Rapid screening of protein profiles of human breast cancer cell lines using non-porous reversed-phase high performance liquid chromatography separation with matrix-assisted laser desorption/ionization time-of-flight mass spectral analysis.

Non-porous reversed-phase (NP-RP) HPLC has been used to rapidly generate protein profiles of whole cell lysates of human breast cancer cell lines. The non-porous packing material used was silica coated with C18, which provided rapid separation with high collection efficiency of proteins from cell lysates. This method was used to study the differences in protein profiles among normal cells and fully malignant cells that share a common genetic background. The highly expressed proteins in each cell type were separated and collected in the liquid state where they were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to obtain the molecular weight of the proteins. The protein fractions were then subjected to tryptic digestion and analyzed by pulsed delay extraction (PDE)-MALDI-TOFMS to obtain the peptide maps. The expressed proteins were identified based upon the molecular weight and peptide map using database-searching procedures. It is shown that key cancer-related proteins can be detected and identified which may be potentially used as biomarkers for cancer detection.