Simulating cellular galectin networks by mixing galectins in vitro reveals synergistic activity

Even though members of the family of adhesion/growth-regulatory galectins are increasingly detected to be co-expressed, they are still being routinely tested separately. The recent discovery of heterodimer formation among galectins-1, -3, and -7 in mixtures prompts further study of their functional activities in mixtures. Cell agglutination, galectin binding to cells, as well as effects on cell proliferation, onset of apoptosis and migration were determined in assays using various cell types and mixtures of galectins-1, -3, and -7. Evidence for a more than additive increases of experimental parameters was consistently obtained. Testing galectins in mixtures simulates the situation of co-expression in situ and reveals unsuspected over-additive activities. This new insight is relevant for analyzing galectin functionality in (patho)physiological conditions. •Galectins-1, -3, and -7 form heterodimers in solution.•Mixtures of galectins simulates galectin co-expression in situ.•Mixtures display synergistic activities in vitro.•Cell agglutination, apoptosis, proliferation, migration affected.•Findings are relevant for galectin functionality in vivo.