NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, D-10589 Berlin, Germany.
J Biol Chem. 2010 Dec 17;285(51):40012-8. doi: 10.1074/jbc.M110.178533. Epub 2010 Oct 20.
High mobility group A1 (HMGA1) proteins belong to a group of architectural transcription factors that are overexpressed in a range of human malignancies, including pancreatic adenocarcinoma. They promote anchorage-independent growth and epithelial-mesenchymal transition and are therefore suggested as potential therapeutic targets. Employing in vitro selection techniques against a chosen fragment of HMGA1, we have generated biostable l-RNA oligonucleotides, so-called Spiegelmers, that specifically bind HMGA1b with low nanomolar affinity. We demonstrate that the best binding Spiegelmers, NOX-A50 and NOX-f33, compete HMGA1b from binding to its natural binding partner, AT-rich double-stranded DNA. We describe a formulation method based on polyplex formation with branched polyethylenimine for efficient delivery of polyethylene glycol-modified Spiegelmers and show improved tissue distribution and persistence in mice. In a xenograft mouse study using the pancreatic cancer cell line PSN-1, subcutaneous administration of 2 mg/kg per day NOX-A50 formulated in polyplexes showed an enhanced delivery of NOX-A50 to the tumor and a significant reduction of tumor volume. Our results demonstrate that intracellular targets can be successfully addressed with a Spiegelmer using polyethylenimine-based delivery and underline the importance of HMGA1 as a therapeutic target in pancreatic cancer.
高迁移率族蛋白 A1(HMGA1)蛋白属于一类结构转录因子,在多种人类恶性肿瘤中过度表达,包括胰腺腺癌。它们促进锚定非依赖性生长和上皮-间充质转化,因此被认为是潜在的治疗靶点。我们采用针对 HMGA1 选定片段的体外选择技术,生成了生物稳定的 l-RNA 寡核苷酸,即所谓的 Spiegelmers,它们以低纳摩尔亲和力特异性结合 HMGA1b。我们证明,最佳结合 Spiegelmers,NOX-A50 和 NOX-f33,可竞争 HMGA1b 与其天然结合伴侣富含 AT 的双链 DNA 的结合。我们描述了一种基于多聚体形成的制剂方法,使用支化聚乙烯亚胺可有效递送至经聚乙二醇修饰的 Spiegelmers,并显示出在小鼠中改善的组织分布和持久性。在使用胰腺癌细胞系 PSN-1 的异种移植小鼠研究中,每天以 2mg/kg 的剂量皮下给予多聚体包封的 NOX-A50,可增强 NOX-A50 向肿瘤的递送,并显著减少肿瘤体积。我们的结果表明,使用基于聚乙烯亚胺的递送可以成功地用 Spiegelmer 靶向细胞内靶标,并强调 HMGA1 作为胰腺癌治疗靶点的重要性。