You have accessJournal of UrologyKidney Cancer: Basic Research III1 Apr 2010354 PHD3 HAS A HIF-INDEPENDENT-ANTIPROLIFERATIVE FUNCTION IN RENAL CELL CARCINOMA Toshiaki Tanaka, Toshihiko Torigoe, Yoshihiko Hirohashi, Eiji Sato, Ichiya Honma, Hiroshi Kitamura, Naoya Masumori, Noriyuki Sato, and Taiji Tsukamoto Toshiaki TanakaToshiaki Tanaka More articles by this author , Toshihiko TorigoeToshihiko Torigoe More articles by this author , Yoshihiko HirohashiYoshihiko Hirohashi More articles by this author , Eiji SatoEiji Sato More articles by this author , Ichiya HonmaIchiya Honma More articles by this author , Hiroshi KitamuraHiroshi Kitamura More articles by this author , Naoya MasumoriNaoya Masumori More articles by this author , Noriyuki SatoNoriyuki Sato More articles by this author , and Taiji TsukamotoTaiji Tsukamoto More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.421AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Hypoxia-inducible factor prolyl hydroxylases (PHD) are involved in the degradation of HIF proteins in cooperation with von-Hippel Lindau (VHL) protein. We found that a member of the family, PHD3, was barely detected in normal adult tissues and frequently overexpressed in renal cell carcinomas (RCCs). The purpose of this study was to examine the function of PHD3 in RCC using RCC cell lines. METHODS The VHL-mutant RCC cell lines SMKT-R2 and SMKT-R3, and VHL wild-type ones Caki-1 and ACHN were used. All cells were cultured under normoxic conditions. Total RNA was extracted from cell lines and tissue specimens and the expression of PHD3 was detected by RT-PCR. Cell lysates were prepared from cell lines, and expression of HIF-1 alpha and HIF-2 alpha was analyzed by western blotting. Small interfering RNAs (siRNAs) were used to downregulate PHD3 in cell lines that had PHD3 overexpression under normoxia. Cell proliferation was assessed by the cell count and WST-1 assay. RESULTS SMKT-R2 and SMKT-R3 had stable overexpression of PHD3. In Caki-1, PHD3 expression was induced in the non-confluent state. ACHN did not have PHD3 expression under normoxia. In Caki-1, PHD3 siRNA promoted cell proliferation compared with control siRNA (p<0.0001, Student t-test). On the other hand, PHD3 siRNA did not induce the expression of HIF proteins. Even in VHL-mutant SMKT-R2 and SMKT-R3, PHD3 siRNA showed the same effect (p<0.05 and p<0.01, respectively). CONCLUSIONS The results of this study suggest that PHD3 has an antiproliferative effect that is independent of HIF accumulation in RCCs. This may be a newly discovered function of PHD3 in RCCs. Sapporo, Japan© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e140-e141 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Toshiaki Tanaka More articles by this author Toshihiko Torigoe More articles by this author Yoshihiko Hirohashi More articles by this author Eiji Sato More articles by this author Ichiya Honma More articles by this author Hiroshi Kitamura More articles by this author Naoya Masumori More articles by this author Noriyuki Sato More articles by this author Taiji Tsukamoto More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...