Differentiation inducing effects of butyrate and DMSO on human intestinal tumor cell lines in culture.

In the present report, we have studied the effects of butyrate and dimethyl sulfoxide (DMSO) on the characteristics of four human intestinal tumor cell lines in vitro; namely a duodenal adenocarcinoma HTB-40 and three adenocarcinomas of colon: HT-29, CCL-218, and CCL-222. In the presence of concentrations of 2 mM butyrate and 2% DMSO the growth of all these four cell lines was significantly inhibited. Both these agents lengthened the doubling time of these cell lines by about twofold. In addition, the morphology of the treated cells was altered. All four cell lines grow in semisolid agar and form characteristic colonies. Butyrate and DMSO inhibited the colony forming efficiency of these cell lines by 40-60%. Using flow cytometric analysis, the cells that were grown in the presence of butyrate and DMSO were analyzed for their lectin-binding properties. For this purpose the lectins used were concanavalin-A (Con-A), peanut agglutinin (PNA), wheat germ agglutinin (WGA), and succinylated wheat germ agglutinin (SWGA). All four cell lines showed an increase in lectin-binding cells. CCL-218, which showed no PNA binding when grown without these agents, acquired about 25% reactivity when grown in the presence of butyrate or DMSO. All these cell lines showed an increase in the percentage of positive cells for the lectin SWGA that unlike WGA does not bind to sialic acid on the cell surface, suggesting an increase in nonsialated residues on all the treated cells. These results indicate a differentiation inducing effect of butyrate and DMSO on these cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)