MP39-10 INTRA-TUMOR HETEROGENEITY IN RENAL CELL CARCINOMA: IMPLICATIONS FOR PROTEOMIC ANALYSIS OF RENAL MASS BIOPSIES

You have accessJournal of UrologyKidney Cancer: Basic Research & Pathophysiology I1 Apr 2017MP39-10 INTRA-TUMOR HETEROGENEITY IN RENAL CELL CARCINOMA: IMPLICATIONS FOR PROTEOMIC ANALYSIS OF RENAL MASS BIOPSIES Rustin Massoudi, Christian Hoerner, Thomas Metzner, Jennifer O'Rourke, Rachael Curtis, Laurel Stell, Chiara Sabatti, James Brooks, Alice Fan, and John Leppert Rustin MassoudiRustin Massoudi More articles by this author , Christian HoernerChristian Hoerner More articles by this author , Thomas MetznerThomas Metzner More articles by this author , Jennifer O'RourkeJennifer O'Rourke More articles by this author , Rachael CurtisRachael Curtis More articles by this author , Laurel StellLaurel Stell More articles by this author , Chiara SabattiChiara Sabatti More articles by this author , James BrooksJames Brooks More articles by this author , Alice FanAlice Fan More articles by this author , and John LeppertJohn Leppert More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1184AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Intra-tumor heterogeneity (ITH) is the presence of cell clones with different genetic or histologic phenotypes that occupy distinct spaces within a tumor. Whether genomic ITH translates into functional ITH on the level of protein expression and activity is less well characterized. We hypothesized that variation in expression and activation of critical RCC signaling proteins is less than genomic ITH, resulting in a limited number of functional phenotypes in a tumor. This framework would allow for representative sampling of RCC using renal mass biopsy and advanced proteomic techniques. METHODS We profiled the expression and activation state of extracellular signal-regulated kinase (ERK), a critical effector of the MAPK signaling pathway, in 131 ex vivo biopsies from 39 clear cell RCC tumors and adjacent normal parenchyma after nephrectomy. We performed fine-needle aspirate (FNA) biopsies of grossly representative sections after bivalving the kidney. We performed nano-scale immunoassays (NIA) to quantify the absolute and relative abundances of the phospho-isoforms of ERK1/2 using the Peggy Sue instrument (Protein Simple). ERK1/2 was interrogated with a pan-ERK antibody. Expression levels of ERK levels were compared across samples by normalization to the levels of the ubiquitously expressed protein HSP70. RESULTS ERK1 was infrequently activated, with most samples (69%) demonstrating no phosphorylation of ERK1. In contrast, ERK2 demonstrated phosphorylation in the majority of the samples. Two distinct mono-phosphorylated ERK2 isoforms were detected (pERK2a and pERK2b), with relative abundances ranging from 0-58% and 1-57%, respectively. The relative abundance of dual-phosphorylated ERK2 (ppERK2) ranged from 0-26%. The overall ITH of ERK2 activation was low (average standard deviation [SD] 6%) compared with the difference in ERK2 activation among the 39 tumors (SD 5% - 22%). CONCLUSIONS The abundance and activation of ERK1/2 can be measured from scant FNAs of RCC using novel proteomic methods. We found little ITH of ERK, which suggests that protein ITH is generally less than functional heterogeneity among tumors. These data suggest that a single renal mass biopsy may accurately measure the activity of relevant signaling pathways within a tumor, which may facilitate future precision medicine approaches. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e496-e497 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Rustin Massoudi More articles by this author Christian Hoerner More articles by this author Thomas Metzner More articles by this author Jennifer O'Rourke More articles by this author Rachael Curtis More articles by this author Laurel Stell More articles by this author Chiara Sabatti More articles by this author James Brooks More articles by this author Alice Fan More articles by this author John Leppert More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...