title: FOXP1 is an androgen-responsive transcription factor that negatively regulates androgen receptor signaling in prostate cancer cells.
abstract: Androgen and androgen receptor (AR) play important roles in the formation and the progression of prostate cancer. AR activates its target genes by recruiting various coregulators and transcriptional factors. Here we show that the FOXP1 forkhead transcription factor is a novel androgen-regulated gene. By sequencing DNA fragments obtained from chromatin immunoprecipitation (ChIP), a bona-fide AR binding site (ARBS) is identified in an intron region of FOXP1 gene. FOXP1 can be induced by androgen in hormone-sensitive prostate cancer LNCaP cells at both mRNA and protein levels. In particular, a smaller FOXP1 variant, FOXP1D, is upregulated in response to androgen. Notably, we demonstrate that FOXP1 directly interacts with AR and negatively regulates AR signaling ligand-dependently, as exemplified by the transcriptional repression of PSA gene regulated by androgen-dependent FOXP1 recruitment on its enhancer region. We show that several other forkhead transcription factors are also androgen-responsive in LNCaP cells. Our study provides a new insight to the function of forkhead transcription factors that modulates AR signaling as an androgen-regulated transcriptional factor, which would contribute to the tumorigenesis of prostate cancer.
authors.affiliation: Department of Geriatric Medicine, Graduate School of Medicine, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Takayama
authors.forename: Kuniko
authors.initials: K
authors.lastname: Horie-Inoue
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ikeda
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Urano
authors.forename: Kayoko
authors.initials: K
authors.lastname: Murakami
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Hayashizaki
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Ouchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Inoue
mesh_terms: D000728:Androgens / Q000378:metabolism* / Q000494:pharmacology; D001665:Binding Sites; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007438:Introns; D008297:Male; D017430:Prostate-Specific Antigen / Q000235:genetics; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: C410798:AR protein, human; D000728:Androgens; C486626:FOXP1 protein, human; D051858:Forkhead Transcription Factors; D012333:RNA, Messenger; D011944:Receptors, Androgen; D012097:Repressor Proteins; D017430:Prostate-Specific Antigen