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Sample records for androgen transcriptional activation

  1. Repressive effects of resveratrol on androgen receptor transcriptional activity.

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    Wen-feng Shi

    Full Text Available BACKGROUND: The chemopreventive effects of resveratrol (RSV on prostate cancer have been well established; the androgen receptor (AR plays pivotal roles in prostatic tumorigenesis. However, the exact underlying molecular mechanisms about the effects of RSV on AR have not been fully elucidated. A model system is needed to determine whether and how RSV represses AR transcriptional activity. METHODOLOGY: The AR cDNA was first cloned into the retroviral vector pOZ-N and then integrated into the genome of AR-negative HeLa cells to generate the AR(+ cells. The constitutively expressed AR was characterized by monitoring hormone-stimulated nuclear translocation, DNA binding, and transcriptional activation, with the AR(- cells serving as controls. AR(+ cells were treated with RSV, and both AR protein levels and AR transcriptional activity were measured simultaneously. Chromatin immunoprecipitation (ChIP assays were used to detect the effects of RSV on the recruitment of AR to its cognate element (ARE. RESULTS: AR in the AR (+ stable cell line functions in a manner similar to that of endogenously expressed AR. Using this model system we clearly demonstrated that RSV represses AR transcriptional activity independently of any effects on AR protein levels. However, neither the hormone-mediated nucleus translocation nor the AR/ARE interaction was affected by RSV treatment. CONCLUSION: We demonstrated unambiguously that RSV regulates AR target gene expression, at least in part, by repressing AR transcriptional activity. Repressive effects of RSV on AR activity result from mechanisms other than the affects of AR nuclear translocation or DNA binding.

  2. SUMOylation modulates the transcriptional activity of androgen receptor in a target gene and pathway selective manner.

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    Sutinen, Päivi; Malinen, Marjo; Heikkinen, Sami; Palvimo, Jorma J

    2014-07-01

    Androgen receptor (AR) plays an important regulatory role in prostate cancer. AR's transcriptional activity is regulated by androgenic ligands, but also by post-translational modifications, such as SUMOylation. To study the role of AR SUMOylation in genuine chromatin environment, we compared androgen-regulated gene expression and AR chromatin occupancy in PC-3 prostate cancer cell lines stably expressing wild-type (wt) or doubly SUMOylation site-mutated AR (AR-K386R,K520R). Our genome-wide gene expression analyses reveal that the SUMOylation modulates the AR function in a target gene and pathway selective manner. The transcripts that are differentially regulated by androgen and SUMOylation are linked to cellular movement, cell death, cellular proliferation, cellular development and cell cycle. Fittingly, SUMOylation mutant AR cells proliferate faster and are more sensitive to apoptosis. Moreover, ChIP-seq analyses show that the SUMOylation can modulate the chromatin occupancy of AR on many loci in a fashion that parallels their differential androgen-regulated expression. De novo motif analyses reveal that FOXA1, C/EBP and AP-1 motifs are differentially enriched at the wtAR- and the AR-K386R,K520R-preferred genomic binding positions. Taken together, our data indicate that SUMOylation does not simply repress the AR activity, but it regulates AR's interaction with the chromatin and the receptor's target gene selection.

  3. Androgen receptor serine 81 phosphorylation mediates chromatin binding and transcriptional activation.

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    Chen, Shaoyong; Gulla, Sarah; Cai, Changmeng; Balk, Steven P

    2012-03-01

    Our previous findings indicated that androgen receptor (AR) phosphorylation at serine 81 is stimulated by the mitotic cyclin-dependent kinase 1 (CDK1). In this report, we extended our previous study and confirmed that Ser-81 phosphorylation increases during mitosis, coincident with CDK1 activation. We further showed blocking cell cycle at G(1) or S phase did not disrupt androgen-induced Ser-81 phosphorylation and AR-dependent transcription, consistent with a recent report that AR was phosphorylated at Ser-81 and activated by the transcriptional CDK9. To assess the function of Ser-81 phosphorylation in prostate cancer (PCa) cells expressing endogenous AR, we developed a ligand switch strategy using a ligand-binding domain mutation (W741C) that renders AR responsive to the antagonist bicalutamide. An S81A/W741C double mutant AR stably expressed in PCa cells failed to transactivate the endogenous AR-regulated PSA or TMPRSS2 genes. ChIP showed that the S81A mutation prevented ligand-induced AR recruitment to these genes, and cellular fractionation revealed that the S81A mutation globally abrogated chromatin binding. Conversely, the AR fraction rapidly recruited to chromatin after androgen stimulation was highly enriched for Ser-81 phosphorylation. Finally, inhibition of CDK1 and CDK9 decreased AR Ser-81 phosphorylation, chromatin binding, and transcriptional activity. These findings indicate that Ser-81 phosphorylation by CDK9 stabilizes AR chromatin binding for transcription and suggest that CDK1-mediated Ser-81 phosphorylation during mitosis provides a pool of Ser-81 phosphorylation AR that can be readily recruited to chromatin for gene reactivation and may enhance AR activity in PCa.

  4. BTG2 is an LXXLL-dependent co-repressor for androgen receptor transcriptional activity

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    Hu, Xu-Dong [School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou 215123 (China); Meng, Qing-Hui [Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057 (United States); Xu, Jia-Ying; Jiao, Yang [School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou 215123 (China); Ge, Chun-Min [Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057 (United States); Jacob, Asha; Wang, Ping [North Shore University Hospital-Long Island Jewish Medical Center and The Feinstein Institute for Medical Research, Manhasset, NY 11030 (United States); Rosen, Eliot M [Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057 (United States); Fan, Saijun, E-mail: sjfan@suda.edu.cn [School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou 215123 (China)

    2011-01-28

    Research highlights: {yields} BTG2 associates with AR, androgen causes an increase of the interaction. {yields} BTG2 as a co-repressor inhibits the AR-mediated transcription activity. {yields} BTG2 inhibits the transcription activity and expression of PSA. {yields} An intact {sup 92}LxxLL{sup 96} motif is essential and necessary for these activities of BTG2, while the {sup 20}LxxLL{sup 24} motif is not required. {yields} Ectopic expression of BTG2 reduces proliferation of prostate cancer cells. -- Abstract: The tumor suppressor gene, BTG2 has been down-regulated in prostate cancer and the ectopic expression of this gene has been shown to inhibit prostate cancer cell growth. Sequence analysis revealed that the BTG2 protein contains two leucine-rich motifs ({sup 20}LxxLL{sup 24} and {sup 92}LxxLL{sup 96}), which are usually found in nuclear receptor co-factors. Based on this, we postulated that there will be an association between BTG2 and AR. In this study, we discovered that BTG2 directly bound to the androgen receptor (AR) in the absence of 5{alpha}-dihydrotestosterone (DHT), and in the presence of the androgen, this interaction was increased. BTG2 bearing the mutant {sup 20}LxxLL{sup 24} motif bound to AR equally efficient as the wild-type BTG2, while BTG2 bearing the mutant {sup 92}LxxLL{sup 96} motif failed to interact with AR. Functional studies indicated that ectopic expression of BTG2 caused a significant inhibition of AR-mediated transcriptional activity and a decreased growth of prostate cancer cells. Androgen-induced promoter activation and expression of prostate-specific antigen (PSA) are significantly attenuated by BTG2. The intact {sup 92}LxxLL{sup 96} motif is required for these activities. These findings, for the first time, demonstrate that BTG2 complexes with AR via an LxxLL-dependent mechanism and may play a role in prostate cancer via modulating the AR signaling pathway.

  5. The impact of point mutations in the human androgen receptor: classification of mutations on the basis of transcriptional activity.

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    Colin W Hay

    Full Text Available Androgen receptor mediated signaling drives prostate cancer cell growth and survival. Mutations within the receptor occur infrequently in prostate cancer prior to hormonal therapy but become prevalent in incurable androgen independent and metastatic tumors. Despite the determining role played by the androgen receptor in all stages of prostate cancer progression, there is a conspicuous dearth of comparable data on the consequences of mutations. In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation. We report the discovery of a novel prevalent class of androgen receptor mutation that possesses loss of function at low levels of androgen yet transforms to a gain of function at physiological levels. Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity. Therefore, the widely accepted supposition that androgen receptor mutations in prostate cancer result in gain of function is appealing, but mistaken. In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element. We discuss the consequences of these findings and the role of androgen receptor mutations for prostate cancer progression and current treatment options.

  6. Global analysis of transcription in castration-resistant prostate cancer cells uncovers active enhancers and direct androgen receptor targets.

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    Toropainen, Sari; Niskanen, Einari A; Malinen, Marjo; Sutinen, Päivi; Kaikkonen, Minna U; Palvimo, Jorma J

    2016-09-19

    Androgen receptor (AR) is a male sex steroid-activated transcription factor (TF) that plays a critical role in prostate cancers, including castration-resistant prostate cancers (CRPC) that typically express amplified levels of the AR. CRPC-derived VCaP cells display an excessive number of chromatin AR-binding sites (ARBs) most of which localize to distal inter- or intragenic regions. Here, we analyzed direct transcription programs of the AR in VCaP cells using global nuclear run-on sequencing (GRO-seq) and integrated the GRO-seq data with the ARB and VCaP cell-specific TF-binding data. Androgen immediately activated transcription of hundreds of protein-coding genes, including IGF-1 receptor and EGF receptor. Androgen also simultaneously repressed transcription of a large number of genes, including MYC. As functional enhancers have been postulated to produce enhancer-templated non-coding RNAs (eRNAs), we also analyzed the eRNAs, which revealed that only a fraction of the ARBs reside at functional enhancers. Activation of these enhancers was most pronounced at the sites that also bound PIAS1, ERG and HDAC3, whereas binding of HDAC3 and PIAS1 decreased at androgen-repressed enhancers. In summary, our genome-wide data of androgen-regulated enhancers and primary target genes provide new insights how the AR can directly regulate cellular growth and control signaling pathways in CPRC cells.

  7. Transcriptional network of androgen receptor in prostate cancer progression.

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    Takayama, Ken-ichi; Inoue, Satoshi

    2013-08-01

    The androgen receptor belongs to the nuclear receptor superfamily and functions as a ligand-dependent transcription factor. It binds to the androgen responsive element and recruits coregulatory factors to modulate gene transcription. In addition, the androgen receptor interacts with other transcription factors, such as forkhead box A1, and other oncogenic signaling pathway molecules that bind deoxyribonucleic acid and regulate transcription. Androgen receptor signaling plays an important role in the development of prostate cancer. Prostate cancer cells proliferate in an androgen-dependent manner, and androgen receptor blockade is effective in prostate cancer therapy. However, patients often progress to castration-resistant prostate cancer with elevated androgen receptor expression and hypersensitivity to androgen. Recently, comprehensive analysis tools, such as complementary DNA microarray, chromatin immunoprecipitation-on-chip and chromatin immunoprecipitation-sequence, have described the androgen-mediated diverse transcriptional program and gene networks in prostate cancer. Furthermore, functional and clinical studies have shown that some of the androgen receptor-regulated genes could be prognostic markers and potential therapeutic targets for the treatment of prostate cancer, particularly castration-resistant prostate cancer. Thus, identifying androgen receptor downstream signaling events and investigating the regulation of androgen receptor activity is critical for understanding the mechanism of carcinogenesis and progression to castration-resistant prostate cancer.

  8. Histone H4 Lys 20 methyltransferase SET8 promotes androgen receptor-mediated transcription activation in prostate cancer

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    Yao, Lushuai [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Yanyan; Du, Fengxia [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); Han, Xiao [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Xiaohua [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); Niu, Yuanjie [Chawnshang Chang Sex Hormone Research Center, Tianjin Institute of Urology, Tianjin Medical University, Tianjin 300070 (China); Ren, Shancheng, E-mail: renshancheng@gmail.com [Department of Urology, Shanghai Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Sun, Yingli, E-mail: sunyl@big.ac.cn [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China)

    2014-07-18

    Highlights: • Dihydrotestosterone stimulates H4K20me1 enrichment at the PSA promoter. • SET8 promotes AR-mediated transcription activation. • SET8 interacts with AR and promotes cell proliferation. - Abstract: Histone methylation status in different lysine residues has an important role in transcription regulation. The effect of H4K20 monomethylation (H4K20me1) on androgen receptor (AR)-mediated gene transcription remains unclear. Here we show that AR agonist stimulates the enrichment of H4K20me1 and SET8 at the promoter of AR target gene PSA in an AR dependent manner. Furthermore, SET8 is crucial for the transcription activation of PSA. Co-immunoprecipitation analyses demonstrate that SET8 interacts with AR. Therefore, we conclude that SET8 is involved in AR-mediated transcription activation, possibly through its interaction with AR and H4K20me1 modification.

  9. Regulation of the transcriptional coactivator FHL2 licenses activation of the androgen receptor in castrate-resistant prostate cancer.

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    McGrath, Meagan J; Binge, Lauren C; Sriratana, Absorn; Wang, Hong; Robinson, Paul A; Pook, David; Fedele, Clare G; Brown, Susan; Dyson, Jennifer M; Cottle, Denny L; Cowling, Belinda S; Niranjan, Birunthi; Risbridger, Gail P; Mitchell, Christina A

    2013-08-15

    It is now clear that progression from localized prostate cancer to incurable castrate-resistant prostate cancer (CRPC) is driven by continued androgen receptor (AR), signaling independently of androgen. Thus, there remains a strong rationale to suppress AR activity as the single most important therapeutic goal in CRPC treatment. Although the expression of ligand-independent AR splice variants confers resistance to AR-targeted therapy and progression to lethal castrate-resistant cancer, the molecular regulators of AR activity in CRPC remain unclear, in particular those pathways that potentiate the function of mutant AR in CRPC. Here, we identify FHL2 as a novel coactivator of ligand-independent AR variants that are important in CRPC. We show that the nuclear localization of FHL2 and coactivation of the AR is driven by calpain cleavage of the cytoskeletal protein filamin, a pathway that shows differential activation in prostate epithelial versus prostate cancer cell lines. We further identify a novel FHL2-AR-filamin transcription complex, revealing how deregulation of this axis promotes the constitutive, ligand-independent activation of AR variants, which are present in CRPC. Critically, the calpain-cleaved filamin fragment and FHL2 are present in the nucleus only in CRPC and not benign prostate tissue or localized prostate cancer. Thus, our work provides mechanistic insight into the enhanced AR activation, most notably of the recently identified AR variants, including AR-V7 that drives CRPC progression. Furthermore, our results identify the first disease-specific mechanism for deregulation of FHL2 nuclear localization during cancer progression. These results offer general import beyond prostate cancer, given that nuclear FHL2 is characteristic of other human cancers where oncogenic transcription factors that drive disease are activated like the AR in prostate cancer.

  10. Comparative study on transcriptional activity of 17 parabens mediated by estrogen receptor α and β and androgen receptor.

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    Watanabe, Yoko; Kojima, Hiroyuki; Takeuchi, Shinji; Uramaru, Naoto; Ohta, Shigeru; Kitamura, Shigeyuki

    2013-07-01

    The structure-activity relationships of parabens which are widely used as preservatives for transcriptional activities mediated by human estrogen receptor α (hERα), hERβ and androgen receptor (hAR) were investigated. Fourteen of 17 parabens exhibited hERα and/or hERβ agonistic activity at concentrations of ≤ 1 × 10(-5)M, whereas none of the 17 parabens showed AR agonistic or antagonistic activity. Among 12 parabens with linear alkyl chains ranging in length from C₁ to C₁₂, heptylparaben (C₇) and pentylparaben (C₅) showed the most potent ERα and ERβ agonistic activity in the order of 10(-7)M and 10(-8)M, respectively, and the activities decreased in a stepwise manner as the alkyl chain was shortened to C₁ or lengthened to C₁₂. Most parabens showing estrogenic activity exhibited ERβ-agonistic activity at lower concentrations than those inducing ERα-agonistic activity. The estrogenic activity of butylparaben was markedly decreased by incubation with rat liver microsomes, and the decrease of activity was blocked by a carboxylesterase inhibitor. These results indicate that parabens are selective agonists for ERβ over ERα; their interactions with ERα/β are dependent on the size and bulkiness of the alkyl groups; and they are metabolized by carboxylesterases, leading to attenuation of their estrogenic activity.

  11. Up-Regulation of Hepatic Alpha-2-HS-Glycoprotein Transcription by Testosterone via Androgen Receptor Activation

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    Jakob Voelkl

    2014-06-01

    Full Text Available Background/Aims: Fetuin-A (alpha-2-HS-glycoprotein, AHSG, a liver borne plasma protein, contributes to the prevention of soft tissue calcification, modulates inflammation, reduces insulin sensitivity and fosters weight gain following high fat diet or ageing. In polycystic ovary syndrome, fetuin-A levels correlate with free androgen levels, an observation pointing to androgen sensitivity of fetuin-A expression. The present study thus explored whether the expression of hepatic fetuin-A is modified by testosterone. Methods: HepG2 cells were treated with testosterone and androgen receptor antagonist flutamide, and were silenced with androgen receptor siRNA. To test the in vivo relevance, male mice were subjected to androgen deprivation therapy (ADT for 7 weeks. AHSG mRNA levels were determined by quantitative RT-PCR and fetuin-A protein abundance by Western blotting. Results: In HepG2 cells, AHSG mRNA expression and fetuin-A protein abundance were both up-regulated following testosterone treatment. The human alpha-2-HS-glycoprotein gene harbors putative androgen receptor response elements in the proximal 5 kb promoter sequence relative to TSS. The effect of testosterone on AHSG mRNA levels was abrogated by silencing of the androgen receptor in HepG2 cells. Moreover, treatment of HepG2 cells with the androgen receptor antagonist flutamide in presence of endogenous ligands in the medium significantly down-regulated AHSG mRNA expression and fetuin-A protein abundance. In addition, ADT of male mice was followed by a significant decrease of hepatic Ahsg mRNA expression and fetuin-A protein levels. Conclusions: Testosterone participates in the regulation of hepatic fetuin-A expression, an effect mediated, at least partially, by androgen receptor activation.

  12. Sequencing the transcriptional network of androgen receptor in prostate cancer.

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    Chng, Kern Rei; Cheung, Edwin

    2013-11-01

    The progression of prostate cancer is largely dependent on the activity of the androgen receptor (AR), which in turn, correlates with the net output of the AR transcriptional regulatory network. A detailed and thorough understanding of the AR transcriptional regulatory network is therefore critical in the strategic manipulation of AR activity for the targeted eradication of prostate cancer cells. In this mini-review, we highlight some of the novel and unexpected mechanistic and functional insights of the AR transcriptional network derived from recent targeted sequencing (ChIP-Seq) studies of AR and its coregulatory factors in prostate cancer cells.

