E-Cadherin Expression and DNA Ploidy Analysis in Invasive Squamous Cell Carcinoma of the Uterine Cervix Comparison with those of CIN

ABSTRACT

Epithelial cadherin (E-cadherin) is a Ca2+ -dependent cell-cell adhesion molecule that connects cells via homotypic interactions. Its function is critical in the induction and maintenance of cell polarity and differentiation, and its loss is associated with an invasive and poorly differentiated phenotype in a wide range of tumors. Formalin-fixed, paraffin-embedded tissue sections from 36 cases of cervical intraepithelial neoplasia (CIN) and 14 cervical squamous cell carcinomas were investigated for the expression of E-cadherin immunohistochemically. While E-cadherin expression was usually restricted on the cell membrane of basal and parabasal cells in normal cervix, the presence of cytoplasmic E-cadherin was found to be associated with its grade in CIN lesions. Also, marked cytoplasmic staining was commonly revealed in poorly differentiated ones than well-differentiated squamous cell carcinomas. More intense reactivity of cytoplasmic E-cadherin was frequently seen in the foci of invasion than adjacent carcinoma in situ, and in its periphery than the center of tumor islands. In addition, DNA ploidy and S-phase fraction of squamous cell carcinomas were analyzed and compared with those of CIN lesion. We found that invasive squamous cell carcinomas more frequently disclosed DNA aneuploidy than CIN lesions, and there was correlation between cytoplasmic E-cadherin expression and DNA aneuploidy. Also, cytoplasmic E-cadherin-reactive cervical neoplasms had a higher rate of cell proliferation than that of membranous E-cadherin-reactive cases. These data suggest that the increased cytoplasmic E-cadherin expression may represent one of the abnormalities underlying the loss of polarity and invasiveness of cancer cells, and the abnormal E-cadherin expression combined with/without DNA ploidy or S-phase fraction may serve as a prognostic indicator.