NSF Nanoscale Science and Engineering Center, Division of Pharmaceutics, College of Pharmacy, Department of Chemical and Biomolecular Engineering, The Comprehensive Cancer Center, and Division of Hematology and Oncology, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA.
Mol Pharm. 2010 Feb 1;7(1):196-206. doi: 10.1021/mp900205r.
Therapeutic use of oligodeoxynucleotides (ODNs) that hybridize to and downregulate target mRNAs encoding proteins that contribute to malignant transformation has a sound rationale, but has had an overall limited clinical success in cancer due to insufficient intracellular delivery. Here we report a development of formulations capable of promoting targeted delivery and enhanced pharmacologic activity of ODNs in acute myeloid leukemia (AML) cell lines and patient primary cells. In this study, transferrin (Tf) conjugated pH-sensitive lipopolyplex nanoparticles (LPs) were prepared to deliver GTI-2040, an antisense ODN against the R2 subunit of ribonucleotide reductase that has been shown to contribute to chemoresistance in AML. LPs had an average particle size around 110 nm and a moderately positive zeta potential at approximately 10 mV. The ODN encapsulation efficiency of LPs was >90%. These nanoparticles could release ODNs at acidic endosomal pH and facilitate the cytoplasmic delivery of ODNs after endocytosis. In addition, Tf-mediated targeted delivery of GTI-2040 was achieved. R2 downregulation at both mRNA and protein levels was improved by 8-fold in Kasumi-1 cells and 2- to 20-fold in AML patient primary cells treated with GTI-2040-Tf-LPs, compared to free GTI-2040 treatment. Moreover, Tf-LPs were more effective than nontargeted LPs, with 10 to 100% improvement at various concentrations in Kasumi-1 cells and an average of 45% improvement at 3 microM concentration in AML patient primary cells. Treatment with 1 microM GTI-2040-Tf-LPs sensitized AML cells to the chemotherapy agent cytarabine, by decreasing its IC(50) value from 47.69 nM to 9.05 nM. This study suggests that the combination of pH sensitive LP formulation and Tf mediated targeting is a promising strategy for antisense ODN delivery in leukemia therapy.
寡脱氧核苷酸（ODN）的治疗用途是与编码导致恶性转化的蛋白质的靶 mRNA 杂交并下调其表达，这具有合理的理论基础，但由于细胞内递呈不足，在癌症中的总体临床疗效有限。在这里，我们报告了一种能够促进靶向递呈和增强急性髓系白血病（AML）细胞系和患者原代细胞中 ODN 药效学活性的制剂的开发。在这项研究中，转铁蛋白（Tf）偶联 pH 敏感的脂多聚物纳米粒（LPs）被制备用于递送 GTI-2040，这是一种针对核昔酸还原酶 R2 亚基的反义 ODN，已被证明有助于 AML 的化疗耐药性。LPs 的平均粒径约为 110nm，zeta 电位约为 10mV，呈中度正电性。LPs 的 ODN 包封效率大于 90%。这些纳米粒可以在酸性内涵体 pH 下释放 ODN，并在细胞内吞作用后促进 ODN 的细胞质递呈。此外，实现了 Tf 介导的靶向递呈 GTI-2040。与游离 GTI-2040 处理相比，Kasumi-1 细胞中 R2 的 mRNA 和蛋白水平下调分别提高了 8 倍，AML 患者原代细胞中提高了 2-20 倍。此外，Tf-LPs 比非靶向 LPs 更有效，在各种浓度下对 Kasumi-1 细胞的有效率提高了 10-100%，在 AML 患者原代细胞中的平均有效率提高了 45%，浓度为 3uM。用 1uM 的 GTI-2040-Tf-LPs 处理可降低阿糖胞昔的 IC50 值（从 47.69nM 降至 9.05nM），从而使 AML 细胞对化疗药物阿糖胞昔敏感。这项研究表明，pH 敏感 LP 制剂与 Tf 介导的靶向相结合是白血病治疗中反义 ODN 递呈的一种很有前途的策略。