  13. Differential modulation of androgen receptor transcriptional activity by the nuclear receptor co-repressor (N-CoR).

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    C.A. Berrevoets (Cor); A. Umar (Arzu); A.O. Brinkmann (Albert); J. Trapman (Jan)

    2004-01-01

    textabstractAntiandrogens are widely used agents in the treatment of prostate cancer, as inhibitors of AR (androgen receptor) action. Although the precise mechanism of antiandrogen action is not yet elucidated, recent studies indicate the involvement of nuclear receptor co-represso

  14. Visualising androgen receptor activity in male and female mice.

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    D Alwyn Dart

    Full Text Available Androgens, required for normal development and fertility of males and females, have vital roles in the reproductive tract, brain, cardiovascular system, smooth muscle and bone. Androgens function via the androgen receptor (AR, a ligand-dependent transcription factor. To assay and localise AR activity in vivo we generated the transgenic "ARE-Luc" mouse, expressing a luciferase reporter gene under the control of activated endogenous AR. In vivo imaging of androgen-mediated luciferase activity revealed several strongly expressing tissues in the male mouse as expected and also in certain female tissues. In males the testes, prostate, seminal vesicles and bone marrow all showed high AR activity. In females, strong activity was seen in the ovaries, uterus, omentum tissue and mammary glands. In both sexes AR expression and activity was also found in salivary glands, the eye (and associated glands, adipose tissue, spleen and, notably, regions of the brain. Luciferase protein expression was found in the same cell layers as androgen receptor expression. Additionally, mouse AR expression and activity correlated well with AR expression in human tissues. The anti-androgen bicalutamide reduced luciferase signal in all tissues. Our model demonstrates that androgens can act in these tissues directly via AR, rather than exclusively via androgen aromatisation to estrogens and activation of the estrogen receptor. Additionally, it visually demonstrates the fundamental importance of AR signalling outside the normal role in the reproductive organs. This model represents an important tool for physiological and developmental analysis of androgen signalling, and for characterization of known and novel androgenic or antiandrogenic compounds.

  15. The transcriptional programme of the androgen receptor (AR) in prostate cancer.

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    Lamb, Alastair D; Massie, Charlie E; Neal, David E

    2014-03-01

    The androgen receptor (AR) is essential for normal prostate and prostate cancer cell growth. AR transcriptional activity is almost always maintained even in hormone relapsed prostate cancer (HRPC) in the absence of normal levels of circulating testosterone. Current molecular techniques, such as chromatin-immunoprecipitation sequencing (ChIP-seq), have permitted identification of direct AR-binding sites in cell lines and human tissue with a distinct coordinate network evident in HRPC. The effectiveness of novel agents, such as abiraterone acetate (suppresses adrenal androgens) or enzalutamide (MDV3100, potent AR antagonist), in treating advanced prostate cancer underlines the on-going critical role of the AR throughout all stages of the disease. Persistent AR activity in advanced disease regulates cell cycle activity, steroid biosynthesis and anabolic metabolism in conjunction with regulatory co-factors, such as the E2F family, c-Myc and signal transducer and activator of transcription (STAT) transcription factors. Further treatment approaches must target these other factors.

  16. Prevalent flucocorticoid and androgen activity in US water sources

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    Stavreva, Diana A.; George, Anuja A.; Klausmeyer, Paul; Varticovski, Lyuba; Sack, Daniel; Voss, Ty C.; Schiltz, R. Louis; Blazer, Vicki; Iwanowiczl, Luke R.; Hager, Gordon L.

    2012-01-01

    Contamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27%, and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism, and interfere with reproductive, endocrine, and immune systems. This prevalent contamination could negatively affect wildlife and human populations.

  17. Nrf1 and Nrf2 transcription factors regulate androgen receptor transactivation in prostate cancer cells.

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    Michelle A Schultz

    Full Text Available Despite androgen deprivation therapy (ADT, persistent androgen receptor (AR signaling enables outgrowth of castration resistant prostate cancer (CRPC. In prostate cancer (PCa cells, ADT may enhance AR activity through induction of oxidative stress. Herein, we investigated the roles of Nrf1 and Nrf2, transcription factors that regulate antioxidant gene expression, on hormone-mediated AR transactivation using a syngeneic in vitro model of androgen dependent (LNCaP and castration resistant (C4-2B PCa cells. Dihydrotestosterone (DHT stimulated transactivation of the androgen response element (ARE was significantly greater in C4-2B cells than in LNCaP cells. DHT-induced AR transactivation was coupled with higher nuclear translocation of p65-Nrf1 in C4-2B cells, as compared to LNCaP cells. Conversely, DHT stimulation suppressed total Nrf2 levels in C4-2B cells but elevated total Nrf2 levels in LNCaP cells. Interestingly, siRNA mediated silencing of Nrf1 attenuated AR transactivation while p65-Nrf1 overexpression enhanced AR transactivation. Subsequent studies showed that Nrf1 physically interacts with AR and enhances AR's DNA-binding activity, suggesting that the p65-Nrf1 isoform is a potential AR coactivator. In contrast, Nrf2 suppressed AR-mediated transactivation by stimulating the nuclear accumulation of the p120-Nrf1 which suppressed AR transactivation. Quantitative RT-PCR studies further validated the inductive effects of p65-Nrf1 isoform on the androgen regulated genes, PSA and TMPRSS2. Therefore, our findings implicate differential roles of Nrf1 and Nrf2 in regulating AR transactivation in PCa cells. Our findings also indicate that the DHT-stimulated increase in p65-Nrf1 and the simultaneous suppression of both Nrf2 and p120-Nrf1 ultimately facilitates AR transactivation in CRPC cells.

  18. Repression of androgen receptor transcription through the E2F1/DNMT1 axis.

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    Conrad David Valdez

    Full Text Available Although androgen receptor (AR function has been extensively studied, regulation of the AR gene itself has been much less characterized. In this study, we observed a dramatic reduction in the expression of androgen receptor mRNA and protein in hyperproliferative prostate epithelium of keratin 5 promoter driven E2F1 transgenic mice. To confirm an inhibitory function for E2F1 on AR transcription, we showed that E2F1 inhibited the transcription of endogenous AR mRNA, subsequent AR protein, and AR promoter activity in both human and mouse epithelial cells. E2F1 also inhibited androgen-stimulated activation of two AR target gene promoters. To elucidate the molecular mechanism of E2F-mediated inhibition of AR, we evaluated the effects of two functional E2F1 mutants on AR promoter activity and found that the transactivation domain appears to mediate E2F1 repression of the AR promoter. Because DNMT1 is a functional intermediate of E2F1 we examined DNMT1 function in AR repression. Repression of endogenous AR in normal human prostate epithelial cells was relieved by DNMT1 shRNA knock down. DNMT1 was shown to be physically associated within the AR minimal promoter located 22 bps from the transcription start site; however, methylation remained unchanged at the promoter regardless of DNMT1 expression. Taken together, our results suggest that DNMT1 operates either as a functional intermediary or in cooperation with E2F1 inhibiting AR gene expression in a methylation independent manner.

  19. Androgen-androgen receptor system improves chronic inflammatory conditions by suppressing monocyte chemoattractant protein-1 gene expression in adipocytes via transcriptional regulation.

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    Morooka, Nobukatsu; Ueguri, Kei; Yee, Karen Kar Lye; Yanase, Toshihiko; Sato, Takashi

    2016-09-02

    Age-related decreases in sex hormones are closely related to chronic inflammation in obesity and metabolic diseases. Particularly, the molecular basis of androgen activity in regulating inflammation and controlling metabolism remains largely unknown. Obese adipocytes secrete monocyte chemoattractant protein-1 (MCP-1), a key chemokine that promotes the infiltration of monocytes/macrophages into adipose tissue, thereby leading to metabolic disorders. Here, we studied the role of androgen-androgen receptor (AR) action in regulating MCP-1 expression in adipose tissue. We observed the induction of Mcp-1 expression in 3T3-L1 adipocytes co-cultured with RAW264.7 macrophages. Additionally, Mcp-1 expression was upregulated by culturing in conditioned medium derived from inflammatory macrophages (M1-Mφ) containing tumor necrosis factor-alpha (TNF-α). We found that sex hormones downregulated TNF-α-induced Mcp-1 and interleukin (Il)-6 expression in 3T3-L1 adipocytes. Furthermore, luciferase-reporter analysis indicated that MCP-1 promoter activity was predominantly suppressed by dihydrotestosterone (DHT)-AR interactions through functional canonical nuclear factor-kappa B (NF-κB) sites, whereas non-canonical NF-κB site containing important flanking sequences exhibited minor contributions to DHT-AR transcriptional repression. These findings suggested that androgen-AR suppressed obesity-induced chronic inflammation in adipose tissue.

  20. Selective androgen receptor modulator activity of a steroidal antiandrogen TSAA-291 and its cofactor recruitment profile.

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    Hikichi, Yukiko; Yamaoka, Masuo; Kusaka, Masami; Hara, Takahito

    2015-10-15

    Selective androgen receptor modulators (SARMs) specifically bind to the androgen receptor and exert agonistic or antagonistic effects on target organs. In this study, we investigated the SARM activity of TSAA-291, previously known as a steroidal antiandrogen, in mice because TSAA-291 was found to possess partial androgen receptor agonist activity in reporter assays. In addition, to clarify the mechanism underlying its tissue selectivity, we performed comprehensive cofactor recruitment analysis of androgen receptor using TSAA-291 and dihydrotestosterone (DHT), an endogenous androgen. The androgen receptor agonistic activity of TSAA-291 was more obvious in reporter assays using skeletal muscle cells than in those using prostate cells. In castrated mice, TSAA-291 increased the weight of the levator ani muscle without increasing the weight of the prostate and seminal vesicle. Comprehensive cofactor recruitment analysis via mammalian two-hybrid methods revealed that among a total of 112 cofactors, 12 cofactors including the protein inhibitor of activated STAT 1 (PIAS1) were differently recruited to androgen receptor in the presence of TSAA-291 and DHT. Prostate displayed higher PIAS1 expression than skeletal muscle. Forced expression of the PIAS1 augmented the transcriptional activity of the androgen receptor, and silencing of PIAS1 by siRNAs suppressed the secretion of prostate-specific antigen, an androgen responsive marker. Our results demonstrate that TSAA-291 has SARM activity and suggest that TSAA-291 may induce different conformational changes of the androgen receptor and recruitment profiles of cofactors such as PIAS1, compared with DHT, to exert tissue-specific activity.

  1. 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)

    NARCIS (Netherlands)

    C.A. Berrevoets (Cor); P. Doesburg (Paul); K. Steketee (Karine); J. Trapman (Jan); A.O. Brinkmann (Albert)

    1998-01-01

    textabstractPrevious studies in yeast and mammalian cells showed a functional interaction between the amino-terminal domain and the carboxy-terminal, ligand-binding domain (LBD) of the human androgen receptor (AR). In the present study, the AR subdomains involved in thi

  2. Identification of an anabolic selective androgen receptor modulator that actively induces death of androgen-independent prostate cancer cells.

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    Schmidt, Azriel; Meissner, Robert S; Gentile, Michael A; Chisamore, Michael J; Opas, Evan E; Scafonas, Angela; Cusick, Tara E; Gambone, Carlo; Pennypacker, Brenda; Hodor, Paul; Perkins, James J; Bai, Chang; Ferraro, Damien; Bettoun, David J; Wilkinson, Hilary A; Alves, Stephen E; Flores, Osvaldo; Ray, William J

    2014-09-01

    Prostate cancer (PCa) initially responds to inhibition of androgen receptor (AR) signaling, but inevitably progresses to hormone ablation-resistant disease. Much effort is focused on optimizing this androgen deprivation strategy by improving hormone depletion and AR antagonism. However we found that bicalutamide, a clinically used antiandrogen, actually resembles a selective AR modulator (SARM), as it partially regulates 24% of endogenously 5α-dihydrotestosterone (DHT)-responsive genes in AR(+) MDA-MB-453 breast cancer cells. These data suggested that passive blocking of all AR functions is not required for PCa therapy. Hence, we adopted an active strategy that calls for the development of novel SARMs, which induce a unique gene expression profile that is intolerable to PCa cells. Therefore, we screened 3000 SARMs for the ability to arrest the androgen-independent growth of AR(+) 22Rv1 and LNCaP PCa cells but not AR(-) PC3 or DU145 cells. We identified only one such compound; the 4-aza-steroid, MK-4541, a potent and selective SARM. MK-4541 induces caspase-3 activity and cell death in both androgen-independent, AR(+) PCa cell lines but spares AR(-) cells or AR(+) non-PCa cells. This activity correlates with its promoter context- and cell-type dependent transcriptional effects. In rats, MK-4541 inhibits the trophic effects of DHT on the prostate, but not the levator ani muscle, and triggers an anabolic response in the periosteal compartment of bone. Therefore, MK-4541 has the potential to effectively manage prostatic hypertrophic diseases owing to its antitumor SARM-like mechanism, while simultaneously maintaining the anabolic benefits of natural androgens.

  3. A novel selective androgen receptor modulator (SARM) MK-4541 exerts anti-androgenic activity in the prostate cancer xenograft R-3327G and anabolic activity on skeletal muscle mass & function in castrated mice.

    Science.gov (United States)

    Chisamore, Michael J; Gentile, Michael A; Dillon, Gregory Michael; Baran, Matthew; Gambone, Carlo; Riley, Sean; Schmidt, Azriel; Flores, Osvaldo; Wilkinson, Hilary; Alves, Stephen E

    2016-10-01

    The androgen receptor (AR) is a member of the nuclear hormone receptor super family of transcription factors. Androgens play an essential role in the development, growth, and maintenance of male sex organs, as well as the musculoskeletal and central nervous systems. Yet with advancing age, androgens can drive the onset of prostate cancer, the second leading cause of cancer death in males within the United States. Androgen deprivation therapy (ADT) by pharmacologic and/or surgical castration induces apoptosis of prostate cells and subsequent shrinkage of the prostate and prostate tumors. However, ADT is associated with significant musculoskeletal and behavioral adverse effects. The unique pharmacological activity of selective androgen receptor modulator (SARM) MK-4541 recently has been reported as an AR antagonist with 5α-reductase inhibitor function. The molecule inhibits proliferation and induces apoptosis in AR positive, androgen dependent prostate cancer cells. Importantly, MK-4541 inhibited androgen-dependent prostate growth in male rats yet maintained lean body mass and bone formation following ovariectomy in female rats. In the present study, we evaluated the effects of SARM MK-4541 in the androgen-dependent Dunning R3327-G prostate carcinoma xenograft mouse model as well as on skeletal muscle mass and function, and AR-regulated behavior in mice. MK-4541 significantly inhibited the growth of R3327-G prostate tumors, exhibited anti-androgen effects on the seminal vesicles, reduced plasma testosterone concentrations in intact males, and inhibited Ki67 expression. MK-4541 treated xenografts appeared similar to xenografts in castrated mice. Importantly, we demonstrate that MK-4541 exhibited anabolic activity in androgen deficient conditions, increasing lean body mass and muscle function in adult castrated mice. Moreover, MK-4541 treatment restored general activity levels in castrated mice. Thus, MK-4541 exhibits an optimum profile as an adjuvant therapy to ADT

  4. Trichosanthes kirilowii Exerts Androgenic Activity via Regulation of PSA and KLK2 in 22Rv1 Prostate Cancer Cells

    Science.gov (United States)

    Jeong, Soo-Jin; Choi, Ji-Yoon; Dong, Mi-Sook; Seo, Chang-Seob; Shin, Hyeun-Kyoo

    2017-01-01

    Background: The androgen comprises a group of hormones that play roles in male reproductive activity as well as personal characteristics. Objective: We investigated the androgenic activity of various herbal medicines in human prostate cancer 22Rv1 cells. Materials and Methods: Herbal extracts of Trichosanthes kirilowii (TK), Asarum sieboldii (AS), Sanguisorba officinalis (SO), and Xanthium strumarium (XS) were selected to have androgenic effects based on a preliminary in vitro screening system. Results: TK, AS, SO, and XS enhanced the proliferation of 22Rv1 cells without having cytotoxic effects. All tested herbal extracts increased androgen receptor (AR)-induced transcriptional activity in the absence or presence of dihydrotestosterone (DHT). In an AR-binding assay, TK, but not AS, SO, or XS, produced a significant inhibition of AR binding activity, indicating it has androgenic activity. Additionally, TK treatment positively regulated mRNA expression of the AR-related molecular targets prostate-specific antigen (PSA) and kallikrein 2 (KLK2) compared with untreated control. Conclusion: Taken together, TK-enhanced AR-mediated transcriptional activity might be an attractive candidate drug for treating androgen-related diseases. SUMMARY Trichosantheskirilowii (TK), Asarumsieboldii (AS), Sanguisorbaofficinalis (SO), and Xanthium strumarium (XS) enhanced the proliferation of 22Rv1 cells without having cytotoxic effects.TK, AS, SO, and XS increased androgen receptor (AR)-induced transcriptional activity.TK, but not AS, SO, or XS, produced a significant inhibition against AR-binding activity.TK treatment positively regulated mRNA expression of the AR-related molecular targets prostate-specific antigen and kallikrein 2. Abbreviations used: BPH: benign prostatic hyperplasia; AR: androgen receptor; DHT: dihydrotestosterone; PSA: prostate-specific antigen; TK: Trichosanthes kirilowii; AS: Asarum sieboldii; SO: Sanguisorba officinalis; XS: Xanthium strumarium; ATCC: American

  5. Small molecule screening reveals a transcription-independent pro-survival function of androgen receptor in castration-resistant prostate cancer.

