Williams, S, Mustoe, T, Mulcahy, T, Griffiths, M, Simpson, D, Antoniou, M et al.. CpG-island fragments from the HNRPA2B1/CBX3 genomic locus reduce silencing and enhance transgene expression from the hCMV promoter/enhancer in mammalian cells. BMC Biotechnol 5: 17

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BMC Biotechnology (Impact Factor: 2.03). 02/2005; 5(1):17. DOI: 10.1186/1472-6750-5-17
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The hCMV promoter is very commonly used for high level expression of transgenes in mammalian cells, but its utility is hindered by transcriptional silencing. Large genomic fragments incorporating the CpG island region of the HNRPA2B1 locus are resistant to transcriptional silencing.
In this report we describe studies on the use of a novel series of vectors combining the HNRPA2B1 CpG island with the hCMV promoter for expression of transgenes in CHO-K1 cells. We show that the CpG island gives at least twenty-fold increases in the levels of EGFP and EPO observed in pools of transfectants, and that transgene expression levels remain high in such pools for more than 100 generations. These novel vectors also allow facile isolation of clonal CHO-K1 cell lines showing stable, high-level transgene expression.
Vectors incorporating the hnRPA2B1 CpG island give major benefits in transgene expression from the hCMV promoter, including substantial improvements in the level and stability of expression. The utility of these vectors for the improved production of recombinant proteins in CHO cells has been demonstrated.

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Available from: Michael N Antoniou, May 09, 2014
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    • ") and β-thalassemia major (Pawliuk et al., 2001; Persons et al., 2003; Puthenveetil et al., 2004) has been achieved using lentivirus vectors that contain complex regulatory sequences from the LCR region. Recent advances in vector design have improved gene transfer for the hemoglobinopathies such as the ubiquitous chromatin opening element (UCOE) augmented spleen focus forming virus (SFFV) promoter/enhancer which provides lentivirus vectors with a natural tropism for the hematopoietic system (Antoniou et al., 2003; Williams et al., 2005) resulting in reproducible and stable function in BM and all differentiated peripheral hematopoietic cell lineages (Zhang et al., 2007). "
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    Frontiers in Pharmacology 12/2014; 5. DOI:10.3389/fphar.2014.00270 · 3.80 Impact Factor
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    • "The best characterized of these elements is derived from the human HNRPA2B1-CBX3 locus, which comprises dual divergently transcribed promoters driving the expression of the heterogeneous ribonucleoprotein A2/B1(HNRP2AB1) and the chromobox homolog 3(CBX3) housekeeping genes [10]. A 1.5 kb sequence derived from this locus, the A2UCOE, has convincingly been demonstrated to prevent promoter silencing and positional effect variegation in vitro and in in vivo transplantation models when placed upstream of internal promoters in the SIN lentiviral configuration [9] [11] [12]. Furthermore, the A2UCOE was demonstrated to sustain promoter specificity in this situation, thus introducing the element as an elegant choice to achieve reliable long-term transgene expression in gene therapy approaches [13] [14]. "
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    • "The UCOE spanning the dual, divergently transcribed promoters of the human TBP-PSMB1 and HNRPA2B1-CBX3 housekeeping genes was shown to mediate stable expression of transgenes even when integrated in heterochromatic regions and reduce variegation effects.14 In combination with the immediate early promoter/enhancer of the human cytomegalovirus (hCMV), the UCOE derived from the HNRPA2B1-CBX3 locus (A2UCOE) mediates improved levels of expression and proportion of cells expressing the transgene at detectable levels.15 Another cis-acting element we examined is the 5′-HS4 chicken-β-globin insulator (cHS4), which has been considered as an ideal candidate for use in gene transfer applications due to its barrier and enhancer-blocking function.16 "
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