School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore637459.
Nanoscale. 2015 Feb 7;7(5):1753-9. doi: 10.1039/c4nr05447d.
MiRNAs are an emerging type of biomarker for diagnostics and prognostics. A reliable sensing strategy that can monitor miRNA expression in living cancer cells would be critical in view of its extensive advantages for fundamental research related to miRNA-associated bioprocesses and biomedical applications. Conventional miRNA sensing methods include northern blot, microarrays and real-time quantitative PCR. However, none of them is able to monitor miRNA levels expressed in living cancer cells in a real-time fashion. Some fluorescennt biosensors developed recently from carbon nanomaterials, such as single-walled carbon nanotubes (SWNTs), graphene oxide (GO), and carbon nanoparticles, have been successfully used for assaying miRNA in vitro; however the preparation processes are often expensive, complicated and time-consuming, which have motivated the research on other substitute and novel materials. Herein we present a novel sensing strategy based on peptide nucleic acid (PNA) probes labeled with fluorophores and conjugated with an NMOF vehicle to monitor multiplexed miRNAs in living cancer cells. The NMOF works as a fluorescence quencher of the labelled PNA that is firmly bound with the metal center. In the presence of a target miRNA, PNA is hybridized and released from the NMOF leading to the recovery of fluorescence. This miRNA sensor not only enables the quantitative and highly specific detection of multiplexed miRNAs in living cancer cells, but it also allows the precise and in situ monitoring of the spatiotemporal changes of miRNA expression.
miRNAs 是一种新兴的生物标志物，可用于诊断和预后。鉴于其在 miRNA 相关生物过程的基础研究和生物医学应用方面具有广泛的优势，因此开发一种能够在活癌细胞中实时监测 miRNA 表达的可靠传感策略至关重要。传统的 miRNA 传感方法包括 northern blot、微阵列和实时定量 PCR。然而，它们都不能实时监测活癌细胞中表达的 miRNA 水平。最近，一些基于碳纳米材料（如单壁碳纳米管 (SWNTs)、氧化石墨烯 (GO) 和碳纳米粒子）的荧光生物传感器已成功用于体外测定 miRNA；然而，制备过程通常昂贵、复杂且耗时，这促使人们研究其他替代和新型材料。在此，我们提出了一种基于肽核酸 (PNA) 探针的新型传感策略，该探针用荧光团标记并与 NMOF 载体偶联，用于监测活癌细胞中的多重 miRNA。NMOF 作为与金属中心牢固结合的标记 PNA 的荧光猝灭剂。在靶 miRNA 的存在下，PNA 杂交并从 NMOF 上释放，从而恢复荧光。这种 miRNA 传感器不仅能够在活癌细胞中定量和高度特异性地检测多重 miRNA，还能够精确原位监测 miRNA 表达的时空变化。
