Human Molecular Genetics, 2000, Vol. 9, No. 2 267-274
© 2000 Oxford University Press
Inhibition of p160-mediated coactivation with increasing androgen receptor polyglutamine length
1Department of Urology, University of Southern California—Norris Cancer Center, 2Department of Molecular Microbiology and Immunology, 3Department of Pathology, 4Department of Biochemistry and Molecular Biology and 5Department of Preventive Medicine, University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
Received 16 September 1999; Revised and Accepted 5 November 1999.
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
Normal polymorphic size variation of the exon 1 CAG microsatellite of the androgen receptor (AR) is associated with prostate cancer, benign prostatic hyperplasia and male infertility. Furthermore, abnormal expansion of the satellite leads to Kennedy’s disease. We have shown recently that the AR N-terminal domain (NTD), which contains the polyglutamine (polyQ) stretch (encoded by the CAG repeat), functionally interacts with the C-termini of p160 coactivators. In the present study we explored possible AR CAG size effects on the p160 coactivator-mediated transactivation activity of the receptor. First, we mapped the p160 coactivator interaction on the AR NTD and found an interaction surface between amino acids 351 and 537. Although this region is ‘downstream’ from the polyQ stretch, it is still within the AR NTD, is implicated in constitutive transactivation activity of the receptor, and thus might be subject to polyQ size modulation. Indeed, cotrans- fection experiments in cultured prostate epithelial cells, using AR constructs of varying CAG sizes and p160 coactivator expression vectors, revealed that increased polyQ length, up to a size of 42 repeats, inhibited both basal and coactivator-mediated AR transactivation activity. AR expression in these cells, on the other hand, was unaffected by the same increased CAG repeat size range. We conclude that the AR NTD contributes to AR transactivation activity via functional interactions with p160 coactivators and that increasing polyQ length negatively affects p160-mediated coactivation of the AR. This molecular mechanism thus might explain, at least in part, the observed phenotypic effects of the AR CAG size polymorphism.
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
The androgen receptor (AR) is a ligand-dependent transcription factor and a member of the superfamily of nuclear receptors (NRs) (1). AR activity is required for the growth, differentiation and maintenance of male reproductive tissues, including the prostate (for reviews see refs 2,3). The AR gene is located on the long arm of the X chromosome (i.e. Xq11–12) and comprises eight exons (4). Exon 1 contains two polymorphic trinucleotide microsatellites, CAG and GGN, that code for variable-length polyglutamine (polyQ) and polyglycine tracts, respectively, in the AR protein. Expansion of the CAG microsatellite to ~40 or more repeats causes a rare, adult-onset, neurodegenerative disorder called spinal and bulbar muscular atrophy (SBMA) or Kennedy’s disease (5,6). Men with this disease frequently develop partial androgen insensitivity (7,8) and this has been correlated with decreased transactivation activity of the mutant AR protein (9,10). Increased CAG sizes within the normal range have also been associated with male infertility (11–13). Indeed, an inverse relationship between AR transactivation activity and CAG size has been demonstrated over an extended size range encompassing that of normal AR alleles (i.e. ~7–36 CAGs) (11,14).
The association of AR CAG repeat length with prostate cancer risk has been studied extensively in recent years (for reviews see refs 15,16). In a 1995 study (17), we showed that racial–ethnic variations in CAG repeat length correlated with prostate cancer risk among men in Los Angeles such that an excess of AR alleles with short CAGs was found in high-risk African-Americans relative to intermediate-risk Whites and low-risk Asian-Americans. Consistent with this finding, we subsequently demonstrated a 2-fold increased risk of prostate cancer among White men with short CAGs (i.e. <20 repeats); this genotype–prostate cancer relationship was especially pronounced for advanced disease (18). These novel observations were later confirmed by two large-scale studies on prostate cancer risk in US Whites (19,20). In particular, Giovannucci et al. (19) detailed a highly significant inverse linear relationship between CAG size and risk for prostate cancer. Associations between AR CAG length and risk of benign prostatic hyperplasia (BPH) have also been observed (21,22). Thus, based on epidemiological and in vitro transactivation studies, a general paradigm has emerged to explain AR function in prostate cancer and BPH risk: longer CAG alleles encode less active receptors that protect against tumorigenesis by causing decreased epithelial cell proliferation. However, the molecular mechanisms that underlie changes in AR transactivation activity due to CAG repeat variation remain largely unknown.
The AR, like other members of the nuclear hormone receptor family, comprises three distinct structural/functional domains: a poorly conserved N-terminal domain (NTD) encoded by exon 1 of the AR gene; a cysteine-rich DNA-binding domain (DBD); and a C-terminal ligand-binding domain (LBD) (1). The NTD contains a ligand-independent, constitutive activation function (generally referred to as AF-1) that is repressed by the apo- or unliganded LBD in the wild-type (wt) AR (23). Deletion mapping studies have localized the NTD activation function to two overlapping but distinct transcriptional activation units (TAUs) called TAU-1 and -5 (24). Moreover, the rat AR TAU-1 area has subsequently been shown to contain two non-contiguous transactivation regions (25). These regions, termed AF-1a and -1b, correspond to amino acids 172–185 and 296–359, respectively, in the human AR. The AR LBD also contains an activation function (i.e. AF-2) but, unlike AF-1, AF-2 is ligand dependent (26,27). Agonist binding to the apo-LBD promotes conformational changes that position the AF-2 core domain appropriately for interactions with NR coactivators (see below). Importantly, targeted transactivation of AR-responsive genes requires the coordinated activities of both AF-1 and AF-2, although their relative contributions to this process can vary depending on the promoter and cellular context (24,28).
Much information has been accrued about how NRs mediate the transactivation of target genes. In general, liganded, dimerized and DNA-bound NRs recruit to the target promoter a large, multisubunit coactivator complex that possesses histone acetyltransferase (HAT) activity (for reviews see refs 29,30). Presumably, through chromatin remodeling and stabilization of the PolII-containing pre-initiation complex (PIC), activated transcription of target genes occurs (30). Central to the NR coactivator complex is a family of 160 kDa proteins (i.e. p160 coactivators) which bind to the LBD (specifically to the AF-2 core domain) of the NR in a ligand-dependent manner via leucine-rich motifs in the coactivators (i.e. LXXLL, where X is any amino acid) called NR boxes (31–33). Three genetically distinct members of the p160 coactivator family have been characterized [i.e. (i) SRC-1/NcoA-1; (ii) AIB1/pCIP/ACTR/TRAM-1/RAC3; and (iii) GRIP1/TIF2/NcoA-2 (29, and references therein)], all of which contain two autonomous activation domains: AD1 and AD2. It is through the centrally located AD1 that interactions with the coactivator, CREB-binding protein (CBP), are mediated, whereas interactions with a novel protein methyltransferase occur via the C-terminal AD2 (34). In transfection experiments, p160 coactivators markedly potentiate NR-mediated transactivation of reporter genes.
Recently, however, it was revealed that p160 coactivators interact with the NTDs of the estrogen receptor (ER) (35,36), the progesterone receptor (PR) (37) and the AR (38) in addition to binding to their respective LBDs. Moreover, AF-1 of each of these NRs was enhanced by this p160 interaction, indicating that AF-1, similarly to AF-2, works at least partially through p160 recruitment. However, since the NTD is the least conserved domain among the NRs, it is likely that the functional relevance of this NTD–p160 contact will vary from receptor to receptor. In the present study, we mapped on the AR NTD the interaction with the p160 coactivator GRIP1 and assessed whether or not p160-mediated coactivation of the AR was influenced by size variations in the NTD polyQ tract (i.e. encoded by the exon 1 CAG repeat).
