Analysis of the expression and localization of tight junction transmembrane proteins, claudin-1, -4, -7, occludin and JAM-A, in human cervical adenocarcinoma.

Abstract

Tight junction proteins have recently been reported to be useful for distinguishing between neoplastic and non-neoplastic tissues. In this study, we evaluated the expression and localization of tight junction transmembrane proteins in human cervical adenocarcinoma and adenocarcinoma in situ (AIS), and we determined whether their expression patterns could distinguish cervical adenocarcinoma from non-neoplastic cervical glands. Fifty-five patients with cervical adenocarcinoma or AIS were included in this study. Surgical specimens were immunohistochemically stained for claudin (CLDN) -1, -4, -7, occludin, and JAM-A. Significantly higher expression levels of CLDNs and JAM-A were found in cervical AIS and adenocarcinoma than in non-neoplastic glands. In cervical AIS and adenocarcinoma, localization of CLDN1 and JAM-A was extended throughout the whole cell membranes, whereas they were predominantly expressed at the most apical cell-cell junction in non-neoplastic glands. ROC curve analysis revealed that immunoreactivities of CLDN-1 or JAM-A successfully distinguished neoplasms from non-neoplastic cervical glands with high specificity (CLDN-1, 79.1%; JAM-A, 79.1%) and high sensitivity (CLDN-1, 84.1%; JAM-A, 95.5%). As expected, there were immunohistochemical differences between cervical adenocarcinoma and non-neoplastic cervical glands by using antibodies against tight junction transmembrane proteins. These results suggest that CLDN-1 and JAM-A are potential biomarkers for cervical adenocarcinoma.