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

J Gene Med. 2010 Aug;12(8):637-46. doi: 10.1002/jgm.1478.


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.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

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


  • Uroporphyrinogen III Synthetase