Selectively expressed RNA molecules as a versatile tool for functionalized cell targeting

Exact targeting of specific mammalian cell types or diseased cells is one of the most urgently needed prerequisites for a new generation of potent pharmaceuticals. Different approaches have been pursued, failing mainly due to a lack of specific surface markers in most cases. Developing a novel RNA-based methodology, we can now ensure exact cell targeting and simultaneously combine this with selective expression of effector proteins, thereby functionalization of the target cell for therapy, diagnostics or cell steering. The specific combination of the molecular properties of antisense technology and mRNA therapy with functional RNA secondary structures based on Nano-DMS-MaP analysis allowed us to develop selectively expressed RNA molecules for medical applications. These so-called seRNAs remain inactive in non-target cells and are only activated by partial degradation to induce translation in preselected cell types of interest. Cell type specificity and type of functionalization are easily adaptable based on a simple modular system. In proof of concept in vitro and in vivo studies we used seRNAs as a highly selective platform technology for powerful cell targeting. We effectively treat breast tumor cell clusters in mixed cell systems and reduce early brain tumors of mice without detectable side effects with just a single treatment. Our data open up new potential avenues for various therapeutic applications. Overall design: Nano-DMS-MaP analysis of seRNA. Selective and non-selective constructs we transfected into cells. RNA structure was determined by Nano-DMS-MaP probing.

精准靶向特定哺乳动物细胞类型或病变细胞，是新一代强效药物研发最亟需的核心前提之一。目前已有多种研发路径被探索，但多数方案最终因缺乏特异性表面标志物而宣告失败。我们开发了一种基于RNA的新型技术方法，如今可实现精准的细胞靶向，同时结合效应蛋白的选择性表达，从而实现靶细胞的功能化，以用于治疗、诊断或细胞操控。将反义技术与mRNA疗法的分子特性，与基于Nano-DMS-MaP分析的功能性RNA二级结构进行特异性结合，我们得以开发出可应用于医学领域的选择性表达RNA分子——这类被称为seRNAs（selectively expressed RNA molecules）的分子在非靶细胞中保持无活性状态，仅通过部分降解被激活，从而在预先选定的目标细胞类型中诱导翻译过程。细胞类型的特异性以及功能化类型，可通过一套简单的模块化系统轻松调整适配。在概念验证的体外与体内研究中，我们将seRNAs作为用于高效细胞靶向的高选择性平台技术进行应用。我们仅通过单次治疗，便有效清除了混合细胞体系中的乳腺肿瘤细胞簇，并缩小了小鼠的早期脑肿瘤，且未检测到任何副作用。我们的研究数据为各类治疗应用开辟了全新的潜在方向。整体实验设计：对seRNAs开展Nano-DMS-MaP分析。将选择性与非选择性构建体转染至细胞中，通过Nano-DMS-MaP探测技术确定RNA结构。