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This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Donze, D Articles by Townes, T. Search for Related Content PubMed PubMed Citation Articles by Donze, D Articles by Townes, T. Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  Activation of delta-globin gene expression by erythroid Krupple-like factor: a potential approach for gene therapy of sickle cell disease D Donze, PH Jeancake and TM Townes Department of Biochemistry and Molecular Genetics, Schools of Medicine and Dentistry, University of Alabama at Birmingham. Hemoglobin A2 (HbA2; alpha 2 delta 2) is a powerful inhibitor of HbS (alpha 2 beta 2(3)) polymerization. However, HbA2 levels are normally low in sickle cell patients. We show that a major reason for low delta- globin gene expression is the defective CACCC box at -90 in the delta- globin promoter. When the CACCC box defect in delta is corrected, expression of an HS2 delta /Luciferase reporter is equivalent to HS2 beta /Luciferase. Erythroid Krupple-like factor (EKLF), which binds to the CACCC box of the beta-globin gene and activates high-level expression, does not bind to the normal delta-globin promoter. Our goal is to design a modified EKLF that binds to the defective delta-globin promoter and enhances delta-globin gene expression. To test the feasibility of this strategy, we inserted the beta-globin CACCC box at - 90 of the delta-globin gene promoter to produce an HS2 delta CAC-beta construct and quantitated human delta- and beta-globin mRNA in stably transformed murine erythroleukemia (MEL) cells. delta- Globin mRNA in these cells was 22.0% +/- 9.0% of total human globin mRNA (delta/delta + beta) as compared with 3.0% +/- 1.3% in the HS2 delta-beta control. In a second set of experiments a GAL4 DNA-binding site was inserted at - 90 of the delta-globin gene to produce an HS2 delta GAL4-beta construct. This construct and a GAL4(1-147)/EKLF expression vector were stably transfected into MEL cells. delta-Globin mRNA in these cells was 27.8% +/- 7.1% of total human globin mRNA as compared with 9.9% +/- 2.5% in the HS2 delta GAL4-beta plus GAL4(1-147) control. These results show that delta-globin gene expression can be significantly increased by a modified EKLF. Based on these results, we suggest that modified EKLFs, which contain zinc fingers designed to bind specifically to the defective delta-globin CACCC box, may be useful in gene therapy approaches to increase HbA2 levels and inhibit HbS polymerization. Volume 88, Issue 10, pp. 4051-4057, 11/15/1996 Copyright © 1996 by The American Society of Hematology CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: L.-G. Guy, N. Delvoye, and L. Wall Expression of a Human beta -Globin Transgene in Mice with the CACC Motif and Upstream Sequences Deleted from the Promoter Still Depends on Erythroid Kruppel-like Factor J. Biol. Chem., February 4, 2000; 275(5): 3675 - 3680. [Abstract] [Full Text] [PDF] D. C. Tang, D. Ebb, R. C. Hardison, and G. P. Rodgers Restoration of the CCAAT Box or Insertion of the CACCC Motif Activate delta -Globin Gene Expression Blood, July 1, 1997; 90(1): 421 - 427. [Abstract] [Full Text] [PDF]

	Copyright © 1996 by American Society of Hematology         Online ISSN: 1528-0020