A Novel Ultrasound system for Epo Gene Therapy

描述（由申请人提供）： 促红细胞生成素（Epo）反应性贫血是慢性肾衰竭、艾滋病/艾滋病毒和接受化疗的癌症患者常见的使人衰弱的并发症。 目前对这种病症的治疗包括重复静脉内或皮下注射重组Epo，尽管很有效，但既昂贵又不方便。 因此，对于这种血清蛋白缺乏症的临床上可应用的基于基因的疗法的开发已经引起了相当大的兴趣。 以前，几个研究小组已经证明，通过单次肌内注射Epo基因，可以在小鼠中稳定产生重组血清Epo，所述Epo基因通过腺病毒载体或通过基于非病毒的电穿孔和基因枪技术递送。 尽管这些最初的成功，这些以前的方法具有实际的缺点（病毒载体的安全性和电穿孔和基因枪的侵入性），这可能会阻止它们广泛的临床应用。 本提案的总体目标是开发一种超声系统，用于在骨骼肌中非侵入性递送编码人促红细胞生成素（hEpo）的质粒DNA，并使用慢性肾衰竭大鼠模型研究超声增强基因治疗的潜力。 提出了三个具体的目标：1）开发一种新的超声系统的基因传递在骨骼肌中，2）在体外优化的声学参数，最有效的基因传递在培养的骨骼肌细胞以最小的损伤，和3）在体内研究超声增强EPO基因治疗慢性肾功能衰竭大鼠模型。 所提出的超声系统的最独特的特征是其能够控制和增强靶组织中的空化，这对于超声介导的骨骼肌基因递送是最关键的。 与其他基于非病毒的基因递送技术相比，超声是非侵入性的、安全的，并且暴露可以在空间和时间上控制。 由于这些独特的优势，超声增强Epo基因治疗的前景是非常有希望的。 除了对慢性肾功能衰竭、HIV感染和癌症导致的贫血患者的潜在益处外，超声介导的基因递送还可以为基于基因的治疗提供可行的选择，其中骨骼肌可以用作微型药房，以产生和分泌具有治疗价值的重组蛋白质进入血流。

DESCRIPTION (provided by applicant): Erythropoietin (Epo)-responsive anemia is a common and debilitating complication in patients of chronic renal failure, AIDS/HIV, and cancer patients undergoing chemotherapy treatment. Current therapy for this condition involves repeated intravenous or subcutaneous injection of recombinant Epo, which, although largely effective, are both expensive and inconvenient. Therefore, there has been considerable interest in the development of clinically applicable gene-based therapies for such serum protein deficiencies. Previously, several groups have demonstrated that stable production of recombinant serum Epo can be produced in mice by a single intramuscular injection of Epo gene delivered either by adenovirus vectors or by non-viral based electroporation and gene gun techniques. Despite of these initial successes, these previous approaches have practical drawbacks (safety for viral vector and invasiveness for electroporation and gene gun) that may prevent them from widespread clinical applications. The overall objective of this proposal is to develop an ultrasound system for non-invasive delivery of plasmid DNA encoding human erythropoietin (hEpo) in skeletal muscle and to investigate the potential of ultrasound-enhanced gene therapy using a rat model with chronic renal failure. Three specific aims are proposed: 1) development of a novel ultrasound system for gene delivery in skeletal muscle, 2) in vitro optimization of acoustic parameters for most efficient gene delivery in cultured skeletal muscle cells with minimal injury, and 3) in vivo investigation of ultrasound-enhanced Epo gene therapy using a rat model with chronic renal failure. The most unique feature of the proposed ultrasound system is its ability to control and enhance cavitation in the target tissue, which is most critical for ultrasound-mediated gene delivery in skeletal muscle. Compared to other non-viral based gene delivery techniques, ultrasound is non-invasive, safe, and the exposure can be controlled both spatially and temporally. Because of these unique advantages, the prospect of ultrasound-enhanced Epo gene therapy is very promising. Besides the potential benefit to patients associated with anemia from chronic renal failure, HIV infection, and cancer, ultrasound-mediated gene delivery may also provide a viable option for gene-based therapies where skeletal muscle can be utilized as miniature pharmacies to produce and secrete recombinant proteins of therapeutic values into the blood stream.