College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
Int J Biol Macromol. 2024 Oct;278(Pt 4):134989. doi: 10.1016/j.ijbiomac.2024.134989. Epub 2024 Aug 22.
Cell surface receptors play a key role in intracellular signaling, and their overexpression and activation are among the drivers of multiple diseases. Selective inhibition of cell surface receptors is important for regulating intracellular signaling pathways and cell behavior. Here, we design engineered aptamers to selectively inhibit receptor function. In this strategy, the aptamer specifically recognizing the extracellular structural domain of the EGFR, was conjugated to an adamantane moiety through linking arms of various lengths in order to obtain better performances toward EGFR. These interactions inhibit EGFR dimerization, thereby impeding the activation of downstream signaling pathways. It is shown that the adamantane-modified aptamers exhibit superior inhibition of downstream effector proteins relative to the unmodified aptamers. The optimal inhibitory effect was observed with a linker arm of 40 T-base in length. Notably, the best-performing adamantane-modified aptamer specifically binds to A549 cells with a dissociation constant (22.6 ± 4.5 nM) that is approximately 4-fold lower than that of the parent EGFR aptamer (94.4 ± 21.9 nM). We further combine the use of the adamantane-modified aptamer with that of genistein, a natural isoflavone compound with EGFR tyrosine kinase inhibition activity, to enhance the inhibitory effect on EGFR and its downstream signaling employing a synergistic action. This study is expected to provide a versatile approach for the improvement of existing aptamers obtaining increased selective inhibition of cell surface receptors.
细胞表面受体在细胞内信号转导中发挥着关键作用，其过表达和激活是多种疾病的驱动因素之一。选择性抑制细胞表面受体对于调节细胞内信号通路和细胞行为非常重要。在这里，我们设计了工程化适体来选择性地抑制受体功能。在这种策略中，特异性识别 EGFR 细胞外结构域的适体通过连接臂与金刚烷部分连接，以获得更好的 EGFR 性能。这些相互作用抑制 EGFR 二聚化，从而阻碍下游信号通路的激活。结果表明，与未修饰的适体相比，金刚烷修饰的适体对下游效应蛋白具有更好的抑制作用。在长度为 40 T-碱基的连接臂上观察到最佳抑制效果。值得注意的是，表现最佳的金刚烷修饰适体与 A549 细胞特异性结合，解离常数（22.6 ± 4.5 nM）约为亲本 EGFR 适体（94.4 ± 21.9 nM）的 4 倍。我们进一步将金刚烷修饰适体与天然异黄酮化合物金雀异黄素（genistein）结合使用，利用协同作用增强对 EGFR 及其下游信号的抑制作用。这项研究有望为提高现有适体的选择性抑制细胞表面受体的能力提供一种通用的方法。
