321 ANTISENSE INHIBITOR TARGETING FULL LENGTH ANDROGEN RECEPTOR AND ITS SPLICE VARIANTS SUPPRESSES MDV3100 RESISTANT PROSTATE CANCER CELL GROWTH (2013)

You have accessJournal of UrologyProstate Cancer: Basic Research (II)1 Apr 2013321 ANTISENSE INHIBITOR TARGETING FULL LENGTH ANDROGEN RECEPTOR AND ITS SPLICE VARIANTS SUPPRESSES MDV3100 RESISTANT PROSTATE CANCER CELL GROWTH Yoshiaki Yamamoto, Eliana Beraldi, Hidetoshi Kuruma, Hiroaki Matsumoto, Yohann Loriot, Alexander Wyatt, Fan Mo, Tianyuan Zhou, Youngsoo Kim, Brett Monia, A. Robert MacLeod, Ladan Fazli, Amina Zoubeidi, and Martin Gleave Yoshiaki YamamotoYoshiaki Yamamoto Vancouver, Canada More articles by this author , Eliana BeraldiEliana Beraldi Vancouver, Canada More articles by this author , Hidetoshi KurumaHidetoshi Kuruma Vancouver, Canada More articles by this author , Hiroaki MatsumotoHiroaki Matsumoto Vancouver, Canada More articles by this author , Yohann LoriotYohann Loriot Vancouver, Canada More articles by this author , Alexander WyattAlexander Wyatt Vancouver, Canada More articles by this author , Fan MoFan Mo Vancouver, Canada More articles by this author , Tianyuan ZhouTianyuan Zhou Carlsbad, CA More articles by this author , Youngsoo KimYoungsoo Kim Carlsbad, CA More articles by this author , Brett MoniaBrett Monia Carlsbad, CA More articles by this author , A. Robert MacLeodA. Robert MacLeod Carlsbad, CA More articles by this author , Ladan FazliLadan Fazli Vancouver, Canada More articles by this author , Amina ZoubeidiAmina Zoubeidi Vancouver, Canada More articles by this author , and Martin GleaveMartin Gleave Vancouver, Canada More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.1706AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES MDV3100 is a potent androgen receptor (AR) antagonist with activity in castration resistant prostate cancer (CRPC); however, progression to MDV3100-resistant (MDV-R) CRPC frequently occurs with rising serum PSA levels, implicating AR full length (AR-FL) or variants (AR-Vs) in disease progression. We studied the effects of Generation 2.5 antisense oligonucleotide (ASO) targeting exon 1, intron 1, or exon 8 designed to suppress AR-FL and/or AR-Vs in MDV-R CRPC models. METHODS We generated by selection MDV-R LNCaP-derived sub-lines that uniformly expressed high levels of both AR-FL and AR-V7 compared to CRPC LNCaP xenografts and sequenced their transcriptomes by next-generation mRNA sequencing. Cell growth rates and gene expression were analyzed using crystal violet assay, flow cytometry, Western blotting and real-time PCR, respectively. Exon 1 ASO was evaluated in MDV-R49F CRPC LNCaP xenografts. RESULTS MDV3100 induced time- and dose-dependent increases in AR-FL and AR-V7 protein levels in LNCaP cells. While transcriptome sequencing detected many AR-Vs in MDV-R-LNCaP cells, only AR-V7 is overtly expressed, although at 20-fold lower levels that AR-FL. No additional mutations in AR other than the T877A inherited from parental LNCaP were detected. All 3 AR-ASO decreased AR-FL and PSA expression in LNCaP derived cells. Exon 1 ASO decreased expression of both AR-FL and AR-V7 in MDV-R-LNCaP cells; in comparison, exon 8 ASO decreased AR-FL without reducing AR-V7 levels. Exon 1 ASO also potently suppressed AR-Vs in M12 cells stably overexpressing AR-V7 and AR-V567es. Despite these differential effects on AR-FL and AR-V7 knockdown, the AR ASO similarly inhibited cell growth and induced apoptosis and G1 cell cycle arrest in MDV-R cell lines. In 22Rv1 cells with higher endogenous expression of AR-V7, exon 1 ASO more potently suppressed AR-FL and AR-V7 levels, AR transcriptional activity and AR-regulated gene expression compared to exon 8 ASO, but inhibition of cell growth did not differ significantly. In vivo, exon 1 AR-ASO significantly suppressed MDV-R CRPC LNCaP tumor growth and serum PSA levels by 40% and 50%, respectively, compared to controls. CONCLUSIONS While MDV3100 induces both AR-FL and AR-V7 levels, the biologic consequences appear cell line dependent and mainly driven by AR-FL. AR-ASO knockdown of AR-FL and AR-Vs suppresses MDV-R LNCaP tumor growth, providing pre-clinical proof of principle to support clinical evaluation in post-AR pathway inhibitor CRPC. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e130 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yoshiaki Yamamoto Vancouver, Canada More articles by this author Eliana Beraldi Vancouver, Canada More articles by this author Hidetoshi Kuruma Vancouver, Canada More articles by this author Hiroaki Matsumoto Vancouver, Canada More articles by this author Yohann Loriot Vancouver, Canada More articles by this author Alexander Wyatt Vancouver, Canada More articles by this author Fan Mo Vancouver, Canada More articles by this author Tianyuan Zhou Carlsbad, CA More articles by this author Youngsoo Kim Carlsbad, CA More articles by this author Brett Monia Carlsbad, CA More articles by this author A. Robert MacLeod Carlsbad, CA More articles by this author Ladan Fazli Vancouver, Canada More articles by this author Amina Zoubeidi Vancouver, Canada More articles by this author Martin Gleave Vancouver, Canada More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...