A gene therapy approach to regulated delivery of erythropoietin as a function of oxygen tension.
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.
Rinsch
C
C
Gene Therapy Center, Centre Hospitalier Universitaire Vaudois, Lausanne University Medical School, Switzerland.
Régulier
E
E
Déglon
N
N
Dalle
B
B
Beuzard
Y
Y
Aebischer
P
P
D000740:Anemia / Q000628:therapy; D000818:Animals; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics; D004339:Drug Compounding; D004921:Erythropoietin / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D015316:Genetic Therapy / Q000379:methods*; D006651:Histocytochemistry; D000860:Hypoxia / Q000378:metabolism; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D051379:Mice; D008811:Mice, Inbred DBA; D009687:Nuclear Proteins / Q000235:genetics; D010100:Oxygen / Q000097:blood / Q000502:physiology*; D010313:Partial Pressure; D010735:Phosphoglycerate Kinase / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D011994:Recombinant Proteins; D014157:Transcription Factors; D019076:Transgenes
D004268:DNA-Binding Proteins; C497443:Hif1a protein, mouse; C497444:Hif1a protein, rat; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D004921:Erythropoietin; D010735:Phosphoglycerate Kinase; D010100:Oxygen