INDUCTION OF TUMORIGENICITY BY GALECTIN-3 IN A NONTUMORIGENIC HUMAN BREAST-CARCINOMA CELL-LINE

The human galectin-3 is a galactoside-binding protein of 31 kDa which functions as a receptor for glycoproteins containing poly N-acetyllact osamine side chains and as a substrate for matrix metalloproteinases-2 and -9. We studied its expression by flow cytoflourimetry, Western, N orthern and Southern analyses, in five cultured human breast carcinoma cell lines previously characterized as nontumorigenic, poorly metasta tic or metastatic in nude mice. The expression of galectin-3 correlate d with the reported tumorigenicity of the cells. The introduction of r ecombinant galectin-3 into the null expressing non-tumorigenic BT-549 cells resulted in the acquisition of anchorage-independent growth prop erties in all and tumorigenicity in 3/4 sense transfected cell clones. The data indicate a relationship between galectin-3 expression and ma lignancy of human breast carcinoma cell lines.