    Science.gov (United States)

    Narizhneva, Natalia V; Tararova, Natalia D; Ryabokon, Petro; Shyshynova, Inna; Prokvolit, Anatoly; Komarov, Pavel G; Purmal, Andrei A; Gudkov, Andrei V; Gurova, Katerina V

    2009-12-15

    In prostate cancer (PCa) patients, initial responsiveness to androgen deprivation therapy is frequently followed by relapse due to development of treatment-resistant androgen-independent PCa. This is typically associated with acquisition of mutations in AR that allow activity as a transcription factor in the absence of ligand, indicating that androgen-independent PCa remains dependent on AR function. Our strategy to effectively target AR in androgen-independent PCa involved using a cell-based readout to isolate small molecules that inhibit AR transactivation function through mechanisms other than modulation of ligand binding. A number of the identified inhibitors were toxic to AR-expressing PCa cells regardless of their androgen dependence. Among these, some only suppressed PCa cell growth (ARTIS), while others induced cell death (ARTIK). ARTIK, but not ARTIS, compounds caused disappearance of AR protein from treated cells. siRNA against AR behaved like ARTIK compounds, while a dominant negative AR mutant that prevents AR-mediated transactivation but does not eliminate the protein showed only a growth suppressive effect. These observations reveal a transcription-independent function of AR that is essential for PCa cell viability and, therefore, is an ideal target for anti-PCa treatment. Indeed, several of the identified AR inhibitors demonstrated in vivo efficacy in mouse models of PCa and are candidates for pharmacologic optimization.

  6. Mechanism of Transcriptional Regulation by Androgen Receptor and its Coactivators in the Context of Chromatin

    Science.gov (United States)

    2002-07-01

    caso - reaction and the mixture was incubated for 20 min at roomteprtr.In co petition says, unlabeled ARE or TRE 󈧎 dex and flutamide. We are...activation and nuclear targeting sig- nals of the human androgen receptor. J Biol Chem 266: LNCaP cells were culture in Roswell Park Memorial Institute 510

  7. The CXCL12/CXCR4 axis promotes ligand-independent activation of the androgen receptor.

    Science.gov (United States)

    Kasina, Sathish; Macoska, Jill A

    2012-04-01

    The molecular mechanisms responsible for the transition of some prostate cancers from androgen ligand-dependent to androgen ligand-independent are incompletely established. Molecules that are ligands for G protein coupled receptors (GPCRs) have been implicated in ligand-independent androgen receptor (AR) activation. The purpose of this study was to examine whether CXCL12, the ligand for the GPCR, CXCR4, might mediate prostate cancer cell proliferation through AR-dependent mechanisms involving functional transactivation of the AR in the absence of androgen. The results of these studies showed that activation of the CXCL12/CXCR4 axis promoted: The nuclear accumulation of both wild-type and mutant AR in several prostate epithelial cell lines; AR-dependent proliferative responses; nuclear accumulation of the AR co-regulator SRC-1 protein; SRC-1:AR protein:protein association; co-localization of AR and SRC-1 on the promoters of AR-regulated genes; AR- and SRC-1 dependent transcription of AR-regulated genes; AR-dependent secretion of the AR-regulated PSA protein; P13K-dependent phosphorylation of AR; MAPK-dependent phosphorylation of SRC-1, and both MAPK- and P13K-dependent secretion of the PSA protein, in the absence of androgen. Taken together, these studies identify CXCL12 as a novel, non-steroidal growth factor that promotes the growth of prostate epithelial cells through AR-dependent mechanisms in the absence of steroid hormones. These findings support the development of novel therapeutics targeting the CXCL12/CXCR4 axis as an ancillary to those targeting the androgen/AR axis to effectively treat castration resistant/recurrent prostate tumors.

  8. The androgen receptor is transcriptionally suppressed by proteins that bind single-stranded DNA.

    Science.gov (United States)

    Grossmann, M E; Tindall, D J

    1995-05-01

    The androgen receptor (AR) is a nuclear transcription factor that is essential for development of the male urogenital tract. In the current work, we have characterized the mouse androgen receptor suppressor (mARS). A single, 20-base pair, region (TCCCCCCACCCACCCCC-CCT) was sufficient for suppression in chloramphenicol acetyltransferase assays. Northern analysis indicated that translational regulation is not necessary for the suppression. Analysis of the AR mRNA half-life indicated that the mARS does not affect AR RNA degradation. Gel mobility assays showed that the mARS is bound by multiple proteins that can recognize single-stranded DNA and RNA. In addition, differing proteins are expressed in distinct tissues. Purification of some of these proteins has shown that a doublet of 33 and 35 kDa binds to the G-rich strand and that a 52-kDa protein binds to the C-rich strand. Southwestern blots have confirmed that these proteins are indeed recognized by the mARS. The results of these experiments indicate that the AR 5'-untranslated region contains a suppressor element that can be bound by multiple proteins. The mARS appears to be acting either by altering transcription initiation or blocking transcription elongation. Characterization of this suppressor may provide insight into the physiological means by which the AR is regulated.

  9. Inhibition of Apoptosis in Prostate Cancer Cells by Androgens Is Mediated through Downregulation of c-Jun N-terminal Kinase Activation

    Directory of Open Access Journals (Sweden)

    Petra Isabel Lorenzo

    2008-05-01

    Full Text Available Androgen deprivation induces the regression of prostate tumors mainly due to an increase in the apoptosis rate; however, the molecular mechanisms underlying the antiapoptotic actions of androgens are not completely understood. We have studied the antiapoptotic effects of androgens in prostate cancer cells exposed to different proapoptotic stimuli. Terminal deoxynucleotidyl transferase-mediated nick-end labeling and nuclear fragmentation analyses demonstrated that androgens protect LNCaP prostate cancer cells from apoptosis induced by thapsigargin, the phorbol ester 12-O-tetradecanoyl-13-phorbol-acetate, or UV irradiation. These three stimuli require the activation of the c-Jun N-terminal kinase (JNK pathway to induce apoptosis and in all three cases, androgen treatment blocks JNK activation. Interestingly, okadaic acid, a phosphatase inhibitor that causes apoptosis in LNCaP cells, induces JNK activation that is also inhibited by androgens. Actinomycin D, the antiandrogen bicalutamide or specific androgen receptor (AR knockdown by small interfering RNA all blocked the inhibition of JNK activation mediated by androgens indicating that this activity requires AR-dependent transcriptional activation. These data suggest that the crosstalk between AR and JNK pathways may have important implications in prostate cancer progression and may provide targets for the development of new therapies.

  10. Complete androgen insensitivity syndrome caused by a novel splice donor site mutation and activation of a cryptic splice donor site in the androgen receptor gene.

    Science.gov (United States)

    Infante, Joana B; Alvelos, Maria I; Bastos, Margarida; Carrilho, Francisco; Lemos, Manuel C

    2016-01-01

    The androgen insensitivity syndrome is an X-linked recessive genetic disorder characterized by resistance to the actions of androgens in an individual with a male karyotype. We evaluated a 34-year-old female with primary amenorrhea and a 46,XY karyotype, with normal secondary sex characteristics, absence of uterus and ovaries, intra-abdominal testis, and elevated testosterone levels. Sequence analysis of the androgen receptor (AR) gene revealed a novel splice donor site mutation in intron 4 (c.2173+2T>C). RT-PCR analysis showed that this mutation resulted in the activation of a cryptic splice donor site located in the second half of exon 4 and in the synthesis of a shorter mRNA transcript and an in-frame deletion of 41 amino acids. This novel mutation associated with a rare mechanism of abnormal splicing further expands the spectrum of mutations associated with the androgen insensitivity syndrome and may contribute to the understanding of the molecular mechanisms involved in splicing defects.

  11. Dual-color bioluminescent bioreporter for forensic analysis: evidence of androgenic and anti-androgenic activity of illicit drugs.

    Science.gov (United States)

    Cevenini, Luca; Michelini, Elisa; D'Elia, Marcello; Guardigli, Massimo; Roda, Aldo

    2013-01-01

    Bioassays represent promising complementary techniques to conventional analytical approaches used in doping analysis to detect illicit drugs like anabolic-androgenic steroids (AAS). The fact that all AAS share a common mechanism of action via the human androgen receptor (hAR) enables the use of bioassays, relying on the activation of hAR as antidoping screening tools. Previously, we developed a dual-color bioreporter based on yeast cells engineered to express hAR and androgen response elements driving the expression of the bioluminescent (BL) reporter protein Photinus pyralis luciferase. A second reporter protein, the red-emitting luciferase PpyRE8, was introduced in the bioreporter as internal viability control. Here, we report the first forensic application of a straightforward, accurate, and cost-effective bioassay, relying on spectral resolution of the two BL signals, in 96-microwell format. The bioreporter responds to dihydrotestosterone as reference androgen in a concentration-dependent manner from 0.08 to 1,000 nM with intra- and inter-assay variation coefficients of 11.4 % and 13.1 %, respectively. We also demonstrated the suitability of this dual-color bioreporter to assess (anti)-androgenic activity of pure AAS, mixtures of AAS, and other illicit drugs provided by the Scientific Police. Significant anti-androgenic activity was observed in samples labeled as marijuana and hashish, containing Δ(9)-tetrahydrocannabinol as major constituent.

  12. Activation of two mutant androgen receptors from human prostatic carcinoma by adrenal androgens and metabolic derivatives of testosterone.

    Science.gov (United States)

    Culig, Z; Stober, J; Gast, A; Peterziel, H; Hobisch, A; Radmayr, C; Hittmair, A; Bartsch, G; Cato, A C; Klocker, H

    1996-01-01

    The androgen receptor (AR) plays a central regulatory role in prostatic carcinoma and is a target of androgen ablation therapy. Recent detection of mutant receptors in tumor specimens suggest a contribution of AR alterations to progression towards androgen independence. In a specimen derived from metastatic prostate cancer we have reported a point mutation in the AR gene that leads to a single amino acid exchange in the ligand binding domain of the receptor. Another amino acid exchange resulting from a point mutation was also identified 15 amino acids away from our mutation. This mutation was detected in the AR gene isolated from an organ-confined prostatic tumor. Here we report the functional characterization of the two mutant receptors in the presence of adrenal androgens and testosterone metabolites. These studies were performed by cotransfecting androgen-responsive reporter genes and either the wild-type or mutant AR expression vectors into receptor negative DU-145 and CV-1 cells. The indicator genes used consisted of the promoter of the androgen-inducible prostate-specific antigen gene or the C' Delta9 enhancer fragment from the promoter of the mouse sex-limited protein driving the expression of the bacterial chloramphenicol acetyl transferase gene. Cotransfection-transactivation assays revealed that the adrenal androgen androstenedione and two products of testosterone metabolism, androsterone and androstandiol, induced reporter gene activity more efficiently in the presence of the mutant receptors than in the presence of the wild-type receptor. No difference between wild-type and mutant receptors was observed in the presence of the metabolite androstandione. The interaction of receptor-hormone complexes with target DNA was studied in vitro by electrophoretic mobility shift assays (EMSA). Dihydrotestosterone and the synthetic androgen mibolerone induced a faster migrating complex with all receptors, whereas the androgen metabolite androstandione induced this

  13. Promoter-dependent activity on androgen receptor N-terminal domain mutations in androgen insensitivity syndrome.

    Science.gov (United States)

    Tadokoro-Cuccaro, Rieko; Davies, John; Mongan, Nigel P; Bunch, Trevor; Brown, Rosalind S; Audi, Laura; Watt, Kate; McEwan, Iain J; Hughes, Ieuan A

    2014-01-01

    Androgen receptor (AR) mutations are associated with androgen insensitivity syndrome (AIS). Missense mutations identified in the AR-N-terminal domain (AR-NTD) are rare, and clinical phenotypes are typically mild. We investigated 7 missense mutations and 2 insertion/deletions located in the AR-NTD. This study aimed to elucidate the pathogenic role of AR-NTD mutants in AIS and to use this knowledge to further define AR-NTD function. AR-NTD mutations (Q120E, A159T, G216R, N235K, G248V, L272F, and P380R) were introduced into AR-expression plasmids. Stably expressing cell lines were established for del57L and ins58L. Transactivation was measured using luciferase reporter constructs under the control of GRE and Pem promoters. Intrinsic fluorescence spectroscopy and partial proteolysis studies were performed for mutations which showed reduced activities by using a purified AR-AF1 protein. Pem-luciferase reporter activation was reduced for A159T, N235K, and G248V but not the GRE-luciferase reporter. Protein structure analysis detected no significant change in the AR-AF1 region for these mutations. Reduced cellular expression and transactivation activity were observed for ins58L. The mutations Q120E, G216R, L272F, P380R, and del57L showed small or no detectable changes in function. Thus, clinical and experimental analyses have identified novel AR-signalling defects associated with mutations in the structurally disordered AR-NTD domain in patients with AIS.

  14. The Master Neural Transcription Factor BRN2 Is an Androgen Receptor-Suppressed Driver of Neuroendocrine Differentiation in Prostate Cancer.

    Science.gov (United States)

    Bishop, Jennifer L; Thaper, Daksh; Vahid, Sepideh; Davies, Alastair; Ketola, Kirsi; Kuruma, Hidetoshi; Jama, Randy; Nip, Ka Mun; Angeles, Arkhjamil; Johnson, Fraser; Wyatt, Alexander W; Fazli, Ladan; Gleave, Martin E; Lin, Dong; Rubin, Mark A; Collins, Colin C; Wang, Yuzhuo; Beltran, Himisha; Zoubeidi, Amina

    2017-01-01

    Mechanisms controlling the emergence of lethal neuroendocrine prostate cancer (NEPC), especially those that are consequences of treatment-induced suppression of the androgen receptor (AR), remain elusive. Using a unique model of AR pathway inhibitor-resistant prostate cancer, we identified AR-dependent control of the neural transcription factor BRN2 (encoded by POU3F2) as a major driver of NEPC and aggressive tumor growth, both in vitro and in vivo Mechanistic studies showed that AR directly suppresses BRN2 transcription, which is required for NEPC, and BRN2-dependent regulation of the NEPC marker SOX2. Underscoring its inverse correlation with classic AR activity in clinical samples, BRN2 expression was highest in NEPC tumors and was significantly increased in castration-resistant prostate cancer compared with adenocarcinoma, especially in patients with low serum PSA. These data reveal a novel mechanism of AR-dependent control of NEPC and suggest that targeting BRN2 is a strategy to treat or prevent neuroendocrine differentiation in prostate tumors.

  15. Androgen receptor driven transcription in molecular apocrine breast cancer is mediated by FoxA1.

    Science.gov (United States)

    Robinson, Jessica L L; Macarthur, Stewart; Ross-Innes, Caryn S; Tilley, Wayne D; Neal, David E; Mills, Ian G; Carroll, Jason S

    2011-06-24

    Breast cancer is a heterogeneous disease and several distinct subtypes exist based on differential gene expression patterns. Molecular apocrine tumours were recently identified as an additional subgroup, characterised as oestrogen receptor negative and androgen receptor positive (ER- AR+), but with an expression profile resembling ER+ luminal breast cancer. One possible explanation for the apparent incongruity is that ER gene expression programmes could be recapitulated by AR. Using a cell line model of ER- AR+ molecular apocrine tumours (termed MDA-MB-453 cells), we map global AR binding events and find a binding profile that is similar to ER binding in breast cancer cells. We find that AR binding is a near-perfect subset of FoxA1 binding regions, a level of concordance never previously seen with a nuclear receptor. AR functionality is dependent on FoxA1, since silencing of FoxA1 inhibits AR binding, expression of the majority of the molecular apocrine gene signature and growth cell growth. These findings show that AR binds and regulates ER cis-regulatory elements in molecular apocrine tumours, resulting in a transcriptional programme reminiscent of ER-mediated transcription in luminal breast cancers.

  16. Direct interaction between AR and PAK6 in androgen-stimulated PAK6 activation.

    Science.gov (United States)

    Liu, Xia; Busby, Jennifer; John, Ciny; Wei, Jianning; Yuan, Xin; Lu, Michael L

    2013-01-01

    A p21-activated kinase 6 (PAK6) was previously identified to be an androgen receptor (AR) interacting protein through a yeast two-hybrid screening. We used hormone responsive prostate cancer LAPC4 and LNCap cell lines as models to study the signaling events associated with androgen stimulation and PAK6. An androgen-stimulated PAK6 kinase activation was observed in LAPC4 cells expressing endogenous PAK6 and in LNCap cells ectopically expressing a wild type PAK6. This activation was likely mediated through a direct interaction between AR and PAK6 since siRNA knock-down of AR in LAPC4 cells downregulated androgen-stimulated PAK6 activation. In addition, LNCap cells expressing a non-AR-interacting PAK6 mutant exhibited dampened androgen-stimulated kinase activation. As a consequence of androgen-stimulated activation, PAK6 was phosphorylated at multiple serine/threonine residues including the AR-interacting domain of PAK6. Furthermore, androgen-stimulation promoted prostate cancer cell motility and invasion were demonstrated in LNCap cells ectopically expressing PAK6-WT. In contrast, LNCap expressing non-AR-interacting mutant PAK6 did not respond to androgen stimulation with increased cell motility and invasion. Our results demonstrate that androgen-stimulated PAK6 activation is mediated through a direct interaction between AR and PAK6 and PAK6 activation promotes prostate cancer cells motility and invasion.

  17. Direct interaction between AR and PAK6 in androgen-stimulated PAK6 activation.

    Directory of Open Access Journals (Sweden)

    Xia Liu

    Full Text Available A p21-activated kinase 6 (PAK6 was previously identified to be an androgen receptor (AR interacting protein through a yeast two-hybrid screening. We used hormone responsive prostate cancer LAPC4 and LNCap cell lines as models to study the signaling events associated with androgen stimulation and PAK6. An androgen-stimulated PAK6 kinase activation was observed in LAPC4 cells expressing endogenous PAK6 and in LNCap cells ectopically expressing a wild type PAK6. This activation was likely mediated through a direct interaction between AR and PAK6 since siRNA knock-down of AR in LAPC4 cells downregulated androgen-stimulated PAK6 activation. In addition, LNCap cells expressing a non-AR-interacting PAK6 mutant exhibited dampened androgen-stimulated kinase activation. As a consequence of androgen-stimulated activation, PAK6 was phosphorylated at multiple serine/threonine residues including the AR-interacting domain of PAK6. Furthermore, androgen-stimulation promoted prostate cancer cell motility and invasion were demonstrated in LNCap cells ectopically expressing PAK6-WT. In contrast, LNCap expressing non-AR-interacting mutant PAK6 did not respond to androgen stimulation with increased cell motility and invasion. Our results demonstrate that androgen-stimulated PAK6 activation is mediated through a direct interaction between AR and PAK6 and PAK6 activation promotes prostate cancer cells motility and invasion.

