title: A combined approach for β-thalassemia based on gene therapy-mediated adult hemoglobin (HbA) production and fetal hemoglobin (HbF) induction.
abstract: Gene therapy might fall short in achieving a complete reversion of the β-thalassemic phenotype due to current limitations in vector design and myeloablative regimen. Following gene transfer, all or a large proportion of erythroid cells might express suboptimal levels of β-globin, impairing the therapeutic potential of the treatment. Our aim was to evaluate whether, in absence of complete reversion of the β-globin phenotype upon gene transfer, it is possible to use fetal hemoglobin induction to eliminate the residual α-globin aggregates and achieve normal levels of hemoglobin. Transgenic K562 cell lines and erythroid precursor cells from β(0)39-thalassemia patients were employed. Gene therapy was performed with the lentiviral vector T9W. Induction of fetal hemoglobin was obtained using mithramycin. Levels of mRNA and hemoglobins were determined by qRT-PCR and HPLC. First, we analyzed the effect of mithramycin on K562 transgenic cell lines harboring different copies of a lentiviral vector carrying the human β-globin gene, showing that γ-globin mRNA expression and HbF production can be induced in the presence of high levels of β-globin gene expression and HbA accumulation. We then treated erythroid progenitor cells from β-thalassemic patients with T9W, which expresses the human β-globin gene and mithramycin separately or in combination. When transduction with our lentiviral vector is insufficient to completely eliminate the unpaired α-globin chains, combination of β-globin gene transfer therapy together with fetal hemoglobin induction might be very efficacious to remove the excess of α-globin proteins in thalassemic erythroid progenitor cells.
authors.affiliation: Department of Biochemistry and Molecular Biology, Section of Molecular Biology, University of Ferrara, Ferrara, Italy. gam@unife.it
authors.forename: Cristina
authors.initials: C
authors.lastname: Zuccato
authors.forename: Laura
authors.initials: L
authors.lastname: Breda
authors.forename: Francesca
authors.initials: F
authors.lastname: Salvatori
authors.forename: Giulia
authors.initials: G
authors.lastname: Breveglieri
authors.forename: Sara
authors.initials: S
authors.lastname: Gardenghi
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Bianchi
authors.forename: Eleonora
authors.initials: E
authors.lastname: Brognara
authors.forename: Ilaria
authors.initials: I
authors.lastname: Lampronti
authors.forename: Monica
authors.initials: M
authors.lastname: Borgatti
authors.forename: Stefano
authors.initials: S
authors.lastname: Rivella
authors.forename: Roberto
authors.initials: R
authors.lastname: Gambari
mesh_terms: D000328:Adult; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology / Q000627:therapeutic use; D002478:Cells, Cultured; D003131:Combined Modality Therapy / Q000379:methods; D015672:Erythroid Precursor Cells / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D005319:Fetal Hemoglobin / Q000378:metabolism*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D057809:HEK293 Cells; D006441:Hemoglobin A / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D020014:K562 Cells; D008926:Plicamycin / Q000494:pharmacology / Q000627:therapeutic use*; D055544:beta-Globins / Q000235:genetics; D017086:beta-Thalassemia / Q000235:genetics / Q000378:metabolism / Q000628:therapy*
chemical_list: D000903:Antibiotics, Antineoplastic; D055544:beta-Globins; D006441:Hemoglobin A; D005319:Fetal Hemoglobin; D008926:Plicamycin