Modulation of galactoside-binding lectins in tumor cells by differentiation-inducing agents

Abstract

The effects of the differentiation-inducing agents N 6, O 2′-dibutyryl cyclic AMP, β-mall-trans retinoic acid, dimethylsulfoxide and butyrate on the levels of galactoside-binding, proteins (lectins) in cultured human and murine tumor cells were examined by immunoblotting. Differentiation was associated with decreased levels of a 34-kDa lectin in the K-1735P and B16-F1 melanoma cells and decreased levels of a 14.5-kDa lectin in S20 neuroblastoma, MDA-MB 175 breast carcinoma, HL-60 and THP-1 leukemia cells. The level of a 14.5-kDa lectin increased during differentiation of F-9 embryonal and KM12P colon carcinoma cells. These results indicate that tumor cell differentiation along specific pathways is accompanied by distinct modulation of lectin expression. These changes may recapitulate the normal developmental regulation of lectin expression.