Korean J Clin Pathol.  1998 Mar;18(1):29-34.

Role of Gamma Globin Promoter Region -269~-240 in Hydroxyurea Treated Erythroid Progenitor Cells

• Park JI
• Kim TG
• Kim DI
• Kim IH
• Jeong JS
• Han JY

Abstract

BACKGROUND: Recently, a great deal of interest has been focused on the use of hydroxyurea and hemin that may augment Hb F levels in patients with hemoglobinopathies and thalassemia, although the molecular mechanism of those chemicals remains unclear. In this study, we examined the effects of hydroxyurea and hemin on human adult peripheral and cord blood erythroid cells grown in a two-phase liquid culture system.
METHODS
Four adult peripheral and four cord blood cells were cultured in two-phase liquid culture, and were treated with hydroxyurea or hemin. We counted isolated erythroid cells by acid benzidine and glycophorin A stains. To determine whether transcription factor binding to the promoter is critical, we also examined the promoter region of gamma globin gene both under uninduced and hydroxyurea or hemin induced conditions using gel mobility shift assay and southwestern blot analysis.
RESULTS
When added together with erythropoietin, hydroxyurea led to significant increase in the percentage of erythroid cells in cord blood. In contrast, hemin greatly accelerated hemoglobin accumulation in adult erythroid progenitor cells. At -230 and -264 regions of gamma globin gene promoter, different protein binding patterns were observed in uninduced and hydroxyurea or hemin induced conditions between adult and cord blood.
CONCLUSIONS
These results suggest that hydroxyurea and hemin may act via alteration in DNA-protein interactions to induce gamma globin gene expression. In addition, we can conclude that different transcription factors may be involved in the gamma globin induction process between the adult and cord blood erythroid cells.

Keyword

Hydroxyurea; Hemin; Gamma globin gene; Transcription

MeSH Terms

Adult
Blotting, Southwestern
Coloring Agents
Electrophoretic Mobility Shift Assay
Erythroid Cells
Erythroid Precursor Cells*
Erythropoietin
Fetal Blood
gamma-Globins*
Gene Expression
Glycophorin
Hemin
Hemoglobinopathies
Humans
Hydroxyurea*
Promoter Regions, Genetic*
Protein Binding
Thalassemia
Transcription Factors
Coloring Agents
Erythropoietin
Glycophorin
Hemin
Hydroxyurea
Transcription Factors
gamma-Globins