イツミ モモエ
  逸見 百江
   所属   川崎医科大学  医学部 一般教養 自然科学
   職種   助教
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 Downregulation of phosphodiesterase 4B (PDE4B) activates protein kinase A and contributes to the progression of prostate cancer.
掲載誌名 正式名:The Prostate
略  称:Prostate
ISSNコード:10970045/02704137
掲載区分国外
巻・号・頁 72(7),pp.741-51
著者・共著者 Eiji Kashiwagi, Masaki Shiota, Akira Yokomizo, Momoe Itsumi, Junichi Inokuchi, Takeshi Uchiumi, Seiji Naito
発行年月 2012/05
概要 BACKGROUND:Prostate cancer is the most commonly diagnosed non-cutaneous cancer in American men. Unfortunately, few successful therapies for castration-resistant prostate cancer (CRPC) exist. The protein kinase A (PKA) pathway is a critical mediator of cellular proliferation and differentiation in various normal and cancerous cells. However, the PKA activity and the mechanism of regulation in CRPC remain unclear. Then, in this study, we intended to reveal the PKA activity and the mechanism of regulation in CRPC.METHODS:Western blotting, quantitative real-time polymerase chain reaction, cytotoxicity analysis, and cell proliferation assay were used to resolve the regulatory role of PKA in prostate cancer cell line, LNCaP and their derivatives.RESULTS:cAMP-specific phosphodiesterase 4B (PDE4B) was downregulated and the PKA pathway was activated in castration-resistant LNCaP derivatives (CxR cells). Rolipram activated the PKA pathway via inhibition of PDE4B, resulting in AR transactivation while the PKA inhibitor, H89 reduced AR transactivation. In response to hydrogen peroxide and in hydrogen peroxide-resistant LNCaP derivatives (HPR50 cells) PDE4B was decreased and as a result PKA activity was increased. Moreover, PDE4B expression was reduced in advanced prostate cancer and PDE4B knockdown promoted castration-resistant growth of LNCaP cells.CONCLUSIONS:Oxidative stress may suppress PDE4B expression and activate the PKA pathway. The PDE4B/PKA pathway contributed to progression of androgen-dependent prostate cancer to CRPC. This pathway may represent an attractive therapeutic molecular target.
DOI 10.1002/pros.21478
PMID 22529021