ABSTRACT
Objective To find early diagnostic biomarkers for colorectal carcinoma by comparing differential(expressing) proteins from colorectal carcinoma and normal colorectal tissues.Methods Colorectal carcinoma tissues and paired normal tumor-adjacent colorectal tissues were collected,and tissue total protein was (extracted);differential proteome profiles were established and analysed by means of immobilized pH(gradient-based) two-dimesional polyacrylamide gel electrophoresis(2D-PAGE) and matrix-assisted laser(desorption)/ionization time of flight mass spectrometry(MALDI-TOF-MS).Results Well-resolved,(reproducible) 2-DE profiles of human colorectal carcinoma tissues and paired normal tumor adjacent colorectal tissues were obtained.For tumor tissue,a total of 1098?28 spots were detected,and for normal tissue,760?45 spots were detected.For normal tissue,The average deviation of spot position was(0.542?(0.12))mm in IEF direction and(0.933?0.098)mm in SDS-PGE direction for tumor tissue.The average deviation of spot position was(0.745?0.130)mm in IEF direction and(1.233?0.272)mm in(SDS-PGE) direction.30 differential expressing proteins were analysed by mass spectrometry and bioinformation,16 of them were well characterized including Apolipoprotein A1(apoA1),calreticulin precursor,glutathione(S-transferase),hepatic fatty acid-binding protein、heat shock protein 27 ect.Conclusions Differential expression proteins can be candidate biomarkers for early diagnosis of colorectal carcinoma;and proteomic technique is valuable for screening the diagnostic biomarkers.