Abstract 637: Quantitative screening of serum protein biomarkers with reverse phase protein arrays

Abstract

Abstract Screening biomarkers in serum samples for different diseases has always been of great interest because it presents an early, reliable, and, most importantly, noninvasive means of diagnosis and prognosis. Reverse phase protein arrays (RPPAs) are a high-throughput platform that can measure single or limited sets of proteins from thousands of patients' samples in parallel. They have been widely used for detection of signaling molecules involved in diseases, especially cancers, and related regulation pathways in cell lysates. However, this approach has been difficult to adapt to serum samples. Previously, we developed a sensitive method called the enhanced protein array to quantitatively measure serum protein levels from large numbers of patient samples. Here, we further refine the technology on several fronts: 1. simplifying the experimental procedure; 2. optimizing multiple parameters to make the assay more robust, including the support matrix, signal reporting method, background control, and antibody validation; and 3. establishing a method for more accurate quantification. Using this technology, we quantitatively measured the expression levels of 6 proteins: AFP, GP73, GDF15, IGFBP2, B2M and OPN from serum samples of 132 hepatocellular carcinoma (HCC) patients and 78 healthy volunteers. We found that all 6 protein expression levels are significantly increased in HCC patients. Statistical and bioinformatical analysis has revealed decent accuracy rates of individual proteins, ranging from 0.617 (B2M) to 0.908 (AFP) as diagnostic biomarkers to distinguish HCC from healthy controls. The combination of these 6 proteins as a specific HCC signature yielded a higher accuracy of 0.923 using LR, LDA, RF and SVM predictive model analyses. Our work reveals promise for using reverse phase protein arrays for biomarker discovery and validation in serum samples. Citation Format: Zhizhou Kuang, Ruochun Huang, Zhiqiang Lv, Jingqiao Lv, Jian Wu, Ruo-Pan Huang. Quantitative screening of serum protein biomarkers with reverse phase protein arrays [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 637.