title: [Regulatory effect of Skp2 on the expression and transactivation of the androgen receptor in the progression of castration-resistant prostate cancer].
abstract: OBJECTIVE
  To determine the expression of Skp2 in different prostate cancer (PCa) cell lines and tissues, and explore its influence on the androgen receptor (AR) signaling pathway and development of castration-resistant prostate cancer (CRPC).
  
  
  METHODS
  The expression levels of Skp2 and AR in different PCa cell lines were detected by Western blot. After knockdown of Skp2 in the C4-2 and 22RV1 cells transfected with shRNA, the expressions of AR and P27 were determined and the activity of ARR3-Luc measured by dual-luciferase reporter gene assay following treatment with dihydrotestosterone (DHT). The expressions of AR and Skp2 in human naïve PCa or CRPC specimens were detected by immunohistochemical staining followed by analysis of their differences and correlation.
  
  
  RESULTS
  The Skp2 protein expression level was significantly higher in the C4-2 or 22RV1 cells than in the LNCaP cells. DHT treatment increased the expression of Skp2 in the C4-2 cells, but knock-down of Skp2 significantly up-regulated the expression of the well-known downstream protein P27 and down-regulated that of AR. Consistently, DHT treatment increased the activity of ARR3-Luc, while knockdown of Skp2 remarkably decreased it in the C4-2 and 22RV1 cells (P < 0.05). In addition, significantly higher expressions of Skp2 and AR were observed in the CRPC than in the naïve specimens (P < 0.05), with a positive correlation between the two proteins (r = 0.658 1, P < 0.05).
  
  
  CONCLUSIONS
  Skp2 can enhance the expression and transcription activity of the AR protein in CRPC cells or tissues and is promising to be a critical molecular therapeutic target.
authors.forename: Yi-ting
authors.initials: YT
authors.lastname: Song
authors.forename: Kai-jie
authors.initials: KJ
authors.lastname: Wu
authors.forename: Xin-yang
authors.initials: XY
authors.lastname: Wang
authors.forename: Yong-gang
authors.initials: YG
authors.lastname: Na
authors.forename: Chuan-min
authors.initials: CM
authors.lastname: Yin
mesh_terms: D000728:Androgens / Q000494:pharmacology; D045744:Cell Line, Tumor; D013196:Dihydrotestosterone / Q000494:pharmacology; D018450:Disease Progression; D055785:Gene Knockdown Techniques; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D064129:Prostatic Neoplasms, Castration-Resistant / Q000378:metabolism*; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D044786:S-Phase Kinase-Associated Proteins / Q000502:physiology*; D015533:Transcriptional Activation; D015854:Up-Regulation
chemical_list: C410798:AR protein, human; D000728:Androgens; D009363:Neoplasm Proteins; D011944:Receptors, Androgen; D044786:S-Phase Kinase-Associated Proteins; D013196:Dihydrotestosterone