Loss of E-cadherin and Acquisition of Vimentin in Epithelial-Mesenchymal Transition are Noble Indicators of Uterine Cervix Cancer Progression

BACKGROUND Epithelial-mesenchymal transition (EMT) has been known to play a key role in the stromal invasion of carcinoma in situ (CIS) lesion. Loss of E-cadherin and acquisition of vimentin are two critical steps in EMT, that are induced by Snail-1 upregulation associated with overexpression of epidermal growth factor receptor (EGFR). However, roles of EMT-related proteins in human cervical tissues have not been fully elucidated. In this study, we investigated the immunoexpressions of EMT-related proteins in CIS, microinvasive squamous cell carcinoma (SCC), and invasive SCC to demonstrate their key roles in tumor progression. METHODS Eighty one CIS, 17 microinvasive, and 21 invasive SCC cases were immunostained with primary antibodies for Snail-1, EGFR, E-cadherin, and vimentin on paraffin-embedded tissue microarray blocks. RESULTS EGFR and Snail-1 proteins were highly expressed but the levels were not significantly different between the three groups. However, loss of E-cadherin and acquisition of vimentin were proven to occur significantly higher in microinvasive and invasive SCC cases than in CIS. CONCLUSIONS E-cadherin and vimentin were found to be two useful indicators of EMT in evaluating stromal invasion of CIS. However, it was not demonstrated for Snail-1 and EGFR proteins to play any key role in the progression of cervix cancer.