Proteomic identification of chemosensitivity-associated proteins in human colorectal carcinomas / 肿瘤

ABSTRACT

Objective:The study aims to screen chemosensitivity-associated proteins in colorectal carcinoma tissues by using two-dimensional gel electrophoresis (2-DE) and mass spectrometry,then identify some differentially-expressed proteins. Methods:The patients with advanced colorectal carcinoma were confirmed by clinical diagnosis. Fresh carcinoma specimens were collected by biopsy and preserved in liquid N2. The tissues were classified into two groups high sensitivity group (HS) and low sensitivity group (LS) based on drug sensitivity test. The total proteins were extracted and separated by 2-DE. The images were composed, compared, and differentially analyzed to identify the proteins with differential expression in HS and LS groups. Then the differentially-expressed protein spots were incised from the gels and digested by trypsin. The peptide mass fingerprintings (PMF) was acquired after matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and the proteins were identified by data searching in the Mascot database. Two proteins with differential expression were detected by Western blotting.Results:The 2-DE spectrum of HS and LS groups were established. Most protein spots were distributed in the area with pH 4-8 and relative molecular weight of (20-100)×10~3. The average number of the protein spots was 842±23 in HS group and 793±19 in LS group,respectively. The mean matching rate was 90.7%. The number of differentially-expressed dots between HS and LS group was 79.00±13.56. Thirty protein dots were selected for mass spectrum and bioinformatic analysis, and 9 proteins were identified. Conclusion:Colorectal carcinoma with different chemosensitivity had differential protein expression profiles. The differentially expressed proteins may be associated with chemosensitivity and could be used for prediction of chemosensitivity of colorectal carcinoma.