Proteins play essential roles in numerous biological processes and being able to pinpoint functional differences between cell or tissue samples can greatly aid in understanding disease processes and metabolic changes. The PEP technology allows systematic analysis of protein functions within a proteome. Hundreds of functional proteins can be separated and functionally assayed to generate a comprehensive three-dimensional landscape of protein families such as protein kinases, phosphatases, proteinases and oxido-reductases. This information can then be integrated into other genomic and proteomic knowledge bases to provide further insight of important biological processes such as cancer development and aging.

In the PEP technology, complex protein mixtures are first separated by a modified two-dimensional gel electrophoresis process, giving enhanced resolution while still maintaining protein function. This is followed by an efficient protein transfer to a specially designed 1536-well Protein Elution Plate. After further transfer of the samples from the PEP plate to multiple 384-well microplates, functional assays can be performed on each well to generate an enzyme activity profile displayed in 3-D. Protein components of each well can be further characterized by mass spectrometry if desired.

Using the PEP technology, functional biomarker candidates have been identified from lung and breast cancer patient serum. Both qualitative and quantitative differences of metabolic enzymes and proteases were observed when comparing the cancer patient serum and normal serum. Some of the active enzymes were identified by mass spectrometry and validated in selected bioassays. It is believed that this functional proteomics technology provides a unique approach in the discovery of potential cancer biomarkers for diagnostic and prognostic applications.

Citation Format: David L. Wang, Guofeng Fu, Micheal Davies, Xing Wang. Functional biomarker discovery from cancer patient serum with PEP technology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5001. doi:10.1158/1538-7445.AM2017-5001