In vitro and in vivo comparative study of chimeric liver-specific promoters.
Targeting therapeutic genes to the liver is essential to improve gene therapy protocols of hepatic diseases and of some hereditary disorders. Transcriptional targeting can be achieved using liver-specific promoters. In this study we have made chimeric constructs combining promoter and enhancer regions of the albumin, alpha 1-antitrypsin, hepatitis B virus core protein, and hemopexin genes. Tissue specificity, activity, and length of gene expression driven from these chimeric regulatory sequences have been analyzed in cultured cells from hepatic and nonhepatic origin as well as in mice livers and other organs. We have identified a collection of liver-specific promoters whose activities range from twofold to less than 1% of the CMV promoter in human hepatoma cells. We found that the best liver specificity was attained when both enhancer and promoter sequences of hepatic genes were combined. In vivo studies were performed to analyze promoter function during a period of 50 days after gene transfer to the mouse liver. We found that among the various chimeric constructs tested in this work, the alpha1-antitrypsin promoter alone or linked to the albumin or hepatitis B enhancers is the most potent in directing stable gene expression in liver cells.
Kramer
M Gabriela
MG
Division of Hepatology and Gene Therapy, Department of Internal Medicine, School of Medicine, University of Navarra, 31008 Pamplona, Spain. mgkramer@unav.es
Barajas
Miguel
M
Razquin
Nerea
N
Berraondo
Pedro
P
Rodrigo
Manuel
M
Wu
Catherine
C
Qian
Cheng
C
Fortes
Puri
P
Prieto
Jesus
J
D000818:Animals; D015139:Blotting, Southern; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000628:therapy; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000235:genetics; D004247:DNA / Q000008:administration & dosage; D004742:Enhancer Elements, Genetic; D005260:Female; D005786:Gene Expression Regulation; D005809:Genes, Regulator / Q000235:genetics*; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000008:administration & dosage; D006466:Hemopexin / Q000235:genetics; D006512:Hepatitis B Core Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008113:Liver Neoplasms / Q000473:pathology / Q000628:therapy; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics*; D011995:Recombination, Genetic; D000515:alpha 1-Antitrypsin / Q000235:genetics
D006512:Hepatitis B Core Antigens; D011993:Recombinant Fusion Proteins; D000515:alpha 1-Antitrypsin; D004247:DNA; D006466:Hemopexin