MP83-15 A NOVEL THERAPY FOR CASTRATION-RESISTANT PROSTATE CANCER THROUGH INHIBITION OF ONCOGENIC MICRORNAS (2017)

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology II1 Apr 2017MP83-15 A NOVEL THERAPY FOR CASTRATION-RESISTANT PROSTATE CANCER THROUGH INHIBITION OF ONCOGENIC MICRORNAS Tyler Sheetz, Dario Palmieri, Vincenzo Coppola, Anna Tessari, Joseph Mills, Ashley Braddom, Erika Reese, Claudia Foray, Kareesma Parbhoo, and Carlo M. Croce Tyler SheetzTyler Sheetz More articles by this author , Dario PalmieriDario Palmieri More articles by this author , Vincenzo CoppolaVincenzo Coppola More articles by this author , Anna TessariAnna Tessari More articles by this author , Joseph MillsJoseph Mills More articles by this author , Ashley BraddomAshley Braddom More articles by this author , Erika ReeseErika Reese More articles by this author , Claudia ForayClaudia Foray More articles by this author , Kareesma ParbhooKareesma Parbhoo More articles by this author , and Carlo M. CroceCarlo M. Croce More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.2583AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recent studies have shed light on the role of microRNAs (miRs) in prostate cancer (PCa). miR-21 is among the most frequently deregulated miRs in cancer, and has been implicated in a castration-resistant prostate cancer (CRPC) phenotype. In addition to miR-21's many oncogenic effects, a positive feedback loop between miR-21 and the androgen receptor (AR) has been reported in PCa. Separately, miRs -221 and -222 have been shown to target tumor suppressor p27Kip1, leading to inhibition of apoptosis and aberrant proliferation. Nucleolin (NCL) is a multifunctional protein found in the nucleocytoplasm of most human cells, and is abnormally translocated to the cell membrane in cancer. One of the mechanisms by which NCL exerts its oncogenic activity is through the biogenesis of miRs -21, -221, and -222. 4LB5 is a novel single-chain fragment variable (scFv) antibody that binds preferentially to cancer cell membranes via the RNA-binding domain of NCL and inhibits production of these oncogenic miRs. The therapeutic and diagnostic potential of 4LB5 has been described in breast and hepatocellular carcinoma cells in previous studies. Given the supporting evidence, we aim to characterize the effects of 4LB5 on CRPC and compare its efficacy among androgen-dependent and androgen-independent cells. METHODS Levels of NCL expression in PCa cell lines DU145, PC3, and LNCaP were investigated with western blot (WB). Cell surface ELISA was performed to compare 4LB5 binding across PCa cell lines. Cell survival assay was performed using 50 nM 4LB5 or control buffer. Levels of mature and precursor forms of miRs in 4LB5-treated cells were assessed using quantitative real-time polymerase chain reaction. MDA-MB-231 cells were used a positive control in all experiments. RESULTS All cell lines expressed NCL as evidenced by WB, and downregulation of NCL was observed with siNCL transfection. ELISA results showed a strong exponential association between 4LB5 concentration and binding activity in DU145 (R2 = 0.9972), PC3 (R2 = 0.9887), and LNCaP (R2 = 0.9897) cells, with more binding units observed in PC3 and DU145 compared to LNCaP. 4LB5 significantly inhibited proliferation of DU145 (p = 0.000016) and PC3 (p = 0.0074) cells, but not LNCaP (p = 0.45). Treatment with 4LB5 caused downregulation of mature forms of miRs 21, 221, and 222 with expected upregulation of precursor forms in PC3 cells, but LNCaP cells exhibited the opposite effect. CONCLUSIONS 4LB5 binds CRPC cells and inhibits proliferation through abrogation of oncogenic miR production. 4LB5 could represent a novel therapeutic option in CRPC patients. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1111-e1112 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Tyler Sheetz More articles by this author Dario Palmieri More articles by this author Vincenzo Coppola More articles by this author Anna Tessari More articles by this author Joseph Mills More articles by this author Ashley Braddom More articles by this author Erika Reese More articles by this author Claudia Foray More articles by this author Kareesma Parbhoo More articles by this author Carlo M. Croce More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...