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
GRIP1 C-terminus binds to the AR NTD downstream of the TAU-1 core region
The AR NTD-GRIP1 C-terminal interaction, previously shown by us to occur in yeast two-hybrid and glutathione S-transferase (GST) pull-down experiments (38), was mapped on the AR NTD. Three overlapping fragments of the AR NTD (amino acids 2–156, 141–366 and 351–538), were expressed as GAL4 AD fusions in the yeast reporter strain along with the GRIP1 C-terminus (amino acids 1122–1462)–GAL4 DBD fusion protein (Fig. 1B). The GRIP1 C-terminal fragment interacted with the AR NTD (amino acids 351–538) fragment but did not bind to either the AR NTD (amino acids 2–156) or (amino acids 141–366) fragments. Thus, a novel GRIP1 interaction surface in the AR NTD is situated downstream of the TAU-1 core region (24) (Fig. 1A).
|
Variation in the AR polyQ tract affects AR transactivation activity
To assess the impact of polyQ size variation on basal AR transactivation activity, several unique vectors were constructed that expressed AR with 9, 21, 29, 42 or 50 glutamine residues in the polyQ tract [i.e. AR(Q)9, AR(Q)21, etc.]. AR(Q)42 and AR(Q)50 are representative mutant SBMA receptors. Ligand-binding assays were performed to estimate the steady-state expression levels of the different AR alleles in PC-3 cells (Fig. 2). Extracts prepared from PC-3 cells transfected with equal amounts of AR expression vector demonstrated similar [3H]dihydrotestosterone (DHT)-binding activity for receptors containing from 9 to 42 glutamines. The ligand-binding activity of AR(Q)50 extracts, however, was significantly lower than the others (P < 0.001; Student’s t-test).
|
To test whether the measured ligand-binding activities correlated with relative AR(Q)n expression levels, anti-AR western blots were carried out on whole-cell extracts from transfected PC-3 cells, and the resultant autoradiograms were quantified by densitometric scanning (Fig. 3A). The relative expression levels determined by this technique for AR(Q)9–AR(Q)42 correlated with ligand-binding activities. In contrast, no full-length AR(Q)50 was detected by this method, suggesting that this protein is markedly unstable in PC-3 cells exposed to DHT for 24 h (Fig. 3A, inset representative autoradiogram). Indeed, an immunopositive band of ~70 kDa, presumably a degradation product, was detected in protein extracts, its amount (relative to the native AR band) increasing with AR polyQ size. The experiment depicted in Figure 3B demonstrates the linear relationship between increasing AR protein content and optical density (OD) of the autoradiographic bands under the conditions used for the quantitative western analyses.
|
Next, a series of transient transfection assays was performed to determine the effect, if any, of the NTD polyQ on AR-mediated transactivation of the MTV-CAT reporter in PC-3 cells (Fig. 4). After correction for expression levels, a statistically significant inverse relationship between polyQ length and AR transactivation activity was observed. There was an ~20% reduction in transactivation activity between AR(Q)9 and AR(Q)42 (P for linear trend = 0.0001; analysis of variance) (Fig. 4). The mean transactivation activity of AR(Q)50 was 80% less than that of AR(Q)9 and the difference was statistically significant (P = 0.0001; analysis of variance).
|
Increasing polyQ length inhibits p160-mediated coactivation of the AR
To determine the effect of polyQ length on p160-mediated coactivation of the AR, a succession of transient cotransfection experiments was performed in which the various AR alleles [AR(Q)9–AR(Q)42] were co-expressed in PC-3 cells along with AIB1, SRC-1a or GRIP1 NR box mutant (Fig. 5). GRIP1(NR*) was used since we have previously shown (38) that this mutant, in which NR boxes II and III were mutated from LXXLL to LXXAA, is unable to mediate transactivation activity via the AR LBD. Thus, this mutant works solely through the NTD of the AR. In each case, DHT-dependent, p160-mediated coactivation of the AR decreased with increasing AR polyQ length. For example, with AIB1, coactivation, measured as DHT-dependent AR activity in the presence of coactivator (Fig. 5, black histograms) minus AR activity in the absence of coactivator (gray histograms), was ~44% lower with AR(Q)42 than with AR(Q)9. The comparable values for SRC-1a and GRIP1(NR*) were 53 and 45%, respectively. In all cases, the relative coactivation levels with AR(Q)42 and with AR(Q)29 were significantly lower than that with AR(Q)9 (Student’s t-test; data not shown). Tests of trend (analysis of variance) revealed a highly significant inverse relationship between AR transactivation activity in the presence of coactivator (Fig. 5, black histograms) and AR polyQ length [polyQ effect, linear trend with AIB1, P < 0.001; polyQ effect, linear trend with SRC-1a, P = 0.003; polyQ effect, linear trend with GRIP1(NR*), P = 0.005]. Although we used GRIP1(NR*) in these experiments (as stated above, this mutant effectively isolates the AR NTD–p160 interaction), similar results were observed with GRIP1 (full length) (data not shown).
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
In light of the epidemiological findings with AR CAG genotype and prostate cancer risk, BPH, sperm production and male infertility, we endeavored to understand the potential molecular mechanism(s) by which apparently normal AR function can lead to the differential phenotypes in men. To this end, physical and functional interactions between the AR NTD, which contains the polymorphic polyQ tract (encoded by the CAG repeat), and a key component of the NR coactivator complex, the p160 coactivator GRIP1, were investigated (38). We observed positive, functional interactions between the AR NTD and a C-terminal fragment of GRIP1 (38). These results lead to a postulated model that predicts a complex AR–GRIP1 interaction involving two distinct binding surfaces in each molecule. Moreover, the model suggests a mechanism for AR AF-1/AF-2 coordination whereby the p160 coactivator bridges communications between the NTD and the LBD through direct contacts. Indeed, this notion is further supported by experiments demonstrating p160-mediated enhancement of the ligand-dependent, cooperative transactivation of a target gene by separate NR LBD and NTD polypeptides (39,40). This putative mechanism may be universal among the Class I steroid hormone receptors since recent reports have shown binding of p160 coactivators to the NTDs of ER
(35,36) and the PR (37). As with the AR, interactions between ER NTD and GRIP1 required the C-terminus of GRIP1 (amino acids 1122–1462) (35). The AR NTD-binding domain on GRIP1 was designated NR interaction domain AF-1 (NIDAF-1) (38). The AR NTD–GRIP1 C-terminal interaction was localized on the NTD to amino acids 351–538 (Fig. 1). This part of the AR NTD corresponds to the TAU-5 region (amino acids 360–528) identified by Jenster et al. (24) as sufficient for transactivation by a constitutively active AR mutant lacking the LBD (38). In that study, deletion of amino acids 244–528 from wt AR resulted in a nearly 80% decrease in ligand-dependent transactivation activity, although deletions of other more N-terminal sequences resulted in comparable deficits. From this and other investigations (41,42), it is clear that almost the entire NTD is required for wt AR transactivation activity, including the region involved in GRIP1 binding. It is intriguing that the newly identified NTD–GRIP1 interface also overlaps with regions of the NTD implicated in interactions with the holo-AR LBD (43–45), the general coactivator CBP (46), and the basal transcription factors TFIIF and TBP (47). This convergence of diverse binding activities on an overlapping region of the NTD suggests a critical function for this domain in the assembly and coordination of a transcriptional activation complex at a target promoter.
