Modeling Truncated AR Expression in a Natural Androgen Responsive Environment and Identification of RHOB as a Direct Transcriptional Target

H.-C. Tsai, D.L. Boucher, A. Martinez, C.G. Tepper, H.-J. Kung

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Recent studies identifying putative truncated androgen receptor isoforms with ligand-independent activity have shed new light on the acquisition of androgen depletion independent (ADI) growth of prostate cancer. In this study, we present a model system in which a C-terminally truncated variant of androgen receptor (TC-AR) is inducibly expressed in LNCaP, an androgen-dependent cell line, which expresses little truncated receptor. We observed that when TC-AR is overexpressed, the endogenous full length receptor (FL-AR) is transcriptionally downmodulated. This in essence allows us to "replace" FL-AR with TC-AR and compare their individual properties in exactly the same genetic and cellular background, which has not been performed before. We show that the TC-AR translocates to the nucleus, activates transcription of AR target genes in the absence of DHT and is sufficient to confer ADI growth to the normally androgen dependent LNCaP line. We also show that while there is significant overlap in the genes regulated by FL- and TC-AR there are also differences in the respective suites of target genes with each AR form regulating genes that the other does not. Among the genes uniquely activated by TC-AR is RHOB which is shown to be involved in the increased migration and morphological changes observed in LN/TC-AR, suggesting a role of RHOB in the regulation of androgen-independent behavior of prostate cancer cells. © 2012 Tsai et al.
Original languageEnglish
JournalPLoS One
Volume7
Issue number11
DOIs
Publication statusPublished - Nov 2012
Externally publishedYes

Fingerprint

Androgen Receptors
androgens
Androgens
Genes
prostatic neoplasms
genes
Prostatic Neoplasms
Cells
receptors
androgen receptors
Transcription
Growth
Protein Isoforms
transcription (genetics)
cell lines
Ligands
Cell Line

Keywords

  • androgen receptor
  • doxycycline
  • heterodimer
  • messenger RNA
  • article
  • biological model
  • carboxy terminal sequence
  • cell migration
  • cell shape
  • cell strain LNCaP
  • controlled study
  • gene
  • gene activation
  • gene identification
  • gene silencing
  • gene targeting
  • genetic transcription
  • protein expression
  • protein function
  • protein localization
  • receptor down regulation
  • reverse transcription polymerase chain reaction
  • RHOB gene
  • transcription regulation
  • upregulation
  • Androgens
  • Cell Line, Tumor
  • Cell Movement
  • Cell Nucleus
  • Chromatin
  • Dihydrotestosterone
  • Doxycycline
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Humans
  • Male
  • Prostatic Neoplasms
  • Protein Binding
  • Protein Multimerization
  • Protein Transport
  • Receptors, Androgen
  • Reproducibility of Results
  • Response Elements
  • rhoB GTP-Binding Protein
  • RNA, Messenger
  • Transcription, Genetic

Cite this

Modeling Truncated AR Expression in a Natural Androgen Responsive Environment and Identification of RHOB as a Direct Transcriptional Target. / Tsai, H.-C.; Boucher, D.L.; Martinez, A.; Tepper, C.G.; Kung, H.-J.

In: PLoS One, Vol. 7, No. 11, 11.2012.

