Nuclear transport of galectin-3 and its therapeutic implications.

Galectin-3, a member of β-galactoside-binding gene family is a multi-functional protein, which regulates pleiotropic biological functions such as cell growth, cell adhesion, cell-cell interactions, apoptosis, angiogenesis and mRNA processing. Its unique structure enables it to interact with a plethora of ligands in a carbohydrate dependent or independent manner. Galectin-3 is mainly a cytosolic protein, but can easily traverse the intracellular and plasma membranes to translocate into the nucleus, mitochondria or get externalized. Depending on the cell type, specific experimental conditions in vitro, cancer type and stage, galectin-3 has been reported to be exclusively cytoplasmic, predominantly nuclear or distributed between the two compartments. In this review we have summarized the dynamics of galectin-3 shuttling between the nucleus and the cytoplasm, the nuclear transport mechanisms of galectin-3, how its specific interactions with the members of β-catenin signaling pathways affect tumor progression, and its implications as a therapeutic target.