Claudins have been shown to be up-regulated in various cancers and have been suggested as possible biomarkers and targets for cancer therapy. The aims of this study were to evaluate the expression patterns of claudin-1 and claudin-7 in squamous cell carcinoma of the uterine cervix and investigate the different expressions according to presence of lymph node metastasis in theses carcinoma.

Tumor specimens were obtained from each 20 patients with invasive squamous cell carcinoma (ISCC) with and without lymph node (LN) metastasis. Normal cervical tissues as control were obtained from 10 patients with benign uterine disease. Immunohistochemical analysis was performed with antibodies to claudin-1 and claudin-7.

The expressions of claudin-1 and claudin-7 were undetectable in normal exocervical mucosa, but had variable staining in endocervical mucosa. The expressions of both claudin-1 and claudin-7, exhibiting mainly membranous staining, were significantly up-regulated in all of the ISCC in comparison to the normal control in similar manner (P<0.001 and P<0.001, respectively). The expressions of claudin-1 and claudin-7 were not significantly different between ISCC with and ISCC without LN metastasis (P=0.54 and P=0.53, respectively). However there was increasing tendency of expressions in ISCC with LN metastasis in comparison to ISCC without LN metastasis.

These results suggest that claudin-1 and claudin-7 may play a significant role in carcinogenesis of squamous cell carcinoma of the uterine cervix and may represent novel markers for this disease.