Biochemistry,：转座子睡美人系统－基因治疗新技术
生物谷报道：美国明尼苏达州的科研人员报道说，睡美人tranposon（Sleeping Beauty tranposon，SB-Tn）系统——一种能够避免病毒转移基因技术缺陷的基因治疗技术，在实验室中能够矫正导致镰状细胞贫血病（SCD）的基因缺陷。
在这项发表在6月12日的ACS' Biochemistry的研究中，Clifford J. Steer和同事指出，病毒作为传递载体引发了多种安全关注。
在SCD中，编码β-球蛋白的基因的一种突变导致血色素异常，使红细胞变成镰刀形。由于对病毒载体的潜在风险和其他问题的逐渐关注，使病毒载体用于基因治疗遇到越来越多的障碍。
利用实验室培养的细胞，研究人员证实SB-Tn系统可以将正常的β-球蛋白基因传递到细胞中。这个系统是一种鱼基因，该基因在沉睡了1500万年后于1997年被其他研究人员再次唤醒。该转座子系统能够满足基因治疗的关键要求。
细胞摄入由SB-Tn技术传递的基因，然后这些基因以长期稳定的状态制造正常的β球蛋白。而且，这些基因能够被遗传，随着细胞增殖而传递下去。
研究人员之所以将这种“睡美人”定义成一个转座子或跳跃基因，是因为它能够从一段DNA上的一个位置跳跃到另外的位置。
原始出处:
Biochemistry,
Web Release Date: May 18,
Erythroid-Specific Expression of 
-Globin by the Sleeping Beauty Transposon for Sickle Cell Disease
and
Department of Medicine and Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, Minnesota 55455
Received November 28, 2006
Revised Manuscript Received February 22, 2007
Abstract:
Sickle cell disease (SCD) results predominately from a single monogenic mutation that affects thousands of individuals worldwide. Gene therapy approaches have focused on using viral vectors to transfer wild-type - or 
-globin transgenes into hematopoietic stem cells for long-term expression of the recombinant globins. In this study, we investigated the use of a novel nonviral vector system, the Sleeping Beauty (SB) transposon (Tn) to insert a wild-type -globin expression cassette into the human genome for sustained expression of -globin. We initially constructed a -globin expression vector composed of the hybrid cytomegalovirus (CMV) enhancer chicken -actin promoter (CAGGS) and full-length -globin cDNA, as well as truncated forms lacking either the 3' or 3' and 5' untranslated regions (UTRs), to optimize expression of -globin. -Globin with its 5' UTR was efficiently expressed from its cDNA in K-562 cells induced with hemin. However, expression was constitutive and not erythroid-specific. We then constructed cis SB-Tn--globin plasmids using a minimal -globin gene driven by hybrid promoter IHK (human ALAS2 intron 8 erythroid-specific enhancer, HS40 core element from human 
LCR, ankyrin-1 promoter), IHp (human ALAS2 intron 8 erythroid-specific enhancer, HS40 core element from human LCR, -globin promoter), or HS3p (HS3 core element from human LCR, -globin promoter) to establish erythroid-specific expression of -globin. Stable genomic insertion of the minimal gene and expression of the -globin transgene for >5 months at a level comparable to that of the endogenous -globin gene were achieved using a SB-Tn -globin cis construct. Interestingly, erythroid-specific expression of -globin driven by IHK was regulated primarily at the translational level, in contrast to post-transcriptional regulation in non-erythroid cells. The SB-Tn system is a promising nonviral vector for efficient genomic insertion conferring stable, persistent erythroid-specific expression of -globin.
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