A comparative study of protein profiling by proteomic analysis in camptothecin-resistant PC3 and camptothecin-sensitive LNCaP human prostate cancer cells

Introduction: Drug resistance is a major obstacle for the therapy of prostate cancer, but its underlying mechanisms are not clarified. To detect some candidate marker proteins which may confer resistance to the anticancer drug camptothecin (CPT; DNA topoisomerase 1 inhibitor), the current study deals with the comparative proteomic profiling of CPT-resistant PC3 and CPT-sensitive LNCaP human prostate cancer cell lines which have been widely employed as a useful model to investigate prostate cancer cells. Materials and Methods: The global profiling of the protein expression was investigated in CPT-resistant PC3 and CPT-sensitive LNCaP prostate cancer cells using 2-dimensional polyacrylamide gel electrophoresis/matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: 144 proteins were identified and their expression levels were compared between the two cell lines. Four proteins-annexin A1, glutathione-S-transferase (GST) pi, galectin (Gal) 3 and glucose-regulated protein 78/Bip - that are suggested to contribute to the development of drug resistance were found to be preferentially or highly expressed in PC3 cells, whereas LNCaP cells did not show detectable expression of annexin A1, GST-pi and Gal-3. Conclusion: The expression level of these proteins and/or mRNAs could be a useful parameter to evaluate the chemotherapy resistance in clinical specimens of prostate cancer. Copyright (c) 2006 S. Karger AG, Basel.