Differential effects of chemical inducers on expression of beta globin genes in murine erythroleukemia cells

Abstract

Murine erythroleukemia cells are induced to erythrodifferentiate by polar compounds such as dimethyl sulfoxide and hexamethylene bisacetamide as well as by fatty acids such as butyric acid and propionic acid. The effect of these inducers on the expression of two beta globin genes, betamaj and betamin, during the course of differentiation of the cells has been examined. After 4 days of culture with hexamethylene bisacetamide or dimethyl sulfoxide, the betamaj-containing hemoglobin (Hbmaj) predominates. By contrast, in the presence of butyric acid or propionic acid, after 4 days of culture, relatively equal amounts of Hbmaj and Hbmin are found. When cultured with dimethyl sulfoxide or hexamethylene bisacetamide, murine erythroleukemia cells synthesize more betamaj than betamin, while about equal amounts of the two globins are synthesized in the presence of butyric acid. When poly(A)-containing RNA from the cells exposed to different inducers is translated in a wheat germ cell-free system, the ratio of betamaj to betamin synthesized reflects that in whole cells. In a strain of murine erythroleukemia cells resistant to dimethyl sulfoxide (DR-10), the preferential stimulation of betamaj synthesis by hexamethylene bisacetamide of the betamin synthesis by butyric acid is more pronounced than with the dimethyl sulfoxide-sensitive cells (DS-19). These data suggest that polar compounds and fatty acids cause different expression of the betamaj and betamin genes in murine erythroleukemia cells.