Abstract: OBJECTIVE: Multidrug resistance (MDR) is a major obstacle for effective treatment of tumors. Previous studies of MDR tended to concentrate in a single or a few related genes and their protein products. We focused on the total protein with the method of proteomics. The aim of this study was to investigate differently expressed protein in B-MD-C1 and B-MD-C1 (ADR+/+) cells by proteomic analysis. METHODS：The holoproteins of human carcinoma of endometrium cell lines B-MD-C1 and B-MD-C1 (ADR+/+) were measured by two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). RESULTS：Thirty-five differential proteins were analyzed by peptide mass fingerprinting. The differentially expressed proteins could be divided into six groups based on their functions：molecular chaperones，cystoskeleton proteins(actin-related protein 3，lamin-B1 and tubulin beta chain)，metabolic enzymes (78 kDa glucose-regulated protein，retinal dehydrogenase)，proteins associated with cell cycle (eukaryotic initiation factor 4A-III)，proteins associated with cell proliferation，differentiation and apoptosis (endoplasmic reticulum protein，endoplasmic reticulum protein)，and proteins associated with carbohydrate metabolism (60S acidic ribosomal protein，alpha-enolase). CONCLUSION：These differentially expressed proteins provided some clues to the mechanism of tumor cell resistant to cisplatin，providing the basis of searching for potential target of carcinoma.

Key words: carcinoma of endometrium, comparative proteomics, multidrugs resistance, mass spectrometry analysis