| 摘要 |
The present invention concerns the use of fetal globin to supplement defective adult globin genes and gene therapy for the treatment of hemoglobinopathies. In particular, the invention concerns the identification of a developmental stage-specific and tissue-restricted protein NF-E4 that, when associated with the ubiquitous transcription factor CP2 induces fetal globin gene expression from the stage selector element of the proximal gamma -promoter. NF-E4 is expressed in fetal liver, cord blood and bone marrow and in the K562 and HEL cell lines, which constitutively express the fetal globin genes. Enforced expression of NF-E4 in K562 cells or primary erythroid progenitors induces endogenous fetal and embryonic globin gene expression and represses adult globin gene expression. The invention provides the isolated NF-E4 polypeptides (in particular, a 22 kD positive regulator polypeptide and a 14 kD dominant negative truncated polypeptide), nucleic acids encoding these polypeptides, expression vectors, screening assays, and strategies for using NF-E4 to modulate globin expression, e.g., to treat hemoglobinopathies such as beta -thalassemia and sickle-cell anemia. |