  18. Assembly of methylated KDM1A and CHD1 drives androgen receptor-dependent transcription and translocation.

    Science.gov (United States)

    Metzger, Eric; Willmann, Dominica; McMillan, Joel; Forne, Ignasi; Metzger, Philipp; Gerhardt, Stefan; Petroll, Kerstin; von Maessenhausen, Anne; Urban, Sylvia; Schott, Anne-Kathrin; Espejo, Alexsandra; Eberlin, Adrien; Wohlwend, Daniel; Schüle, Katrin M; Schleicher, Michael; Perner, Sven; Bedford, Mark T; Jung, Manfred; Dengjel, Jörn; Flaig, Ralf; Imhof, Axel; Einsle, Oliver; Schüle, Roland

    2016-02-01

    Prostate cancer evolution is driven by a combination of epigenetic and genetic alterations such as coordinated chromosomal rearrangements, termed chromoplexy. TMPRSS2-ERG gene fusions found in human prostate tumors are a hallmark of chromoplexy. TMPRSS2-ERG fusions have been linked to androgen signaling and depend on androgen receptor (AR)-coupled gene transcription. Here, we show that dimethylation of KDM1A at K114 (to form K114me2) by the histone methyltransferase EHMT2 is a key event controlling androgen-dependent gene transcription and TMPRSS2-ERG fusion. We identified CHD1 as a KDM1A K114me2 reader and characterized the KDM1A K114me2-CHD1 recognition mode by solving the cocrystal structure. Genome-wide analyses revealed chromatin colocalization of KDM1A K114me2, CHD1 and AR in prostate tumor cells. Together, our data link the assembly of methylated KDM1A and CHD1 with AR-dependent transcription and genomic translocations, thereby providing mechanistic insight into the formation of TMPRSS2-ERG gene fusions during prostate-tumor evolution.

  19. Androgen receptor is the key transcriptional mediator of the tumor suppressor SPOP in prostate cancer.

    Science.gov (United States)

    Geng, Chuandong; Rajapakshe, Kimal; Shah, Shrijal S; Shou, John; Eedunuri, Vijay Kumar; Foley, Christopher; Fiskus, Warren; Rajendran, Mahitha; Chew, Sue Anne; Zimmermann, Martin; Bond, Richard; He, Bin; Coarfa, Cristian; Mitsiades, Nicholas

    2014-10-01

    Somatic missense mutations in the substrate-binding pocket of the E3 ubiquitin ligase adaptor SPOP are present in up to 15% of human prostate adenocarcinomas, but are rare in other malignancies, suggesting a prostate-specific mechanism of action. SPOP promotes ubiquitination and degradation of several protein substrates, including the androgen receptor (AR) coactivator SRC-3. However, the relative contributions that SPOP substrates may make to the pathophysiology of SPOP-mutant (mt) prostate adenocarcinomas are unknown. Using an unbiased bioinformatics approach, we determined that the gene expression profile of prostate adenocarcinoma cells engineered to express mt-SPOP overlaps greatly with the gene signature of both SRC-3 and AR transcriptional output, with a stronger similarity to AR than SRC-3. This finding suggests that in addition to its SRC-3-mediated effects, SPOP also exerts SRC-3-independent effects that are AR-mediated. Indeed, we found that wild-type (wt) but not prostate adenocarcinoma-associated mutants of SPOP promoted AR ubiquitination and degradation, acting directly through a SPOP-binding motif in the hinge region of AR. In support of these results, tumor xenografts composed of prostate adenocarcinoma cells expressing mt-SPOP exhibited higher AR protein levels and grew faster than tumors composed of prostate adenocarcinoma cells expressing wt-SPOP. Furthermore, genetic ablation of SPOP was sufficient to increase AR protein levels in mouse prostate. Examination of public human prostate adenocarcinoma datasets confirmed a strong link between transcriptomic profiles of mt-SPOP and AR. Overall, our studies highlight the AR axis as the key transcriptional output of SPOP in prostate adenocarcinoma and provide an explanation for the prostate-specific tumor suppressor role of wt-SPOP.

  20. In vitro translation of androgen receptor cRNA results in an activated androgen receptor protein

    NARCIS (Netherlands)

    G.G.J.M. Kuiper (George); P.E. de Ruiter (Petra); J. Trapman (Jan); G.W. Jenster (Guido); A.O. Brinkmann (Albert)

    1993-01-01

    textabstractTranslation of androgen receptor (AR) cRNA in a reticulocyte lysate and subsequent analysis of the translation products by SDS/PAGE showed a protein with an apparent molecular mass of 108 kDa. Scatchard-plot analysis revealed a single binding component with

  1. A physiological role for androgen actions in the absence of androgen receptor DNA binding activity.

    Science.gov (United States)

    Pang, Tammy P S; Clarke, Michele V; Ghasem-Zadeh, Ali; Lee, Nicole K L; Davey, Rachel A; MacLean, Helen E

    2012-01-01

    We tested the hypothesis that androgens have physiological actions via non-DNA binding-dependent androgen receptor (AR) signaling pathways in males, using our genetically modified mice that express a mutant AR with deletion of the 2nd zinc finger of the DNA binding domain (AR(ΔZF2)) that cannot bind DNA. In cultured genital skin fibroblasts, the mutant AR(ΔZF2) has normal ligand binding ability, phosphorylates ERK-1/2 in response to 1 min DHT treatment (blocked by the AR antagonist bicalutamide), but has reduced androgen-dependent nuclear localization compared to wildtype (WT). AR(ΔZF2) males have normal baseline ERK-1/2 phosphorylation, with a 1.5-fold increase in Akt phosphorylation in AR(ΔZF2) muscle vs WT. To identify physiological actions of non-DNA binding-dependent AR signaling, AR(ΔZF2) males were treated for 6 weeks with dihydrotestosterone (DHT). Cortical bone growth was suppressed by DHT in AR(ΔZF2) mice (6% decrease in periosteal and 7% decrease in medullary circumference vs untreated AR(ΔZF2) males). In conclusion, these data suggest that non-DNA binding dependent AR actions suppress cortical bone growth, which may provide a mechanism to fine-tune the response to androgens in bone.

  2. The structural basis of androgen receptor activation: Intramolecular and intermolecular amino–carboxy interactions

    Science.gov (United States)

    Schaufele, Fred; Carbonell, Xavier; Guerbadot, Martin; Borngraeber, Sabine; Chapman, Mark S.; Ma, Aye Aye K.; Miner, Jeffrey N.; Diamond, Marc I.

    2005-01-01

    Nuclear receptors (NRs) are ligand-regulated transcription factors important in human physiology and disease. In certain NRs, including the androgen receptor (AR), ligand binding to the carboxy-terminal domain (LBD) regulates transcriptional activation functions in the LBD and amino-terminal domain (NTD). The basis for NTD–LBD communication is unknown but may involve NTD–LBD interactions either within a single receptor or between different members of an AR dimer. Here, measurement of FRET between fluorophores attached to the NTD and LBD of the AR established that agonist binding initiated an intramolecular NTD–LBD interaction in the nucleus and cytoplasm. This intramolecular folding was followed by AR self-association, which occurred preferentially in the nucleus. Rapid, ligand-induced intramolecular folding and delayed association also were observed for estrogen receptor-α but not for peroxisome proliferator activated receptor-γ2. An antagonist ligand, hydroxyflutamide, blocked the NTD–LBD association within AR. NTD–LBD association also closely correlated with the transcriptional activation by heterologous ligands of AR mutants isolated from hormone-refractory prostate tumors. Intramolecular folding, but not AR–AR affinity, was disrupted by mutation of an α-helical (23FQNLF27) motif in the AR NTD previously described to interact with the AR LBD in vitro. This work establishes an intramolecular NTD–LBD conformational change as an initial component of ligand-regulated NR function. PMID:15994236

  3. Androgens and skeletal muscle: cellular and molecular action mechanisms underlying the anabolic actions.

    Science.gov (United States)

    Dubois, Vanessa; Laurent, Michaël; Boonen, Steven; Vanderschueren, Dirk; Claessens, Frank

    2012-05-01

    Androgens increase both the size and strength of skeletal muscle via diverse mechanisms. The aim of this review is to discuss the different cellular targets of androgens in skeletal muscle as well as the respective androgen actions in these cells leading to changes in proliferation, myogenic differentiation, and protein metabolism. Androgens bind and activate a specific nuclear receptor which will directly affect the transcription of target genes. These genes encode muscle-specific transcription factors, enzymes, structural proteins, as well as microRNAs. In addition, anabolic action of androgens is partly established through crosstalk with other signaling molecules such as Akt, myostatin, IGF-I, and Notch. Finally, androgens may also exert non-genomic effects in muscle by increasing Ca(2+) uptake and modulating kinase activities. In conclusion, the anabolic effect of androgens on skeletal muscle is not only explained by activation of the myocyte androgen receptor but is also the combined result of many genomic and non-genomic actions.

  4. Sry is a transcriptional activator.

    Science.gov (United States)

    Dubin, R A; Ostrer, H

    1994-09-01

    The SRY gene functions as a genetic switch in gonadal ridge initiating testis determination. The mouse Sry and human SRY open reading frames (ORFs) share a conserved DNA-binding domain (the HMG-box) yet exhibit no additional homology outside this region. As judged by the accumulation of lacZ-SRY hybrid proteins in the nucleus, both the human and mouse SRY ORFs contain a nuclear localization signal. The mouse Sry HMG-box domain selectively binds the sequence NACAAT in vitro when challenged with a random pool of oligonucleotides and binds AACAAT with the highest affinity. When put under the control of a heterologous promotor, the mouse Sry gene activated transcription of a reporter gene containing multiple copies of the AACAAT binding site. Activation was likewise observed for a GAL4-responsive reporter gene, when the mouse Sry gene was linked to the DNA-binding domain of GAL4. Using this system, the activation function was mapped to a glutamine/histidine-rich domain. In addition, LexA-mouse Sry fusion genes activated a LexA-responsive reporter gene in yeast. In contrast, a GAL4-human SRY fusion gene did not cause transcriptional activation. These studies suggest that both the human and the mouse SRY ORFs encode nuclear, DNA-binding proteins and that the mouse Sry ORF can function as a transcriptional activator with separable DNA-binding and activator domains.

  5. Androgen receptor mutations

    NARCIS (Netherlands)

    A.O. Brinkmann (Albert); G.W. Jenster (Guido); C. Ris-Stalpers (Carolyn); J.A.G.M. van der Korput (J. A G M); H.T. Brüggenwirth (Hennie); A.L.M. Boehmer (Annemie); J. Trapman (Jan)

    1995-01-01

    textabstractMale sexual differentiation and development proceed under direct control of androgens. Androgen action is mediated by the intracellular androgen receptor, which belongs to the superfamily of ligand-dependent transcription factors. At least three pathological situations are associated wit

  6. Obstructing Androgen Receptor Activation in Prostate Cancer Cells Through Post-translational Modification by NEDD8

    Science.gov (United States)

    2012-11-01

    Nonidet P - 40 ). Pre-cleared with 25 µl protein-A/G agarose beads, 700 µg lysate was subjected to immunoprecipitation with 20 µl anti-FLAG antibody...cell growth. REPORTABLE OUTCOMES: 1. Chang, K. H., Hsiao, P .-W. and Chen, J. D. Modulation of Androgen Receptor Activity by Reversible NEDD8...Hsiao, P .-W. and Chen, J. D. Modulation of Androgen Receptor Activity by Reversible NEDD8 Modification. (under revision) 1 Modulation of

  7. Isotope-Dilution Mass Spectrometry for Quantification of Urinary Active Androgens Separated by Gas Chromatography

    OpenAIRE

    Su Hyeon Lee; Man Ho Choi; Won-Yong Lee; Bong Chul Chung

    2010-01-01

    Cross reacting antibodies can cause an overestimation of the results of immunoassays. Therefore, alternative methodsare needed for the accurate quantification of steroids. Gas chromatography combined with isotope-dilution mass spectrometry(GC-IDMS) is developed to quantify urinary active androgens, testosterone, epitestosterone and dihydrotestosterone, which areclinically relevant androgens to both hair-loss and prostate diseases. The method devised involves enzymatic hydrolysis with β-glucur...

  8. Transcriptional regulation of myotrophic actions by testosterone and trenbolone on androgen-responsive muscle.

    Science.gov (United States)

    Ye, Fan; McCoy, Sean C; Ross, Heather H; Bernardo, Joseph A; Beharry, Adam W; Senf, Sarah M; Judge, Andrew R; Beck, Darren T; Conover, Christine F; Cannady, Darryl F; Smith, Barbara K; Yarrow, Joshua F; Borst, Stephen E

    2014-09-01

    Androgens regulate body composition and skeletal muscle mass in males, but the molecular mechanisms are not fully understood. Recently, we demonstrated that trenbolone (a potent synthetic testosterone analogue that is not a substrate for 5-alpha reductase or for aromatase) induces myotrophic effects in skeletal muscle without causing prostate enlargement, which is in contrast to the known prostate enlarging effects of testosterone. These previous results suggest that the 5α-reduction of testosterone is not required for myotrophic action. We now report differential gene expression in response to testosterone versus trenbolone in the highly androgen-sensitive levator ani/bulbocavernosus (LABC) muscle complex of the adult rat after 6weeks of orchiectomy (ORX), using real time PCR. The ORX-induced expression of atrogenes (Muscle RING-finger protein-1 [MuRF1] and atrogin-1) was suppressed by both androgens, with trenbolone producing a greater suppression of atrogin-1 mRNA compared to testosterone. Both androgens elevated expression of anabolic genes (insulin-like growth factor-1 and mechano-growth factor) after ORX. ORX-induced increases in expression of glucocorticoid receptor (GR) mRNA were suppressed by trenbolone treatment, but not testosterone. In ORX animals, testosterone promoted WNT1-inducible-signaling pathway protein 2 (WISP-2) gene expression while trenbolone did not. Testosterone and trenbolone equally enhanced muscle regeneration as shown by increases in LABC mass and in protein expression of embryonic myosin by western blotting. In addition, testosterone increased WISP-2 protein levels. Together, these findings identify specific mechanisms by which testosterone and trenbolone may regulate skeletal muscle maintenance and growth.

  9. Environmental polycyclic aromatic hydrocarbons affect androgen receptor activation in vitro

    DEFF Research Database (Denmark)

    Vinggaard, Anne Marie; Hnida, Christina; Larsen, John Christian

    2000-01-01

    Nine structurally different polycyclic aromatic hydrocarbons (PAHs) were tested for their ability to either agonize or antagonize the human androgen receptor (hAR) in a sensitive reporter gene assay based on CHO cells transiently cotransfected with a hAR vector and an MMTV-LUC vector. Benz...

  10. Research Resource: Androgen Receptor Activity Is Regulated Through the Mobilization of Cell Surface Receptor Networks.

    Science.gov (United States)

    Hsiao, Jordy J; Ng, Brandon H; Smits, Melinda M; Martinez, Harryl D; Jasavala, Rohini J; Hinkson, Izumi V; Fermin, Damian; Eng, Jimmy K; Nesvizhskii, Alexey I; Wright, Michael E

    2015-08-01

    The aberrant expression of androgen receptor (AR)-dependent transcriptional programs is a defining pathology of the development and progression of prostate cancers. Transcriptional cofactors that bind AR are critical determinants of prostate tumorigenesis. To gain a deeper understanding of the proteins linked to AR-dependent gene transcription, we performed a DNA-affinity chromatography-based proteomic screen designed to identify proteins involved in AR-mediated gene transcription in prostate tumor cells. Functional experiments validated the coregulator roles of known AR-binding proteins in AR-mediated transcription in prostate tumor cells. More importantly, novel coregulatory functions were detected in components of well-established cell surface receptor-dependent signal transduction pathways. Further experimentation demonstrated that components of the TNF, TGF-β, IL receptor, and epidermal growth factor signaling pathways modulated AR-dependent gene transcription and androgen-dependent proliferation in prostate tumor cells. Collectively, our proteomic dataset demonstrates that the cell surface receptor- and AR-dependent pathways are highly integrated, and provides a molecular framework for understanding how disparate signal-transduction pathways can influence AR-dependent transcriptional programs linked to the development and progression of human prostate cancers.

  11. Aberrant splicing of androgenic receptor mRNA results in synthesis of a nonfunctional receptor protein in a patient with androgen insensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Ris-Stalpers, C.; Kuiper, G.G.J.M.; Faber, P.W.; van Rooij, H.C.J.; Degenhart, H.J.; Trapman, J.; Brinkmann, A.O. (Erasmus Univ., Rotterdam (Netherlands)); Schweikert, H.U. (Univ. of Bonn (Germany)); Zegers, N.D. (Medical Biological Laboratory-Organization for Applied Scientific Research, Rijswijk (Netherlands)); Hodgins, M.B. (Glasgow Univ. (United Kingdom))

    1990-10-01

    Androgen insensitivity is a disorder in which the correct androgen response in an androgen target cell is impaired. The clinical symtpoms of this X chromosome-linked syndrome are presumed to be caused by mutations in the androgen receptor gene. The authors report a G {r arrow} T mutation in the splice donor site of intron 4 of the androgen receptor gene of a 46, XY subject lacking detectable androgen binding to the receptor and with the complete form of androgen insensitivity. This point mutation completely abolishes normal RNA splicing at the exon 4/intron 4 boundary and results in the activation of a cryptic splice donor site in exon 4, which leads to the deletion of 123 nucleotides from the mRNA. Translation of the mutant mRNA results in an androgen receptor protein {approx}5 kDa smaller than the wild type. This mutated androgen receptor protein was unable to bind androgens and unable to activate transcription of an androgen-regulated reporter gene construct. This mutation in the human androgen receptor gene demonstrates the importance of an intact steroid-binding domain for proper androgen receptor functioning in vivo.

  12. Design, Syntheses and Bioactivities of Androgen Receptor Targeted Taxane Analogs, Simplified Fluorescently Labeled Discodermolide Analogs, and Conformationally Constrained Discodermolide Analogs

    OpenAIRE

    Qi, Jun

    2010-01-01

    Prostate cancer is the most common non-skin cancer for men in America. The androgen receptor exerts transcriptional activity and plays an important role for the proliferation of prostate cancer cells. Androgen receptor ligands bind the androgen receptor and inhibit its transcriptional activity effectively. However, prostate cancer can progress to hormone refractory prostate cancer (HRPC) to avoid this effect. Chemotherapies are currently the primary treatments for HRPC. Unfortunately, none of...

  13. Synthesis, structure-activity relationships, and characterization of novel nonsteroidal and selective androgen receptor modulators.

