Galectin-3, a member of the beta-galactoside-binding proteins, is an intracellular and extracellular lectin that interacts with intracellular glycoproteins, cell surface molecules and extracellular matrix proteins. Galectin-3 is expressed widely in epithelial and immune cells and the level of expression varies in many cancer cells relative to the normal tissues from which they arise. We investigated whether the expression of galectin-3 is associated with the progression of cervical neoplasia.

The galectin-3 expression was evaluated by immunohistochemistry in 90 formalin-fixed paraffin-embedded cervical tissues: 10 normal cervical specimens, 20 low-grade squamous intraepithelial lesions (LSILs), 20 high-grade squamous intraepithelial lesions (HSILs), and 40 invasive squamous cell carcinomas (ISCCs).

The immunohistochemical staining showed that the expression of galectin-3 was strong in all normal cervical squamous epithelia. Staining gradually decreased in accordance with the histopathologic grades from an LSIL to an HSIL and an ISCC (P<0.001). In particular, the expression of galectin-3 was significantly decreased in HSILs (P=0.001) and this down-regulation was more pronounced in ISCCs than normal tissues (P<0.001).

These data constitute the first observation that the expression of galectin-3 is down-regulated in cervical cancer tissues and suggest the decreased expression of this galactoside-binding lectin is associated with the progression of cervical neoplasia.