Galectin-1 and galectin-3 binding pattern expression in renal cell carcinomas

We studied 2 families of molecules whose role remains uncharacterized or ob scure in the progress of renal cell carcinoma (RCC): galectins, a major cla ss of glycoproteins, and the Thomsen-Friedenreich (T) antigen. We character ized the level of expression of galectin-1 and galectin-3 and their respect ive binding sites in a series of 74 RCCs. We also characterized the Level o f expression of laminin, a natural ligand for galectins. Finally, we charac terized the level of T antigen expression and the T antigen binding sites. All levels of expression were quantitatively determined by using computer-a ssisted microscopy on immunohistochemically or glycohistochemically stained slides. A small concentration of galectin-1 binding sites or a large conce ntration heterogeneity of galectin-3 can be associated with unfavorable pro gnoses for patients with grade II or mRCCs. In contrast, T antigen and T an tigen binding sites revealed no change across the 2 RCC groups that exhibit ed different clinical outcomes. We established discriminant scores that per mitted a clear distinction between the 2 RCC groups analyzed. Modifications to the expression of galectin-1 and galectin-3, but not of T antigen, para llel art increase in RCC aggressiveness. Galectins represent a family of mo lecules with a meaningful role in RCC progression.