Immunohistochemical localization of syndecan-1 in normal and pathological human uterine cervix

Expression of syndecan‐1, a cell surface proteoglycan that binds growth factors and extracellular matrix components, was studied in normal and pathological human uterine cervix using immunohistochemical methods. Normal cervical squamous epithelium showed positive staining for syndecan‐1 in all cell layers, except the basal cell layer, whereas endocervical columnar epithelium stained weakly. In non‐neoplastic reactive lesions, metaplastic squamous cells were positive for syndecan‐1, whereas columnar cells showed weak or negative staining. In cervical condylomas, cells showing koilocytotic atypia were positive for syndecan‐1. The progression of cervical intraepithelial neoplasia (CIN) grade I to grade III was associated with reduced syndecan‐1 expression and localization of syndecan‐1 to more superficial cell layers. In squamous cell carcinomas (SCCs), syndecan‐1 expression correlated with histological differentiation, being absent from most poorly differentiated tumours. The results suggest that loss of syndecan‐1 from atypical cells is an early event during cervical carcinogenesis and show a close association of syndecan‐1 expression with preserved epithelial morphology and differentiation.