Development of local drug disposition analysis and delivery methods in human solid tumors

为了建立一种有效和安全的实体瘤体内给药系统的策略，进行了一系列局部给药后的药代动力学研究。在大鼠步行者256组织分离肿瘤制备物中，使用原位单向血管灌注技术研究了第二代反义寡核苷酸的肿瘤内药代动力学。一些第一代寡核苷酸也用于比较。这些寡核苷酸以两种方式直接施用到肿瘤中：恒定动脉输注和直接瘤内注射。结果表明，该寡核苷酸可用于直接局部注射到实体瘤中。另一方面，在携带实体瘤的小鼠中检查裸质粒DNA和基因表达的肿瘤内药代动力学。质粒DNA从注射部位迅速消除，并观察到淋巴转移。将编码荧光素酶基因的裸质粒DNA瘤内注射到皮下接种的小鼠结肠肿瘤中导致显著的基因表达。同时注射一定浓度的聚阴离子可抑制基因的表达，提示细胞对质粒DNA的摄取可能存在一种特殊的机制。这些结果表明，肿瘤组织可能是裸质粒DNA直接基因转移的良好靶点。因此，本研究提供了有用的信息，基因药物，如反义寡核苷酸和质粒DNA在实体瘤中的基本处置特性。

To construct a strategy for developing efficient and safe in vivo drug delivery systems to solid tumors, a series of pharmacokinetic studies following local administration were carried out. The intratumoral pharmacokinetics of a second-generation antisense oligonucleotid were studied in rat Walker 256 tissue-isolated tumor preparations using an in situ single-pass vascular perfusion technique. Some first-generation oligonucleotides were also used for comparison. These oligonucleotides were administrated directly into the tumor in two ways : constant arterial infusion and direct intratumoral injection. The results suggested that the oligonucleotide may be useful for direct local injection into solid tumors. On the other hand, the intratumoral pharmacokinetics of naked plasmid DNA and gene expression were examined in mice bearing solid tumors. Plasmid DNA was rapidly eliminated from the injection site and lymphatic transfer was observed. Intratumoral injection of naked naked plasmid DNA encoding the luciferase gene into subcutaneously inoculated mouse colon tumor resulted in significant gene expression. The gene expression was inhibited when defined polyanions were injected simultaneously, implying the involvement of a specific mechanism in cellular uptake of plasmid DNA These results demonstrated that tumor tissue might be a promising target for direct gene transfer.with naked plasmid DNA. Thus, the present study provides useful information about the basic disposition characteristics of gene drugs, such as antisense oligonucleotides and plasmid DNA in solid tumors.