title: MAR characteristic motifs mediate episomal vector in CHO cells.
abstract: An ideal gene therapy vector should enable persistent transgene expression without limitations in safety and reproducibility. Recent researches' insight into the ability of chromosomal matrix attachment regions (MARs) to mediate episomal maintenance of genetic elements allowed the development of a circular episomal vector. Although a MAR-mediated engineered vector has been developed, little is known on which motifs of MAR confer this function during interaction with the host genome. Here, we report an artificially synthesized DNA fragment containing only characteristic motif sequences that served as an alternative to human beta-interferon matrix attachment region sequence. The potential of the vector to mediate gene transfer in CHO cells was investigated. The short synthetic MAR motifs were found to mediate episomal vector at a low copy number for many generations without integration into the host genome. Higher transgene expression was maintained for at least 4 months. In addition, MAR was maintained episomally and conferred sustained EGFP expression even in nonselective CHO cells. All the results demonstrated that MAR characteristic sequence-based vector can function as stable episomes in CHO cells, supporting long-term and effective transgene expression.
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China; State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Life Science and Technology, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Zhaoxi
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China. Electronic address: wtianyuncn@126.com.
authors.forename: Tianyun
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Dong
authors.affiliation: Department of Life Science and Technology, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Changqin
authors.initials: C
authors.lastname: Jing
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Xianjun
authors.initials: X
authors.lastname: Yang
mesh_terms: D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D003412:Cricetulus; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D045170:Matrix Attachment Regions / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*
keywords: Episomal vector; MAR characteristic components; Persistent high expression; S/MAR