title: Estrogen-dependent signaling in a molecularly distinct subclass of aggressive prostate cancer.
abstract: BACKGROUND
  The majority of prostate cancers harbor gene fusions of the 5'-untranslated region of the androgen-regulated transmembrane protease serine 2 (TMPRSS2) promoter with erythroblast transformation-specific transcription factor family members. The common fusion between TMPRESS2 and v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG) is associated with a more aggressive clinical phenotype, implying the existence of a distinct subclass of prostate cancer defined by this fusion.
  
  
  METHODS
  We used complementary DNA-mediated annealing, selection, ligation, and extension to determine the expression profiles of 6144 transcriptionally informative genes in archived biopsy samples from 455 prostate cancer patients in the Swedish Watchful Waiting cohort (1987-1999) and the United States-based Physicians(') Health Study cohort (1983-2003). A gene expression signature for prostate cancers with the TMPRSS2-ERG fusion was determined using partitioning and classification models and used in computational functional analysis. Cell proliferation and TMPRSS2-ERG expression in androgen receptor-negative (NCI-H660) prostate cancer cells after treatment with vehicle or estrogenic compounds were assessed by viability assays and quantitative polymerase chain reaction, respectively. All statistical tests were two-sided.
  
  
  RESULTS
  We identified an 87-gene expression signature that distinguishes TMPRSS2-ERG fusion prostate cancer as a discrete molecular entity (area under the curve = 0.80, 95% confidence interval [CI] = 0.792 to 0.81; P < .001). Computational analysis suggested that this fusion signature was associated with estrogen receptor (ER) signaling. Viability of NCI-H660 cells decreased after treatment with estrogen (viability normalized to day 0, estrogen vs vehicle at day 8, mean = 2.04 vs 3.40, difference = 1.36, 95% CI = 1.12 to 1.62) or ERbeta agonist (ERbeta agonist vs vehicle at day 8, mean = 1.86 vs 3.40, difference = 1.54, 95% CI = 1.39 to 1.69) but increased after ERalpha agonist treatment (ERalpha agonist vs vehicle at day 8, mean = 4.36 vs 3.40, difference = 0.96, 95% CI = 0.68 to 1.23). Similarly, expression of TMPRSS2-ERG decreased after ERbeta agonist treatment (fold change over internal control, ERbeta agonist vs vehicle at 24 hours, NCI-H660, mean = 0.57- vs 1.0-fold, difference = 0.43-fold, 95% CI = 0.29- to 0.57-fold) and increased after ERalpha agonist treatment (ERalpha agonist vs vehicle at 24 hours, mean = 5.63- vs 1.0-fold, difference = 4.63-fold, 95% CI = 4.34- to 4.92-fold).
  
  
  CONCLUSIONS
  TMPRSS2-ERG fusion prostate cancer is a distinct molecular subclass. TMPRSS2-ERG expression is regulated by a novel ER-dependent mechanism.
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Sunita R
authors.initials: SR
authors.lastname: Setlur
authors.forename: Kirsten D
authors.initials: KD
authors.lastname: Mertz
authors.forename: Yujin
authors.initials: Y
authors.lastname: Hoshida
authors.forename: Francesca
authors.initials: F
authors.lastname: Demichelis
authors.forename: Mathieu
authors.initials: M
authors.lastname: Lupien
authors.forename: Sven
authors.initials: S
authors.lastname: Perner
authors.forename: Andrea
authors.initials: A
authors.lastname: Sboner
authors.forename: Yudi
authors.initials: Y
authors.lastname: Pawitan
authors.forename: Ove
authors.initials: O
authors.lastname: Andrén
authors.forename: Laura A
authors.initials: LA
authors.lastname: Johnson
authors.forename: Jeff
authors.initials: J
authors.lastname: Tang
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
authors.forename: Stefano
authors.initials: S
authors.lastname: Calza
authors.forename: Arul M
authors.initials: AM
authors.lastname: Chinnaiyan
authors.forename: Daniel
authors.initials: D
authors.lastname: Rhodes
authors.forename: Scott
authors.initials: S
authors.lastname: Tomlins
authors.forename: Katja
authors.initials: K
authors.lastname: Fall
authors.forename: Lorelei A
authors.initials: LA
authors.lastname: Mucci
authors.forename: Philip W
authors.initials: PW
authors.lastname: Kantoff
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.forename: Swen-Olof
authors.initials: SO
authors.lastname: Andersson
authors.forename: Eberhard
authors.initials: E
authors.lastname: Varenhorst
authors.forename: Jan-Erik
authors.initials: JE
authors.lastname: Johansson
authors.forename: Myles
authors.initials: M
authors.lastname: Brown
authors.forename: Todd R
authors.initials: TR
authors.lastname: Golub
authors.forename: Mark A
authors.initials: MA
authors.lastname: Rubin
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology* / Q000627:therapeutic use; D019540:Area Under Curve; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D047369:Chromatin Immunoprecipitation; D018076:DNA, Complementary / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000037:antagonists & inhibitors* / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000819:agonists* / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006306:Health Surveys; D006801:Humans; D008297:Male; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D009570:Nitriles / Q000494:pharmacology; D015514:Oncogene Proteins, Fusion / Q000378:metabolism*; D010636:Phenols; D010820:Physicians / Q000706:statistics & numerical data; D016133:Polymerase Chain Reaction; D011422:Propionates / Q000494:pharmacology; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D011720:Pyrazoles / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013548:Sweden / Q000453:epidemiology; D014162:Transfection
chemical_list: C486182:2,3-bis(4-hydroxyphenyl)-propionitrile; D018931:Antineoplastic Agents, Hormonal; D018076:DNA, Complementary; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D009570:Nitriles; D015514:Oncogene Proteins, Fusion; D010636:Phenols; D011422:Propionates; D011720:Pyrazoles; C515553:TMPRSS2-ERG fusion protein, human; C486184:4,4',4''-(4-propyl-((1)H)-pyrazole-1,3,5-triyl) tris-phenol; D004958:Estradiol; D012697:Serine Endopeptidases; C421305:TMPRSS2 protein, human