Research output: Contribution to journalArticle

@article{c7cda1e7c1bc477fb5130b9c7e95b198,
title = "Modeling Truncated AR Expression in a Natural Androgen Responsive Environment and Identification of RHOB as a Direct Transcriptional Target",
abstract = "Recent studies identifying putative truncated androgen receptor isoforms with ligand-independent activity have shed new light on the acquisition of androgen depletion independent (ADI) growth of prostate cancer. In this study, we present a model system in which a C-terminally truncated variant of androgen receptor (TC-AR) is inducibly expressed in LNCaP, an androgen-dependent cell line, which expresses little truncated receptor. We observed that when TC-AR is overexpressed, the endogenous full length receptor (FL-AR) is transcriptionally downmodulated. This in essence allows us to {"}replace{"} FL-AR with TC-AR and compare their individual properties in exactly the same genetic and cellular background, which has not been performed before. We show that the TC-AR translocates to the nucleus, activates transcription of AR target genes in the absence of DHT and is sufficient to confer ADI growth to the normally androgen dependent LNCaP line. We also show that while there is significant overlap in the genes regulated by FL- and TC-AR there are also differences in the respective suites of target genes with each AR form regulating genes that the other does not. Among the genes uniquely activated by TC-AR is RHOB which is shown to be involved in the increased migration and morphological changes observed in LN/TC-AR, suggesting a role of RHOB in the regulation of androgen-independent behavior of prostate cancer cells. {\circledC} 2012 Tsai et al.",
keywords = "androgen receptor, doxycycline, heterodimer, messenger RNA, article, biological model, carboxy terminal sequence, cell migration, cell shape, cell strain LNCaP, controlled study, gene, gene activation, gene identification, gene silencing, gene targeting, genetic transcription, protein expression, protein function, protein localization, receptor down regulation, reverse transcription polymerase chain reaction, RHOB gene, transcription regulation, upregulation, Androgens, Cell Line, Tumor, Cell Movement, Cell Nucleus, Chromatin, Dihydrotestosterone, Doxycycline, Gene Expression Regulation, Neoplastic, Gene Knockdown Techniques, Humans, Male, Prostatic Neoplasms, Protein Binding, Protein Multimerization, Protein Transport, Receptors, Androgen, Reproducibility of Results, Response Elements, rhoB GTP-Binding Protein, RNA, Messenger, Transcription, Genetic",
author = "H.-C. Tsai and D.L. Boucher and A. Martinez and C.G. Tepper and H.-J. Kung",
note = "引用次數:9 Export Date: 5 March 2018 通訊地址: Kung, H.-J.; Department of Biochemistry and Molecular Medicine, School of Medicine and Cancer Center, University of California Davis, Davis, CA, United States; 電子郵件: hkung@ucdavis.edu 化學物質/CAS: doxycycline, 10592-13-9, 17086-28-1, 564-25-0, 94088-85-4; Androgens; Chromatin; Dihydrotestosterone, 521-18-6; Doxycycline, 564-25-0; RNA, Messenger; Receptors, Androgen; rhoB GTP-Binding Protein, 3.6.5.2 參考文獻: Tan, J., Sharief, Y., Hamil, K.G., Gregory, C.W., Zang, D.Y., Dehydroepiandrosterone activates mutant androgen receptors expressed in the androgen-dependent human prostate cancer xenograft CWR22 and LNCaP cells (1997) Mol Endocrinol, 11, pp. 450-459; Tepper, C.G., Boucher, D.L., Ryan, P.E., Ma, A.H., Xia, L., Characterization of a novel androgen receptor mutation in a relapsed CWR22 prostate cancer xenograft and cell line (2002) Cancer Res, 62, pp. 6606-6614; Chlenski, A., Nakashiro, K., Ketels, K.V., Korovaitseva, G.I., Oyasu, R., Androgen receptor expression in androgen-independent prostate cancer cell lines (2001) Prostate, 47, pp. 66-75; Li, Y., Alsagabi, M., Fan, D., Bova, G.S., Tewfik, A.H., Intragenic rearrangement and altered RNA splicing of the androgen receptor in a cell-based model of prostate cancer progression (2011) Cancer Res, 71, pp. 