OBJECTIVE: To establish a protein expression profile of human normal colonic epithelia. METHODS: Two-dimensional gel electrophoresis (2-DE) was applied to separate the total proteins of 20 human normal colonic epithelial tissues. The expression proteins in the human normal colonic epithelia were identified by both matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and electrospray ionization tandem mass spectrometry (ESI-Q-TOF), and the biological function and subcellular locations of the identified proteins were analyzed by bioinformatics. RESULTS: A 2-DE reference map of human normal colonic epithelium was established. On the 2-DE map, 1020+/-50 protein spots were detected, 204 protein spots representing 162 non-redundant proteins were identified, and 37 proteins had posttranslational modification. The identified proteins were categorized into several protein groups according to their functions or subcellular locations, whose data were available at our website (http://www.xyproteomics.org). CONCLUSION A protein expression profile of human normal colonic epithelia is established for the first time, which provides useful information for investigating the physiological functions and pathologic process of colonic epithelia.
Adult ; Aged ; Colon ; chemistry ; Electrophoresis, Gel, Two-Dimensional ; Epithelium ; chemistry ; Humans ; Male ; Middle Aged ; Peptide Mapping ; Protein Array Analysis ; Proteins ; analysis ; chemistry ; genetics

This study was aimed to investigate the effect of AML1-ETO fusion protein on the anti-apoptotic gene BCL-2 in leukemic cells and to explore its role in leukemogenesis. The apoptotic levels of U937-WT, U937-Mock and U937-A/E1-4 cells were examined by flow cytometry. And cleaved caspase-3 protein expression was detected by Western blot. BCL-2 gene expression both in AML1-ETO-expressing cells or U937 nonexpressing cells and in leukemia cells of AML patients with or without t(8;21) was assessed by quantitative PCR. The chromatin immunoprecipitation (ChIP)-based PCR was used to investigate the direct interaction between the AML1-ETO and BCL-2 promoter in AML1-ETO positive leukemia cell line. The results indicated that in U937-A/E cells but not in U937-WT or U937-Mock cells, apoptotic cells statistically significantly increased, and AML1-ETO expression also significantly enhanced activation of caspase-3. AML1-ETO-expressing cell subclones displayed significantly low levels of BCL-2 mRNA in comparison with the non-transfected U937. In primary bone marrow cells of acute myeloid leukemia containing AML1-ETO, levels of BCL-2 mRNA were markedly lower as compared with other acute myeloid leukemias lacking this translocation. The enriched regions in transfected cells were located within BCL-2 promoter. It is concluded that BCL-2 is the direct target gene of AML1-ETO. AML1-ETO can down-regulate the expression of BCL-2.
Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; Gene Expression Regulation, Leukemic ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RUNX1 Translocation Partner 1 Protein ; U937 Cells