Comparative Proteomics Analysis of Colorectal Cancer

BACKGROUND AND OBJECTIVE: Protein expression in colon and rectal cancer (CRC) and paired normal tissues was examined by two-dimensional gel electrophoresis (2-DE) to identify differentially expressed proteins. MATERIALS AND METHODS: Five fresh colorectal cancer and paired adjacent normal tissues were obtained and differentially expressed protein spots were determined using PDQuest software, with identification on the basis of MALDI- TOF mass spectra. RESULTS: Compared with normal colorectal mucosa, protein abnormal expression of 65 spots varying more than 1.5 times were found in 2-DE gels from colorectal cancer samples (P<0.05); forty-two proteins were up-regulated and 23 were down-regulated; twelve protein spots were identified using mass spectrometry, of which 8 were up-regulated, including HSPB1 and Annexin A4, while 4 were down-regulated, the results being consistent with Western blot findings. CONCLUSIONS: Two-dimensional electrophoresis reference maps for CRC tissues and adjacent normal mucosa (NMC) were established and 12 differentially expressed proteins were identified. Up-regulated HSPB1 and Annexin A4 may play many important roles in the pathogenesis of colorectal cancer.