2108-2117; Libertini, S.J., Tepper, C.G., Rodriguez, V., Asmuth, D.M., Kung, H.J., Evidence for calpain-mediated androgen receptor cleavage as a mechanism for androgen independence (2007) Cancer Res, 67, pp. 9001-9005; Dehm, S.M., Schmidt, L.J., Heemers, H.V., Vessella, R.L., Tindall, D.J., Splicing of a novel androgen receptor exon generates a constitutively active androgen receptor that mediates prostate cancer therapy resistance (2008) Cancer Res, 68, pp. 5469-5477; Hu, R., Dunn, T.A., Wei, S., Isharwal, S., Veltri, R.W., Ligand-independent androgen receptor variants derived from splicing of cryptic exons signify hormone-refractory prostate cancer (2009) Cancer Res, 69, pp. 16-22; Guo, Z., Yang, X., Sun, F., Jiang, R., Linn, D.E., A novel androgen receptor splice variant is up-regulated during prostate cancer progression and promotes androgen depletion-resistant growth (2009) Cancer Res, 69, pp. 2305-2313; Hornberg, E., Ylitalo, E.B., Crnalic, S., Antti, H., Stattin, P., Expression of androgen receptor splice variants in prostate cancer bone metastases is associated with castration-resistance and short survival (2011) PLoS One, 6, pp. e19059; Hu, R., Isaacs, W.B., Luo, J., A snapshot of the expression signature of androgen receptor splicing variants and their distinctive transcriptional activities (2011) Prostate, 71, pp. 1656-1667; Sun, S., Sprenger, C.C., Vessella, R.L., Haugk, K., Soriano, K., Castration resistance in human prostate cancer is conferred by a frequently occurring androgen receptor splice variant (2010) J Clin Invest, 120, pp. 2715-2730; Guo, Z., Qiu, Y., A new trick of an old molecule: androgen receptor splice variants taking the stage?! (2011) Int J Biol Sci, 7, pp. 815-822; Haile, S., Sadar, M.D., Androgen receptor and its splice variants in prostate cancer (2011) Cell Mol Life Sci; Zhou, Z.X., Sar, M., Simental, J.A., Lane, M.V., Wilson, E.M., A ligand-dependent bipartite nuclear targeting signal in the human androgen receptor. Requirement for the DNA-binding domain and modulation by NH2-terminal and carboxyl-terminal sequences (1994) J Biol Chem, 269, pp. 13115-13123; Watson, P.A., Chen, Y.F., Balbas, M.D., Wongvipat, J., Socci, N.D., Constitutively active androgen receptor splice variants expressed in castration-resistant prostate cancer require full-length androgen receptor (2010) Proc Natl Acad Sci U S A, 107, pp. 16759-16765; Zhang, B., Kirov, S., Snoddy, J., WebGestalt: an integrated system for exploring gene sets in various biological contexts (2005) Nucleic Acids Res, 33, pp. W741-W748; Shang, Y., Myers, M., Brown, M., Formation of the androgen receptor transcription complex (2002) Mol Cell, 9, pp. 601-610; Hsia, D.A., Tepper, C.G., Pochampalli, M.R., Hsia, E.Y., Izumiya, C., KDM8, a H3K36me2 histone demethylase that acts in the cyclin A1 coding region to regulate cancer cell proliferation (2010) Proc Natl Acad Sci U S A, 107, pp. 9671-9676; Ji, H., Jiang, H., Ma, W., Johnson, D.S., Myers, R.M., An integrated software system for analyzing ChIP-chip and ChIP-seq data (2008) Nat Biotechnol, 26, pp. 1293-1300; Ji, H., Wong, W.H., TileMap: create chromosomal map of tiling array hybridizations (2005) Bioinformatics, 21, pp. 3629-3636; Shen, R., Dorai, T., Szaboles, M., Katz, A.E., Olsson, C.A., Transdifferentiation of cultured human prostate cancer cells to a neuroendocrine cell phenotype in a hormone-depleted medium (1997) Urol Oncol, 3, pp. 67-75; Wheeler, A.P., Ridley, A.J., Why three Rho proteins? RhoA, RhoB, RhoC, and cell motility (2004) Exp Cell Res, 301, pp. 43-49; Prendergast, G.C., Actin' up: RhoB in cancer and apoptosis (2001) Nat Rev Cancer, 1, pp. 162-168; Chen, C.D., Welsbie, D.S., Tran, C., Baek, S.H., Chen, R., Molecular determinants of resistance to antiandrogen therapy (2004) Nat Med, 10, pp. 33-39; Tararova, N.D., Narizhneva, N., Krivokrisenko, V., Gudkov, A.V., Gurova, K.V., Prostate cancer cells tolerate a narrow range of androgen receptor expression and activity (2007) Prostate, 67, pp. 