Role of epigenetic modifications in normal globin gene regulation and butyrate-mediated induction of fetal hemoglobin.
Butyrate is a prototype of histone deacetylase inhibitors that is believed to reactivate silent genes by inducing epigenetic modifications. Although butyrate was shown to induce fetal hemoglobin (HbF) production in patients with hemoglobin disorders, the mechanism of this induction has not been fully elucidated. Our studies of the epigenetic configuration of the beta-globin cluster suggest that DNA methylation and histone H3 acetylation are important for the regulation of developmental stage-specific expression of the beta-like globin genes, whereas acetylation of both histones H3 and H4 seem to be important for the regulation of tissue-specific expression. These studies suggest that DNA methylation may be important for the silencing of the beta-like globin genes in nonerythroid hematopoietic cells but may not be necessary for their silencing in nonhematopoietic cells. Furthermore, our studies demonstrate that butyrate exposure results in a true reversal of the normal developmental switch from gamma- to beta-globin expression. This is associated with increased histone acetylation and decreased DNA methylation of the gamma-globin genes, with opposite changes in the beta-globin gene. These studies provide strong support for the role of epigenetic modifications in the normal developmental and tissue-specific regulation of globin gene expression and in the butyrate-mediated pharmacologic induction of HbF production.
Fathallah
Hassana
H
Division of Hematology and Medical Oncology, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029, USA. hassana.fathallah@mssm.edu
Weinberg
Rona S
RS
Galperin
Yelena
Y
Sutton
Millicent
M
Atweh
George F
GF
D000107:Acetylation; D002087:Butyrates / Q000494:pharmacology*; D002478:Cells, Cultured; D042002:Chromatin Assembly and Disassembly / Q000187:drug effects; D019175:DNA Methylation; D044127:Epigenesis, Genetic / Q000502:physiology*; D005319:Fetal Hemoglobin / Q000378:metabolism*; D005914:Globins / Q000235:genetics*; D006367:HeLa Cells; D051548:Histone Acetyltransferases / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D020014:K562 Cells
D002087:Butyrates; D006657:Histones; D005914:Globins; D005319:Fetal Hemoglobin; D051548:Histone Acetyltransferases