Galectin‑3 promotes the adhesion, but not the migration of thyroid carcinoma cells in a β‑galactoside‑specific manner

Abstract

In thyroid carcinoma cells, the soluble β‑galactoside‑specific lectin, galectin‑3, is extra‑ and intracellularly expressed and plays a significant role in thyroid cancer diagnosis. The functional relevance of this molecule, particularly in its extracellular environment however, warrants further elucidation. To gain insight into this topic, the present study characterized principal functional properties of galectin‑3 in 3 commonly used thyroid carcinoma cell lines (B‑CPAP, Cal‑62 and FTC‑133) that express the molecule intra‑ and extracellulary. Cell‑intrinsic galectin‑3 harbors a functional carbohydrate recognition domain as determined by affinity purification. Moreover, cell surface expressed galectin‑3 can be partially removed by treatment with lactose or asialofetuin, but not with sucrose. Thyroid carcinoma cells adhere to substrate‑bound galectin‑3 in a β‑galactoside‑specific manner, whereby only cell adhesion, but not cell migration is promoted. Thus, thyroid tumor cells harbor functional active galectin‑3 that, inter alia, specifically interacts with cell surface‑expressed molecular ligands in a β‑galactoside‑dependent manner, whereby the molecule can at least interfere with cell adhesion. The modulation of galectin‑3 expression level or its ligands in such tumor cells could be of therapeutic interest and needs further experimental clarification.