Quantitative proteomic analysis of primary prostate cancer tissue specimens

Currently, comprehensive and quantitative proteomic analysis of human prostate cancer tissue specimens remains scarce, hindering the identification of protein complexes and pathways deregulated in prostate cancer. In this study, we applied TMT-SPS-MS3-based quantitative proteomics to analzye 9 normal controls, 9 low-grade prostate cancer, and 9 high-grade prostate cancer. About 3,600 proteins were quantified across all the 27 prostate specimens. Statistical analysis identified 651 proteins that are differentially expressed in high-grade prostate cancer and normal prostate. Pathway enrichment analysis revealed that the LXR/RXR activation and integrin signaling pathways are substantially downregulated in high-grade prostate cancer, compared with normal prostate cancer. In addition, protein complex analysis suggested that mitochondrial ribosomes and ribosome-biogenesis complexes are significnatly overexpressed, whereas the cholesterol effluex and focal adhesion comlexes are significantly downregulated in high-grade prostate cancer, compared with normal controls. Furthermore, differential correlation analysis indicated that the spliceosome machinery might be more active in low-grade prostate cancer, compared with normal controls. The results are expected to shed light on the molecular mechnanisms underlying the development and progression of primary prostate cancer in human patients.