1801-1815; Ceraline, J., Cruchant, M.D., Erdmann, E., Erbs, P., Kurtz, J.E., Constitutive activation of the androgen receptor by a point mutation in the hinge region: a new mechanism for androgen-independent growth in prostate cancer (2004) Int J Cancer, 108, pp. 152-157; Burnstein, K.L., Regulation of androgen receptor levels: implications for prostate cancer progression and therapy (2005) J Cell Biochem, 95, pp. 657-669; Wolf, D.A., Herzinger, T., Hermeking, H., Blaschke, D., Horz, W., Transcriptional and posttranscriptional regulation of human androgen receptor expression by androgen (1993) Mol Endocrinol, 7, pp. 924-936; Blok, L.J., Themmen, A.P., Peters, A.H., Trapman, J., Baarends, W.M., Transcriptional regulation of androgen receptor gene expression in Sertoli cells and other cell types (1992) Mol Cell Endocrinol, 88, pp. 153-164; Grad, J.M., Dai, J.L., Wu, S., Burnstein, K.L., Multiple androgen response elements and a Myc consensus site in the androgen receptor (AR) coding region are involved in androgen-mediated up-regulation of AR messenger RNA (1999) Mol Endocrinol, 13, pp. 1896-1911; Kumar, M.V., Jones, E.A., Grossmann, M.E., Blexrud, M.D., Tindall, D.J., Identification and characterization of a suppressor element in the 5′-flanking region of the mouse androgen receptor gene (1994) Nucleic Acids Res, 22, pp. 3693-3698; Wang, L.G., Ossowski, L., Ferrari, A.C., Androgen receptor level controlled by a suppressor complex lost in an androgen-independent prostate cancer cell line (2004) Oncogene, 23, pp. 5175-5184; Cai, C., He, H.H., Chen, S., Coleman, I., Wang, H., Androgen receptor gene expression in prostate cancer is directly suppressed by the androgen receptor through recruitment of lysine-specific demethylase 1 (2011) Cancer Cell, 20, pp. 457-471; Ding, X.F., Anderson, C.M., Ma, H., Hong, H., Uht, R.M., Nuclear receptor-binding sites of coactivators glucocorticoid receptor interacting protein 1 (GRIP1) and steroid receptor coactivator 1 (SRC-1): multiple motifs with different binding specificities (1998) Mol Endocrinol, 12, pp. 302-313; Jenster, G., van der Korput, H.A., Trapman, J., Brinkmann, A.O., Identification of two transcription activation units in the N-terminal domain of the human androgen receptor (1995) J Biol Chem, 270, pp. 7341-7346; Hu, R., Lu, C., Mostaghel, E.A., Yegnasubramanian, S., Gurel, M., Distinct transcriptional programs mediated by the ligand-dependent full-length androgen receptor and its splice variants in castration-resistant prostate cancer (2012) Cancer Res, 72, pp. 3457-3462; Bourboulia, D., Stetler-Stevenson, W.G., Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs): Positive and negative regulators in tumor cell adhesion (2010) Semin Cancer Biol; Karlsson, R., Pedersen, E.D., Wang, Z., Brakebusch, C., Rho GTPase function in tumorigenesis (2009) Biochim Biophys Acta, 1796, pp. 91-98; Mazieres, J., Antonia, T., Daste, G., Muro-Cacho, C., Berchery, D., Loss of RhoB expression in human lung cancer progression (2004) Clin Cancer Res, 10, pp. 2742-2750; Bousquet, E., Mazieres, J., Privat, M., Rizzati, V., Casanova, A., Loss of RhoB expression promotes migration and invasion of human bronchial cells via activation of AKT1 (2009) Cancer Res, 69, pp. 6092-6099; Fritz, G., Brachetti, C., Bahlmann, F., Schmidt, M., Kaina, B., Rho GTPases in human breast tumours: expression and mutation analyses and correlation with clinical parameters (2002) Br J Cancer, 87, pp. 635-644; Vasilaki, E., Papadimitriou, E., Tajadura, V., Ridley, A.J., Stournaras, C., Transcriptional regulation of the small GTPase RhoB gene by TGF{beta}-induced signaling pathways (2010) FASEB J, 24, pp. 891-905; Yoneda, M., Hirokawa, Y.S., Ohashi, A., Uchida, K., Kami, D., RhoB enhances migration and MMP1 expression of prostate cancer DU145 (2010) Exp Mol Pathol, 88, pp. 90-95",
year = "2012",
month = "11",
doi = "10.1371/journal.pone.0049887",
language = "English",
volume = "7",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "11",

