Many diseases result in specific and characteristic changes in the molecular profiles of biological fluids (e.g., urine) and tissues. For cancer, thes changes can be utilized for screening, or as indicators of disease progression or of treatment-associated changes, which can significantly improve the medical outcome. Mass spectrometry (MS), a highly sensitive analytical technology with multiplex analysis capability, has been utilized for detecting changes in protein expression. The sensitivity of MS is inherently dependent on the available analyte concentration and the level of background interference, so specimens such as urine require extensive preparation (i.e., HPLC) prior to the analytical phase. These preparatory processes can result in significant loss of the analyte and are cumbersome, time consuming, not amenable to automation, and more susceptible to contaminations, which significantly impact the overall assay performance such as limit of detection (LOD). To address the need, this project aims to develop a novel biospecimen preparation technology that can process entire available urine samples rapidly (d 30 minutes) by concentrating multiple target analytes (e 102- fold) to enable high throughput multiplex targeted cancer proteomics with significantly lower LOD. The proposed sample preparation utilizes the stimuli-responsive binary reagent system for effective and rapid chromatography without solid phase. The key innovation lies in the combination of stimuli-responsive reagents, including magnetic nanoparticles (mNPs) and polymer-antibody conjugates to maximize the analyte binding efficiency while maintaining effective magnetic separation. This binary reagent system can achieve significantly higher analyte binding then the existing magnetic microparticle by simply applying a larger amount of the antibody conjugates without increasing the mass of magnetic nanoparticles because the antibodies are not attached to the particle surfaces. When a stimulus (e.g., heating) is applied to the solution, both stimuli- responsive reagents, including mNPs and polymer-antibody conjugates, form large aggregates that can be separated using a modest magnetic field to concentrate the bound analytes. We will develop a temperature- responsive separation module for isolating multiple analytes simultaneously in urine. The separation module will be optimized for processing the entire available urine (ca. 200 ml) and interfacing with MS for target protein quantification. Additionally, we will utilize clinical urine samples to evaluate the multiplex capability of the proposed specimen preparation process in conjunction with the MS assay improvement. The success of the project will result in a biospecimen preparation technology that can rapidly (d 30 minutes) process the entire available urine sample to produce multiple concentrated target analytes (e 102-fold) to enable high throughput multiplex target proteomics via MS with significantly lower assay LOD. The technology is applicable to different specimens (e.g., serum) for different analyte panels, which will significantly accelerate cancer proteomics and facilitate high quality cancer diagnosis in the future.
Cancer results in characteristic changes in the molecular profiles of biological fluids (e.g., urine, serum) and tissues. These specific molecular changes can be used for screening, or as indicators of treatment-associated changes, which can significantly improve the medical outcome. In order to detect these changes, this project aims to develop high throughput and robust biospecimen processing technologies that can reduce pre- analytical sample variations to accelerate targeted protein quantification using mass spectrometry.
|Shi, Tujin; Gao, Yuqian; Quek, Sue Ing et al. (2014) A highly sensitive targeted mass spectrometric assay for quantification of AGR2 protein in human urine and serum. J Proteome Res 13:875-82|