Changes of Cell Adhesion and Extracellular Matrix (ECM) Components in Cervical Intraepithelial Neoplasia

Cell-cell and cell-extracellular matrix interaction is crucial in tumor progression. Tight junction (TJ) proteins as occludin and claudins (CLDNs) play important role in this process together with several extracellular matrix components, as syndecan. Our previous work suggested significant changes in the expression of claudins even in the early stages of cervical carcinogenesis. The aim of our present work was to study the expression of occludin and syndecan-1, as compared to CLDNs, in early phases of cervical carcinogenesis. Paraffin sections of 50 samples were studied by immunohistochemistry, including cervical intraepithelial neoplasias (CIN-I-II-III), in situ carcinomas (CIS) and normal cervical samples. Occludin and CLDN-2 were found colocalized in the basal layer, while syndecan-1 and CLDN-1, -4 and -7 were coexpressed in the parabasal and intermedier layers in normal epithelia. Intensity of occludin staining decreased in CIN/CIS lesions, although it was more extended towards the upper epithelial layers with inverse relation with grades, as seen in the case of CLDN -2 expression. CLDN -1, -2, -4 and -7 were detected in the entire epithelium in CIN, showing decrease in CIS. The progression of CIN was associated with reduced syndecan-1 expression, in contrast to CLDN -1, -4 and -7 which increased toward CIS. The obtained data suggest that significant changes occur in the composition of cell adhesion complexes even in early stages of cervical carcinogenesis. The pattern of expression is characteristic for the alteration, the changes in the different components, however, are not parallel with each other.