Expression profiling of RNAs or proteins has become a promising means to investigate the heterogeneity of histopathologically defined classes of @entity5 . Peptides, representing degradation as well as processing products of proteins offer an even closer insight into cell physiology. Peptides are related to the turnover of cellular proteins and are capable to reflect disease-related changes in homoeostasis of the @entity1 body. Furthermore, peptides derived from @entity5 cells are potentially useful markers in the early detection of @entity5 . In this study, we introduced a method called differential peptide display (DPD) for separating, detecting, and identifying native peptides derived from whole cell extracts. This method is a highly standardized procedure, combining the power of reversed-phase chromatography with mass spectrometry. This technology is suitable to analyze cell lines, various tissue types and @entity1 body fluids. Peptide-based profiling of normal @entity1 mammary epithelial cells (HMEC) and the @entity0 cell line MCF-7 revealed complex peptide patterns comprising of up to 2300 peptides. Most of these peptides were common to both cell lines whereas about 8% differed in their abundance. Several of the differentially expressed peptides were identified as fragments of known proteins such as intermediate filament proteins, thymosins or @entity10815 . Comparing cell lines with @entity5 , overlapping peptide patterns were found between HMEC and a @entity5 (CP) on the one hand and MCF-7 cells and tissue from a @entity513 (DC) on the other hand.

Expression profiling of XXXX cells by differential peptide display.

@entity1 :: ('9606', 'Species') :: ['human'] @entity10815 :: ('1509', 'Gene') :: ['Cathepsin D'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'phylloides tumor', 'cancer', 'native tumors'] @entity513 :: ('MESH:D044584', 'Disease') :: ['invasive ductal carcinoma']
@entity0 :: (MESH:D001943,Disease) :: ['breast cancer']
