MP99-05 ELL2 REGULATES DNA DOUBLE-STRAND BREAK REPAIR IN PROSTATE CANCER CELLS

Abstract

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology IV1 Apr 2017MP99-05 ELL2 REGULATES DNA DOUBLE-STRAND BREAK REPAIR IN PROSTATE CANCER CELLS Yachen zang, Yibin Zhou, Leizhen Wei, Joel B. Nelson, Lan LI, Boxin xue, Yuxi Shan, and Zhou Wang Yachen zangYachen zang More articles by this author , Yibin ZhouYibin Zhou More articles by this author , Leizhen WeiLeizhen Wei More articles by this author , Joel B. NelsonJoel B. Nelson More articles by this author , Lan LILan LI More articles by this author , Boxin xueBoxin xue More articles by this author , Yuxi ShanYuxi Shan More articles by this author , and Zhou WangZhou Wang More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.3091AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Androgens are known to protect prostate cancer cells from DNA damage. Recent studies showed regulation of DNA repair genes by androgen receptor (AR) signaling in prostate cancers. We recently reported that androgen-regulated protein and potential tumor suppressor ELL2-associated factor 2 (EAF2) can enhance DNA repair through Ku70/Ku80 in the prostate. ELL2 (elongation factor, RNA polymerase II, 2), a component of the super elongation complex (SEC), is an important factor for RNA Pol II transiting from promoter-proximal paused state into elongation state. ELL2 is also regulated by androgens and frequently down-regulated in prostate cancer. These observations led to our hypothesis that ELL2 can regulate DNA repair through Ku70/Ku80 in prostate cancer cells. METHODS Prostate cancer cells, in the presence or absence of siRNA of ELL2, were treated with ?-irradiation or doxorubicin and then collected for detecting the level of DNA damage marker ?H2ax or neutral comet assay. Nonhomologous end-joining (NHEJ) and homologous recombination (HR) assays were used to test the role of ELL2 in these two double-strand break (DSB) repair pathways. Co-immunoprecipitation was used to determine the interaction between ELL2 and NHEJ pathway proteins Ku70 and Ku80. We examined the effect of ELL2 knockdown on Ku70 and Ku80 recruitment in response to laser microirradiation. RESULTS Knockdown of ELL2 sensitized prostate cancer cells to DNA damage and overexpression of ELL2 protected prostate cancer cells from DNA damage. Knockdown of ELL2 impaired NHEJ repair but not HR. Transfected ELL2 co-immunoprecipitated with both Ku70 and Ku80 proteins. ELL2 could binds to and co-accumulated with Ku70/Ku80 proteins at sites of DNA damage. Knockdown of ELL2 dramatically/significantl inhibited Ku70 and Ku80 accumulation and retention at DSB sites in prostate cancer cells, and also impaired recruitment of Ku70/Ku80 to DSB sites. The impaired recruitment of Ku70 and Ku80 proteins to DNA damage sites upon ELL2 knockdown was rescued by re-expression of an ELL2 transgene insensitive to siELL2. CONCLUSIONS This study suggests that ELL2 is an important factor mediating androgen protection of DNA damage via Ku70/Ku80 in prostate cancer cells. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1321-e1322 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Yachen zang More articles by this author Yibin Zhou More articles by this author Leizhen Wei More articles by this author Joel B. Nelson More articles by this author Lan LI More articles by this author Boxin xue More articles by this author Yuxi Shan More articles by this author Zhou Wang More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...