Evaluation of the role of tight junction molecules

Abstract

Background According to the results of the National Population-based Cancer Registry Program, bladder cancer is the second most common cancer after liver cancer that is prevalent among Egyptian males. About 70% of bladder cancers are diagnosed as nonmuscle invasive cancers with high risk of recurrence, besides the risk of progression to muscularis propria invasion. The challenge is to identify noninvasive cancers using a reliable method for accurate diagnosis as well as for predicting the prognosis. Aim We aimed to evaluate the immuno-histochemical expression of claudin-1 (CLDN-1) and CLDN-4 in invasive and noninvasive urothelial lesions and correlate them with clinicopathological findings. Patients and methods This retrospective study included 36 different cases of urinary bladder lesions: 30 cases of urothelial carcinomas (UCs) and six papillary urothelial neoplasms of low malignant potential in addition to six normal control cases. Cases were graded according to the WHO classification and staged according to the TNM pathological staging system. Slides were subjected to immunohistochemical staining by CLDN-1 and CLDN-4. Results CLDN-1 showed the highest level of expression among carcinoma cases, while CLDN-4 showed the highest expression among control cases (P<0.000 for both). Increased CLDN-1 expression was significantly related to muscle invasion (P=0.000), advanced T stage (P=0.000), and high tumor grade (P=0.012). CLDN-4 expression showed a statistically significant difference in UCs without muscle invasion (P=0.000), earlier T stage, and low tumor grade (P=0.006). Conclusion CLDN-1 and CLDN-4 could be used as potential markers to differentiate invasive from noninvasive and low grade from high grade UC. They can predict the clinical outcome and play a role in the assessment of patients with UC.