Analysis of proteomic spectra in serum from patients with colorectal cancer by SELDI-TOF mass spectrometry

AIM: To study the changes of proteomic spectra in serum from patients with colorectal cancer in order to detect the specific protein markers. METHODS: Proteomic spectra of sixty-four serum samples from patients with colorectal cancer (preoperation and postoperation) and forty from normal individuals were generated by IMAC-Cu proteinchip array and SELDI-TOF mass spectroscopy (surface enhanced laser desorption/ionization-time of flight). The discriminatory profiling between cancer and normal samples was analyzed by Biomarker Wizard software and Biomarker Pattern softwar. RESULTS: Nineteen differentially expressed proteins in serum were screened by analysis of protemic spectra of preoperative patients and normal individuals. Five proteins (5972.67 D, 5927.21 D, 6113.48 D, 5908.55 D and 4292.51 D) were obtained for making up marker patterns that was able to class the patients-team and normal-team. Corresponding correct ratio were 97.5% (56/64) and 80% (32/40). The proteins that overexprssed in preoperation were obviously down-regulated when postoperation. CONCLUSION: The preliminary results suggest that classification system will provide a highly accurate and innovative approach for the early diagnosis of colorectal cancer and judgment of prognosis. SELDI-TOF mass spectrometry is a useful tool for the detection and identification of new protein markers in serum.