    Science.gov (United States)

    Schlienger, Nathalie; Lund, Birgitte W; Pawlas, Jan; Badalassi, Fabrizio; Bertozzi, Fabio; Lewinsky, Rasmus; Fejzic, Alma; Thygesen, Mikkel B; Tabatabaei, Ali; Bradley, Stefania Risso; Gardell, Luis R; Piu, Fabrice; Olsson, Roger

    2009-11-26

    Herein we describe the discovery of ACP-105 (1), a novel and potent nonsteroidal selective androgen receptor modulator (SARM) with partial agonist activity relative to the natural androgen testosterone. Compound 1 was developed from a series of compounds found in a HTS screen using the receptor selection and amplification technology (R-SAT). In vivo, 1 improved anabolic parameters in a 2-week chronic study in castrated male rats. In addition to compound 1, a number of potent antiandrogens were discovered from the same series of compounds whereof one compound, 13, had antagonist activity at the AR T877A mutant involved in prostate cancer.

  14. Complex modulation of androgen responsive gene expression by methoxyacetic acid

    Directory of Open Access Journals (Sweden)

    Stanley Kerri A

    2011-03-01

    Full Text Available Abstract Background Optimal androgen signaling is critical for testicular development and spermatogenesis. Methoxyacetic acid (MAA, the primary active metabolite of the industrial chemical ethylene glycol monomethyl ether, disrupts spermatogenesis and causes testicular atrophy. Transcriptional trans-activation studies have indicated that MAA can enhance androgen receptor activity, however, whether MAA actually impacts the expression of androgen-responsive genes in vivo, and which genes might be affected is not known. Methods A mouse TM3 Leydig cell line that stably expresses androgen receptor (TM3-AR was prepared and analyzed by transcriptional profiling to identify target gene interactions between MAA and testosterone on a global scale. Results MAA is shown to have widespread effects on androgen-responsive genes, affecting processes ranging from apoptosis to ion transport, cell adhesion, phosphorylation and transcription, with MAA able to enhance, as well as antagonize, androgenic responses. Moreover, testosterone is shown to exert both positive and negative effects on MAA gene responses. Motif analysis indicated that binding sites for FOX, HOX, LEF/TCF, STAT5 and MEF2 family transcription factors are among the most highly enriched in genes regulated by testosterone and MAA. Notably, 65 FOXO targets were repressed by testosterone or showed repression enhanced by MAA with testosterone; these include 16 genes associated with developmental processes, six of which are Hox genes. Conclusions These findings highlight the complex interactions between testosterone and MAA, and provide insight into the effects of MAA exposure on androgen-dependent processes in a Leydig cell model.

  15. Molecular cell biology of androgen receptor signalling.

    Science.gov (United States)

    Bennett, Nigel C; Gardiner, Robert A; Hooper, John D; Johnson, David W; Gobe, Glenda C

    2010-06-01

    The classical action of androgen receptor (AR) is to regulate gene transcriptional processes via AR nuclear translocation, response element binding and recruitment of, or crosstalk with, transcription factors. AR also utilises non-classical, non-genomic mechanisms of signal transduction. These precede gene transcription or protein synthesis, and involve steroid-induced modulation of cytoplasmic or cell membrane-bound regulatory proteins. Despite many decades of investigation, the role of AR in gene regulation of cells and tissues remains only partially characterised. AR exerts most of its effects in sex hormone-dependent tissues of the body, but the receptor is also expressed in many tissues not previously thought to be androgen sensitive. Thus it is likely that a complex, more over-arching, role for AR exists. Each AR domain co-ordinates a multitude of individual and vital roles via a diverse array of interacting partner molecules that are necessary for cellular and tissue development and maintenance. Aberrant AR activity, promoted by mutations or binding partner misregulation, can present as many clinical manifestations including androgen insensitivity syndrome and prostate cancer. In the case of malignant prostate cancer, treatment generally revolves around androgen deprivation therapies designed to interfere with AR action and the androgen signalling axis. Androgen therapies for prostate cancer often fail, highlighting a real need for increased research into AR function.

  16. Gene expression changes in rat prostate after activation or blocking of the androgen and estrogen receptor

    DEFF Research Database (Denmark)

    Nellemann, Christine Lydia; Dalgaard, Majken; Holst, Bjørn;

    2005-01-01

    Several endpoints of different molecular complexity were studied in the Hershberger assay in order to evaluate the specificity and suitability of this test as a broad screening model. Androgen and estrogen receptors were activated or blocked, and expression of typical estrogen- or androgen...... and the anti-estrogen, ICI 182780, only affected ODC expression. Therefore, estrogenic or anti-estrogenic compounds would not be expected to seriously affect the outcome of a Hershberger test. However, EB given alone to castrated rats resulted in various effects. EB increased seminal vesicle weight, an effect...... reversed by ICI 182780, and affected TRPM-2, PBP C3, ODC, IGF-1, AR, and ERa mRNA levels. AR expression in the prostate seemed to be under regulation of both estrogens and androgens, as ICI 182780 inhibited the testosterone-induced AR expression, and flutamide inhibited the EB-induced AR expression...

  17. Interlaboratory comparison of four in vitro assays for assessing androgenic and antiandrogenic activity of environmental chemicals

    DEFF Research Database (Denmark)

    Körner, Wolfgang; Vinggaard, Anne; Terouanne, B.;

    2004-01-01

    , the calculated androgenic potencies relative to the positive control (RAPs) remained within one order of magnitude. However, laboratory 3 calculated a 50-fold higher RAP for 4-androsten-3,17-dione. All assays detected and quantified the antiandrogenic effect of vinclozolin [median inhibitory concentration (IC50......) values ranging from 1.1 x 10(-7) M to 4.7 x 10(-7) M]. In assays 2 and 3, vinclozolin showed partial androgenic activity at the highest concentrations tested. For vinclozolin, calculated antiandrogenic potencies relative to bicalutamide (RAAPs) differed no more than a factor of 10, and IC50 values...

  18. Androgenic activity in surface water samples detected using the AR-LUX assay: indications for mixture effects

    NARCIS (Netherlands)

    Blankvoort, B.M.G.; Rodenburg, R.J.T.; Murk, A.J.; Koeman, J.H.; Schilt, R.; Aarts, J.M.M.J.G.

    2005-01-01

    This paper describes the screening of 22 extracts from 18 different aquatic environmental samples for androgenic activity, including indirect and interactive effects on androgen receptor (AR)-mediated signal transduction, using the AR-LUX bioassay. Four samples, originating from an industrial wastew

  19. Androgenic activity in surface water samples detected using the AR-LUX assay: Indications for mixture effects

    NARCIS (Netherlands)

    Blankvoort, B.M.G.; Rodenburg, R.J.T.; Murk, A.J.; Koeman, J.H.; Schilt, R.; Aarts, J.M.M.J.G.

    2005-01-01

    This paper describes the screening of 22 extracts from 18 different aquatic environmental samples for androgenic activity, including indirect and interactive effects on androgen receptor (AR)-mediated signal transduction, using the AR-LUX bioassay. Four samples, originating from an industrial wastew

  20. EPI-001, A Compound Active against Castration-Resistant Prostate Cancer, Targets Transactivation Unit 5 of the Androgen Receptor.

    Science.gov (United States)

    De Mol, Eva; Fenwick, R Bryn; Phang, Christopher T W; Buzón, Victor; Szulc, Elzbieta; de la Fuente, Alex; Escobedo, Albert; García, Jesús; Bertoncini, Carlos W; Estébanez-Perpiñá, Eva; McEwan, Iain J; Riera, Antoni; Salvatella, Xavier

    2016-09-16

    Castration-resistant prostate cancer is the lethal condition suffered by prostate cancer patients that become refractory to androgen deprivation therapy. EPI-001 is a recently identified compound active against this condition that modulates the activity of the androgen receptor, a nuclear receptor that is essential for disease progression. The mechanism by which this compound exerts its inhibitory activity is however not yet fully understood. Here we show, by using high resolution solution nuclear magnetic resonance spectroscopy, that EPI-001 selectively interacts with a partially folded region of the transactivation domain of the androgen receptor, known as transactivation unit 5, that is key for the ability of prostate cells to proliferate in the absence of androgens, a distinctive feature of castration-resistant prostate cancer. Our results can contribute to the development of more potent and less toxic novel androgen receptor antagonists for treating this disease.

  1. Development of selective androgen receptor modulators and their therapeutic applications.

    Science.gov (United States)

    Chen, Fang; Rodan, Gideon A; Schmidt, Azi

    2002-01-01

    Androgens control a broad range of physiological functions. The androgen receptor (AR), a steroid receptor that mediates the diverse biological actions of androgens, is a ligand inducible transcription factor. Abnormalities in the androgen signaling system result in many disturbances ranging from changes in gender determination and sexual development to psychiatric and emotional disorders. Androgen replacement therapy can improve many clinical conditions including hypogonadism and osteoporosis, but is limited by the lack of efficacious and safe therapeutic agents with easy delivery options. Recent progress in the area of gene regulation by steroid receptors and by selective receptor modulators provides an opportunity to examine if selective androgen receptor modulators (SARMs) could address some of the problems associated with current androgen therapy. Since the composition of the transcriptional initiation complex recruited by liganded AR determines the specificity of gene regulation, synthetic ligands aimed at initiating transcription of tissue and promoter specific genes offers hope for developing better androgen therapy. Establishment of assays that predict synthetic ligand activity is critical for SARM development. Advancement in high throughput compound screening and gene fingerprinting technologies, such as microarrays and proteomics, will facilitate and accelerate identification of effective SARMs.

  2. High-Content Positional Biosensor Screening Assay for Compounds to Prevent or Disrupt Androgen Receptor and Transcriptional Intermediary Factor 2 Protein–Protein Interactions

    OpenAIRE

    Hua, Yun; Shun, Tong Ying; Strock, Christopher J.; Johnston, Paul A.

    2014-01-01

    The androgen receptor–transcriptional intermediary factor 2 (AR-TIF2) positional protein–protein interaction (PPI) biosensor assay described herein combines physiologically relevant cell-based assays with the specificity of binding assays by incorporating structural information of AR and TIF2 functional domains along with intracellular targeting sequences and fluorescent reporters. Expression of the AR-red fluorescent protein (RFP) “prey” and TIF2-green fluorescent protein (GFP) “bait” compon...

  3. Contributions by the CAG-repeat Polymorphism of the Androgen Receptor Gene and Circulating Androgens to Muscle Size. Odense Androgen Study - A Population-based Study of 20-29 Year-old Danish Men

    DEFF Research Database (Denmark)

    Nielsen, Torben Leo; Hagen, Claus; Wraae, Kristian;

    2007-01-01

    Context: The number of CAG-repeats within the CAG-repeat polymorphism of the androgen receptor gene is inversely correlated with the transcriptional activity of the androgen receptor. Objective: To study the effect of the CAG-repeat number and circulating androgens on muscle size, to examine......-repeat number correlated inversely with thigh and axial muscle area and with lower and upper extremity lean body mass. Except for upper extremity lean body mass, these findings remained significant in multivariate analyses controlling for circulating androgens, physical activity, smoking, alcohol intake...

  4. Mutated human androgen receptor gene detected in a prostatic cancer patient is also activated by estradiol

    Energy Technology Data Exchange (ETDEWEB)

    Elo, J.P.; Kvist, L.; Leinonen, K.; Isomaa, V. [Univ. of Oulu (Finland)] [and others

    1995-12-01

    Androgens are necessary for the development of prostatic cancer. The mechanisms by which the originally androgen-dependent prostatic cancer cells are relieved of the requirement to use androgen for their growth are largely unknown. The human prostatic cancer cell line LNCaP has been shown to contain a point mutation in the human androgen receptor gene (hAR), suggesting that changes in the hAR may contribute to the abnormal hormone response of prostatic cells. To search for point mutations in the hAR, we used single strand conformation polymorphism analysis and a polymerase chain reaction direct sequencing method to screen 23 prostatic cancer specimens from untreated patients, 6 prostatic cancer specimens from treated patients, and 11 benign prostatic hyperplasia specimens. One mutation was identified in DNA isolated from prostatic cancer tissue, and the mutation was also detected in the leukocyte DNA of the patient and his offspring. The mutation changed codon 726 in exon E from arginine to leucine and was a germ line mutation. The mutation we found in exon E of the hAR gene does not alter the ligand binding specificity of the AR, but the mutated receptor was activated by estradiol to a significantly greater extent than the wild-type receptor. The AR gene mutation described in this study might be one explanation for the altered biological activity of prostatic cancer. 36 refs., 4 figs.

  5. Androgen-induced cell migration: role of androgen receptor/filamin A association.

    Directory of Open Access Journals (Sweden)

    Gabriella Castoria

    Full Text Available BACKGROUND: Androgen receptor (AR controls male morphogenesis, gametogenesis and prostate growth as well as development of prostate cancer. These findings support a role for AR in cell migration and invasiveness. However, the molecular mechanism involved in AR-mediated cell migration still remains elusive. METHODOLOGY/PRINCIPAL FINDINGS: Mouse embryo NIH3T3 fibroblasts and highly metastatic human fibrosarcoma HT1080 cells harbor low levels of transcriptionally incompetent AR. We now report that, through extra nuclear action, AR triggers migration of both cell types upon stimulation with physiological concentrations of the androgen R1881. We analyzed the initial events leading to androgen-induced cell migration and observed that challenging NIH3T3 cells with 10 nM R1881 rapidly induces interaction of AR with filamin A (FlnA at cytoskeleton. AR/FlnA complex recruits integrin beta 1, thus activating its dependent cascade. Silencing of AR, FlnA and integrin beta 1 shows that this ternary complex controls focal adhesion kinase (FAK, paxillin and Rac, thereby driving cell migration. FAK-null fibroblasts migrate poorly and Rac inhibition by EHT impairs motility of androgen-treated NIH3T3 cells. Interestingly, FAK and Rac activation by androgens are independent of each other. Findings in human fibrosarcoma HT1080 cells strengthen the role of Rac in androgen signaling. The Rac inhibitor significantly impairs androgen-induced migration in these cells. A mutant AR, deleted of the sequence interacting with FlnA, fails to mediate FAK activation and paxillin tyrosine phosphorylation in androgen-stimulated cells, further reinforcing the role of AR/FlnA interaction in androgen-mediated motility. CONCLUSIONS/SIGNIFICANCE: The present report, for the first time, indicates that the extra nuclear AR/FlnA/integrin beta 1 complex is the key by which androgen activates signaling leading to cell migration. Assembly of this ternary complex may control organ development

  6. Identification of anabolic selective androgen receptor modulators with reduced activities in reproductive tissues and sebaceous glands.

    Science.gov (United States)

    Schmidt, Azriel; Harada, Shun-Ichi; Kimmel, Donald B; Bai, Chang; Chen, Fang; Rutledge, Su Jane; Vogel, Robert L; Scafonas, Angela; Gentile, Michael A; Nantermet, Pascale V; McElwee-Witmer, Sheila; Pennypacker, Brenda; Masarachia, Patricia; Sahoo, Soumya P; Kim, Yuntae; Meissner, Robert S; Hartman, George D; Duggan, Mark E; Rodan, Gideon A; Towler, Dwight A; Ray, William J

    2009-12-25

    Androgen replacement therapy is a promising strategy for the treatment of frailty; however, androgens pose risks for unwanted effects including virilization and hypertrophy of reproductive organs. Selective Androgen Receptor Modulators (SARMs) retain the anabolic properties of androgens in bone and muscle while having reduced effects in other tissues. We describe two structurally similar 4-aza-steroidal androgen receptor (AR) ligands, Cl-4AS-1, a full agonist, and TFM-4AS-1, which is a SARM. TFM-4AS-1 is a potent AR ligand (IC(50), 38 nm) that partially activates an AR-dependent MMTV promoter (55% of maximal response) while antagonizing the N-terminal/C-terminal interaction within AR that is required for full receptor activation. Microarray analyses of MDA-MB-453 cells show that whereas Cl-4AS-1 behaves like 5alpha-dihydrotestosterone (DHT), TFM-4AS-1 acts as a gene-selective agonist, inducing some genes as effectively as DHT and others to a lesser extent or not at all. This gene-selective agonism manifests as tissue-selectivity: in ovariectomized rats, Cl-4AS-1 mimics DHT while TFM-4AS-1 promotes the accrual of bone and muscle mass while having reduced effects on reproductive organs and sebaceous glands. Moreover, TFM-4AS-1 does not promote prostate growth and antagonizes DHT in seminal vesicles. To confirm that the biochemical properties of TFM-4AS-1 confer tissue selectivity, we identified a structurally unrelated compound, FTBU-1, with partial agonist activity coupled with antagonism of the N-terminal/C-terminal interaction and found that it also behaves as a SARM. TFM-4AS-1 and FTBU-1 represent two new classes of SARMs and will allow for comparative studies aimed at understanding the biophysical and physiological basis of tissue-selective effects of nuclear receptor ligands.

  7. LINE-1 ORF-1p functions as a novel androgen receptor co-activator and promotes the growth of human prostatic carcinoma cells.

    Science.gov (United States)

    Lu, Yinying; Feng, Fan; Yang, Yutao; Gao, Xudong; Cui, Jiajun; Zhang, Chuanfu; Zhang, Fan; Xu, Zhongxian; Qv, Jianhui; Wang, Chunping; Zeng, Zhen; Zhu, Yunfeng; Yang, Yongping

    2013-02-01

    Widespread interest in the mechanism of transcriptional regulation by the androgen receptor (AR) has been stimulated by the finding that AR signaling is critically important in the progression of human prostate cancers. Co-factors, the co-repressors, or the co-activators are responsible for the regulation of AR activation. The pro-oncogene human Long Interspersed Nucleotide acid Element-1 (LINE-1) encodes LINE-1 ORF-1p and plays important roles in the development and progression of several human carcinomas. In this study, the results showed that LINE-1 ORF-1p increased the AR transcriptional activity and in turn enhanced the expression of prostate specific antigen (PSA) in the presence of R1881. A physical protein-protein interaction between the AR signaling and the LINE-1 ORF-1p was identified by the immunoprecipitation assays and GST pull-down assays. Furthermore, LINE-1 ORF-1p would function as a novel AR positive co-regulator through modulating its cytoplasm/nucleus translocation and the recruitment to the androgen response element in the PSA gene promoter. Our date also showed that the LINE-1 ORF-1p promoted the proliferation and anchor-independent growth of LNCaP (ligand dependent) and PC-3 (ligand independent) human prostatic carcinoma cells. By investigating a novel role of the LINE-1 ORF-1p in the androgen/androgen receptor signaling pathway regulation, our study identifies that LINE-1 ORF-1p may be a novel AR co-regulator and molecular target for human prostate carcinoma therapy.

