Study of distinct serum proteomics for the biomarkers discovery in colorectal cancer

To utilize surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) to identify potential biomarkers for diagnosis, preoperative pathological classification, staging, and postoperative prognosis in patients with colorectal cancer (CRC), a total of 152 samples were analyzed in this study, including 53 untreated CRC, 12 colorectal adenoma, 15 healthy volunteers, 30 post-treatment CRC patients with stable disease, and 42 post-treatment CRC with progressive disease. The samples were all analyzed by SELDI-TOF-MS and CM10 ProteinChip technology. The proteomic profiles were validated using a bioinformatics tool based on support vector machine (SVM) and undecimated discrete wavelet transform (UDWT) methods. Seven protein peaks were selected as potential biomarkers for CRC, with a specificity of 85.19% and a sensitivity of 96.23%. Four protein peaks were selected as potential markers for colorectal mucinous adenocarcinoma and non-mucinous adenocarcinoma, with a specificity of 95.12% and sensitivity of 83.33%. In addition, SELDI-based serum profiling discriminated between patients with locally advanced (stage I-II) and regionally advanced (stage III) CRC, and between patients with locoregional (stage I-III) and systemic (stage IV) CRC, with high specificity and sensitivity. A protein peak at 5909 Da was identified as a potential marker for tumor progression and prognosis in CRC. In conclusion, we have demonstrated that ProteinChip technology with SELDI-TOF-MS could provide a novel, non-invasive tool for diagnosis, potential preoperative biomarkers for pathological classification, staging, and postoperative prognostic markers for patients with CRC.