title: Role of androgen receptor in progression of LNCaP prostate cancer cells from G1 to S phase.
abstract: BACKGROUND
  The androgen receptor (AR) plays a critical role in the proliferation of prostate cancer cells. However, its mechanism of action in proliferation remains unknown. An understanding of the mechanism of AR action in proliferation may lead to the development of effective strategies for the treatment of prostate cancer.
  
  
  RESULTS
  In this study we report that pulse treatment of synchronized LNCaP cells with Casodex, an AR-antagonist, for 4 hours in mid-G(1) phase was sufficient to prevent cells from entering S phase. Since the assembly of pre-replication complex (pre-RC) in G(1) is required for the progression of cells from G(1) to S phase, the effect of Casodex during mid-G(1) suggested that the role of AR in proliferation might be to regulate the assembly of pre-RC. To test this possibility, we investigated the interaction between AR and Cdc6, an essential component of pre-RC in LNCaP cells. AR co-localized and co-immunoprecipitated with Cdc6, and Casodex treatment disrupted this interaction. AR-immunoprecipitate (AR-IP) also contained cyclin E and cyclin A, which play a critical role in pre-RC assembly and cell cycle entry into S phase, and DNA polymerase-α, PCNA, and ribonucleotide reductase, which are essential for the initiation of DNA synthesis. In addition, in cells in S phase, AR co-sedimented with components of the DNA replication machinery of cells that entered S phase.
  
  
  CONCLUSIONS
  Together, these observations suggest a novel role of AR as a component of the pre-RC to exert control over progression of LNCaP cells from G(1) to S phase through a mechanism that is independent of its role as a transcription factor.
authors: Vattikuti Urology Institute, Henry Ford Hospital, Detroit, Michigan, USA.
authors: Shalini
authors: S
authors: Murthy
authors: Min
authors: M
authors: Wu
authors: V Uma
authors: VU
authors: Bai
authors: Zizheng
authors: Z
authors: Hou
authors: Mani
authors: M
authors: Menon
authors: Evelyn R
authors: ER
authors: Barrack
authors: Sahn-Ho
authors: SH
authors: Kim
authors: G Prem-Veer
authors: GP
authors: Reddy
mesh_terms: D059002:Androgen Receptor Antagonists / Q000008:administration & dosage*; D000813:Anilides / Q000008:administration & dosage*; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D019925:Cyclin A / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism; D004261:DNA Replication / Q000187:drug effects; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006801:Humans; D008297:Male; D009570:Nitriles / Q000008:administration & dosage*; D009687:Nuclear Proteins / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D014105:Tosyl Compounds / Q000008:administration & dosage*
chemical_list: C410798:AR protein, human; D059002:Androgen Receptor Antagonists; D000813:Anilides; C103706:CDC6 protein, human; D018797:Cell Cycle Proteins; D019925:Cyclin A; D019927:Cyclin E; D009570:Nitriles; D009687:Nuclear Proteins; D011944:Receptors, Androgen; D014105:Tosyl Compounds; C053541:bicalutamide