Lee R, Boasquevisque C H, Boglione M M, Hiratsuka M, Scheule R K, Cooper J D, Patterson G A
Division of Cardiothoracic Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Ann Thorac Surg. 1998 Sep;66(3):903-7. doi: 10.1016/s0003-4975(98)00603-1.
Gene therapy is a promising strategy for the treatment of inoperable pulmonary tumors and rejection after lung transplantation. However, unlike ex vivo administration, intravenous in vivo transfection lacks organ specificity and has a limited duration of expression. The objectives of this study were to limit transfection to a single lung and to increase the duration of gene expression in vivo.
Sixteen male Fisher rats were anesthetized and divided into two groups. Animals in group I (n = 7) received an intrajugular administration of 1,320 microg of chloramphenicol acetyl transferase (CAT) complementary DNA complexed with cationic liposomes. Animals in group II (n = 9) received 660 microg of CAT complementary DNA complexed with cationic liposomes into the pulmonary artery of an isolated left lung over 10 minutes. After 40 minutes of incubation, the lung was flushed with 10 mL of normal saline solution, and the perfusate was suctioned through a left pulmonary venotomy. The circulation to the left lung was then restored. After 48 hours, the animals were divided into subgroups (a and b) and CAT activity was assessed in the lungs, hearts, livers, and kidneys of groups Ia (n = 3) and IIa (n = 5). After 21 days, CAT activity was assessed in the left lungs of groups Ib (n = 4) and IIb (n = 4).
After 48 hours, animals that had received intravenous administration of CAT cDNA showed strong expression in the lungs and hearts and negligible expression in the livers and kidneys. In contrast, animals in group IIa, which had received isolated left lung perfusion of CAT cDNA showed expression only in the left lung. After 21 days, the left lungs of animals in group Ib, which had received intravenous administration of CAT complementary DNA, showed no CAT expression, but the left lungs of animals in group IIb, which had received isolated left lung perfusion of CAT complementary DNA, exhibited strong CAT expression.
Compared with intravenous administration, isolated lung liposome-mediated gene transfer provides prolonged organ-specific gene expression. This provides a useful model to study the effects of gene therapy on pulmonary tumors, which may have further application when gene therapy is used in clinical practice.
基因治疗是治疗无法手术的肺部肿瘤和肺移植后排斥反应的一种有前景的策略。然而，与体外给药不同，静脉内体内转染缺乏器官特异性且表达持续时间有限。本研究的目的是将转染限制在单肺，并增加体内基因表达的持续时间。
16只雄性Fisher大鼠麻醉后分为两组。第一组（n = 7）动物经颈静脉给予1320微克与阳离子脂质体复合的氯霉素乙酰转移酶（CAT）互补DNA。第二组（n = 9）动物在10分钟内将660微克与阳离子脂质体复合的CAT互补DNA注入分离出的左肺的肺动脉。孵育40分钟后，用10毫升生理盐水冲洗肺，并通过左肺静脉切开术抽吸灌注液。然后恢复左肺的血液循环。48小时后，将动物分为亚组（a和b），并评估第一亚组（Ia，n = 3）和第二亚组（IIa，n = 5）的肺、心脏、肝脏和肾脏中的CAT活性。21天后，评估第一亚组（Ib，n = 4）和第二亚组（IIb，n = 4）左肺中的CAT活性。
48小时后，静脉注射CAT cDNA的动物在肺和心脏中显示出强表达，而在肝脏和肾脏中表达可忽略不计。相比之下，接受CAT cDNA分离左肺灌注的第二亚组（IIa）动物仅在左肺中显示表达。21天后，接受静脉注射CAT互补DNA的第一亚组（Ib）动物的左肺未显示CAT表达，但接受CAT互补DNA分离左肺灌注的第二亚组（IIb）动物的左肺表现出强CAT表达。
与静脉注射相比，分离肺脂质体介导的基因转移可提供延长的器官特异性基因表达。这为研究基因治疗对肺部肿瘤的影响提供了一个有用的模型，当基因治疗应用于临床实践时可能会有进一步的应用。