To address whether or not variation in the size of the polyQ tract of the AR NTD affects p160-mediated coactivation of the AR, we first assessed AR transactivation activity alone (i.e. without co-expressed coactivator) in PC-3 cells. Following correction for relative AR expression levels, as measured by ligand-binding activity, we found a highly significant inverse relationship between polyQ length and AR transactivation activity on the MTV-CAT reporter gene at saturating DHT concentrations (Figs 2–4). Our findings are consistent with those of others who have shown that in the presence of normal ligand-binding affinities, ARs with increased polyQ length have decreased transactivation activity (9,10,14). On the other hand, our findings do not support those of Gao et al. (41) who found that both expansion and contraction of the polyQ from 20 residues resulted in blunted AR transactivation activity. Furthermore, we found no polyQ-dependent differences in protein expression levels for ARs with polyQ lengths from 9 to 42 (Fig. 3), as has been reported previously (48). We did, however, note a much lower level of expression of AR(Q)50 in PC-3 cells treated with DHT for 24 h (Fig. 3). Since we measured appreciable levels of AR(Q)50 by ligand binding (Fig. 2), in which cells were exposed to DHT for 1 h, we conclude that this protein undergoes ligand-dependent degradation in this cell type. The increasing presence (relative to native AR), with increasing polyQ size, of an ~70 kDa degradation fragment in extracts from transfected PC-3 cells supports the observations of Butler et al. (49) showing increased production of a 74 kDa C-terminally truncated form of an SBMA mutant AR [AR(Q)52] in COS-7 and NB2a/d1 neuroblastoma cells.
Evidence suggests that SBMA mutant ARs become sequestered and degraded in cytoplasmic and nuclear aggregates in a ligand- and polyQ size-dependent manner (49,50), and this phenomenon has been offered as an explanation for the observed decreases in their relative transactivation activities (49). Our data with AR(Q)50 are in agreement with this hypothesis since its low relative transactivation activity is coincident with greatly reduced protein levels (Figs 2 and 4). Lack of AR(Q)50 protein expression, on the other hand, may partially be due to decreased mRNA expression as proposed by Choong et al. (48), although we did not address this issue directly in the present study.
Our observations support the existence of a moderate polyQ size effect on AR transactivation activity in PC-3 cells transfected with AR(Q)9–AR(Q)42. Although the effects were moderate in magnitude, they were statistically highly significant. The moderate magnitude is to be expected, since larger effects probably would not be tolerated by Darwinian selection. Importantly, the phenotypic effects ascribed to the CAG size variation are in most cases the consequence of a lifetime ‘exposure’ to the AR activity differences. What are the mechanism(s) underlying these effects? Presumably, increased polyQ length causes allosteric changes in the AR NTD that negatively influence interactions with the NR coactivator complex and thus result in reduced transactivation potency. Because the co-overexpression of exogenous p160 coactivator (38) or CBP (46,51) results in enhancement of AR-mediated transactivation, endogenous levels of these factors must be limiting. In light of this, measurement of relative AR transactivation activities in the absence of co-expressed coactivator may even result in an underestimation of polyQ effects if the coactivator is itself involved in mediating them. Indeed, in transient cotransfection experiments, relative p160-mediated enhancement of AR activity decreased with increasing polyQ size more dramatically than AR transactivation activity measured alone. Moreover, levels of p160 coactivation were statistically different between ARs with polyQ sizes in the normal size range (9 versus 29). These results suggest that the observed effects of the NTD polyQ on AR transactivation activity are mediated through functional interactions with the NR coactivator complex. With respect to the p160 coactivator, these effects may be direct, consequences of steric hindrance imposed on AR–p160 interactions by increased polyQ size, or indirect, and therefore mediated by other cell-, promoter- and/or AR-specific cofactors. One such cofactor may be a Ras-related nuclear G-protein (Ran) (52), recently shown to bind the polyQ region of the AR NTD and to coactivate the AR in an apparently polyQ size-dependent manner (53).
Although not addressed directly in the present study, it is interesting to note that the GRIP1-binding region of the AR NTD contains two homopolymeric amino acid tracts: polyglycine (polyG) and polyproline (polyP) (Fig. 2A). The polyG tract is encoded by a polymorphic GGN microsatellite, the size of which varies in the normal population from ~8 to 18 repeats. Men with certain AR GGN alleles have a significantly increased risk for prostate cancer (26,29). Very little is known about the role(s) of polyG in AR function, although its deletion resulted in an ~50% decrease in AR transactivation activity (41). We are presently investigating the effects of polyG size variation on p160-mediated coactivation of the AR. The functional relevance of the non-polymorphic polyP tract also remains obscure, although homopolymeric proline tracts can activate transcription when linked to an autologous DBD (54). This transcription potential is likely to be due to polyP-mediated recruitment/stabilization of basal and/or accessory transcription factors.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
Plasmids
Mammalian expression vector pcDNA-hAR was constructed by inserting a pCMV.AR0-derived (25) KpnI–XbaI fragment encoding the full-length human AR into the corresponding restriction endonuclease sites of pcDNA3.1(+) (Invitrogen, Carlsbad, CA). To construct pcDNA-AR(Q)n vectors encoding ARs with different polyQ lengths, NheI–AflII fragments were PCR amplified (primers F1 and R1; Table 1) from genomic DNA samples and inserted into pcDNA-hAR digested with the corresponding restriction enzymes. Mammalian expression vectors pSG5.HA-GRIP1(NR*) (45), pcDNA3.1-AIB1 (55) and pMTV-CAT, which encodes the chloramphenicol acetyltransferase gene (CAT) under the control of the murine mammary tumor virus promoter (56), were described previously.
|
Yeast expression vectors encoding GAL4 AD fused with AR NTD (amino acids 2–538), AR NTD (amino acids 2–156), AR NTD (amino acids 141–366) and AR NTD (amino acids 351–538) were constructed by inserting BamHI–XhoI PCR fragments into the corresponding restriction sites of pACT2 (Clontech, Palo Alto, CA). The PCR primers used were the following: amino acids 2–538, F2 and R2; amino acids 2–156, F2 and R3; amino acids 141–366, F3 and R4; and amino acids 351–538, F4 and R2 (Table 1). Yeast expression vector pGBT9-GRIP1(1122–1462) (34) was described previously.
Yeast two-hybrid assays
Transformations of the Saccharomyces cerevisiae reporter strain CG-1945 (Clontech) were performed according to the LiAc method (57–59). Yeast transformants were grown in selective media deficient in tryptophan and/or leucine. Total cellular extracts were prepared in Z-buffer (60 mM Na2HPO4·7H2O, 40 mM NaH2PO4, 10 mM KCl, 1 mM MgSO4·7H2O) by repeated freezing and thawing. ß-galactosidase (ß-gal) assays were performed using the Luminescent ß-galactosidase Detection kit II (Clontech). ß-gal activities were corrected for culture densities (c.p.m./OD600). Data presented are the means ± SE from three different yeast transformants and are representative of at least two independent experiments.