}

TY - JOUR

T1 - Modeling Truncated AR Expression in a Natural Androgen Responsive Environment and Identification of RHOB as a Direct Transcriptional Target

AU - Tsai, H.-C.

AU - Boucher, D.L.

AU - Martinez, A.

AU - Tepper, C.G.

AU - Kung, H.-J.

N1 - 引用次數:9 Export Date: 5 March 2018 通訊地址: Kung, H.-J.; Department of Biochemistry and Molecular Medicine, School of Medicine and Cancer Center, University of California Davis, Davis, CA, United States; 電子郵件: hkung@ucdavis.edu 化學物質/CAS: doxycycline, 10592-13-9, 17086-28-1, 564-25-0, 94088-85-4; Androgens; Chromatin; Dihydrotestosterone, 521-18-6; Doxycycline, 564-25-0; RNA, Messenger; Receptors, Androgen; rhoB GTP-Binding Protein, 3.6.5.2 參考文獻: Tan, J., Sharief, Y., Hamil, K.G., Gregory, C.W., Zang, D.Y., Dehydroepiandrosterone activates mutant androgen receptors expressed in the androgen-dependent human prostate cancer xenograft CWR22 and LNCaP cells (1997) Mol Endocrinol, 11, pp. 450-459; Tepper, C.G., Boucher, D.L., Ryan, P.E., Ma, A.H., Xia, L., Characterization of a novel androgen receptor mutation in a relapsed CWR22 prostate cancer xenograft and cell line (2002) Cancer Res, 62, pp. 6606-6614; Chlenski, A., Nakashiro, K., Ketels, K.V., Korovaitseva, G.I., Oyasu, R., Androgen receptor expression in androgen-independent prostate cancer cell lines (2001) Prostate, 47, pp. 66-75; Li, Y., Alsagabi, M., Fan, D., Bova, G.S., Tewfik, A.H., Intragenic rearrangement and altered RNA splicing of the androgen receptor in a cell-based model of prostate cancer progression (2011) Cancer Res, 71, pp. 2108-2117; Libertini, S.J., Tepper, C.G., Rodriguez, V., Asmuth, D.M., Kung, H.J., Evidence for calpain-mediated androgen receptor cleavage as a mechanism for androgen independence (2007) Cancer Res, 67, pp. 9001-9005; Dehm, S.M., Schmidt, L.J., Heemers, H.V., Vessella, R.L., Tindall, D.J., Splicing of a novel androgen receptor exon generates a constitutively active androgen receptor that mediates prostate cancer therapy resistance (2008) Cancer Res, 68, pp. 5469-5477; Hu, R., Dunn, T.A., Wei, S., Isharwal, S., Veltri, R.W., Ligand-independent androgen receptor variants derived from splicing of cryptic exons signify hormone-refractory prostate cancer (2009) Cancer Res, 69, pp. 16-22; Guo, Z., Yang, X., Sun, F., Jiang, R., Linn, D.E., A novel androgen receptor splice variant is up-regulated during prostate cancer progression and promotes androgen depletion-resistant growth (2009) Cancer Res, 69, pp. 2305-2313; Hornberg, E., Ylitalo, E.B., Crnalic, S., Antti, H., Stattin, P., Expression of androgen receptor splice variants in prostate cancer bone metastases is associated with castration-resistance and short survival (2011) PLoS One, 6, pp. e19059; Hu, R., Isaacs, W.B., Luo, J., A snapshot of the expression signature of androgen receptor splicing variants and their distinctive transcriptional activities (2011) Prostate, 71, pp. 1656-1667; Sun, S., Sprenger, C.C., Vessella, R.L., Haugk, K., Soriano, K., Castration resistance in human prostate cancer is conferred by a frequently occurring androgen receptor splice variant (2010) J Clin Invest, 120, pp. 