Abstract
Background: Claudin 4 is one of the tight junction proteins
which considered one of the protective barriers that are mostly

involved in the regulation of intercellular communication,

paracellular transport and apical cell-to-cell adhesion. Overexpression
of COX-2 and subsequent increase in prostaglandins


(PGs) concentration have emerged in recent years as important
players in cancer progression.
Aim of Study:
To explore immunohisto chemically the

expression of both claudin-4 and COX2 in nasopharyngeal
carcinoma and correlate their expression with each other and
with different clinicopathological parameters.
Material and Methods: This retrospective study was done
upon formalin fixed, paraffin blocks of 32 nasopharngeal
carcinoma cases and 6 non-neoplastic nasopharyngeal epithelium.
The materials were obtained from archieves of Pathology

Departement and Early Cancer Detection Unit (ECDU),
Faculty of Medicine, Benha University during the years 2012-
2017. The immunohistochemical stain with Claudin 4 and

COX2 was done and evaluated for each case.
Results: High expression of claudin 4 was observed in

44% of studied nasopharyngeal cases with statistically significant
correlation with tumor stage and distant metastasis

(p