Cell culture and transfections
PC-3 cells (60) obtained from the American Type Culture Collection (Manassas, VA) were maintained in RPMI medium that contained 10% fetal bovine serum (FBS). Approximately 24 h prior to transfection, 106 cells were seeded into each 60 mm dish. Cells were transfected with Lipofectamine reagent (Life Technologies, Rockville, MD) according to the manufacturer’s protocol with a total amount of 4.5 µg (CAT experiments) or 5.0 µg (ligand-binding assays and western blots) DNA per dish. After transfection, cells were grown in RPMI media (without phenol red) that contained 10% charcoal/dextran-stripped FBS (Gemini Bio Products, Calabasas, CA) for 48 h before harvest; where indicated, medium was supplemented with 10 nM DHT during the last 24 h of growth. Whole-cell extracts were prepared in 0.25 M Tris–HCl pH 8.0 by repeated freezing and thawing. CAT assays were performed using the Quant-T-CAT kit (Amersham Pharmacia Biotech, Piscataway, NJ) and total cellular protein was measured using the BioRad (Hercules, CA) Protein Assay kit. Relative CAT activities (c.p.m./OD595) are shown as the means ± SE of three dishes, each transfected with a unique liposome/DNA preparation.
Western blotting and scanning densitometry
PC-3 cells were maintained and transfected as above. Following 24 h exposure to 10 nM DHT, transfected cells were harvested in 100 µl RIPA buffer (10 mM sodium phosphate pH 7.2, 2 mM EDTA pH 8.0, 150 mM NaCl, 50 mM NaF, 0.1% SDS, 1% Nonidet NP-40, 1% sodium deoxycholate, 0.2 mM Na3VO4) that contained mammalian protease inhibitors. Total cellular protein was measured using the BioRad Protein Assay kit and equal amounts of each extract were analyzed by SDS–PAGE. Proteins were transferred to Hybond-P membrane (Amersham Pharmacia Biotech) and probed with rabbit polyclonal anti-AR antibody AR(N20) (sc-816; Santa Cruz Biotechnology, Santa Cruz, CA) at 1 µg/ml. Horseradish peroxidase-conjugated anti-rabbit IgG (sc-2004; Santa Cruz Biotechnology) was used as the secondary antibody at 80 ng/ml (1:5000 dilution). Proteins were visualized by membrane treatment with Luminol Reagent (Santa Cruz Biotechnology) and exposure to Hyperfilm ECL (Amersham Pharmacia Biotech). Autoradiograms from three independent experiments were analyzed by scanning densitometry using a BioRad Model GS-700 Imaging Densitometer and data are reported as mean OD units ± SE.
Ligand-binding assays
PC-3 cells were maintained and transfected as above. Forty-eight hours after transfection, cells received fresh medium supplemented with 10% charcoal/dextran-stripped FBS and 2 nM [3H]DHT. Following a 1 h incubation at 37°C/5% CO2, cells were washed extensively with ice-cold phosphate-buffered saline that contained 1% bovine serum albumin and then were dissolved in 500 µl of 1% SDS. Total bound c.p.m. was determined by scintillation counting. Non-specific ligand binding (i.e. total bound c.p.m. from cells transfected with 5.0 µg of pcDNA3.1) was subtracted from each value. Data presented are the means ± SE of three dishes, each transfected with a unique liposome/DNA preparation.
|
ACKNOWLEDGEMENTS |
|---|
We thank Lucy Xia for technical assistance and Sue Ingles for valuable discussions. We thank Drs M.-J. Tsai and B.W. O’Malley (Baylor College of Medicine, Houston, TX) for cDNA encoding hSRC-1a, Dr R. Miesfeld (University of Arizona, Tucson, AZ) for the plasmid encoding hAR (pCMV.AR0), Dr P. Meltzer (NHGRI, NIH, Bethesda, MD) for the plasmid encoding AIB1 (pcDNA3.1-AIB1), Dr R.M. Evans (The Salk Institute, La Jolla, CA) for the MTV-CAT reporter plasmid and Dr D.C. Rubinsztein (Cambridge University, Cambridge, UK) for genomic DNA from SBMA patients. This work was supported by NIH grants DK 43093 (to M.R.S.) and CA/OD 72821 (to G.A.C.). R.A.I. was supported by NIH training grants 5 T32 CA 09569 and 5 T32 A107078-17.
|
FOOTNOTES |
|---|
+ To whom correspondence should be addressed at: University of Southern California—Norris Cancer Center, NOR 5421, MS 73, 1441 Eastlake Avenue, Los Angeles, CA 90033, USA. Tel: +1 323 865 0631; Fax: +1 323 865 0634; Email: coetzee_g@froggy.hsc.usc.edu
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
1 Mangelsdorf, D.J., Thummel, C., Beato, M., Herrlich, P., Schutz, G., Umesono K., Blumberg, B., Kastner, P., Mark, M., Chambon, P. and Evans, R.E. (1995) The nuclear receptor superfamily: the second decade. Cell, 83, 835–839.[Web of Science][Medline]
2 Lindzey, J., Kumar, V.M., Grossman, M., Young, C. and Tindall, D.J. (1994) Molecular mechanisms of androgen action. Vitamins Horm., 49, 383–432.[Web of Science][Medline]
3 Choong, C.S. and Wilson, E.M. (1998) Trinucleotide repeats in the human androgen receptor: a molecular basis for disease. Mol. Endocrinol., 21, 235–257.
4 Lubahn, D.B., Brown, T.R., Simental, J.A., Higgs, H.N., Migeon, C.J., Wilson, E.M. and French, F.S. (1989) Sequence of the intron/exon junctions of the coding region of the human androgen receptor gene and identification of a point mutation in a family with complete androgen insensitivity. Proc. Natl Acad. Sci. USA, 86, 9534–9538.
5 La Spada, A.R., Wilson, E.M., Lubahn, D.B., Harding, A.E. and Fischbeck, K.H. (1991) Androgen receptor gene mutations in X-linked spinal and bulbar muscular atrophy. Nature, 352, 77–79.[Medline]
6 La Spada, A.R., Roling, D.B., Harding A.E., Warner, C.L., Spiegel, R., Hausmanowa-Petrusewicz, I., Yee, W.C. and Fischbeck, K.H. (1992) Meiotic stability and genotype–phenotype correlation of the trinucleotide repeat in X-linked spinal and bulbar muscular atrophy. Nature Genet., 2, 301–304.[Web of Science][Medline]
7 Arbizu, T., Santamaria, J., Gomex, J.M., Quilez, A. and Serra, J.P. (1983) A family with adult spinal and bulbar muscular atrophy, X-linked inheritance and associated testicular failure. J. Neurol. Sci., 59, 371–382.[Web of Science][Medline]
8 Nagashima, T., Seko, K., Hirose, K., Mannen, T., Yoshimura, S., Arima, R., Nagashima, K. and Morimatsu, Y. (1988) Familial bulbo-spinal muscular atrophy associated with testicular atrophy and sensory neuropathy (Kennedy-Alter-Sung syndrome). Autopsy case report of two brothers. J. Neurol. Sci., 87, 141–152.[Web of Science][Medline]
9 Mahtre, A.N., Trifiro, M.A., Kaufman, M., Kazemi-Esfarjani, P., Figlewicz, D., Rouleau, G. and Pinsky, L. (1993) Reduced transcriptional regulatory competence of the androgen receptor in X-linked spinal and bulbar muscular atrophy. Nature Genet., 5, 184–188.[Web of Science][Medline]
10 Chamberlain, N.L., Driver, E.D. and Miesfeld, R.L. (1994) The length and location of CAG trinucleotide repeats in the androgen receptor N-terminal domain affect transactivation function. Nucleic Acids Res., 22, 3181–3186.