2715-2730; Guo, Z., Qiu, Y., A new trick of an old molecule: androgen receptor splice variants taking the stage?! (2011) Int J Biol Sci, 7, pp. 815-822; Haile, S., Sadar, M.D., Androgen receptor and its splice variants in prostate cancer (2011) Cell Mol Life Sci; Zhou, Z.X., Sar, M., Simental, J.A., Lane, M.V., Wilson, E.M., A ligand-dependent bipartite nuclear targeting signal in the human androgen receptor. Requirement for the DNA-binding domain and modulation by NH2-terminal and carboxyl-terminal sequences (1994) J Biol Chem, 269, pp. 13115-13123; Watson, P.A., Chen, Y.F., Balbas, M.D., Wongvipat, J., Socci, N.D., Constitutively active androgen receptor splice variants expressed in castration-resistant prostate cancer require full-length androgen receptor (2010) Proc Natl Acad Sci U S A, 107, pp. 16759-16765; Zhang, B., Kirov, S., Snoddy, J., WebGestalt: an integrated system for exploring gene sets in various biological contexts (2005) Nucleic Acids Res, 33, pp. W741-W748; Shang, Y., Myers, M., Brown, M., Formation of the androgen receptor transcription complex (2002) Mol Cell, 9, pp. 601-610; Hsia, D.A., Tepper, C.G., Pochampalli, M.R., Hsia, E.Y., Izumiya, C., KDM8, a H3K36me2 histone demethylase that acts in the cyclin A1 coding region to regulate cancer cell proliferation (2010) Proc Natl Acad Sci U S A, 107, pp. 9671-9676; Ji, H., Jiang, H., Ma, W., Johnson, D.S., Myers, R.M., An integrated software system for analyzing ChIP-chip and ChIP-seq data (2008) Nat Biotechnol, 26, pp. 1293-1300; Ji, H., Wong, W.H., TileMap: create chromosomal map of tiling array hybridizations (2005) Bioinformatics, 21, pp. 3629-3636; Shen, R., Dorai, T., Szaboles, M., Katz, A.E., Olsson, C.A., Transdifferentiation of cultured human prostate cancer cells to a neuroendocrine cell phenotype in a hormone-depleted medium (1997) Urol Oncol, 3, pp. 67-75; Wheeler, A.P., Ridley, A.J., Why three Rho proteins? RhoA, RhoB, RhoC, and cell motility (2004) Exp Cell Res, 301, pp. 43-49; Prendergast, G.C., Actin' up: RhoB in cancer and apoptosis (2001) Nat Rev Cancer, 1, pp. 162-168; Chen, C.D., Welsbie, D.S., Tran, C., Baek, S.H., Chen, R., Molecular determinants of resistance to antiandrogen therapy (2004) Nat Med, 10, pp. 33-39; Tararova, N.D., Narizhneva, N., Krivokrisenko, V., Gudkov, A.V., Gurova, K.V., Prostate cancer cells tolerate a narrow range of androgen receptor expression and activity (2007) Prostate, 67, pp. 1801-1815; Ceraline, J., Cruchant, M.D., Erdmann, E., Erbs, P., Kurtz, J.E., Constitutive activation of the androgen receptor by a point mutation in the hinge region: a new mechanism for androgen-independent growth in prostate cancer (2004) Int J Cancer, 108, pp. 152-157; Burnstein, K.L., Regulation of androgen receptor levels: implications for prostate cancer progression and therapy (2005) J Cell Biochem, 95, pp. 657-669; Wolf, D.A., Herzinger, T., Hermeking, H., Blaschke, D., Horz, W., Transcriptional and posttranscriptional regulation of human androgen receptor expression by androgen (1993) Mol Endocrinol, 7, pp. 924-936; Blok, L.J., Themmen, A.P., Peters, A.H., Trapman, J., Baarends, W.M., Transcriptional