Purpose: Galectin-9 (Gal-9) induces adhesion and aggregation of certain cell types and can be a prognostic factor in the patients with melanoma and breast cancer. We assessed the experiments to resolve whether Gal-9 expression in cervical neoplasm links to malignant potential of cervical squamous cell carcinoma (SCC) cells.
Methods: Gal-9 expression was examined with immunohistochemical techniques in 23 normal cervical squamous epithelia, 17 cervical intraepithelial neoplasia (CIN), and 38 cervical SCC compared to E-cadherin. CIN was divided into low-grade and high-grade squamous intraepithelial lesions (8 LSIL and 9 HSIL), and SCC was into well-, moderately and poorly differentiated SCC (6 WSCC, 20 MSCC and 12 PSCC).
Results: Gal-9 and E-cadherin were evidently detected in normal epithelium and endocervical glands, but those in CIN and SCC were significantly faint. Moreover, both the Gal-9 and E-cadherin expressions in HSIL were significant lower than those in LSIL, suggesting their association with malignant transformation. Unexpectedly, Gal-9 and E-cadherin in WSCC were significantly high compared to those in HSIL. Furthermore, those in SCC were inversely correlated with the grade of differentiation (WSCC >> MSCC >> PSCC), implying the possible involvement of Gal-9 and E-cadherin in the differentiation of SCC. In contrast, they were not different among the FIGO stage. Gal-9 expression was well correlated with E-cadherin expression in CIN and SCC but not in normal cervical epithelia.
Conclusion: The present results suggest that decreased Gal-9 expression is inversely associated with malignant potential or differentiation of cervical CIN and SCC as a differentiation biomarker.