A parallel association between differentiation and induction of galectin-1, and inhibition of galectin-3 by retinoic acid in mouse embryonal carcinoma F9 cells

Soluble endogenous lactoside-binding lectins, galectins, have been implicat ed in cell adhesion, growth, differentiation, neoplastic transformation, an d metastasis. Two major classes of these lectins, galectin-1 and galectin-3 , are developmentally regulated. To explore the mechanisms by which the exp ression of the galectins is regulated and to examine their association with the differentiation processes induced by all-trans retinoic acid (RA), dib utyryl cyclic AMP (Bt(2)cAMP) and their combination, we used the murine emb ryonal carcinoma (EC) cell line F9 and its RA-resistant mutant, RA-3-10. RA induced endodermal differentiation and a concurrent induction of galectin- 1 and its complementary glycoconjugates (laminin and lysosomal-associated m embrane protein, LAMP) in the F9 wild-type (wt) line, but failed to induce differentiation and had no effects on or even reduced the expression of gal ectin-1, laminin, and LAMP in the RA-3-10 line. On the other hand, RA inhib ited expression of galectin-3 in the wildtype line but had no effect on the RA-3-10 line. The galectin-1 gene is at least partially regulated at the t ranscriptional level. These results demonstrate a parallel association betw een differentiation and induction of galectin-1, and inhibition of galectin -3 in Fg cells by PA. The study suggests that a regulated expression of gal ectins and their complementary glycoconjugates is involved in the different iation pathway induced by RA in F9 cells.