11 Tut, T.G., Ghadessy, F.J., Trifiro, M.A., Pinsky, L. and Yong, E.L. (1997) Long polyglutamine tracts in the androgen receptor are associated with reduced trans-activation, impaired sperm production, and male infertility. J. Clin. Endocrinol. Metab., 82, 3777–3782.
12 Yong, E.L., Ghadessy, F., Wang, Q., Mifsud, A. and Ng, S.C. (1998) Androgen receptor transactivation domain and control of spermatogenesis. Rev. Reprod., 3, 141–144.[Abstract]
13 Dowsing, A.T., Yong, E.L., Clark, M., McLachlan, R.I., de Kretser, D.M. and Trounson, A.O. (1999) Linkage between male infertility and trinucleotide repeat expansion in the androgen-receptor gene. Lancet, 354, 640–643.[Web of Science][Medline]
14 Kazemi-Esfarjani, P., Trifiro, M.A. and Pinsky, L. (1995) Evidence for a repressive function of the long polyglutamine tract in the human androgen receptor: possible pathogenetic relevance for the (CAG)n-expanded neuronopathies. Hum. Mol. Genet., 4, 523–527.
15 Ross, R.K., Pike, M.C., Coetzee, G.A., Reichardt, J.K.V., Yu, M.C., Feigelson, H., Stanczyk, F.Z., Kolonel, L.N. and Henderson, B.E. (1998) Androgen metabolism and prostate cancer: establishing a model of genetic susceptibility. Cancer Res., 58, 4497–4504.
16 Kantoff, P., Giovannucci, E. and Brown, M. (1998) The androgen receptor CAG repeat polymorphism and its relationship to prostate cancer. Biochim. Biophys. Acta, 1378, C1–C5.[Medline]
17 Irvine, R.A., Yu, M.C., Ross, R.K. and Coetzee, G.A. (1995) The CAG and GGC microsatellites of the androgen receptor gene are in linkage disequilibrium in men with prostate cancer. Cancer Res., 55, 1937–1940.
18 Ingles, S.A., Ross, R.K., Yu, M.C., Irvine, R.A., La Pera, G., Haile, R.W. and Coetzee, G.A. (1997) Association of prostate cancer risk with genetic polymorphisms in vitamin D receptor and androgen receptor. J. Natl Cancer Inst., 89, 166–170.
19 Giovannucci, E., Stampfer, M.J., Krithivas, K., Brown, M., Dahl, D., Brufsky, A., Talcott, J., Hennekens, C.H. and Kantoff, P.W. (1997) The CAG repeat within the androgen receptor gene and its relationship to prostate cancer. Proc. Natl Acad. Sci. USA, 94, 3320–3323.
20 Stanford, J.L., Just, J.J., Gibbs, M., Wichlund, K.G., Neal, C.L., Blumenstein, B.A. and Ostrander, E.A. (1997) Polymorphic repeats in the androgen receptor gene: molecular markers of prostate cancer risk. Cancer Res., 57, 1194–1198.
21 Giovannucci, E., Platz, E.A., Stampfer, M.J., Chan, A., Krithivas, K., Kawachi, I., Willett, W.C. and Kantoff, P.W. (1999) The CAG repeat within the androgen receptor gene and benign prostatic hyperplasia. Urology, 53, 121–125.[Web of Science][Medline]
22 Giovannucci, E., Stampfer, M.J., Chan, A., Krithivas, K., Gann, P.H., Hennekens, C.H. and Kantoff, P.W. (1999) CAG repeat within the androgen receptor gene and incidence of surgery for benign prostatic hyperplasia in U.S. physicians. Prostate, 39, 130–134.[Web of Science][Medline]
23 Jenster, G., van der Korput, H.A.G.M., van Vroonhoven, C., van der Kwast, T.H., Trapman, J. and Brinkmann, A.O. (1991) Domains of the human androgen receptor involved in steroid binding, transcriptional activation, and subcellular localization. Mol. Endocrinol., 5, 1396–1404.
24 Jenster, G., van der Korput, H.A.G.M., Trapman, J. and Brinkmann, A.O. (1995) Identification of two transcription activation units in the N-terminal domain of the human androgen receptor. J. Biol. Chem., 270, 7341–7346.
25 Chamberlain, N.L., Whitacre, D.C. and Miesfeld, R.L. (1996) Delineation of two distinct type 1 activation functions in the androgen receptor amino-terminal domain. J. Biol. Chem., 271, 26772–26778.
26 Danielian, P.S., White, R., Lees, J.A. and Parker, M.G. (1992) Identification of a conserved region required for hormone dependent transcriptional activation by steroid hormone receptors. EMBO J., 11, 1025–1033.[Web of Science][Medline]
27 Moras, D. and Gronemeyer, H. (1998) The nuclear receptor ligand-binding domain: structure and function. Curr. Opin. Cell Biol., 10, 384–391.[Web of Science][Medline]
28 Snoek, R., Bruchovsky, N., Kasper, S., Matusik, R.J., Gleave, M., Sato, N., Mawji, N.R. and Rennie, P.S. (1988) Differential transactivation by the androgen receptor in prostate cancer cells. Prostate, 36, 256–263.
29 Torchia, J., Glass, C. and Rosenfeld, M.G. (1998) Co-activators and co-repressors in the integration of transcriptional responses. Curr. Opin. Cell Biol., 10, 373–383.[Web of Science][Medline]
30 Xu, L., Glass, C. and Rosenfeld, M.G. (1999) Coactivator and corepressor complexes in nuclear receptor function. Curr. Opin. Genet. Dev., 9, 140–147.[Web of Science][Medline]
31 Heery, D.M., Kalkhoven, E., Hoare, S. and Parker, M.G. (1997) A signature motif in transcriptional co-activators mediates binding to nuclear receptors. Nature, 387, 733–736.[Medline]
32 Torchia, J., Rose, D.W., Inostroza, J., Kamei, Y., Westin, S., Glass, C.K. and Rosenfeld, M.G. (1997) The transcriptional co-activator p/CIP binds CBP and mediates nuclear-receptor function. Nature, 387, 677–684.[Medline]
33 Ding, X.F., Anderson, C.M., Ma, H., Hong, H., Uht, R.M., Kushner, P.J. and Stallcup, M.R. (1998) 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. Mol. Endocrinol., 12, 302–313.
34 Chen, D., Ma, H., Hong, H., Koh, S.S., Huang, S.-M., Schurter, B.T., Aswad, D.W. and Stallcup, M.R. (1999) Regulation of transcription by a protein methyltransferase. Science, 284, 2174–2177.
35 Webb, P., Nguyen, P., Shinsako, J., Anderson, C., Feng, W., Nguyen, M.P., Chen, D., Huang, S.-M., Subramanian, S., McKinerney, E. et al. (1998) Estrogen receptor activation function 1 works by binding p160 coactivator proteins. Mol. Endocrinol., 12, 1605–1618.