  8. Effect of androgen withdrawal on activation of ERKs and expression of cell cycle regulation molecules in human prostate carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    YE Ding-wei; LI Hui; TSENG Jane; CHAUVIN Priscilla; QIAN Song-xi; ZHENG Jia-fu; SUN Ying-hao; MA Yong-jiang

    2002-01-01

    Objective: To explore the possible mechanisms of growth regression of human androgen dependentprostate carcinoma cells caused by androgen withdrawal. Methods: After 24 h of treatment with 1×10-9mol/L dihydrotestosterone (DHT), the expression of phosphorylated ERK proteins and cell cycle regulationmolecules including CDK2, CDK4, CDK6 and P27kip1 in human androgen dependent prostate carcinoma cellline LNCaP was measured by Western blot analysis 0 h, 8 h and 24 h of after androgen withdrawal. Humanandrogen independent prostate carcinoma cell line PC-3 was also examined as control. Results: Down-regula-tion of phosphorylated ERK, CDK2, CDK4 and CDK6 and up-regulation of P27kip1 were found initially inLNCaP cell line 8 h after androgen withdrawal. The levels of phosphorylated ERK and CDKs decreased con-tinuously and reached the lowest after 24 h, while continuous elevation of P27kip1 was detected thereafter to 24h. No expression change of phosphorylated ERK, CDKs and P27kip1 were detected in PC-3 cell line. Conclu-sion: The androgen withdrawal can cause ERKs activation decrease and cell cycle regulation moleculeschanges, which may be one of the mechanisms for inhibited growth of androgen dependent prostate carcinomaafter androgen ablation by either operative or medicine methods.

  9. The genomic transcriptional response of female fathead minnows (Pimephales promelas) to an acute exposure to the androgen, 17β-trenbolone

    Science.gov (United States)

    Dorts, Jennifer; Richter, Catherine A.; Wright-Osment, Maureen K.; Ellersieck, Mark R.; Carter, Barbara J.; Tillitt, Donald E.

    2009-01-01

    We investigated the genomic transcriptional response of female fathead minnows (Pimephales promelas) to an acute (4 days) exposure to 0.1 or 1.0 ??g/L of 17??-trenbolone (TB), the active metabolite of an anabolic androgenic steroid used as a growth promoter in cattle and a contaminant of concern in aquatic systems. Our objectives were to investigate the gene expression profile induced by TB, define biomarkers of exposure to TB, and increase our understanding of the mechanisms of adverse effects of TB on fish reproduction. In female gonad tissue, microarray analysis using a 22 K oligonucleotide microarray (EcoArray Inc., Gainesville, FL) showed 99 significantly upregulated genes and 741 significantly downregulated genes in response to 1 ??g TB/L. In particular, hydroxysteroid (17??) dehydrogenase 12a (hsd17b12a), zona pellucida glycoprotein 2.2 (zp2.2), and protein inhibitor of activated STAT, 2 (pias2) were all downregulated in gonad. Q-PCR measurements in a larger sample set were consistent with the microarray results in the direction and magnitude of these changes in gene expression. However, several novel potential biomarkers were verified by Q-PCR in the same samples, but could not be validated in independent samples. In liver, Q-PCR measurements showed a significant decrease in vitellogenin 1 (vtg1) mRNA expression. In brain, cytochrome P450, family 19, subfamily A, polypeptide 1b (cyp19a1b, previously known as aromatase B) transcript levels were significantly reduced following TB exposure. Our study provides a candidate gene involved in mediating the action of TB, hsd17b12a, and two potential biomarkers sensitive to acute TB exposure, hepatic vtg1 and brain cyp19a1b.

  10. Mitotic Transcriptional Activation: Clearance of Actively Engaged Pol II via Transcriptional Elongation Control in Mitosis.

    Science.gov (United States)

    Liang, Kaiwei; Woodfin, Ashley R; Slaughter, Brian D; Unruh, Jay R; Box, Andrew C; Rickels, Ryan A; Gao, Xin; Haug, Jeffrey S; Jaspersen, Sue L; Shilatifard, Ali

    2015-11-05

    Although it is established that some general transcription factors are inactivated at mitosis, many details of mitotic transcription inhibition (MTI) and its underlying mechanisms are largely unknown. We have identified mitotic transcriptional activation (MTA) as a key regulatory step to control transcription in mitosis for genes with transcriptionally engaged RNA polymerase II (Pol II) to activate and transcribe until the end of the gene to clear Pol II from mitotic chromatin, followed by global impairment of transcription reinitiation through MTI. Global nascent RNA sequencing and RNA fluorescence in situ hybridization demonstrate the existence of transcriptionally engaged Pol II in early mitosis. Both genetic and chemical inhibition of P-TEFb in mitosis lead to delays in the progression of cell division. Together, our study reveals a mechanism for MTA and MTI whereby transcriptionally engaged Pol II can progress into productive elongation and finish transcription to allow proper cellular division.

  11. Xeno-oestrogens Bisphenol A and Diethylstilbestrol Selectively Activating Androgen Receptor Mediated AREs-TATA Reporter System

    Institute of Scientific and Technical Information of China (English)

    WU Jing; WEI Wei; YANG Nan-yang; SHEN Xiao-yan; TSUJI Ichiro; YAMAMURA Takaki; LI Jiang

    2013-01-01

    We cloned the three androgen response elements(AREs,including AREⅠ,AREⅡ,and AREⅢ) with a core transactivation TATA element of the prostate-specific antigen(PSA) promoter into pGL2 basic vector to create an artificial pGL2/AREs-TATA reporter system,which was applied to evaluating the effects of different xenooestrogens[bisphenol A(BPA),4-nonylphenol(4-NP),dichlorodiphenyl trichloroethane(DDT) or diethylstilbestrol (DES)] on androgen receptor(AR) abnormal activation to regulate PSA expression and cell proliferation.In all the three AREs,AREⅢ-TATA displayed as a major element responsive to AR-mediated DHT stimulation of PSA promoter.Therefore,pGL2/AREⅢ-TATA reporter was adopted to analyze the activation capacity of AR activated by four different xeno-oestrogens.The activation ofpGL2/AREⅢ-TATA reporter by each xeno-oestrogen was analyzed in two different cell lines,one was HEK293T(Human Embryonic Kidney 293T) cell line,and the other was AR stably expressed DU145 cell line,which was produced by infecting AR with pLenti-puro-AR into the prostate cancer DU145 cells and that were scanned with puromycin and tested by AR antibody.In both the two cell lines,BPA or DES significantly induced AR-mediated transcriptional activity of AREⅢ-TATA reporter,whereas DDT or 4-nonylphenol did not.Moreover,AR-mediated cell proliferation in response to each of four xeno-oestrogens was measured in MTT assays in both HEK293T cell or AR stably expressed DU145 cell lines.BPA or DES,as an AR inducer,exhibited an enhanced effect in cell proliferation,rather than the effect of DDT or 4-NP,in both cell lines.Finally,we demonstrated that BPA or DES stimulated PSA expression and enhanced the recruitment of AR onto thePSA promoter,resulting in stronger binding to AREⅢ sites.Taken together,four xeno-oestrogens were identified to have different activities on AR.BPA and DES are demonstrated to be androgenic effectors in the regulation of PSA activation or cell proliferation.

  12. Androgens and bone.

    Science.gov (United States)

    Vanderschueren, Dirk; Vandenput, Liesbeth; Boonen, Steven; Lindberg, Marie K; Bouillon, Roger; Ohlsson, Claes

    2004-06-01

    Loss of estrogens or androgens increases the rate of bone remodeling by removing restraining effects on osteoblastogenesis and osteoclastogenesis, and also causes a focal imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, androgens, as well as estrogens, maintain cancellous bone mass and integrity, regardless of age or sex. Although androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs), can exert these effects, their relative contribution remains uncertain. Recent studies suggest that androgen action on cancellous bone depends on (local) aromatization of androgens into estrogens. However, at least in rodents, androgen action on cancellous bone can be directly mediated via AR activation, even in the absence of ERs. Androgens also increase cortical bone size via stimulation of both longitudinal and radial growth. First, androgens, like estrogens, have a biphasic effect on endochondral bone formation: at the start of puberty, sex steroids stimulate endochondral bone formation, whereas they induce epiphyseal closure at the end of puberty. Androgen action on the growth plate is, however, clearly mediated via aromatization in estrogens and interaction with ERalpha. Androgens increase radial growth, whereas estrogens decrease periosteal bone formation. This effect of androgens may be important because bone strength in males seems to be determined by relatively higher periosteal bone formation and, therefore, greater bone dimensions, relative to muscle mass at older age. Experiments in mice again suggest that both the AR and ERalpha pathways are involved in androgen action on radial bone growth. ERbeta may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males. In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and

  13. Androgen regulation of the TMPRSS2 gene and the effect of a SNP in an androgen response element.

    Science.gov (United States)

    Clinckemalie, Liesbeth; Spans, Lien; Dubois, Vanessa; Laurent, Michaël; Helsen, Christine; Joniau, Steven; Claessens, Frank

    2013-12-01

    More than 50% of prostate cancers have undergone a genomic reorganization that juxtaposes the androgen-regulated promoter of TMPRSS2 and the protein coding parts of several ETS oncogenes. These gene fusions lead to prostate-specific and androgen-induced ETS expression and are associated with aggressive lesions, poor prognosis, and early-onset prostate cancer. In this study, we showed that an enhancer at 13 kb upstream of the TMPRSS2 transcription start site is crucial for the androgen regulation of the TMPRSS2 gene when tested in bacterial artificial chromosomal vectors. Within this enhancer, we identified the exact androgen receptor binding sequence. This newly identified androgen response element is situated next to two binding sites for the pioneer factor GATA2, which were identified by DNase I footprinting. Both the androgen response element and the GATA-2 binding sites are involved in the enhancer activity. Importantly, a single nucleotide polymorphism (rs8134378) within this androgen response element reduces binding and transactivation by the androgen receptor. The presence of this SNP might have implications on the expression and/or formation levels of TMPRSS2 fusions, because both have been shown to be influenced by androgens.

  14. Functional cyclic AMP response element in the breast cancer resistance protein (BCRP/ABCG2) promoter modulates epidermal growth factor receptor pathway- or androgen withdrawal-mediated BCRP/ABCG2 transcription in human cancer cells.

    Science.gov (United States)

    Xie, Yi; Nakanishi, Takeo; Natarajan, Karthika; Safren, Lowell; Hamburger, Anne W; Hussain, Arif; Ross, Douglas D

    2015-03-01

    Phosphorylated cyclic-AMP (cAMP) response element binding protein (p-CREB) is a downstream effector of a variety of important signaling pathways. We investigated whether the human BCRP promoter contains a functional cAMP response element (CRE). 8Br-cAMP, a cAMP analogue, increased the activity of a BCRP promoter reporter construct and BCRP mRNA in human carcinoma cells. Epidermal growth factor receptor (EGFR) pathway activation also led to an increase in p-CREB and in BCRP promoter reporter activity via two major downstream EGFR signaling pathways: the phosphotidylinositol-3-kinase (PI3K)/AKT pathway and the mitogen-activated protein kinase (MAPK) pathway. EGF treatment increased the phosphorylation of EGFR, AKT, ERK and CREB, while simultaneously enhancing BCRP mRNA and functional protein expression. EGF-stimulated CREB phosphorylation and BCRP induction were diminished by inhibition of EGFR, PI3K/AKT or RAS/MAPK signaling. CREB silencing using RNA interference reduced basal levels of BCRP mRNA and diminished the induction of BCRP by EGF. Chromatin immunoprecipitation assays confirmed that a putative CRE site on the BCRP promoter bound p-CREB by a point mutation of the CRE site abolished EGF-induced stimulation of BCRP promoter reporter activity. Furthermore, the CREB co-activator, cAMP-regulated transcriptional co-activator (CRTC2), is involved in CREB-mediated BCRP transcription: androgen depletion of LNCaP human prostate cancer cells increased both CREB phosphorylation and CRTC2 nuclear translocation, and enhanced BCRP expression. Silencing CREB or CRTC2 reduced basal BCRP expression and BCRP induction under androgen-depletion conditions. This novel CRE site plays a central role in mediating BCRP gene expression in several human cancer cell lines following activation of multiple cancer-relevant signaling pathways.

  15. The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells.

    Science.gov (United States)

    Ghotbaddini, Maryam; Powell, Joann B

    2015-07-06

    The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR). TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to induce degradation of hormone receptors. The studies reported here, evaluate the effect of TCDD exposure on androgen receptor (AR) expression and activity in androgen-sensitive LNCaP and castration-resistant C4-2 prostate cancer cells. Our results show that TCDD exposure does not induce AhR or AR degradation in C4-2 cells. However, both AhR and AR are degraded in LNCaP cells following TCDD exposure. In addition, TCDD enhances AR phosphorylation and induces expression of AR responsive genes in LNCaP cells. Our data reveals that TCDD effect on AR expression and activity differs in androgen-sensitive and castration-resistant prostate cancer cell models.

  16. The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Maryam Ghotbaddini

    2015-07-01

    Full Text Available The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR. TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to induce degradation of hormone receptors. The studies reported here, evaluate the effect of TCDD exposure on androgen receptor (AR expression and activity in androgen-sensitive LNCaP and castration-resistant C4-2 prostate cancer cells. Our results show that TCDD exposure does not induce AhR or AR degradation in C4-2 cells. However, both AhR and AR are degraded in LNCaP cells following TCDD exposure. In addition, TCDD enhances AR phosphorylation and induces expression of AR responsive genes in LNCaP cells. Our data reveals that TCDD effect on AR expression and activity differs in androgen-sensitive and castration-resistant prostate cancer cell models.

  17. Zipper-interacting protein kinase is involved in regulation of ubiquitination of the androgen receptor, thereby contributing to dynamic transcription complex assembly.

    Science.gov (United States)

    Felten, A; Brinckmann, D; Landsberg, G; Scheidtmann, K H

    2013-10-10

    We have recently identified apoptosis-antagonizing transcription factor (AATF), tumor-susceptibility gene 101 (TSG101) and zipper-interacting protein kinase (ZIPK) as novel coactivators of the androgen receptor (AR). The mechanisms of coactivation remained obscure, however. Here we investigated the interplay and interdependence between these coactivators and the AR using the endogenous prostate specific antigen (PSA) gene as model for AR-target genes. Chromatin immunoprecipitation in combination with siRNA-mediated knockdown revealed that recruitment of AATF and ZIPK to the PSA enhancer was dependent on AR, whereas recruitment of TSG101 was dependent on AATF. Association of AR and its coactivators with the PSA enhancer or promoter occurred in cycles. Dissociation of AR-transcription complexes was due to degradation because inhibition of the proteasome system by MG132 caused accumulation of AR at enhancer/promoter elements. Moreover, inhibition of degradation strongly reduced transcription, indicating that continued and efficient transcription is based on initiation, degradation and reinitiation cycles. Interestingly, knockdown of ZIPK by siRNA had a similar effect as MG132, leading to reduced transcription but enhanced accumulation of AR at androgen-response elements. In addition, knockdown of ZIPK, as well as overexpression of a dominant-negative ZIPK mutant, diminished polyubiquitination of AR. Furthermore, ZIPK cooperated with the E3 ligase Mdm2 in AR-dependent transactivation, assembled into a single complex on chromatin and phosphorylated Mdm2 in vitro. These results suggest that ZIPK has a crucial role in regulation of ubiquitination and degradation of the AR, and hence promoter clearance and efficient transcription.

  18. In silico and biological analysis of anti-androgen activity of the brominated flame retardants ATE, BATE and DPTE in zebrafish.

    Science.gov (United States)

    Pradhan, Ajay; Asnake, Solomon; Kharlyngdoh, Joubert Banjop; Modig, Carina; Olsson, Per-Erik

    2015-05-25

    The brominated flame retardants (BFRs) 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH or DBE-DCBH) and allyl 2,4,6-tribromophenyl ether (ATE or TBP-AE) are alternative BFRs that have been introduced to replace banned BFRs. TBECH is a potential endocrine disrupter in human, chicken and zebrafish and in a recent study we showed that ATE, along with the structurally similar BFR 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE or TBP-DBPE) and its metabolite 2-bromoallyl 2,4,6-tribromophenyl ether (BATE or TBP-BAE) are potential endocrine and neuronal disrupters in human. In this study we analyzed ATE, BATE and DPTE for zebrafish androgen receptor (zAR) modulating properties. In silico analysis with two softwares, Molecular Operating Environment (MOE) and Internal Coordinate Mechanics (ICM), showed that ATE, BATE and DPTE bind to zAR. In vitro AR activation assay revealed that these three BFRs down-regulate 11-ketotestosterone (KT) mediated zAR activation. Exposure to 10 μM DPTE resulted in reduced hatching success and like TBECH, BATE and DPTE at 10 μM also had teratogenic properties with 20% and 50% back-bone curvature respectively. Gene transcription analysis in zebrafish embryos as well as in juveniles showed down-regulation of the androgen receptor and androgen response genes, which further support that these BFRs are androgen antagonists and potential endocrine disrupting compounds. Genes involved in steroidogenesis were also down-regulated by these BFRs. In view of this, the impact of these BFRs on humans and wildlife needs further analysis.

  19. Cyclooxygenase-2 expression is dependent upon epidermal growth factor receptor expression or activation in androgen independent prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Rui-Peng Jia; Lu-Wei Xu; Qi Su; Jian-Hua Zhao; Wen-Cheng Li; Feng Wang; Zheng Xu

    2008-01-01

    Aim: To investigate the expression of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) and the possible mechanism in the development in androgen independent prostate cancer (AIPC). Methods: Immunohis- tochemistry was performed on paraffin-embedded sections with goat polyclonal against COX-2 and mouse mono- clonal antibody against EGFR in 30 AIPC and 18 androgen dependent prostate cancer (ADPC) specimens. The effect of epidermal growth factor (EGF) treatments on the expression of COX-2 and signal pathway in PC-3 and DU-145 cells was studied using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. ELISA was used to measure prostaglandin E2 (PGE2) levels in the media of PC-3 and DU-145 incubated with EGF for 24 h. Results: COX-2 was positively expressed in AIPC and ADPC, which were predominantly in endochylema of prostate cancer (Pca) cells. Intense staining was seen in AIPC (80%) and in ADPC (55.5%), but there was no significant association between the two groups. EGFR expression was also positive in the two groups (61.8% in ADPC and 90% in AIPC, P < 0.01). A significant association was found between EGFR expression and a higher Gleason score (P < 0.05) or tumor stage (P < 0.05). The expression of PGE2 was increased in PC-3 and DU-145 cells after being incubated with EGF. Both p38MAPK and PI-3K pathway were involved in the PC-3 cell COX-2 upregulation course. In DU- 145, only p38MAPK pathway was associated with COX-2 upregulation. Conclusion: EGFR activation induces COX-2 expression through PI-3K and/or p38MAPK pathways. COX-2 and EGFR inhibitors might have a cooperative anti-tumor effect in Pca.

