[Colorectal cancer 2D-proteomics: identification of altered protein expression]

Modern proteomic techniques make it possible to identify numerous changes in protein expression in tumor in comparison to normal tissues. Despite the wide application of proteomics in current studies, identification of proteins with stable concentration differences in normal and cancer cells remains rather difficult. The current study was directed to the search of new potential protein colorectal cancer markers using comparative proteomics of protein extracts obtained from primary tumors and adjacent normal tissues. This widespread neoplasm is characterized by lack of evident symptoms at early stages of cancerogenesis. It is highly important to develop fast and sensitive methods of molecular diagnostics. We studied paired cancerous and normal clinical tissue samples from 11 patients with colorectal adenocarcinomas by comparative 2-D PAGE and MALDI-TOF mass-spectrometry identification. Sixteen proteins with stable differential expression were selected and identified, including 13 overexpressed and 3 downregulated proteins. In summary, we describe the discovery overexpression of GPD1 and RRBP1 proteins and lack of expression for HNRNPH1 and SERPINB6 proteins which are new candidate biomarkers of colon cancer.