title: The SWI/SNF ATPase Brm is a gatekeeper of proliferative control in prostate cancer.
abstract: Factors that drive prostate cancer progression remain poorly defined, thus hindering the development of new therapeutic strategies. Disseminated tumors are treated through regimens that ablate androgen signaling, as prostate cancer cells require androgen for growth and survival. However, recurrent, incurable tumors that have bypassed the androgen requirement ultimately arise. This study reveals that the Brm ATPase, a component of selected SWI/SNF complexes, has significant antiproliferative functions in the prostate that protect against these transitions. First, we show that targeted ablation of Brm is causative for the development of prostatic hyperplasia in mice. Second, in vivo challenge revealed that Brm-/- epithelia acquire the capacity for lobe-specific, castration-resistant cellular proliferation. Third, investigation of human specimens revealed that Brm mRNA and protein levels are attenuated in prostate cancer. Fourth, Brm down-regulation was associated with an increased proliferative index, consistent with the mouse model. Lastly, gene expression profiling showed that Brm loss alters factors upstream of E2F1; this was confirmed in murine models, wherein Brm loss induced E2F1 deregulation in a tissue-specific manner. Combined, these data identify Brm as a major effector of serum androgen-induced proliferation in the prostate that is disrupted in human disease, and indicate that loss of Brm confers a proliferative advantage in prostate cancer.
authors.affiliation: Department of Cell and Cancer Biology, University of Cincinnati, Cincinnati Children's Hospital, Cincinnati, Ohio, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
authors.forename: Nathan
authors.initials: N
authors.lastname: Powers
authors.forename: Nitin
authors.initials: N
authors.lastname: Saini
authors.forename: Clay E S
authors.initials: CE
authors.lastname: Comstock
authors.forename: Ankur
authors.initials: A
authors.lastname: Sharma
authors.forename: Katherine
authors.initials: K
authors.lastname: Weaver
authors.forename: Monica P
authors.initials: MP
authors.lastname: Revelo
authors.forename: William
authors.initials: W
authors.lastname: Gerald
authors.forename: Erin
authors.initials: E
authors.lastname: Williams
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Jessen
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Aronow
authors.forename: Gary
authors.initials: G
authors.lastname: Rosson
authors.forename: Bernard
authors.initials: B
authors.lastname: Weissman
authors.forename: Christian
authors.initials: C
authors.lastname: Muchardt
authors.forename: Moshe
authors.initials: M
authors.lastname: Yaniv
authors.forename: Karen E
authors.initials: KE
authors.lastname: Knudsen
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D048708:Cell Growth Processes / Q000502:physiology; D050687:E2F1 Transcription Factor / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D011470:Prostatic Hyperplasia / Q000201:enzymology / Q000473:pathology; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000473:pathology*; D011944:Receptors, Androgen / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D050687:E2F1 Transcription Factor; D011944:Receptors, Androgen; C499503:Smarca2 protein, mouse; D014157:Transcription Factors; D000251:Adenosine Triphosphatases