  20. Androgens and women's health.

    Science.gov (United States)

    Redmond, G P

    1998-01-01

    Androgenic disorders are those conditions in women characterized by excessive androgen action. They are the most common endocrinopathy of women, affecting from 10% to 20%. Signs are: persistent acne, hirsutism and androgenic alopecia, which is the female equivalent of male pattern baldness. A subgroup, those traditionally labeled as having polycystic ovary syndrome (PCOS), additionally have anovulation, as well as menstrual abnormalities and, often, obesity. Although women with androgenic disorders usually present themselves for help with the skin or menstrual changes, there are other important implications regarding their health. Women with PCOS have varying degrees of insulin resistance, and an increased incidence of Type II diabetes mellitus, as well as unfavorable lipid patterns. The presence of these risk factors is suggested by upper segment obesity, darkening of the skin, and the other skin changes that make up acanthosis nigricans. Diagnosis involves measurement of circulating androgens (of which free testosterone is most important), together with prolactin and FSH when menstrual dysfunction is present. Many women with androgenic skin changes have normal serum androgen levels, suggesting increased end organ sensitivity to androgens. Others have hyperandrogenism (of ovarian or adrenal origin). Treatment is usually successful in controlling acne, reducing hirsutism and stabilizing, or partially reversing, androgenic alopecia. Pharmacological approaches involve suppressing androgen levels, for example, the use of an appropriate oral contraceptive, or antagonizing androgen action with several medications that have this activity. Unfortunately, most women with androgenic disorders are frustrated in their efforts to obtain medical help. Understanding androgenic disorders will enable the physician to significantly help the majority of women with these conditions.

  1. Bioluminescence Microscopy as a Method to Measure Single Cell Androgen Receptor Activity Heterogeneous Responses to Antiandrogens

    Science.gov (United States)

    Jain, Pallavi; Neveu, Bertrand; Velot, Lauriane; Wu, Lily; Fradet, Yves; Pouliot, Frédéric

    2016-01-01

    Cancer cell heterogeneity is well-documented. Therefore, techniques to monitor single cell heterogeneous responses to treatment are needed. We developed a highly translational and quantitative bioluminescence microscopy method to measure single cell androgen receptor (AR) activity modulation by antiandrogens from fluid biopsies. We showed that this assay can detect heterogeneous cellular response to drug treatment and that the sum of single cell AR activity can mirror the response in the whole cell population. This method may thus be used to monitor heterogeneous dynamic treatment responses in cancer cells. PMID:27678181

  2. Comparison of in vitro and in vivo screening models for androgenic and estrogenic activities.

    Science.gov (United States)

    Sonneveld, Edwin; Riteco, Jacoba A C; Jansen, Hendrina J; Pieterse, Bart; Brouwer, Abraham; Schoonen, Willem G; van der Burg, Bart

    2006-01-01

    Identification of nuclear receptor-mediated endocrine activities is important in a variety of fields, ranging from pharmacological and clinical screening, to food and feed safety, toxicological monitoring, and risk assessment. Traditionally animal studies such as the Hershberger and Allen-Doisy tests are used for the assessment of androgenic and estrogenic potencies, respectively. To allow fast analysis of the activities of new chemicals, food additives, and pharmaceutical compounds, high-throughput screening strategies have been developed. Here, a panel of mainly steroidal compounds, screened in different in vitro assays, was compared with two human U2-OS cell line-based CALUX (Chemically Activated LUciferase eXpression) reporter gene assays for androgens (AR CALUX) and estrogens (ERalpha CALUX). Correlations found between the data of these two CALUX reporter gene assays and data obtained with other in vitro screening assays measuring receptor binding or reporter gene activation (CHO cell line-based) were good (correlation coefficients (r2) between 0.54 and 0.76; p vitro and in vivo data (correlation coefficient r2 = 0.46 for the AR CALUX vs. Hershberger assay and r2 = 0.87 for the ERalpha CALUX vs. Allen-Doisy assay). The variations in the results obtained with the reporter gene assays (CALUX vs. CHO cell line based) were relatively small, showing the robustness of these types of assays. Using hierarchical clustering, bioactivity relationships between compounds but also relationships between various bioassays were determined. The in vitro assays were found to be good predictors of in vivo androgenic or estrogenic activity of a range of compounds, allowing prescreen and/or possible reduction of animal studies.

  3. Linking Prenatal Androgens to Gender-Related Attitudes, Identity, and Activities: Evidence From Girls With Congenital Adrenal Hyperplasia.

    Science.gov (United States)

    Endendijk, Joyce J; Beltz, Adriene M; McHale, Susan M; Bryk, Kristina; Berenbaum, Sheri A

    2016-10-01

    Key questions for developmentalists concern the origins of gender attitudes and their implications for behavior. We examined whether prenatal androgen exposure was related to gender attitudes, and whether and how the links between attitudes and gendered activity interest and participation were mediated by gender identity and moderated by hormones. Gender attitudes (i.e., gender-role attitudes and attitudes about being a girl), gender identity, and gender-typed activities were reported by 54 girls aged 10-13 years varying in degree of prenatal androgen exposure, including 40 girls with classical congenital adrenal hyperplasia (C-CAH) exposed to high prenatal androgens and 14 girls with non-classical (NC) CAH exposed to low, female-typical, prenatal androgens. Both girls with C-CAH and NC-CAH reported positive attitudes about being a girl and egalitarian gender attitudes, consistent with their female-typical gender identity. In contrast, girls with C-CAH had more male-typed activity interest and participation than girls with NC-CAH. Gender attitudes were linked to activities in both groups, with gender identity mediating the links. Specifically, gender-role attitudes and positive attitudes about being a girl were associated with feminine gender identity, which in turn was associated with decreased male-typed activity interests and participation, and increased female-typed activity interests. Our results are consistent with schema theories, with attitudes more closely associated with gender identity than with prenatal androgens.

  4. Chemometric and chemoinformatic analyses of anabolic and androgenic activities of testosterone and dihydrotestosterone analogues.

    Science.gov (United States)

    Alvarez-Ginarte, Yoanna María; Crespo-Otero, Rachel; Marrero-Ponce, Yovani; Noheda-Marin, Pedro; Garcia de la Vega, Jose Manuel; Montero-Cabrera, Luis Alberto; Ruiz García, José Alberto; Caldera-Luzardo, José A; Alvarado, Ysaias J

    2008-06-15

    Predictive quantitative structure-activity relationship (QSAR) models of anabolic and androgenic activities for the testosterone and dihydrotestosterone steroid analogues were obtained by means of multiple linear regression using quantum and physicochemical molecular descriptors (MD) as well as a genetic algorithm for the selection of the best subset of variables. Quantitative models found for describing the anabolic (androgenic) activity are significant from a statistical point of view: R(2) of 0.84 (0.72 and 0.70). A leave-one-out cross-validation procedure revealed that the regression models had a fairly good predictability [q(2) of 0.80 (0.60 and 0.59)]. In addition, other QSAR models were developed to predict anabolic/androgenic (A/A) ratios and the best regression equation explains 68% of the variance for the experimental values of AA ratio and has a rather adequate q(2) of 0.51. External validation, by using test sets, was also used in each experiment in order to evaluate the predictive power of the obtained models. The result shows that these QSARs have quite good predictive abilities (R(2) of 0.90, 0.72 (0.55), and 0.53) for anabolic activity, androgenic activity, and A/A ratios, respectively. Last, a Williams plot was used in order to define the domain of applicability of the models as a squared area within +/-2 band for residuals and a leverage threshold of h=0.16. No apparent outliers were detected and the models can be used with high accuracy in this applicability domain. MDs included in our QSAR models allow the structural interpretation of the biological process, evidencing the main role of the shape of molecules, hydrophobicity, and electronic properties. Attempts were made to include lipophilicity (octanol-water partition coefficient (logP)) and electronic (hardness (eta)) values of the whole molecules in the multivariate relations. It was found from the study that the logP of molecules has positive contribution to the anabolic and androgenic

  5. Anabolic and androgenic activities of Bulbine natalensis stem in male Wistar rats.

    Science.gov (United States)

    Yakubu, Musa T; Afolayan, Anthony J

    2010-05-01

    Aqueous extract of Bulbine natalensis Baker (Asphodelaceae) stem at 25, 50 and 100 mg/kg body weight was investigated for anabolic and androgenic effects in male Wistar rats. Sixty male rats were grouped into four (A-D) consisting of 15 each. Group A (control) was orally treated with 0.5 mL of distilled water for 14 days while groups B, C and D were treated like the control except they received 0.5 mL containing 25, 50, and 100 mg/kg body weight of the extract respectively. All the doses of the extract increased (P 0.05) with the controls for glycogen and cholesterol. The testicular and serum testosterone concentration were increased except in the 100 mg/kg body weight where the effect on the tissue and serum hormone did not manifest until after the first and seven daily doses respectively. Testicular acid phosphatase activity, serum follicle stimulating and luteinizing hormone concentrations also increased at all the doses except in the 100 mg/kg body weight where the effect on the enzyme and the hormone did not manifest until after seven days. The increases were most pronounced in the 50 mg/kg body weight extract treated animals. The results indicate anabolic and androgenic activities of Bulbine natalensis stem in male rat testes with the 50 mg/kg body weight of the extract exhibiting the highest anabolizing and androgenic activities. These activities further support the folkloric use of the plant most especially at 50 mg/kg body weight in the management of male sexual dysfunction in South Africa.

  6. Bulbocavernosus muscle area measurement: a novel method to assess androgenic activity

    Directory of Open Access Journals (Sweden)

    Ali A Dabaja

    2014-08-01

    Full Text Available Serum testosterone does not correlate with androgen tissue activity, and it is critical to optimize tools to evaluate such activity in males. Ultrasound measurement of bulbocavernosus muscle (BCM was used to assess the relationship between the number of CAG repeats (CAGn in the androgen receptor (AR and the BCM size; the changes in the number of CAGn over age were also evaluated. Transperineal ultrasound measurement of the BCM was also performed. AR CAGn were determined by high performance liquid chromatography, and morning hormone levels were determined using immunoassays. Forty-eight men had CAG repeat analysis. Twenty-five were 45 years of age, mean 53 years (s.d. = 5.58. The median CAGn was 21 (13-29. BCM area was greater when the number of CAGn were 24 (P = 0.04. There was a linear correlation between the number of CAGn and the BCM area R 2 = 16% (P = 0.01. In the 45 to 65-years-old group, a much stronger negative correlation (R 2 = 29%, P = 0.01 was noticed. In the 19 to 29-years-old group, no such correlation was found (R 2 = 4%, P = 0.36. In older men, the number of CAGn increased with age (R 2 = 32%, P = 0.01. The number of CAGn in the AR correlates with the area of the BCM. Ultrasound assessment of the BCM is an effective surrogate to evaluate end-organ activity of androgens. The number of CAGn may increase with age.

  7. Identification of an AR mutation-negative class of androgen insensitivity by determining endogenous AR activity

    NARCIS (Netherlands)

    Hornig, N.C.; Ukat, M.; H.U. Schweikert (H.); O. Hiort (Olaf); Werner, R.; S.L.S. Drop (Stenvert); M.L. Cools (Martine); I.A. Hughes (Ieuan A.); L. Audí (Laura); S.F. Ahmed (S. Faisal); Demiri, J.; Rodens, P.; Worch, L.; Wehner, G.; Kulle, A.E.; Dunstheimer, D.; Müller-Roßberg, E.; T. Reinehr (Thomas); Hadidi, A.T.; Eckstein, A.K.; Van Der Horst, C.; Seif, C.; R. Siebert (Reiner); O. Ammerpohl (Ole); P-M. Holterhus (Paul-Martin)

    2016-01-01

    textabstractContext: Only approximately 85%of patients with a clinical diagnosis complete androgen insensitivity syndrome and less than 30%with partial androgen insensitivity syndrome can be explained by inactivating mutations in the androgen receptor (AR) gene. Objective: The objective of the study

  8. Screening of bisphenol A, triclosan and paraben analogues as modulators of the glucocorticoid and androgen receptor activities.

    Science.gov (United States)

    Kolšek, Katra; Gobec, Martina; Mlinarič Raščan, Irena; Sollner Dolenc, Marija

    2015-02-01

    A homeostasis of the glucocorticoid and androgen endocrine system is essential to human health. Their disturbance can lead to various diseases, for example cardiovascular, inflammatory and autoimmune diseases, infertility, cancer. Fifteen widely used industrial chemicals that disrupt endocrine activity were selected for evaluation of potential (anti)glucocorticoid and (anti)androgenic activities. The human breast carcinoma MDA-kb2 cell line was utilized for reporter gene assays, since it expresses both the androgen and the glucocorticoid-responsive reporter. Two new antiandrogens, 4,4'-sulfonylbis(2-methylphenol) (dBPS) and 4,4'-thiodiphenol (THIO), and two new antiglucocorticoids, bisphenol Z and its analog bis[4-(2-hydroxyethoxy)phenyl] sulfone (BHEPS) were identified. Moreover, four new glucocorticoid agonists (methyl paraben, ethyl paraben, propyl paraben and bisphenol F) were found. To elucidate the structure-activity relationship of bisphenols, we performed molecular docking experiments with androgen and glucocorticoid receptor. These docking experiments had shown that bulky structures such as BHEPS and bisphenol Z act as antiglucocorticoid, because they are positioned toward helix H12 in the antagonist conformation and could therefore be responsible for H12 conformational change and the switch between agonistic and antagonistic conformation of receptor. On the other hand smaller structures cannot interact with H12. The results of in vitro screening of fifteen industrial chemicals as modulators of the glucocorticoid and androgen receptor activities demand additional in vivo testing of these chemicals for formulating any relevant hazard identification to human health.

  9. TRIM24 Is an Oncogenic Transcriptional Activator in Prostate Cancer.

    Science.gov (United States)

    Groner, Anna C; Cato, Laura; de Tribolet-Hardy, Jonas; Bernasocchi, Tiziano; Janouskova, Hana; Melchers, Diana; Houtman, René; Cato, Andrew C B; Tschopp, Patrick; Gu, Lei; Corsinotti, Andrea; Zhong, Qing; Fankhauser, Christian; Fritz, Christine; Poyet, Cédric; Wagner, Ulrich; Guo, Tiannan; Aebersold, Ruedi; Garraway, Levi A; Wild, Peter J; Theurillat, Jean-Philippe; Brown, Myles

    2016-06-13

    Androgen receptor (AR) signaling is a key driver of prostate cancer (PC). While androgen-deprivation therapy is transiently effective in advanced disease, tumors often progress to a lethal castration-resistant state (CRPC). We show that recurrent PC-driver mutations in speckle-type POZ protein (SPOP) stabilize the TRIM24 protein, which promotes proliferation under low androgen conditions. TRIM24 augments AR signaling, and AR and TRIM24 co-activated genes are significantly upregulated in CRPC. Expression of TRIM24 protein increases from primary PC to CRPC, and both TRIM24 protein levels and the AR/TRIM24 gene signature predict disease recurrence. Analyses in CRPC cells reveal that the TRIM24 bromodomain and the AR-interacting motif are essential to support proliferation. These data provide a rationale for therapeutic TRIM24 targeting in SPOP mutant and CRPC patients.

  10. Conazole fungicides inhibit Leydig cell testosterone secretion and androgen receptor activation in vitro

    Directory of Open Access Journals (Sweden)

    Maarke J.E. Roelofs

    2014-01-01

    Full Text Available Conazole fungicides are widely used in agriculture despite their suspected endocrine disrupting properties. In this study, the potential (anti-androgenic effects of ten conazoles were assessed and mutually compared with existing data. Effects of cyproconazole (CYPRO, fluconazole (FLUC, flusilazole (FLUS, hexaconazole (HEXA, myconazole (MYC, penconazole (PEN, prochloraz (PRO, tebuconazole (TEBU, triadimefon (TRIA, and triticonazole (TRIT were examined using murine Leydig (MA-10 cells and human T47D-ARE cells stably transfected with an androgen responsive element and a firefly luciferase reporter gene. Six conazoles caused a decrease in basal testosterone (T secretion by MA-10 cells varying from 61% up to 12% compared to vehicle-treated control. T secretion was concentration-dependently inhibited after exposure of MA-10 cells to several concentrations of FLUS (IC50 = 12.4 μM or TEBU (IC50 = 2.4 μM in combination with LH. The expression of steroidogenic and cholesterol biosynthesis genes was not changed by conazole exposure. Also, there were no changes in reactive oxygen species (ROS formation that could explain the altered T secretion after exposure to conazoles. Nine conazoles decreased T-induced AR activation (IC50s ranging from 10.7 to 71.5 μM and effect potencies (REPs were calculated relative to the known AR antagonist flutamide (FLUT. FLUC had no effect on AR activation by T. FLUS was the most potent (REP = 3.61 and MYC the least potent (REP = 0.03 AR antagonist. All other conazoles had a comparable REP from 0.12 to 0.38. Our results show distinct in vitro anti-androgenic effects of several conazole fungicides arising from two mechanisms: inhibition of T secretion and AR antagonism, suggesting potential testicular toxic effects. These effects warrant further mechanistic investigation and clearly show the need for accurate exposure data in order to perform proper (human risk assessment of this class of compounds.

