Established of Serum Diagnostic Model for Colorectal Cancer Patients Using MB-WCX and MALDI-TOF MS

Abstract

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.

Keywords

• colorectal cancer
• proteomics
• diagnostic model