regulation of androgen receptor gene expression in Sertoli cells and other cell types (1992) Mol Cell Endocrinol, 88, pp. 153-164; Grad, J.M., Dai, J.L., Wu, S., Burnstein, K.L., Multiple androgen response elements and a Myc consensus site in the androgen receptor (AR) coding region are involved in androgen-mediated up-regulation of AR messenger RNA (1999) Mol Endocrinol, 13, pp. 1896-1911; Kumar, M.V., Jones, E.A., Grossmann, M.E., Blexrud, M.D., Tindall, D.J., Identification and characterization of a suppressor element in the 5′-flanking region of the mouse androgen receptor gene (1994) Nucleic Acids Res, 22, pp. 3693-3698; Wang, L.G., Ossowski, L., Ferrari, A.C., Androgen receptor level controlled by a suppressor complex lost in an androgen-independent prostate cancer cell line (2004) Oncogene, 23, pp. 5175-5184; Cai, C., He, H.H., Chen, S., Coleman, I., Wang, H., Androgen receptor gene expression in prostate cancer is directly suppressed by the androgen receptor through recruitment of lysine-specific demethylase 1 (2011) Cancer Cell, 20, pp. 457-471; Ding, X.F., Anderson, C.M., Ma, H., Hong, H., Uht, R.M., Nuclear receptor-binding sites of coactivators glucocorticoid receptor interacting protein 1 (GRIP1) and steroid receptor coactivator 1 (SRC-1): multiple motifs with different binding specificities (1998) Mol Endocrinol, 12, pp. 302-313; Jenster, G., van der Korput, H.A., Trapman, J., Brinkmann, A.O., Identification of two transcription activation units in the N-terminal domain of the human androgen receptor (1995) J Biol Chem, 270, pp. 7341-7346; Hu, R., Lu, C., Mostaghel, E.A., Yegnasubramanian, S., Gurel, M., Distinct transcriptional programs mediated by the ligand-dependent full-length androgen receptor and its splice variants in castration-resistant prostate cancer (2012) Cancer Res, 72, pp. 3457-3462; Bourboulia, D., Stetler-Stevenson, W.G., Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs): Positive and negative regulators in tumor cell adhesion (2010) Semin Cancer Biol; Karlsson, R., Pedersen, E.D., Wang, Z., Brakebusch, C., Rho GTPase function in tumorigenesis (2009) Biochim Biophys Acta, 1796, pp. 91-98; Mazieres, J., Antonia, T., Daste, G., Muro-Cacho, C., Berchery, D., Loss of RhoB expression in human lung cancer progression (2004) Clin Cancer Res, 10, pp. 2742-2750; Bousquet, E., Mazieres, J., Privat, M., Rizzati, V., Casanova, A., Loss of RhoB expression promotes migration and invasion of human bronchial cells via activation of AKT1 (2009) Cancer Res, 69, pp. 6092-6099; Fritz, G., Brachetti, C., Bahlmann, F., Schmidt, M., Kaina, B., Rho GTPases in human breast tumours: expression and mutation analyses and correlation with clinical parameters (2002) Br J Cancer, 87, pp. 635-644; Vasilaki, E., Papadimitriou, E., Tajadura, V., Ridley, A.J., Stournaras, C., Transcriptional regulation of the small GTPase RhoB gene by TGF{beta}-induced signaling pathways (2010) FASEB J, 24, pp. 891-905; Yoneda, M., Hirokawa, Y.S., Ohashi, A., Uchida, K., Kami, D., RhoB enhances migration and MMP1 expression of prostate cancer DU145 (2010) Exp Mol Pathol, 88, pp. 90-95

