TY - JOUR TI - Secretome analysis reveals upregulated granzyme B in human androgen-repressed prostate cancer cells with mesenchymal and invasive phenotype AU - Bou-Dargham, Mayassa J. AU - Sang, Qing-Xiang Amy T2 - PLOS ONE AB - Epithelial-mesenchymal transition (EMT) is a critical early step in cancer metastasis and a complex process that involves multiple factors. In this study, we used proteomics approaches to investigate the secreted proteins (secretome) of paired human androgen-repressed prostate cancer (ARCaP) cell lines, representing the epithelial (ARCaP-E) and mesenchymal (ARCaP-M) phenotypes. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses showed high levels of proteins involved in bone remodeling and extracellular matrix degradation in the ARCaP-M cells, consistent with the bone metastasis phenotype. Furthermore, LC-MS/MS showed a significantly higher level of the serine protease granzyme B (GZMB) in ARCaP-M conditioned media (CM) compared to that of ARCaP-E. Using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) to detect mRNA and Western blot to detect protein expression, we further demonstrated that the GZMB gene was expressed by ARCaP-M and the protein was secreted extracellularly. ARCaP-M cells with GZMB gene knockdown using small interfering RNA (siRNA) have markedly reduced invasiveness as demonstrated by the Matrigel invasion assay in comparison with the scrambled siRNA negative control. This study reports that GZMB secretion by mesenchymal-like androgen-repressed human prostate cancer cells promotes invasion, suggesting a possible extracellular role for GZMB in addition to its classic role in immune cell-mediated cytotoxicity. DA - 2020/08/07/ PY - 2020 DO - 10.1371/journal.pone.0237222 DP - PLoS Journals VL - 15 IS - 8 SP - e0237222 J2 - PLOS ONE LA - en SN - 1932-6203 UR - https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237222 Y2 - 2020/08/11/22:32:37 KW - Extracellular matrix proteins KW - Gene expression KW - Metastasis KW - Polymerase chain reaction KW - Prostate cancer KW - Secretion KW - Small interfering RNA KW - Transfection ER -