Gene Imaging for Studying Pharmacokinetics of Gene in Vivo at the Real Time

本研究的目的是利用核医学模式，发展基因成像技术，研究mRNA的位置、过表达量和分布情况。人表皮样癌细胞系；KB-31，其mdr1转染细胞系；KB-G2和人甲状腺肿瘤；在体外和体内研究中均使用过表达mdr1的TCO-1。反义DNA （AS）和义DNA (S)在Donald J Hnatowich博士（麻省大学医学院教授）的指导下用Tc-99m标记，然后与KB-31、KB-G2和TCO-1细胞孵育。我们发现as的积累是通过反义机制发生的。将Tc-99m-AS注射到植入小鼠大腿的KB-G2肿瘤中，成功获得基因成像。这是国际上关于反义成像的首次报道。3 . Tc-99m-AS经小鼠静脉注射后特异性积累到KB-G2肿瘤中，但其积累量不足以获得图像。jetPEI、Neophectin和Chariot等转染剂使Tc-99m-AS在KB-G2细胞中的积累量比裸as dna增加了3-8倍，但在体内研究中未观察到这种增加。用我们独特的方法制备了tc -99m-链亲和啶- tat - as纳米颗粒，与裸as dna相比，这些纳米颗粒在细胞内的积累量更高。目前正在进行体内研究。

The aim of this study was to develop the gene imaging for studying where the mRNA is located, how much it overexpress, and how it is distributed by using the nuclear medicine modality. Human epidermoid carcinoma cell line; KB-31, its mdr1 transfected cell line; KB-G2, and human thyroid tumor; TCO-1 which overexpress mdr1, were used throughout the in vitro and in vivo studies.1. Antisense DNA (AS) and sense DNA (S) were labeled with Tc-99m under supervised by Dr. Donald J Hnatowich (Professor, University Massachusetts Medical School), and then they were incubated with KB-31, KB-G2 and TCO-1 cells. We found AS-accumulations occurred by the antisense mechanism.2. Gene imaging was successfully obtained when Tc-99m-AS was injected into the KB-G2 tumor implanted into the thigh of mice. This is the first report of antisense imaging in the world.3. Tc-99m-AS was accumulated specifically into the KB-G2 tumors when it was injected into mice intravenously, but its accumulation was not high enough to get the image.4. Transfecting agents such as jetPEI, Neophectin and Chariot enhanced the accumulation of Tc-99m-AS into KB-G2 cells with 3-8-fold comparing with the naked AS-DNAs, but these increases were not observed significantly in vivo study.5. Nanoparticles consisting of Tc-99m-Streptavidine-TAT-AS were prepared by our unique methods and these showed the higher accumulations into the cell comparing with naked AS-DNAs. In vivo studies are now undergoing.