You have accessJournal of UrologyProstate Cancer: Basic Research III1 Apr 2012474 PROTEOMIC PROFILING OF EXOSOMES REVEALS NOVEL CANDIDATE MARKERS FOR PROSTATE CANCER Diederick Duijvesz, Mirella S. Vredenbregt-van den Berg, A. Marije Hoogland, Marina A. Gritsenko, Kristin E. Burnum, Theo M. Luider, Geert L.H.J. van Leenders, Ljiljana Pasa-Tolic, Chris H. Bangma, and Guido Jenster Diederick DuijveszDiederick Duijvesz Rotterdam, Netherlands More articles by this author , Mirella S. Vredenbregt-van den BergMirella S. Vredenbregt-van den Berg Rotterdam, Netherlands More articles by this author , A. Marije HooglandA. Marije Hoogland Rotterdam, Netherlands More articles by this author , Marina A. GritsenkoMarina A. Gritsenko Richland, WA More articles by this author , Kristin E. BurnumKristin E. Burnum Richland, WA More articles by this author , Theo M. LuiderTheo M. Luider Rotterdam, Netherlands More articles by this author , Geert L.H.J. van LeendersGeert L.H.J. van Leenders Rotterdam, Netherlands More articles by this author , Ljiljana Pasa-TolicLjiljana Pasa-Tolic Richland, WA More articles by this author , Chris H. BangmaChris H. Bangma Rotterdam, Netherlands More articles by this author , and Guido JensterGuido Jenster Rotterdam, Netherlands More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.543AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Current markers for prostate cancer (PCa), such as PSA, lack specificity. Therefore, novel biomarkers are needed for optimal diagnoses and reliable prognosis. Unfortunately, biomarker discovery from body fluids is often hampered by the abundance of many proteins unrelated to this disease. An attractive alternative way of biomarker discovery is by their selective enrichment. An interesting option is isolation of subcelullar structures such as exosomes. These exosomes are small vesicles (∼100 nm) that are shed in body fluids by all benign and malignant tissues in the body. They contain proteins and RNAs that are highly specific to the tissue from which they are derived and therefore can be considered as ”treasure chests” for disease-specific marker discovery. The aim of this study is to isolate, characterize and profile PCa and non-PCa exosomes in order to identify novel protein biomarkers for PCa. METHODS Exosomes were isolated from two PCa cell lines (PC346C and VCaP) and two non-PCa cell lines (PNT2C2 and VCaP). Isolation was performed by differential ultracentrifugation steps. Electron Microscopy (EM) was used for visualization and morphological characterization. Proteomic analysis was performed by nanoLC-LTQ-Orbitrap mass spectrometry (MS/MS) in triplicate. Protein expression levels were validated by Western blotting. Immunohistochemistry (IHC) and Tissue Micro Arrays (TMA, containing 481 PCa prostatectomy samples) were applied to validate the most promising candidate markers. RESULTS EM confirmed the presence of 100 nm sized vesicles, homogeneous in size and shape within all four samples. MS/MS revealed 263 unique proteins with an enrichment of proteins that are normally located in the cytoplasm or plasma membrane. Unsupervised hierarchical clustering showed grouping of triplicate measurements and of PCa samples. Based on peak intensity values, 9 proteins were significantly higher expressed in both PCa samples as compared to both non-PCa samples. Western blotting confirmed the expression of these proteins in the PCa samples. IHC revealed that FASN and XPO1 expression increases with Gleason score. TMAs showed that cytoplasmic XPO1 staining is strongly correlated with higher Gleason scores and local recurrence (P<0.001). CONCLUSIONS Exosomes derived from PCa contain tissue-specific proteins that are highly of interest as biomarkers for PCa. XPO1 is proposed as novel biomarker for prostate cancer. Prospective patient samples should be evaluated in order to determine the exact clinical value of XPO1 in PCa. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e194 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Diederick Duijvesz Rotterdam, Netherlands More articles by this author Mirella S. Vredenbregt-van den Berg Rotterdam, Netherlands More articles by this author A. Marije Hoogland Rotterdam, Netherlands More articles by this author Marina A. Gritsenko Richland, WA More articles by this author Kristin E. Burnum Richland, WA More articles by this author Theo M. Luider Rotterdam, Netherlands More articles by this author Geert L.H.J. van Leenders Rotterdam, Netherlands More articles by this author Ljiljana Pasa-Tolic Richland, WA More articles by this author Chris H. Bangma Rotterdam, Netherlands More articles by this author Guido Jenster Rotterdam, Netherlands More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...