Galectin-inhibitory thiodigalactoside ester derivatives have antimigratory effects in cultured lung and prostate cancer cells.

Aromatic 3,3'-diesters of thiodigalactoside were synthesized in a rapid three-step sequence from commercially available thiodigalactoside and evaluated as inhibitors of cancer- and immunity-related galectins. For each of galectins-1, -3, -7, and -9N-terminal domain, aromatic 3,3'-diesters of thiodigalactoside were found to have affinities in the low micromolar range, which represents a 7-70 fold enhancement over thiodigalactoside itself. No significant improvement was found for galectin-8 N-terminal domain. Two of the compounds were selected for testing in cell culture and were shown to have potent antimigratory effects on human PC-3 prostate and human A549 nonsmall-cell lung cancer cells.