Fig. 1.

Gal-3 interacting molecules in cancer metastasis. Gal-3 localizes to four biological compartments, i.e., nucleus, cytoplasm, extracellular space, and circulation, and plays unique roles through interaction with numerous proteins. Due to nuclear translocation, secretion, and internalization, Gal-3 can circulate among the nucleus, cytoplasm, extracellular space, and blood stream. The figure was produced using Servier Medical Art on www.servier.com with permission. Inset: protein structures of the Galectin family, which is classified into three molecular types: (1) prototypical, (2) tandem repeat, and (3) chimeric structure. Gal-3 is the only chimera protein, and its monomers are linked through their N-terminal domain, establishing pentameric structures. This complex of multivalent interactions modulates the extracellular function of Gal-3 in the tumor microenvironment. After exposure to proteolytic enzymes (MMP and/or PSA), intact Gal-3 is cleaved at the site of collagen α-like sequence, which leads to the disruption of pentameric structures and the production of cleaved Gal-3