Recent Advances in Capillary Electrophoresis-Based Proteomic Techniques for Biomarker Discovery

Due to the inherent disadvantage of biomarker dilution in complex biological fluids such as serum/plasma, urine, and saliva,investigative studies directed at tissues obtained from the primary site of pathology probably afford the best opportunityfor the discovery of disease biomarkers. Still, the large variation of protein relative abundances with clinical specimensoften exceeds the dynamic range of currently available proteomic techniques. Furthermore, since the sizes of human tissuebiopsies are becoming significantly smaller due to the advent of minimally invasive methods and early detection and treatmentof lesions, a more effective discovery-based proteomic technology is critically needed to enable comprehensive and comparativestudies of protein profiles that will have diagnostic and therapeutic relevance.
This review therefore focuses on the most recent advances in capillary electrophoresis-based single and multidimensional separationscoupled with mass spectrometry for performing comprehensive proteomic analysis of clinical specimens. In addition to proteinidentification, monitoring quantitative changes in protein expression is essential for the discovery of disease-associatedbiomarkers. Comparative proteomics involving measurements in changes of biological pathways or functional processes are furtherexpected to provide relevant markers and networks, molecular relationships among different stages of disease, and molecularmechanisms that drive the progression of disease.