434 NOVEL RENAL CELL CARCINOMA BIOMARKER IDENTIFICATION FROM URINARY EXOSOMES

Abstract

You have accessJournal of UrologyKidney Cancer: Basic Research III1 Apr 2012434 NOVEL RENAL CELL CARCINOMA BIOMARKER IDENTIFICATION FROM URINARY EXOSOMES Todd M. Morgan, Kevin L. Schey, David L. Hachey, Salisha Hill, and Peter E. Clark Todd M. MorganTodd M. Morgan Nashville, TN More articles by this author , Kevin L. ScheyKevin L. Schey Nashville, TN More articles by this author , David L. HacheyDavid L. Hachey Nashville, TN More articles by this author , Salisha HillSalisha Hill Nashville, TN More articles by this author , and Peter E. ClarkPeter E. Clark Nashville, TN More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.501AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Proteomic technologies have shown great promise in the identification of biomarkers, however these efforts in renal cell carcinoma (RCC) have been hampered by technical limitations. We have developed a novel approach utilizing lipid microvesicles, termed exosomes, to circumvent many of the obstacles to urinary biomarker identification. We sought to test whether shotgun proteomics of urinary exosomes can be utilized to identify candidate biomarkers of RCC. METHODS Urine was obtained from 8 patients with clear cell RCC prior to nephrectomy and from 12 patients without malignancy undergoing non-urologic surgery. Exosomes were isolated by ultracentrifugation and proteins were analyzed by multidimensional protein identification technology (MudPIT). Differentially expressed peptides were identified by quasi-likelihood Poisson regression modeling using a false discovery rate <0.05. As an exploratory and validation measure, angiotensin converting enzyme (ACE) immunohistochemistry (IHC) was performed on a tissue microarray containing 139 matched RCC and normal cores. RESULTS An average of ∼1,500 proteins were identified in each of the 22 patient samples. There were 14 differentially expressed proteins identified with a p<0.05 between RCC and control samples, as well as 2 additional proteins that approached statistical significance. Six were upregulated in RCC and 10 were downregulated compared to controls. In order to validate our approach, we focused our attention on those that have been previously proposed as cancer biomarkers (Table). Since ACE has been associated with RCC in a prior study, we tested this by IHC. Consistent with the results by MudPIT, we found no expression in 69/70 RCC cores and high expression in 69/69 matched normal cores. Table. Notable differentially expressed proteins in RCC vs. control patients. Protein Gene Description Ratio (RCC:Control) p A8K1D9 PTPN11/SHP2 Protein tyrosine phosphatase, non-receptor type 11 0.15 0.008 B2RD06 ENPP3 Ectonucleotide pyrophosphatase/phosphodiesterase family member 3 0.064 0.029 HIP1R DNASE2 Deoxyribonuclease II 3.50 0.038 Q96CZ9 HIP1R Huntingtin-interacting protein 1-related protein 0.001 0.038 B2R9V9 CDH11 Cadherin 11 type 2, OB-cadherin 10.00 0.045 B2RMS9 DYRK2 Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 2 0.057 0.048 B2RMS9 ITIH4 Inter-alpha (Globulin) inhibitor H4 2.20 0.048 B7Z544 GLS Inter-alpha-trypsin inhibitor heavy chain H4 2.23 0.048 ACE ACE Angiotensin-converting enzyme 0.23 0.073 CONCLUSIONS Rich in cell-specific protein signatures, exosomes are upregulated in several cancers and provide a unique source for urinary biomarkers. We utilized a novel proteomic approach to evaluate urinary exosomes and identified a number of putative biomarkers, suggesting this novel approach may be an effective approach to biomarker discovery in RCC. Further work is ongoing to evaluate the urinary expression of these candidate markers in patients with RCC. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e178 Peer Review Report Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Todd M. Morgan Nashville, TN More articles by this author Kevin L. Schey Nashville, TN More articles by this author David L. Hachey Nashville, TN More articles by this author Salisha Hill Nashville, TN More articles by this author Peter E. Clark Nashville, TN More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...