Fetal calf serum contains activities that induce fetal hemoglobin in adult erythroid cell cultures

Abstract

Cultures of peripheral blood or bone marrow erythroid progenitors display stimulated production of fetal hemoglobin. We investigated whether this stimulation is due to factors contained in the sera of the culture medium. Comparisons of γ/γ + β biosynthetic ratios in erythroid colonies grown in fetal calf serum (FCS) or in charcoal treated FCS (C-FCS) showed that FCS-grown cells had significantly higher γ/γ + β ratios. This increase in globin chain biosynthesis was reflected by an increase in relative amounts of steady-state γ-globin mRNA. In contrast to its effect on adult cells, FCS failed to influence γ-chain synthesis in fetal burst forming units-erythroid (BFU-E) colonies. There was a high correlation of γ-globin expression in paired cultures done with C-FCS or fetal sheep serum. Dose-response experiments showed that the induction of γ-globin expression is dependent on the concentration of FCS. These results indicate that FCS contains an activity that induces γ-globin expression in adult erythroid progenitor cell cultures. © 1990 by The American Society of Hematology.