensity of staining).
Results: In normal colonic mucosa, Claudin-1 showed only weak membranous staining. Marked increase of Claudin-1 expression was detected in adenomas, even in those without any dysplastic changes. Similarly, adenocarcinomas overexpressed the protein, and the differences between adenomas and carcinomas were not significant. However, we demonstrated different protein location. Claudin-1 remained located in cytoplasmic membranes in adenomas without or with mild degree of dysplasia, whereas the shift to the cytoplasma with only cytoplasmic or membranous/cytoplasmic expression was observed in severe dysplasias and in carcinomas.
Increased expression of Claudin-1 was observed in histologically normal mucosa close to the neoplastic areas, when compared to distant areas.
Conclusion: We demonstrated that Claudin-1 deregulation is involved in early stage of colon cancerogenesis and itsubstantially may contribute to the neoplastic transformation.
This work was supported by grants GACR P304/10/1070 and MSM 6198959216.
Datum přednesení příspěvku: 23. 4. 2010