Proteome study of colorectal carcinogenesis

Development of cancer is a complex process involving multiple changes in ge ne expression. To unravel these alterations, a proteome approach aimed at t he identification of qualitative and quantitative changes in protein compos ition, including their post-translational modifications, attracts great att ention. Our study was focused on the identification of proteins whose amoun t is altered in the course of malignant transformation of colon mucosa. Pro teins extracted from tissue specimens or cell lysates were separated by two -dimensional gel electrophoresis (2-DE). Comparative analyses of 2-DE prote in patterns were done using computerized image analysis. Selected proteins exhibiting statistically significant abundance alterations comparing health y and diseased tissues were identified by mass spectrometry. Globally, we h ave found 57 proteins that exhibited either a significant decrease or incre ase in amount in pathological tissues, and 18 of these were annotated by ma ss spectrometry. The alterations in the expression of nine proteins were co mmon for both precancerous and neoplastic tissues suggesting their role in colon tumorigenesis. The epithelial origin of all identified spots was chec ked in two cell lines Caco-2 and DLD-1 originating from well-differentiated and poorly differentiated colon carcinoma, respectively.