PY - 2012/11

Y1 - 2012/11

N2 - Recent studies identifying putative truncated androgen receptor isoforms with ligand-independent activity have shed new light on the acquisition of androgen depletion independent (ADI) growth of prostate cancer. In this study, we present a model system in which a C-terminally truncated variant of androgen receptor (TC-AR) is inducibly expressed in LNCaP, an androgen-dependent cell line, which expresses little truncated receptor. We observed that when TC-AR is overexpressed, the endogenous full length receptor (FL-AR) is transcriptionally downmodulated. This in essence allows us to "replace" FL-AR with TC-AR and compare their individual properties in exactly the same genetic and cellular background, which has not been performed before. We show that the TC-AR translocates to the nucleus, activates transcription of AR target genes in the absence of DHT and is sufficient to confer ADI growth to the normally androgen dependent LNCaP line. We also show that while there is significant overlap in the genes regulated by FL- and TC-AR there are also differences in the respective suites of target genes with each AR form regulating genes that the other does not. Among the genes uniquely activated by TC-AR is RHOB which is shown to be involved in the increased migration and morphological changes observed in LN/TC-AR, suggesting a role of RHOB in the regulation of androgen-independent behavior of prostate cancer cells. © 2012 Tsai et al.

AB - Recent studies identifying putative truncated androgen receptor isoforms with ligand-independent activity have shed new light on the acquisition of androgen depletion independent (ADI) growth of prostate cancer. In this study, we present a model system in which a C-terminally truncated variant of androgen receptor (TC-AR) is inducibly expressed in LNCaP, an androgen-dependent cell line, which expresses little truncated receptor. We observed that when TC-AR is overexpressed, the endogenous full length receptor (FL-AR) is transcriptionally downmodulated. This in essence allows us to "replace" FL-AR with TC-AR and compare their individual properties in exactly the same genetic and cellular background, which has not been performed before. We show that the TC-AR translocates to the nucleus, activates transcription of AR target genes in the absence of DHT and is sufficient to confer ADI growth to the normally androgen dependent LNCaP line. We also show that while there is significant overlap in the genes regulated by FL- and TC-AR there are also differences in the respective suites of target genes with each AR form regulating genes that the other does not. Among the genes uniquely activated by TC-AR is RHOB which is shown to be involved in the increased migration and morphological changes observed in LN/TC-AR, suggesting a role of RHOB in the regulation of androgen-independent behavior of prostate cancer cells. © 2012 Tsai et al.

KW - androgen receptor

KW - doxycycline

KW - heterodimer

KW - messenger RNA

KW - article

KW - biological model

KW - carboxy terminal sequence

KW - cell migration

KW - cell shape

KW - cell strain LNCaP

KW - controlled study

KW - gene

KW - gene activation

KW - gene identification

KW - gene silencing

KW - gene targeting

KW - genetic transcription

KW - protein expression

KW - protein function

KW - protein localization

KW - receptor down regulation

KW - reverse transcription polymerase chain reaction

KW - RHOB gene

KW - transcription regulation

KW - upregulation

KW - Androgens

KW - Cell Line, Tumor

KW - Cell Movement

KW - Cell Nucleus

KW - Chromatin

KW - Dihydrotestosterone

KW - Doxycycline

KW - Gene Expression Regulation, Neoplastic

KW - Gene Knockdown Techniques

KW - Humans

KW - Male

KW - Prostatic Neoplasms

KW - Protein Binding

KW - Protein Multimerization

KW - Protein Transport

KW - Receptors, Androgen

KW - Reproducibility of Results

KW - Response Elements

KW - rhoB GTP-Binding Protein

KW - RNA, Messenger

KW - Transcription, Genetic

U2 - 10.1371/journal.pone.0049887

DO - 10.1371/journal.pone.0049887

M3 - Article

VL - 7

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 11

ER -