title: Efficient protein expression from the endogenous RNA polymerase I promoter using a human ribosomal DNA targeting vector.
abstract: Vector systems to deliver, integrate and express therapeutic genes in host cells are essential for gene therapy. In the present study, we investigated a novel vector system for integration and expression of a transgene. In this system, the transgene expression was driven by an endogenous RNA polymerase I (Pol I) promoter after being integrated into the ribosomal DNA (rDNA) locus. Human coagulation factor IX coding sequence (FIX), with an internal ribosome entry sites element at its leader region, was targeted into the 18S rDNA locus via homologous recombination. FIX protein expression, which was under the control of the endogenous Pol I promoter, was found to be similar to that of a moderate Pol II promoter. The average FIX expression level of the rDNA recombinants was additionally enhanced to that from a strong Pol II promoter as a result of elimination of position effects. Our data suggest the possibility of applying this system in gene therapy for hereditary diseases.
authors.affiliation: National Laboratory of Medical Genetics of China, Xiangya Hospital, Central South University, 88 Xiangya Road, Changsha, Hunan 410078, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wen
authors.forename: De Sheng
authors.initials: DS
authors.lastname: Liang
authors.forename: Ling Qian
authors.initials: LQ
authors.lastname: Wu
authors.forename: Fang
authors.initials: F
authors.lastname: Cai
authors.forename: Qian
authors.initials: Q
authors.lastname: Pan
authors.forename: Zhi Gao
authors.initials: ZG
authors.lastname: Long
authors.forename: He Ping
authors.initials: HP
authors.lastname: Dai
authors.forename: Kun
authors.initials: K
authors.lastname: Xia
authors.forename: Jia Hui
authors.initials: JH
authors.lastname: Xia
mesh_terms: D045744:Cell Line, Tumor; D004275:DNA, Ribosomal / Q000235:genetics*; D005164:Factor IX / Q000096:biosynthesis* / Q000235:genetics; D005354:Fibrosarcoma / Q000235:genetics* / Q000378:metabolism*; D018390:Gene Targeting / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D015202:Protein Engineering / Q000379:methods*; D012318:RNA Polymerase I / Q000235:genetics*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D004275:DNA, Ribosomal; D011994:Recombinant Proteins; D005164:Factor IX; D012318:RNA Polymerase I