Objective Serum protein expression profiling was examined using magnetic bead-based matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-MS) to establish a serum proteomic diagnostic model for colorectal cancer.
Methods Serum samples of normal control (CRTL, n=72), colorectal cancer (pre-operation CRC, n=72, and post-operation CRC, n=72) were collected from 2014-9-1 to 2016-9-1. Peptidome of all samples were extracted by magnetic-bead-based weak cation-exchange chromatography (MB-WCX) and detected by calibrated Autoflex Ⅲ MALDI-TOF-MS. Peptide mass fingerprinting were analyzed by ClinProtTools 2.0 software, and the differentially-expressioned peptides were further identified using LC-ESI-MS/MS.
Results MALDI-TOF-MS identified 80 peaks (m/z), in which 12 peaks showed significant differences among CRTL, pre-operation and post-operation CRC patients (P < 0.01). 9 peaks were up-regulated and 3 peaks were down-regulated in CRC compared with CRTL, and these peaks showed a tendency to CRTL after operation. Based on the GA model, CRC patients could be discriminated from CRTL with 99.31% sensitivity and 96.49% specificity. Moreover, 3 peaks (m/z: 2663.36, m/z: 4793.17 and m/z: 5343.48) of the GA model were identified as protein FGA, SETD7 and MUC5AC respectively.
Conclusion The serum proteomic diagnostic model could accurately distinguish between CRTL and CRC, but it needs further research.
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