36 Lavinsky, R.M., Jepsen, K., Heinzel, T., Torchia, J., Mullen, T.-M., Schiff, R., Del-Rio, A.L., Ricote, M., Ngo, S., Gemsch, J. et al. (1998) Diverse signaling pathways modulate nuclear receptor recruitment of N-CoR and SMRT complexes. Proc. Natl Acad. Sci. USA, 95, 2920–2925.
37 Onate, S.A., Boonyaratanakornkit, V., Spencer, T.E., Tsai, S.Y., Tsai, M.-J., Edwards, D.P. and O’Malley, B. (1998) The steroid receptor coactivator-1 contains multiple receptor interacting and activation domains that cooperatively enhance the activation function 1 (AF1) and AF2 domains of steroid receptors. J. Biol. Chem., 273, 12101–12108.
38 Ma, H., Hong, H., Huang, S.-M., Irvine, R.A., Webb, P., Kushner, P.J., Coetzee, G.A. and Stallcup, M.R. (1999) Multiple signal input and output domains of the 160-kDa nuclear receptor coactivator proteins. Mol. Cell. Biol., 19, 6164–6173.
39 McInerney, E.M., Tsai, M.-J., O’Malley, B.W. and Katzenellenbogen, B.S. (1996) Analysis of estrogen receptor transcriptional enhancement by a nuclear hormone receptor coactivator. Proc. Natl Acad. Sci. USA, 93, 10069–10073.
40 Ikonen, T., Palvino, J.J. and Janne, O.A. (1997) Interaction between the amino- and carboxyl-terminal regions of the rat androgen receptor modulates transcriptional activity and is influenced by nuclear receptor coactivators. J. Biol. Chem., 272, 29821–29828.
41 Gao, T., Marcelli, M. and McPaul, M.J. (1996) Transcriptional activation and transient expression of the human androgen receptor. J. Steroid Biochem. Mol., 59, 9–20.
42 Gast, A., Schneikert, J. and Cato, C.B. (1998) N-terminal sequences of the human androgen receptor in DNA binding and transrepressing functions. J. Steroid Biochem. Mol., 65, 117–123.
43 Langley, E., Zhou, Z. and Wilson, E. (1995) Evidence for an anti-parallel orientation of the ligand-activated human androgen receptor dimer. J. Biol. Chem., 270, 29983–29990.
44 Doesburg, P., Kuil, C.W., Berrevoets, C.A., Steketee, K., Faber, P.W., Mulder, E., Brinkmann, A.O. and Trapman, J. (1997) Functional in vivo interaction between the amino-terminal, transactivation domain and the ligand binding domain of the androgen receptor. Biochemistry, 36, 1052–1064.[Medline]
45 Berrevoets, C.A., Doesburg, P., Steketee, K., Trapman, J. and Brinkmann, A.O. (1998) Functional interactions of the AF-2 activation domain core region of the human androgen receptor with the amino-terminal domain and with the transcriptional coactivator TIF2 (transcriptional intermediary factor2). Mol. Endocrinol., 12, 1172–1183.
46 Fronsdal, K., Engedal, N., Slagsvold, T. and Saatcioglu, F. (1998) CREB binding protein is a coactivator for the androgen receptor and mediates cross-talk with AP-1. J. Biol. Chem., 273, 31853–31859.
47 McEwan, I.J. and Gustafsson, J.-A. (1997) Interaction of the human androgen receptor transactivation function with the general transcription factor TFIIF. Proc. Natl Acad. Sci. USA, 94, 8485–8490.
48 Choong, C.S., Kemppainen, J.A., Zhou, Z. and Wilson, E.M. (1996) Reduced androgen receptor gene expression with first exon CAG repeat expansion. Mol. Endocrinol., 10, 1527–1535.
49 Butler, R., Leigh, P.N., McPhaul, M.J. and Gallo, J.-M. (1998) Truncated forms of the androgen receptor are associated with polyglutamine expansion in X-linked spinal and bulbar muscular atrophy. Hum. Mol. Genet., 7, 121–127.
50 Stenoien, D.L., Cummings, C.J., Adams, H.P., Mancini, M.G., Kavita, P., Demartino, G.N., Marcelli, M., Weigel, N.L. and Mancini, M.A. (1999) Polyglutamine-expanded androgen receptors form aggregates that sequester heat shock proteins, proteasome components and SRC-1, and are suppressed by the HDJ-2 chaperone. Hum. Mol. Genet., 8, 731–741.
51 Aarnisalo, P., Palvino, J.J. and Janne, O.A. (1998) CREB-binding protein in androgen receptor-mediated signaling. Proc. Natl Acad. Sci. USA, 95, 2122–2127.
52 Bischoff, F.R. and Ponstingl, H. (1991) Mitotic regulator protein RCC1 is complexed with a nuclear ras-related polypeptide. Proc. Natl Acad. Sci. USA, 88, 10830–10834.
53 Hsiao, P.-W., Lin, D.-L., Nakao, R. and Chang, C. (1999) The linkage of Kennedy’s neuron disease to ARA24, the first identified androgen receptor polyglutamine region-associated coactivator. J. Biol. Chem., 274, 20229–20234.
54 Gerber, H.-P., Seipel, K., Georgiev, O., Hofferer, M., Hug, M., Rusconi, S. and Schaffner, W. (1994) Transcriptional activation modulated by homopolymeric glutamine and proline stretches. Science, 263, 808–811.
55 Anzick, S.L., Kononen, J., Walker, R.L., Azorsa, D.O., Tanner, M.M., Guan, X.-Y., Sauter, G., Kallioniemi, O.-P., Trent, J.M. and Meltzer, P.S. (1997) AIB1, a steroid receptor coactivator amplified in breast and ovarian cancer. Science, 277, 965–968.
56 Giguere, V., Hollenberg, S.M. and Evans, R.M. (1986) Functional domains of the human glucocorticoid receptor. Cell, 46, 645–652.[Web of Science][Medline]
57 Schiestl, R.H. and Gietz, R.D. (1989) High efficiency transformation of intact yeast cells using single stranded nucleic acids as a carrier. Curr. Genet., 16, 339–346.[Web of Science][Medline]
58 Hill, J., Donald, K.A.I.G. and Griffiths, D.E. (1991) DMSO-enhanced whole cell yeast transformation. Nucleic Acids Res., 19, 5791.
59 Gietz, D., St Jean, A., Woods, R.A. and Schiestl, R.H. (1992) Improved method for high efficiency transformation of intact yeast cells. Nucleic Acids Res., 20, 1425.
