DNA transposon-based vectors are effective nonviral tools for gene therapy and genetic engineering of cells. However, promoter DNA methylation and a near-random integration profile, which can result in transgene integration into heterochromatin, renders such vectors vulnerable to transcriptional repression. Therefore, to secure persistent transgene expression it may be necessary to protect transposon-embedded transgenes with anti-transcriptional silencing elements. We compare four different protective strategies in CHO-K1 cells. Our findings show robust protection from silencing of transgene cassettes mediated by the ubiquitous chromatin-opening element (UCOE) derived from the HNRPA2B1-CBX3 locus. Using a bioinformatic approach, we define a shorter HNRPA2B1-CBX3 UCOE core fragment and demonstrate that this can robustly maintain transgene expression after extended passaging of CHO-K1 cells carrying DNA transposon vectors equipped with this protective feature. Our findings contribute to the understanding of the mechanism of HNRPA2B1-CBX3 UCOE-based transgene protection and support the use of a correctly oriented core fragment of this UCOE for DNA transposon vector-based production of recombinant proteins in CHO-K1 cells.

中文翻译：

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含有HNRPA2B1-CBX3普遍存在的染色质开放元件（UCOE）核心片段的睡眠美容DNA转座子的持续转基因表达

基于DNA转座子的载体是用于细胞基因治疗和基因工程的有效非病毒工具。然而，启动子DNA甲基化和近乎随机的整合谱可导致转基因整合入异染色质，使此类载体易受转录抑制。因此，为了确保持久的转基因表达，可能有必要用抗转录沉默元件保护转座子包埋的转基因。我们在CHO-K1细胞中比较了四种不同的保护策略。我们的发现显示出强大的保护作用，可防止源自HNRPA2B1-CBX3基因座的普遍存在的染色质开放元件（UCOE）介导的转基因盒沉默。使用生物信息学方法，我们定义了一个较短的HNRPA2B1-CBX3 UCOE核心片段，并证明了在携带带有这种保护功能的DNA转座子载体的CHO-K1细胞延长传代后，它可以稳定地维持转基因表达。我们的发现有助于对基于HNRPA2B1-CBX3 UCOE的转基因保护机制的理解，并支持此UCOE的正确定向核心片段用于在CHO-K1细胞中基于DNA转座子载体的重组蛋白生产。