Modeling of congenital erythropoietic porphyria by RNA interference: a new tool for preclinical gene therapy evaluation.

Abstract

BACKGROUND:

Congenital erythropoietic porphyria (CEP) is a severe autosomal recessive disorder characterized by a deficiency in uroporphyrinogen III synthase (UROS), the fourth enzyme of the heme biosynthetic pathway. We recently demonstrated the definitive cure of a murine model of CEP by lentiviral vector-mediated hematopoietic stem cell (HSC) gene therapy. In the perspective of a gene therapy clinical trial, human cellular models are required to evaluate the therapeutic potential of lentiviral vectors in UROS-deficient cells. However, the rare incidence of the disease makes difficult the availability of HSCs derived from patients.

METHODS:

RNA interference (RNAi) has been used to develop a new human model of the disease from normal cord blood HSCs. Lentivectors were developed for this purpose.

RESULTS:

We were able to down-regulate the level of human UROS in human cell lines and primary hematopoietic cells. A 97% reduction of UROS activity led to spontaneous uroporphyrin accumulation in human erythroid bone marrow cells of transplanted immune-deficient mice, recapitulating the phenotype of cells derived from patients. A strong RNAi-induced UROS inhibition allowed us to test the efficiency of different lentiviral vectors with the aim of selecting a safer vector. Restoration of UROS activity in these small hairpin RNA-transduced CD34(+) cord blood cells by therapeutic lentivectors led to a partial correction of the phenotype in vivo.

CONCLUSIONS:

The RNAi strategy is an interesting new tool for preclinical gene therapy evaluation.

• Authors: Elodie Robert-Richard, Magalie Lalanne, Isabelle Lamrissi-Garcia, Véronique Guyonnet-Duperat, Emmanuel Richard, Vincent Pitard, Fréderic Mazurier, François Moreau-Gaudry, Cécile Ged, Hubert de Verneuil
• Journal: The journal of gene medicine (J Gene Med) Vol. 12 Issue 8 Pg. 637-46 (Aug 2010) ISSN: 1521-2254 [Electronic] England
• PMID: 20586119 (Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2010 John Wiley & Sons, Ltd.

Chemical References

• Uroporphyrinogen III Synthetase

Topics

• Animals
• Disease Models, Animal
• Genetic Therapy (methods)
• Hematopoietic Stem Cells (metabolism)
• Humans
• K562 Cells
• Lentivirus (genetics, metabolism)
• Mice
• Porphyria, Erythropoietic (enzymology, genetics, therapy)
• RNA Interference
• Uroporphyrinogen III Synthetase (genetics, metabolism)