Evaluation of metabolic labeling for comparative proteomics in breast cancer cells

Protein expression patterns in the cytosol of MCF-7 cells resistant to adriamycin and to adriamycin/verapamil were compared to that of the parental MCF-7 cell line and to each other using metabolic labeling and two-dimensional gel electrophoresis. Growing the parental MCF-7 cell line in C-13(6)-arginine- and C-13(6)-lysine-enriched medium resulted in C-terminal labeling of all tryptic peptides. The culture media was optimized for the incorporation of these labeled amino acids under conditions that also supported cell growth. Protein abundances were found to be distinctive in MCF-7 cells resistant to adriamycin and those selected for resistance to both adriamycin and verapamil.