title: Matrix attachment region combinations increase transgene expression in transfected Chinese hamster ovary cells.
abstract: Matrix attachment regions (MARs) are cis-acting DNA elements that can increase transgene expression levels in a CHO cell expression system. To investigate the effects of MAR combinations on transgene expression and the underlying regulatory mechanisms, we generated constructs in which the enhanced green fluorescent protein (eGFP) gene flanked by different combinations of human β-interferon and β-globin MAR (iMAR and gMAR, respectively), which was driven by the cytomegalovirus (CMV) or simian virus (SV) 40 promoter. These were transfected into CHO-K1 cells, which were screened with geneticin; eGFP expression was detected by flow cytometry. The presence of MAR elements increased transfection efficiency and transient and stably expression of eGFP expression under both promoters; the level was higher when the two MARs differed (i.e., iMAR and gMAR) under the CMV but not the SV40 promoter. For the latter, two gMARs showed the highest activity. We also found that MARs increased the ratio of stably transfected positive colonies. These results indicate that combining the CMV promoter with two different MAR elements or the SV40 promoter with two gMARs is effective for inducing high expression level and stability of transgenes.
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China.
authors.forename: Chun-Peng
authors.initials: CP
authors.lastname: Zhao
authors.affiliation: Pharmacy College, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China.
authors.forename: Si-Jia
authors.initials: SJ
authors.lastname: Chen
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China.
authors.forename: Chang-Zheng
authors.initials: CZ
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China.
authors.forename: Jun-He
authors.initials: JH
authors.lastname: Zhang
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China.
authors.forename: Shao-Nan
authors.initials: SN
authors.lastname: Chen
authors.affiliation: Pharmacy College, Xinxiang Medical University, Xinxiang 453003, Henan, China.
authors.forename: Yan-Long
authors.initials: YL
authors.lastname: Jia
authors.affiliation: Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China.
authors.forename: Tian-Yun
authors.initials: TY
authors.lastname: Wang
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016899:Interferon-beta / Q000235:genetics*; D045170:Matrix Attachment Regions; D014162:Transfection / Q000379:methods*; D019076:Transgenes; D055544:beta-Globins / Q000235:genetics*
chemical_list: D055544:beta-Globins; D049452:Green Fluorescent Proteins; D016899:Interferon-beta