A gene therapy approach to regulated delivery of erythropoietin as a function of oxygen tension

• Published in: Human gene therapy Vol. 8; no. 16; p. 1881
• Main Authors: Rinsch, C, Régulier, E, Déglon, N, Dalle, B, Beuzard, Y, Aebischer, P
• Format: Journal Article
• Language: English
• Published: United States 01.11.1997
• Subjects: Anemia - therapy; Animals; Cells, Cultured; DNA-Binding Proteins - genetics; Drug Compounding; Erythropoietin - blood; Erythropoietin - genetics; Erythropoietin - metabolism; Gene Expression Regulation; Genetic Therapy - methods; Histocytochemistry; Hypoxia - metabolism; Hypoxia-Inducible Factor 1; Hypoxia-Inducible Factor 1, alpha Subunit; Mice; Mice, Inbred DBA; Nuclear Proteins - genetics; Oxygen - blood; Oxygen - physiology; Partial Pressure; Phosphoglycerate Kinase - genetics; Plasmids - genetics; Promoter Regions, Genetic - genetics; Rats; Rats, Inbred F344; Recombinant Proteins; Transcription Factors; Transgenes
• ISSN: 1043-0342
• DOI: 10.1089/hum.1997.8.16-1881

Current therapy for several forms of anemia involves a weekly regime of multiple subcutaneous injections of recombinant human erythropoietin (hEpo). In an effort to provide a physiologically regulated administration of erythropoietin, we are developing cell lines genetically engineered to release hEpo as a function of oxygen tension. C2C12 cells were transfected using a vector containing the hEpo cDNA driven by the hypoxia-responsive promoter to the murine phosphoglycerate kinase gene. In vitro, these cells showed a threefold increase in hEpo secretion as oxygen levels were shifted from 21% to 1.3% oxygen. To test in vivo response, C2C12-hEpo cells were encapsulated in a microporous membrane and implanted subcutaneously on the dorsal flank of DBA/2J mice. On average, serum hEpo levels in animals exposed to 7% oxygen were two-fold higher than values seen in their control counterparts kept at 21% oxygen. Similar studies employing rats confirmed that hEpo delivery is regulated as a function of oxygen tension. These results suggest the feasibility of developing an oxygen-regulated, encapsulated cell-based system for hEpo delivery.