Development of Magnetic Sensors for MRI Cancer Imaging

描述（由申请人提供）：需要在细胞水平上了解癌症生物学，需要对mRNA和蛋白质进行高通量的综合分析，最好同时进行。该研究的总体目标是扩展申请人的初步实验，以进一步开发，验证和优化能够感知不同类型分子靶标的磁性纳米传感器（磁松弛开关，MRS）。在初步实验中，我们已经表明，当单分散磁性纳米粒子自组装成低聚纳米组件时，通过核磁共振技术可以检测到周围水的自旋-自旋弛豫时间（T2）相应减少。这一基本观察使我们能够测量DNA-DNA，蛋白质-蛋白质，小分子蛋白质相互作用以及酶活性（Nat Biotech 2002; 20,816 -820）。磁松弛开关（MRS）技术非常灵敏，可以使用台式探测器在飞摩尔水平检测目标分子，也可以通过高分辨率MR成像在原子摩尔水平检测目标分子。该分析在溶液中进行，不需要对样品进行分离或纯化。在拟进行的研究中，申请人将利用端粒酶作为癌症相关靶点，追求三个特定目标：(1)设计和优化独立识别端粒酶mrna、-蛋白和酶活性的MRS探针；(2)开发和优化同时筛选端粒酶mrna、-蛋白和-活性的磁共振技术；(3)开发和优化端粒酶MRS探针的内化方案，使其能够在完整细胞内检测目标。假设端粒酶mRNA、端粒酶蛋白和端粒酶活性可以在细胞裂解物和组织提取物中检测，而无需事先纯化或扩增使用开发的MRS技术。该技术的主要生物技术和医学应用在于：1)开发同时询问RNA和蛋白质的技术；2)开发高通量溶液相阵列；3)通过磁共振成像成像分子相互作用的能力。拟议的研究将在多学科环境中进行，综合培训和研究计划将使候选人成为一名独立的癌症研究人员。

DESCRIPTION (provided by applicant): The need to understand cancer biology at a cellular level requires a comprehensive interrogation of mRNA and proteins at high throughput and preferably simultaneously. The overall goal of the proposed research is to expand preliminary experiments by the applicant to further develop, validate and optimize magnetic nanosensors (magnetic relaxation switches, MRS) capable of sensing different types of molecular targets. In preliminary experiments we have shown that when monodisperse magnetic nanoparticles self-assemble into oligomeric nanoassemblies, there is a corresponding decrease in the spin-spin relaxation times (T2) of surrounding water detectable by NMR techniques. This fundamental observation has allowed us to measure DNA-DNA, protein-protein, small molecule protein interactions as well as enzyme activities (Nat Biotech 2002;20, 816-820). The magnetic relaxation switch (MRS) technique is exceedingly sensitive, allowing the detection of target molecules at femtomole levels with bench-top detectors and attomole levels by high-resolution MR imaging. The assay is performed in solution and does not require isolation or purification of the sample. In the proposed research the applicant will pursue three specific aims using telomerase as a cancer related target: (1) design and optimize MRS probes that independently recognize telomerase-mRNA, -protein and enzyme activity; (2) develop and optimize magnetic resonance techniques for simultaneous screening of telomerase-mRNA, -protein and -activity; and (3) develop and optimize internalization protocols for telomerase MRS probes that would allow detection of a target inside intact cells. It is hypothesized that telomerase mRNA, telomerase protein and telomerase activity can be detected in cell lysates and tissue extracts without prior purification or amplification using the developed MRS technique. Major biotechnical and medical applications of the developed technique lie in 1) the development of techniques to simultaneously interrogate RNA and proteins, 2) the development of high-throughput solution phase arrays, and 3) the ability to image molecular interactions by magnetic resonance imaging. The proposed research will be conducted in a multidisciplinary environment and the integrated training and research program will enable the candidate to establish himself as an independent cancer researcher.