Quantitative Cancer Proteomics: Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC) as a Tool for Prostate Cancer Research*□S

Microarrays have been the primary means for large-scale analyses of genes implicated in cancer progression. How-ever, more recently a need has been recognized for in-vestigating cancer development directly at the protein level. In this report, we have applied a comparative pro-teomic technique to the study of metastatic prostate can-cer. This technology, termed stable isotope labeling with amino acids in cell culture (SILAC), has recently gained popularity for its ability to compare the expression levels of hundreds of proteins in a single experiment. SILAC makes use of 12C- and 13C-labeled amino acids added to the growth media of separately cultured cell lines, giving rise to cells containing either “light ” or “heavy ” proteins, respectively. Upon mixing lysates collected from these cells, proteins can be identified by tandem mass spec