Differential expression of endogenous galectin-1 and galectin-3 in human prostate cancer cell lines and effects of overexpressing galectin-1 on cell phenotype

We have analyzed the expression of galectin-1 and galectin-3 in four human prostate carcinoma cell lines. Northern analysis and immunoblotting experim ents showed that three cell lines express both galectins. However, only gal ectin-1 was detected on the surface of these cells. The LNCaP line expresse d neither galectin. LNCaP was transfected with galectin-1 and four clones w ere isolated, all of which expressed galectin-1 on the cell surface. Kineti cs of binding to extracellular matrix proteins appeared to be accelerated i n the transfected lines, but overall binding was not enhanced. When the sam e experiments were performed in the presence of EDTA to eliminate the effec ts of integrins, binding of a galectin-1 clone to laminin and fibronectin w as increased relative to the control cell line. We propose that galectins m ay contribute to the adhesive properties of some prostate cancer cells.