Increased gene expression by cationic liposomes (TFL-3) in lung metastases following intravenous injection
Increased gene expression by cationic liposomes (TFL-3) in lung metastases following intravenous injection
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DOI：
10.1248/bpb.28.701
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发表时间：
2005-04-01
影响因子：
2
通讯作者：
Kiwada, H
中科院分区：
文献类型：
--
作者：
Li, WH;Ishida, T;Kiwada, H
我们最近表明，大小，而不是表面电荷，是体外脂质转染效率的pDNA/TFL-3复合物（lipoplex）的主要决定因素，即使在血清的存在下。在这项研究中，作为与血清蛋白相互作用的结果，脂质复合物的大小对体外脂质转染的影响和这与体内脂质转染的关系在鼠肺转移模型中进行了检查。如前所述，pDNA与脂质的比率（P/L比率）影响脂质复合物的大小和ζ电位。体外研究还表明，B16 BL 6细胞中的转基因表达在很大程度上取决于脂质复合物的大小，无论是在不存在或存在（50%（v/v））血清的情况下。体内脂质转染实验表明，肺中的主要基因表达仅发生在荷瘤小鼠中，而不是在正常小鼠中。基于体外研究，在血清（50%（v/v））存在下，该肿瘤相关基因表达与lipoplex大小无关，表明由于与血流中血清蛋白相互作用而导致的大小变化在全身注射的情况下可能不起重要作用。此外，肺转移瘤中基因的有效表达与肺转移的进展无关。荧光显微镜下观察到荷瘤肺中区域特异性基因表达，这在很大程度上取决于脂质复合物的P/L比。虽然区域特异性转基因表达的潜在机制尚不清楚，但它可能与脂质复合物与肿瘤细胞、血管生成下的血管内皮细胞和肺中的正常细胞的相互作用有关。证明了TFL-3对于将pDNA靶向递送至肺和肿瘤相关的脂质转染是有用的效用的可能性。这一结果表明，肺转移瘤中的区域特异性基因表达可以通过控制lipoplex的理化性质，即P/L比来实现。
We recently showed that size, not surface charge, is a major determinant of the in vitro lipofection efficiency of pDNA/TFL-3 complex (lipoplex), even in the presence of serum. In this study, the effect of lipoplex size as a result of interaction with serum proteins on in vitro lipofection and the relationship of this with in vivo lipofection was examined in a murine lung metastasis model. As previously described, the pDNA to lipid ratio (P/L ratio) affected both the size and zeta potential of the lipoplex. In vitro studies also indicated that transgene expression in B16BL6 cells was largely dependent on the size of the lipoplex, both in the absence or presence (50% (v/v)) of serum. An in vivo lipofection experiment showed that predominant gene expression in lungs occurred only in tumor-bearing mice, not in normal mice. Based on the in vitro study, this tumor-related gene expression was not related to lipoplex size in the presence of serum (50% (v/v)), suggesting that the size alteration, as the result of interactions with serum proteins in the blood stream may not play an important role in the case of systemic injections. In addition, the efficient gene expression in tumor-bearing lung was not related to the progression of lung metastases. The area-specific gene expression in tumor-bearing lungs, which was largely dependent on the P/L ratio of the lipoplexes, was observed by fluorescent microscopy. Although the underlying mechanism for the area-specific transgene expression is not clear, it may be related to the interaction of lipoplexes with tumor cells, vascular enclothelial cells under angiogenesis and normal cells in the lungs. The possibility that TFL-3 is a useful utility to the targeted delivery of pDNA to lungs and tumor-related lipofection is demonstrated. This result suggests that area-specific gene expression in lung metastases may be achieved by controlling the physicochemical properties of the lipoplex, i.e. the P/L ratio.