Z Gastroenterol 2009; 47 - A5
DOI: 10.1055/s-0029-1223984

Claudin expression in different pancreatic cancers and its significance in differential diagnostics

K Borka 1, A Korompay 1, E Szabó 1, P Kaliszky 2, P Kupcsulik 2, Z Schaff 1, A Kiss 1
  • 12nd Department of Pathology, Semmelweis University, Budapest, Hungary
  • 21st Department of Surgery, Semmelweis University, Budapest, Hungary

Introduction: Claudins (CLDNs) are essential proteins of tight junctions. Changes in their expression pattern have been demonstrated in a number of tumors. CLDNs-3 and -4 are receptors of the Clostridium perfringens enterotoxin, cytolytic effects of the toxin are well known. The aim of our studies was to compare the different CLDN expression patterns in normal pancreas cells, pancreatic endocrine tumors, adenocarcinomas, mucinous cystic tumors and acinar cell carcinomas.

Material and methods: Retrospective series of 74 formalin fixed, paraffin embedded tissues were obtained from the archives of the 2nd Department of Pathology of the Semmelweis University and expressions of CLDN-1, -2, -3, -4 and -7 proteins were examined using immunohistochemical as well as RT-PCR techniques.

Results: In addition to the well-known CLDN-1 and -4 expression CLDN-2, -3 and -7 proteins were demonstrated in ductal cells, CLDN-3 and -7 proteins showed expression in acinar cells. The adenocarcinomas and cystic mucinous tumors of exocrine origin denoted CLDN-1, -2, -4 and -7 positivity, whereas acinar cell carcinomas expressed only CLDN-1 and -2 positivity. High CLDN-3 and -7 expressions were detected in all endocrine tumors. This is the first description of CLDN protein expression in endocrine tumors. The level of CLDN-1, -4 and -7 protein expressions in borderline cystic tumors is inbetween that of benign and malignant tumors. This is a first review on childhood acinar cell carcinoma causing Cushing syndrome.

Conclusions: CLDN-1, -2 and -4 proteins are definitive markers of ductal differentiation, CLDN-1 protein is of acinar while CLDN-3 is of endocrine differentiation. The increased CLDN-4 expression in adenocarcinomas and mucinous cystic tumors, as well as the high CLDN-3 expression in endocrine tumors may open up new prospects in the targeted therapy of these tumours. The claudin expression pattern of pancreas tumors may be employed in the differenzial diagnosis of these tumors and may be of help in deciding dignity.