Department of Pathology, the Methodist Hospital and the Methodist Hospital Research Institute, Houston, TX 77030, USA.
J Nanobiotechnology. 2011 Jan 31;9:2. doi: 10.1186/1477-3155-9-2.
Many in vitro studies have demonstrated that silencing of cancerous genes by siRNAs is a potential therapeutic approach for blocking tumor growth. However, siRNAs are not cell type-selective, cannot specifically target tumor cells, and therefore have limited in vivo application for siRNA-mediated gene therapy.
In this study, we tested a functional RNA nanocomplex which exclusively targets and affects human anaplastic large cell lymphoma (ALCL) by taking advantage of the abnormal expression of CD30, a unique surface biomarker, and the anaplastic lymphoma kinase (ALK) gene in lymphoma cells. The nanocomplexes were formulated by incorporating both ALK siRNA and a RNA-based CD30 aptamer probe onto nano-sized polyethyleneimine-citrate carriers. To minimize potential cytotoxicity, the individual components of the nanocomplexes were used at sub-cytotoxic concentrations. Dynamic light scattering showed that formed nanocomplexes were ~140 nm in diameter and remained stable for more than 24 hours in culture medium. Cell binding assays revealed that CD30 aptamer probes selectively targeted nanocomplexes to ALCL cells, and confocal fluorescence microscopy confirmed intracellular delivery of the nanocomplex. Cell transfection analysis showed that nanocomplexes silenced genes in an ALCL cell type-selective fashion. Moreover, exposure of ALCL cells to nanocomplexes carrying both ALK siRNAs and CD30 RNA aptamers specifically silenced ALK gene expression, leading to growth arrest and apoptosis.
Taken together, our findings indicate that this functional RNA nanocomplex is both tumor cell type-selective and cancer gene-specific for ALCL cells.
许多体外研究表明，通过 siRNA 沉默致癌基因是阻止肿瘤生长的一种潜在治疗方法。然而，siRNA 不是细胞类型选择性的，不能特异性地靶向肿瘤细胞，因此在体内应用 siRNA 介导的基因治疗中受到限制。
在这项研究中，我们利用 CD30 这一独特的表面生物标志物在淋巴瘤细胞中的异常表达和间变性淋巴瘤激酶（ALK）基因，测试了一种专门针对并影响人类间变性大细胞淋巴瘤（ALCL）的功能性 RNA 纳米复合物。该纳米复合物通过将 ALK siRNA 和基于 RNA 的 CD30 适体探针整合到纳米级聚亚乙基亚胺-柠檬酸载体上而形成。为了最大限度地降低潜在的细胞毒性，纳米复合物的各个组成部分都以亚细胞毒性浓度使用。动态光散射表明形成的纳米复合物的直径约为 140nm，并在培养基中稳定超过 24 小时。细胞结合实验表明，CD30 适体探针选择性地将纳米复合物靶向 ALCL 细胞，共焦荧光显微镜证实了纳米复合物的细胞内递送。细胞转染分析表明，纳米复合物以 ALCL 细胞类型选择性的方式沉默基因。此外，将携带 ALK siRNAs 和 CD30 RNA 适体的纳米复合物暴露于 ALCL 细胞中，特异性地沉默了 ALK 基因表达，导致细胞生长停滞和凋亡。
综上所述，我们的研究结果表明，这种功能性 RNA 纳米复合物对 ALCL 细胞既具有肿瘤细胞类型选择性，又具有癌症基因特异性。