60 Ohnuki, Y., Marnell, M.M., Babcock, M.S., Lechner, J.F. and Kaighn M.E. (1980) Chromosomal analysis of human prostatic adenocarcinoma cell lines. Cancer Res., 40, 524–534.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  E. F. Need, H. I. Scher, A. A. Peters, N. L. Moore, A. Cheong, C. J. Ryan, G. A. Wittert, V. R. Marshall, W. D. Tilley, and G. Buchanan A Novel Androgen Receptor Amino Terminal Region Reveals Two Classes of Amino/Carboxyl Interaction-Deficient Variants with Divergent Capacity to Activate Responsive Sites in Chromatin Endocrinology, June 1, 2009; 150(6): 2674 - 2682. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. P. Steinkamp, O. A. O'Mahony, M. Brogley, H. Rehman, E. W. LaPensee, S. Dhanasekaran, M. D. Hofer, R. Kuefer, A. Chinnaiyan, M. A. Rubin, et al. Treatment-Dependent Androgen Receptor Mutations in Prostate Cancer Exploit Multiple Mechanisms to Evade Therapy Cancer Res., May 15, 2009; 69(10): 4434 - 4442. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Suzuki, Y. Zhao, S. Ito, S. Sawatsubashi, T. Murata, T. Furutani, Y. Shirode, K. Yamagata, M. Tanabe, S. Kimura, et al. Aberrant E2F activation by polyglutamine expansion of androgen receptor in SBMA neurotoxicity PNAS, March 10, 2009; 106(10): 3818 - 3822. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Davies, K. Watt, S. M Kelly, C. Clark, N. C Price, and I. J McEwan Consequences of poly-glutamine repeat length for the conformation and folding of the androgen receptor amino-terminal domain J. Mol. Endocrinol., November 1, 2008; 41(5): 301 - 314. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. M. Centenera, J. M. Harris, W. D. Tilley, and L. M. Butler Minireview: The Contribution of Different Androgen Receptor Domains to Receptor Dimerization and Signaling Mol. Endocrinol., November 1, 2008; 22(11): 2373 - 2382. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S. Perrin, P.-Y. Herve, G. Leonard, M. Perron, G. B. Pike, A. Pitiot, L. Richer, S. Veillette, Z. Pausova, and T. Paus Growth of White Matter in the Adolescent Brain: Role of Testosterone and Androgen Receptor J. Neurosci., September 17, 2008; 28(38): 9519 - 9524. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Albertelli, O. A. O'Mahony, M. Brogley, J. Tosoian, M. Steinkamp, S. Daignault, K. Wojno, and D. M. Robins Glutamine tract length of human androgen receptors affects hormone-dependent and -independent prostate cancer in mice Hum. Mol. Genet., January 1, 2008; 17(1): 98 - 110. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Dehm, K. M. Regan, L. J. Schmidt, and D. J. Tindall Selective Role of an NH2-Terminal WxxLF Motif for Aberrant Androgen Receptor Activation in Androgen Depletion Independent Prostate Cancer Cells Cancer Res., October 15, 2007; 67(20): 10067 - 10077. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Zitzmann and E. Nieschlag Androgen Receptor Gene CAG Repeat Length and Body Mass Index Modulate the Safety of Long-Term Intramuscular Testosterone Undecanoate Therapy in Hypogonadal Men J. Clin. Endocrinol. Metab., October 1, 2007; 92(10): 3844 - 3853. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Wedren, C. Magnusson, K. Humphreys, H. Melhus, A. Kindmark, F. Stiger, M. Branting, I. Persson, J. Baron, and E. Weiderpass Associations between Androgen and Vitamin D Receptor Microsatellites and Postmenopausal Breast Cancer Cancer Epidemiol. Biomarkers Prev., September 1, 2007; 16(9): 1775 - 1783. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B Lapauw, S Goemaere, P Crabbe, J M Kaufman, and J B Ruige Is the effect of testosterone on body composition modulated by the androgen receptor gene CAG repeat polymorphism in elderly men? Eur. J. Endocrinol., March 1, 2007; 156(3): 395 - 401. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Hietala, T. Sandberg, A. Borg, H. Olsson, and H. Jernstrom Testosterone levels in relation to oral contraceptive use and the androgen receptor CAG and GGC length polymorphisms in healthy young women Hum. Reprod., January 1, 2007; 22(1): 83 - 91. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Werner, P.-M. Holterhus, G. Binder, H.-P. Schwarz, M. Morlot, D. Struve, C. Marschke, and O. Hiort The A645D Mutation in the Hinge Region of the Human Androgen Receptor (AR) Gene Modulates AR Activity, Depending on the Context of the Polymorphic Glutamine and Glycine Repeats J. Clin. Endocrinol. Metab., September 1, 2006; 91(9): 3515 - 3520. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Albertelli, A. Scheller, M. Brogley, and D. M. Robins Replacing the Mouse Androgen Receptor with Human Alleles Demonstrates Glutamine Tract Length-Dependent Effects on Physiology and Tumorigenesis in Mice Mol. Endocrinol., June 1, 2006; 20(6): 1248 - 1260. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. M. Butler, M. M. Centenera, P. J. Neufing, G. Buchanan, C. S. Y. Choong, C. Ricciardelli, K. Saint, M. Lee, A. Ochnik, M. Yang, et al. Suppression of Androgen Receptor Signaling in Prostate Cancer Cells by an Inhibitory Receptor Variant Mol. Endocrinol., May 1, 2006; 20(5): 1009 - 1024. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Rajpert-De Meyts Developmental model for the pathogenesis of testicular carcinoma in situ: genetic and environmental aspects Hum. Reprod. Update, May 1, 2006; 12(3): 303 - 323. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Callewaert, N. Van Tilborgh, and F. Claessens Interplay between Two Hormone-Independent Activation Domains in the Androgen Receptor Cancer Res., January 1, 2006; 66(1): 543 - 553. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. M. Kaufman and A. Vermeulen The Decline of Androgen Levels in Elderly Men and Its Clinical and Therapeutic Implications Endocr. Rev., October 1, 2005; 26(6): 833 - 876. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. R. Zinn, P. Ramos, F. F. Elder, K. Kowal, C. Samango-Sprouse, and J. L. Ross Androgen Receptor CAGn Repeat Length Influences Phenotype of 47,XXY (Klinefelter) Syndrome J. Clin. Endocrinol. Metab., September 1, 2005; 90(9): 5041 - 5046. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. L. Terry, I. De Vivo, L. Titus-Ernstoff, M.-C. Shih, and D. W. Cramer Androgen Receptor Cytosine, Adenine, Guanine Repeats, and Haplotypes in Relation to Ovarian Cancer Risk Cancer Res., July 1, 2005; 65(13): 5974 - 5981. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. P. Zeegers, L. A.L.M. Kiemeney, A. M. Nieder, and H. Ostrer How Strong Is the Association Between CAG and GGN Repeat Length Polymorphisms in the Androgen Receptor Gene and Prostate Cancer Risk? Cancer Epidemiol. Biomarkers Prev., November 1, 2004; 13(11): 1765 - 1771. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Buchanan, M. Yang, A. Cheong, J. M. Harris, R. A. Irvine, P. F. Lambert, N. L. Moore, M. Raynor, P. J. Neufing, G. A. Coetzee, et al. Structural and functional consequences of glutamine tract variation in the androgen receptor Hum. Mol. Genet., August 15, 2004; 13(16): 1677 - 1692. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Q. Wang, T. S. Udayakumar, T. S. Vasaitis, A. M. Brodie, and J. D. Fondell Mechanistic Relationship between Androgen Receptor Polyglutamine Tract Truncation and Androgen-dependent Transcriptional Hyperactivity in Prostate Cancer Cells J. Biol. Chem., April 23, 2004; 279(17): 17319 - 17328. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Heinlein and C. Chang Androgen Receptor in Prostate Cancer Endocr. Rev., April 1, 2004; 25(2): 276 - 308. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. G. Nelson, A. M. De Marzo, and W. B. Isaacs Prostate Cancer N. Engl. J. Med., July 24, 2003; 349(4): 366 - 381. [Full Text] [PDF]
