International Joint Cancer Institute, the Second Military Medical University, Shanghai 200433, PR China.
Biomaterials. 2012 Jan;33(1):270-82. doi: 10.1016/j.biomaterials.2011.09.035. Epub 2011 Oct 2.
The development of immunoliposomes for systemic siRNA (small interfering RNA) delivery is highly desired. We reported previously the development of targeted LPD (liposome-polycation-DNA complex) conjugated with anti-EGFR (epidermal growth factor receptor) Fab' (TLPD-FCC) for siRNA delivery, which showed superior gene silencing activity in EGFR-overexpressing breast cancers. However, TLPD-FCC did not achieve satisfactory gene silencing activity in EGFR-overexpressing hepatocellular carcinoma (HCC). In this study, some modifications including increased antibody conjugation efficiency and reduced PEGylation degree were made to TLPD-FCC to increase gene silencing activity in HCC. The resultant optimized liposomes denoted as TLPD-FP75 efficiently bound and delivered to EGFR-overexpressing HCC, resulting in enhanced gene silencing activity compared to untargeted LPD (NTLPD-FP75). Tissue distribution in vivo revealed that the accumulation of TLPD-FP75 was higher than NTLPD-FP75 in orthotopic HCC model of mice. The promoted uptake of TLPD-FP75 in HCC cells was confirmed by confocal microscopy. To investigate the in vivo gene silencing activity, we administered TLPD-FP75 by intravenous injections into mice bearing orthotopic HCC. The results showed TLPD-FP75 potently suppressed luciferase expression, while little silencing was observed in NTLPD-FP75. TLPD-FP75 was demonstrated to possess potent gene silencing activity in HCC and will potentially increase the feasibility of HCC gene therapy.
免疫脂质体系统递送小干扰 RNA（siRNA）的开发是非常需要的。我们之前报道了靶向 LPD（脂质体-聚阳离子-DNA 复合物）与抗表皮生长因子受体（EGFR）Fab'（TLPD-FCC）偶联用于 siRNA 递送的开发，该制剂在 EGFR 过表达的乳腺癌中显示出优异的基因沉默活性。然而，TLPD-FCC 在 EGFR 过表达的肝细胞癌（HCC）中并未达到令人满意的基因沉默活性。在这项研究中，对 TLPD-FCC 进行了一些修饰，包括增加抗体偶联效率和降低 PEG 化程度，以提高 HCC 中的基因沉默活性。所得优化的脂质体表示为 TLPD-FP75，能够有效地结合并递送至 EGFR 过表达的 HCC，与未靶向 LPD（NTLPD-FP75）相比，基因沉默活性增强。体内组织分布显示，TLPD-FP75 在荷瘤原位 HCC 模型小鼠中的积累高于 NTLPD-FP75。通过共聚焦显微镜证实了 TLPD-FP75 在 HCC 细胞中的摄取增加。为了研究体内基因沉默活性，我们通过静脉注射将 TLPD-FP75 递送至荷瘤原位 HCC 小鼠。结果表明，TLPD-FP75 强力抑制了荧光素酶的表达，而 NTLPD-FP75 则几乎没有沉默。TLPD-FP75 被证明在 HCC 中具有强大的基因沉默活性，并且可能会增加 HCC 基因治疗的可行性。
