Nanoparticles as probes for imaging mass-cytometry analysis of microRNA

Fluidigm Canada Inc.的核心技术是大规模细胞术，能够实时定量分析单个细胞中的生物标志物。该技术的前提是使用稳定同位素作为标签，通过将标记的细胞引入电感耦合等离子体，并通过飞行时间质谱法分析离子云。基于级联杂交试验的扩增方法用于分析信使RNA和蛋白质；然而，这种方法对短的核酸靶标如microrna无效。因此，具有高特异性和高检测信号的替代信号放大策略是感兴趣的。提出的工作研究dna功能化纳米颗粒，将交联在卵黄蛋白存在的microRNA作为大规模细胞术的探针。将研究纳米颗粒的细胞摄取、交联和随后的排泄或去除。由于每个纳米粒子由数千个原子组成，细胞中纳米粒子数量的变化（由于聚集程度的不同）将导致信号的巨大差异。我们将研究microRNA水平与细胞计数信号的相关性。该项目将扩大大规模细胞术在蛋白质组学和信使RNA之外的应用范围，并进一步加强生物医学研究，研究mirna在各种疾病中的作用，包括癌症、先兆子痫和心血管疾病。

The core technology of Fluidigm Canada Inc. is mass cytometry that enables real-time quantitative analysis ofbiomarkers in single cells. The technology is premised on the use of stable isotopes as labels whereby thetagged cells are introduced into an inductively coupled plasma and the ion cloud is analyzed by time-of-flightmass spectrometry. Amplification methods based on a cascaded hybridization assay are employed for analyzingmessenger RNA and proteins; however, this approach is ineffective for short nucleic acid targets such asmicroRNA. Hence alternative signal amplification strategies with high specificity and high detection signalsare of interest. The proposed work investigates DNA-functionalized nanoparticles that will cross-link in vitroin the presence of microRNA as probes for mass cytometry. The cellular uptake, cross-linking and subsequentexcretion or removal of the nanoparticles will be investigated. With each nanoparticle consisting of thousandsof atoms, variations in the number of nanoparticles in cells as a result of differences in the extent ofaggregation will give large differences in the signal. The correlation between microRNA level and masscytometry signal will be examined. The project will expand the applicability of mass cytometry beyondproteomics and messenger RNA and further empower biomedical research that investigates the role of miRNAin various diseases, including cancer, pre-eclampsia and cardio vascular diseases.