|
|
|
|
|
|
T. Okuda, H. Hattori, S. Takeuchi, J. Shimizu, H. Ueda, J. J. Palvimo, I. Kanazawa, H. Kawano, M. Nakagawa, and H. Okazawa PQBP-1 transgenic mice show a late-onset motor neuron disease-like phenotype Hum. Mol. Genet., April 1, 2003; 12(7): 711 - 725. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Jia, J. Kim, H. Shen, P. E. Clark, W. D. Tilley, and G. A. Coetzee Androgen Receptor Activity at the Prostate Specific Antigen Locus: Steroidal and Non-Steroidal Mechanisms Mol. Cancer Res., March 1, 2003; 1(5): 385 - 392. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Li, H. Lee, S. Guo, T. G. Unterman, G. Jenster, and W. Bai AKT-Independent Protection of Prostate Cancer Cells from Apoptosis Mediated through Complex Formation between the Androgen Receptor and FKHR Mol. Cell. Biol., January 1, 2003; 23(1): 104 - 118. [Abstract] [Full Text]
|
|
|
|
|
|
J. Reid, I. Murray, K. Watt, R. Betney, and I. J. McEwan The Androgen Receptor Interacts with Multiple Regions of the Large Subunit of General Transcription Factor TFIIF J. Biol. Chem., October 18, 2002; 277(43): 41247 - 41253. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Chen, N. Lamharzi, N. S. Weiss, R. Etzioni, D. A. Dightman, M. Barnett, D. DiTommaso, and G. Goodman Androgen Receptor Polymorphisms and the Incidence of Prostate Cancer Cancer Epidemiol. Biomarkers Prev., October 1, 2002; 11(10): 1033 - 1040. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. P. Lieberman, G. Harmison, A. D. Strand, J. M. Olson, and K. H. Fischbeck Altered transcriptional regulation in cells expressing the expanded polyglutamine androgen receptor Hum. Mol. Genet., August 15, 2002; 11(17): 1967 - 1976. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S.-H. Yeh, C.-F. Chang, W.-Y. Shau, Y.-W. Chen, H.-C. Hsu, P.-H. Lee, D.-S. Chen, and P.-J. Chen Dominance of Functional Androgen Receptor Allele with Longer CAG Repeat in Hepatitis B Virus-related Female Hepatocarcinogenesis Cancer Res., August 1, 2002; 62(15): 4346 - 4351. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. P. Gelmann Molecular Biology of the Androgen Receptor J. Clin. Oncol., July 1, 2002; 20(13): 3001 - 3015. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C.-Y. Chang and D. P. McDonnell Evaluation of Ligand-Dependent Changes in AR Structure Using Peptide Probes Mol. Endocrinol., April 1, 2002; 16(4): 647 - 660. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ueda, N. Bruchovsky, and M. D. Sadar Activation of the Androgen Receptor N-terminal Domain by Interleukin-6 via MAPK and STAT3 Signal Transduction Pathways J. Biol. Chem., February 22, 2002; 277(9): 7076 - 7085. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M.-W. Yu, Y.-C. Yang, S.-Y. Yang, S.-W. Cheng, Y.-F. Liaw, S.-M. Lin, and C.-J. Chen Hormonal Markers and Hepatitis B Virus-Related Hepatocellular Carcinoma Risk: a Nested Case-Control Study Among Men J Natl Cancer Inst, November 7, 2001; 93(21): 1644 - 1651. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ishii, S. Sato, K. Kosaki, G. Sasaki, K. Muroya, T. Ogata, and N. Matsuo Micropenis and the AR Gene: Mutation and CAG Repeat-Length Analysis J. Clin. Endocrinol. Metab., November 1, 2001; 86(11): 5372 - 5378. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Stanbrough, I. Leav, P. W. L. Kwan, G. J. Bubley, and S. P. Balk Prostatic intraepithelial neoplasia in mice expressing an androgen receptor transgene in prostate epithelium PNAS, September 4, 2001; (2001) 191235898. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. Taplin and S.-M. Ho The Endocrinology of Prostate Cancer J. Clin. Endocrinol. Metab., August 1, 2001; 86(8): 3467 - 3477. [Full Text] [PDF]
|
|
|
|
|
|
Y. Giguere, E. Dewailly, J. Brisson, P. Ayotte, N. Laflamme, A. Demers, V.-I. Forest, S. Dodin, J. Robert, and F. Rousseau Short Polyglutamine Tracts in the Androgen Receptor Are Protective against Breast Cancer in the General Population Cancer Res., August 1, 2001; 61(15): 5869 - 5874. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. R. Rebbeck, Y. Wang, P. W. Kantoff, K. Krithivas, S. L. Neuhausen, A. K. Godwin, M. B. Daly, S. A. Narod, J.-S. Brunet, D. Vesprini, et al. Modification of BRCA1- and BRCA2-associated Breast Cancer Risk by AIB1 Genotype and Reproductive History Cancer Res., July 1, 2001; 61(14): 5420 - 5424. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W.-M. Xue, G. A. Coetzee, R. K. Ross, R. Irvine, L. Kolonel, B. E. Henderson, and S. A. Ingles Genetic Determinants of Serum Prostate-specific Antigen levels in Healthy Men from a Multiethnic Cohort Cancer Epidemiol. Biomarkers Prev., June 1, 2001; 10(6): 575 - 579. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Westberg, F. Baghaei, R. Rosmond, M. Hellstrand, M. Landen, M. Jansson, G. Holm, P. Bjorntorp, and E. Eriksson Polymorphisms of the Androgen Receptor Gene and the Estrogen Receptor {beta} Gene Are Associated with Androgen Levels in Women J. Clin. Endocrinol. Metab., June 1, 2001; 86(6): 2562 - 2568. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Buchanan, N. M. Greenberg, H. I. Scher, J. M. Harris, V. R. Marshall, and W. D. Tilley Collocation of Androgen Receptor Gene Mutations in Prostate Cancer Clin. Cancer Res., May 1, 2001; 7(5): 1273 - 1281. [Abstract] [Full Text]
|
|
|
|
|
|
M.-W. Yu, S.-W. Cheng, M.-W. Lin, S.-Y. Yang, Y.-F. Liaw, H.-C. Chang, T.-J. Hsiao, S.-M. Lin, S.-D. Lee, P.-J. Chen, et al. Androgen-Receptor Gene CAG Repeats, Plasma Testosterone Levels, and Risk of Hepatitis B-Related Hepatocellular Carcinoma J Natl Cancer Inst, December 20, 2000; 92(24): 2023 - 2028. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Park, R. A. Irvine, G. Buchanan, S. S. Koh, J. M. Park, W. D. Tilley, M. R. Stallcup, M. F. Press, and G. A. Coetzee Breast Cancer Susceptibility Gene 1 (BRCA1) Is a Coactivator of the Androgen Receptor Cancer Res., November 1, 2000; 60(21): 5946 - 5949. [Abstract] [Full Text]
|
|
|
|
|
|
A. McCampbell, J. P. Taylor, A. A. Taye, J. Robitschek, M. Li, J. Walcott, D. Merry, Y. Chai, H. Paulson, G. Sobue, et al. CREB-binding protein sequestration by expanded polyglutamine Hum. Mol. Genet., September 1, 2000; 9(14): 2197 - 2202. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Stanbrough, I. Leav, P. W. L. Kwan, G. J. Bubley, and S. P. Balk Prostatic intraepithelial neoplasia in mice expressing an androgen receptor transgene in prostate epithelium PNAS, September 11, 2001; 98(19): 10823 - 10828. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||