  11. Rad51 activates polyomavirus JC early transcription.

    Directory of Open Access Journals (Sweden)

    Martyn K White

    Full Text Available The human neurotropic polyomavirus JC (JCV causes the fatal CNS demyelinating disease progressive multifocal leukoencephalopathy (PML. JCV infection is very common and after primary infection, the virus is able to persist in an asymptomatic state. Rarely, and usually only under conditions of immune impairment, JCV re-emerges to actively replicate in the astrocytes and oligodendrocytes of the brain causing PML. The regulatory events involved in the reactivation of active viral replication in PML are not well understood but previous studies have implicated the transcription factor NF-κB acting at a well-characterized site in the JCV noncoding control region (NCCR. NF-κB in turn is regulated in a number of ways including activation by cytokines such as TNF-α, interactions with other transcription factors and epigenetic events involving protein acetylation--all of which can regulate the transcriptional activity of JCV. Active JCV infection is marked by the occurrence of rapid and extensive DNA damage in the host cell and the induction of the expression of cellular proteins involved in DNA repair including Rad51, a major component of the homologous recombination-directed double-strand break DNA repair machinery. Here we show that increased Rad51 expression activates the JCV early promoter. This activation is co-operative with the stimulation caused by NF-κB p65, abrogated by mutation of the NF-κB binding site or siRNA to NFκB p65 and enhanced by the histone deacetylase inhibitor sodium butyrate. These data indicate that the induction of Rad51 resulting from infection with JCV acts through NF-κB via its binding site to stimulate JCV early transcription. We suggest that this provides a novel positive feedback mechanism to enhance viral gene expression during the early stage of JCV infection.

  12. Activation of P-TEFb by Androgen Receptor-Regulated Enhancer RNAs in Castration-Resistant Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Yu Zhao

    2016-04-01

    Full Text Available The androgen receptor (AR is required for castration-resistant prostate cancer (CRPC progression, but the function and disease relevance of AR-bound enhancers remain unclear. Here, we identify a group of AR-regulated enhancer RNAs (e.g., PSA eRNA that are upregulated in CRPC cells, patient-derived xenografts (PDXs, and patient tissues. PSA eRNA binds to CYCLIN T1, activates P-TEFb, and promotes cis and trans target gene transcription by increasing serine-2 phosphorylation of RNA polymerase II (Pol II-Ser2p. We define an HIV-1 TAR RNA-like (TAR-L motif in PSA eRNA that is required for CYCLIN T1 binding. Using TALEN-mediated gene editing we further demonstrate that this motif is essential for increased Pol II-Ser2p occupancy levels and CRPC cell growth. We have uncovered a P-TEFb activation mechanism and reveal altered eRNA expression that is related to abnormal AR function and may potentially be a therapeutic target in CRPC.

  13. Androgen resistance.

    Science.gov (United States)

    Hughes, Ieuan A; Deeb, Asma

    2006-12-01

    Androgen resistance causes the androgen insensitivity syndrome in its variant forms and is a paradigm of clinical syndromes associated with hormone resistance. In its complete form, the syndrome causes XY sex reversal and a female phenotype. Partial resistance to androgens is a common cause of ambiguous genitalia of the newborn, but a similar phenotype may result from several other conditions, including defects in testis determination and androgen biosynthesis. The biological actions of androgens are mediated by a single intracellular androgen receptor encoded by a gene on the long arm of the X chromosome. Mutations in this gene result in varying degrees of androgen receptor dysfunction and phenotypes that often show poor concordance with the genotype. Functional characterization and three-dimensional modelling of novel mutant receptors has been informative in understanding the mechanism of androgen action. Management issues in syndromes of androgen insensitivity include decisions on sex assignment, timing of gonadectomy in relation to tumour risk, and genetic and psychological counselling.

  14. Novel series of potent, nonsteroidal, selective androgen receptor modulators based on 7H-[1,4]oxazino[3,2-g]quinolin-7-ones.

    Science.gov (United States)

    Higuchi, Robert I; Arienti, Kristen L; López, Francisco J; Mani, Neelakhanda S; Mais, Dale E; Caferro, Thomas R; Long, Yun Oliver; Jones, Todd K; Edwards, James P; Zhi, Lin; Schrader, William T; Negro-Vilar, Andrés; Marschke, Keith B

    2007-05-17

    Recent interest in orally available androgens has fueled the search for new androgens for use in hormone replacement therapy and as anabolic agents. In pursuit of this, we have discovered a series of novel androgen receptor modulators derived from 7H-[1,4]oxazino[3,2-g]quinolin-7-ones. These compounds were synthesized and evaluated in competitive binding assays and an androgen receptor transcriptional activation assay. A number of compounds from the series demonstrated single-digit nanomolar agonist activity in vitro. In addition, lead compound (R)-16e was orally active in established rodent models that measure androgenic and anabolic properties of these agents. In this assay, (R)-16e demonstrated full efficacy in muscle and only partially stimulated the prostate at 100 mg/kg. These data suggest that these compounds may be utilized as selective androgen receptor modulators or SARMs. This series represents a novel class of compounds for use in androgen replacement therapy.

  15. Plasma androgenic activity in women with acne vulgaris and in healthy girls before, during and after puberty.

    Science.gov (United States)

    Odlind, V; Carlström, K; Michaëlsson, G; Vahlqvist, A; Victor, A; Mellbin, T

    1982-03-01

    The possible relationship between plasma androgenic activity and acne vulgaris was investigated. Plasma testosterone and sex hormone binding globulin (SHBG) levels were determined in healthy girls during different stages of puberty, in healthy adult women and in women with acne vulgaris. Testosterone increase during puberty, whereas SHBG decreased during the early stages before it increased and stabilized plasma concentrations of testosterone and SHBG. Women with severe acne vulgaris had testosterone levels in the same range but the SHBG levels were significantly lower than those of healthy women and women with mild acne. These results show a high androgenic activity in the intermediate stages of puberty, when acne vulgaris is a common complaint and an increased androgenic activity in adult women with severe acne vulgaris.

  16. Evaluation of androgenic activity of Zingiber officinale and Pentadiplandra brazzeana in male rats

    Institute of Scientific and Technical Information of China (English)

    KamtP; FandGYM

    2002-01-01

    Aim:Aqueous extracts of Zingiber officinale and Pentadiplandra brazzeana were tested for their possible androgenic activity in male Wistar rats.Methods:The aqueous extracts of the two plants were gavaged separately to 2 groups of rats at a similar dose of 600 mg·kg-1·day-1 for 8days.At the end of the treatment,the animals were killed and the blood,testis,epididymis,seminal vesicles and prostate were collected for biochemical analysis.Results:The aqueous Extract of z.officinale significantly increased in the relative weight of the testis,the serum testosterone level,testicular cholesterol level and epididymal α-glucosidase activity.The aqueous extract of P.brazzeana significantly increased the weights of the testis,seminal vesicles and prostate.It also significantly increased the serum and testicular testosterone level.The fructose,α-glucosidase and cholesterol levels in P.brazzeanatreated rats were increased by 28%,35% and 114%,respectively.Conclusion:The aqueous extracts of both P.brazzeana and Z.officinale have an androgenic activity,which seems to be more potent with P.brazzeana than with z.officinale.

  17. Effects of Nutrition Relevant Mixtures of Phytoestrogens on Steroidogenesis, Aromatase, Estrogen, and Androgen Activity

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Engell-Kofoed, Anders Elleby; Sonne-Hansen, Katrine;

    2010-01-01

    Phytoestrogens (PEs) are naturally occurring plant components produced in a large range of plants. They can induce biologic responses in vertebrates by mimicking or modulating the action or production of endogenous hormones. This study examined mixtures of 12 food relevant PEs for effects...... on steroid hormone production, aromatase activity, estrogenic activity, and for interaction with the androgen receptor. The results show that a mixture of all tested PEs increased estradiol production and decreased testosterone production in H295R human adrenal corticocarcinoma cells, indicating an induced...... aromatase activity. Furthermore, exposure of the H295R cells to isoflavonoids caused a decrease in testosterone production, and various mixtures of PEs significantly stimulated MCF-7 human breast adenocarcinoma cell growth and induced aromatase activity in JEG-3 choriocarcinoma cells. The estrogenic effect...

  18. High-Content Positional Biosensor Screening Assay for Compounds to Prevent or Disrupt Androgen Receptor and Transcriptional Intermediary Factor 2 Protein–Protein Interactions

    Science.gov (United States)

    Hua, Yun; Shun, Tong Ying; Strock, Christopher J.

    2014-01-01

    Abstract The androgen receptor–transcriptional intermediary factor 2 (AR-TIF2) positional protein–protein interaction (PPI) biosensor assay described herein combines physiologically relevant cell-based assays with the specificity of binding assays by incorporating structural information of AR and TIF2 functional domains along with intracellular targeting sequences and fluorescent reporters. Expression of the AR-red fluorescent protein (RFP) “prey” and TIF2-green fluorescent protein (GFP) “bait” components of the biosensor was directed by recombinant adenovirus constructs that expressed the ligand binding and activation function 2 surface domains of AR fused to RFP with nuclear localization and nuclear export sequences, and three α-helical LXXLL motifs from TIF2 fused to GFP and an HIV Rev nucleolar targeting sequence. In unstimulated cells, AR-RFP was localized predominantly to the cytoplasm and TIF2-GFP was localized to nucleoli. Dihydrotestosterone (DHT) treatment induced AR-RFP translocation into the nucleus where the PPIs between AR and TIF2 resulted in the colocalization of both biosensors within the nucleolus. We adapted the translocation enhanced image analysis module to quantify the colocalization of the AR-RFP and TIF2-GFP biosensors in images acquired on the ImageXpress platform. DHT induced a concentration-dependent AR-TIF2 colocalization and produced a characteristic condensed punctate AR-RFP PPI nucleolar distribution pattern. The heat-shock protein 90 inhibitor 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) and antiandrogens flutamide and bicalutamide inhibited DHT-induced AR-TIF2 PPI formation with 50% inhibition concentrations (IC50s) of 88.5±12.5 nM, 7.6±2.4 μM, and 1.6±0.4 μM, respectively. Images of the AR-RFP distribution phenotype allowed us to distinguish between 17-AAG and flutamide, which prevented AR translocation, and bicalutamide, which blocked AR-TIF2 PPIs. We screened the Library of Pharmacologically Active

  19. High-content positional biosensor screening assay for compounds to prevent or disrupt androgen receptor and transcriptional intermediary factor 2 protein-protein interactions.

    Science.gov (United States)

    Hua, Yun; Shun, Tong Ying; Strock, Christopher J; Johnston, Paul A

    2014-09-01

    The androgen receptor-transcriptional intermediary factor 2 (AR-TIF2) positional protein-protein interaction (PPI) biosensor assay described herein combines physiologically relevant cell-based assays with the specificity of binding assays by incorporating structural information of AR and TIF2 functional domains along with intracellular targeting sequences and fluorescent reporters. Expression of the AR-red fluorescent protein (RFP) "prey" and TIF2-green fluorescent protein (GFP) "bait" components of the biosensor was directed by recombinant adenovirus constructs that expressed the ligand binding and activation function 2 surface domains of AR fused to RFP with nuclear localization and nuclear export sequences, and three α-helical LXXLL motifs from TIF2 fused to GFP and an HIV Rev nucleolar targeting sequence. In unstimulated cells, AR-RFP was localized predominantly to the cytoplasm and TIF2-GFP was localized to nucleoli. Dihydrotestosterone (DHT) treatment induced AR-RFP translocation into the nucleus where the PPIs between AR and TIF2 resulted in the colocalization of both biosensors within the nucleolus. We adapted the translocation enhanced image analysis module to quantify the colocalization of the AR-RFP and TIF2-GFP biosensors in images acquired on the ImageXpress platform. DHT induced a concentration-dependent AR-TIF2 colocalization and produced a characteristic condensed punctate AR-RFP PPI nucleolar distribution pattern. The heat-shock protein 90 inhibitor 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) and antiandrogens flutamide and bicalutamide inhibited DHT-induced AR-TIF2 PPI formation with 50% inhibition concentrations (IC50s) of 88.5±12.5 nM, 7.6±2.4 μM, and 1.6±0.4 μM, respectively. Images of the AR-RFP distribution phenotype allowed us to distinguish between 17-AAG and flutamide, which prevented AR translocation, and bicalutamide, which blocked AR-TIF2 PPIs. We screened the Library of Pharmacologically Active Compounds (LOPAC) set

  20. Human α(2)β(1)(HI) CD133(+VE) epithelial prostate stem cells express low levels of active androgen receptor.

    Science.gov (United States)

    Williamson, Stuart C; Hepburn, Anastasia C; Wilson, Laura; Coffey, Kelly; Ryan-Munden, Claudia A; Pal, Deepali; Leung, Hing Y; Robson, Craig N; Heer, Rakesh

    2012-01-01

    Stem cells are thought to be the cell of origin in malignant transformation in many tissues, but their role in human prostate carcinogenesis continues to be debated. One of the conflicts with this model is that cancer stem cells have been described to lack androgen receptor (AR) expression, which is of established importance in prostate cancer initiation and progression. We re-examined the expression patterns of AR within adult prostate epithelial differentiation using an optimised sensitive and specific approach examining transcript, protein and AR regulated gene expression. Highly enriched populations were isolated consisting of stem (α(2)β(1)(HI) CD133(+VE)), transiently amplifying (α(2)β(1)(HI) CD133(-VE)) and terminally differentiated (α(2)β(1)(LOW) CD133(-VE)) cells. AR transcript and protein expression was confirmed in α(2)β(1)(HI) CD133(+VE) and CD133(-VE) progenitor cells. Flow cytometry confirmed that median (±SD) fraction of cells expressing AR were 77% (±6%) in α(2)β(1)(HI) CD133(+VE) stem cells and 68% (±12%) in α(2)β(1)(HI) CD133(-VE) transiently amplifying cells. However, 3-fold lower levels of total AR protein expression (peak and median immunofluorescence) were present in α(2)β(1)(HI) CD133(+VE) stem cells compared with differentiated cells. This finding was confirmed with dual immunostaining of prostate sections for AR and CD133, which again demonstrated low levels of AR within basal CD133(+VE) cells. Activity of the AR was confirmed in prostate progenitor cells by the expression of low levels of the AR regulated genes PSA, KLK2 and TMPRSS2. The confirmation of AR expression in prostate progenitor cells allows integration of the cancer stem cell theory with the established models of prostate cancer initiation based on a functional AR. Further study of specific AR functions in prostate stem and differentiated cells may highlight novel mechanisms of prostate homeostasis and insights into tumourigenesis.

  1. The effects of androgen on penile reflex, erectile responseto electrical stimulation and penile NOS activity in the rat

    Institute of Scientific and Technical Information of China (English)

    SeongIISeo

    1999-01-01

    Aim: To investigate the effects of androgen on penile erection through the reflex arc and penile corpus cavernosum,and study the respective roles of testosterone (T) and dihydrotestosterone (DHT) in penile erection ira rats. Methods:Male Sprague-Dawley rats were castrated and implanted with silastic brand silicone tube containing T or DHT, with orwithout daily injections of a 5a-reductase inhibitor, MKM-434. The penile reflex, erectile response to electrical stimula-tion (ES) of the cavernous nerves and penile nitric-oxide synthase (NOS) activity were observed under varying andro-genic status. Results: Penile reflex erection in the rat was, on the whole, related to serum T levels though the numberof glans engorgernents was not. The number of cups and flips was significantly decreased by castration, and restoredto the control level by T supplementation. Erectile response to ES and NOS activity in penile tissue was also related toserum T level. T administered together with a ,5a-reductase inhibitor no longer restored the number of reflex erection,erectile responses to ES and NOS activity in the corpus cavemosum. Conclusion: Androgen influenced the penile re-flex arc, corpus cavemosum, and the perinea] striated muscles, ha reflex erection, erectile response to ES and penileNOS activity in the rat, T seeras to be first conyerted to DHT, the more active androgen modality. (Asian JAndrol1999Dec; 1: 169-174)

  2. Immune activation is inversely related to, but does not cause variation in androgen levels in a cichlid fish species

    NARCIS (Netherlands)

    Ros, Albert F. H.; Oliveira, Rui F.; Dijkstra, Peter D.; Groothuis, Ton G. G.

    2012-01-01

    Studies on birds and mammals indicate that sexual traits may signal superior health because active immunity, like inflammatory responses to infections, is suppressive to the production of androgens that facilitate the expression of these traits. Here we test this possible pathway for honest signalin

  3. Linking Prenatal Androgens to Gender-Related Attitudes, Identity, and Activities : Evidence From Girls With Congenital Adrenal Hyperplasia

    NARCIS (Netherlands)

    Endendijk, Joyce J.; Beltz, Adriene M.; McHale, Susan M.; Bryk, Kristina; Berenbaum, Sheri A.

    2016-01-01

    Key questions for developmentalists concern the origins of gender attitudes and their implications for behavior. We examined whether prenatal androgen exposure was related to gender attitudes, and whether and how the links between attitudes and gendered activity interest and participation were media

  4. Synergic prodegradative activity of Bicalutamide and trehalose on the mutant androgen receptor responsible for spinal and bulbar muscular atrophy

    NARCIS (Netherlands)

    Giorgetti, Elise; Rusmini, Paola; Crippa, Valeria; Cristofani, Riccardo; Boncoraglio, Alessandra; Cicardi, Maria E.; Galbiati, Mariarita; Poletti, Angelo

    2015-01-01

    Spinal and bulbar muscular atrophy (SBMA) is an X-linked motoneuron disease due to a CAG triplet-repeat expansion in the androgen receptor (AR) gene, which is translated into an elongated polyglutamine (polyQ) tract in AR protein (ARpolyQ). ARpolyQ toxicity is activated by the AR ligand testosterone

  5. A satellite cell-specific knockout of the androgen receptor reveals myostatin as a direct androgen target in skeletal muscle.

    Science.gov (United States)

    Dubois, Vanessa; Laurent, Michaël R; Sinnesael, Mieke; Cielen, Nele; Helsen, Christine; Clinckemalie, Liesbeth; Spans, Lien; Gayan-Ramirez, Ghislaine; Deldicque, Louise; Hespel, Peter; Carmeliet, Geert; Vanderschueren, Dirk; Claessens, Frank

    2014-07-01

    Androgens have well-established anabolic actions on skeletal muscle, although the direct effects of the androgen receptor (AR) in muscle remain unclear. We generated satellite cell-specific AR-knockout (satARKO) mice in which the AR is selectively ablated in satellite cells, the muscle precursor cells. Total-limb maximal grip strength is decreased by 7% in satARKO mice, with soleus muscles containing ∼10% more type I fibers and 10% less type IIa fibers than the corresponding control littermates. The weight of the perineal levator ani muscle is markedly reduced (-52%). Thus, muscle AR is involved in fiber-type distribution and force production of the limb muscles, while it is a major determinant of the perineal muscle mass. Surprisingly, myostatin (Mstn), a strong inhibitor of skeletal muscle growth, is one of the most androgen-responsive genes (6-fold reduction in satARKO) through direct transcription activation by the AR. Consequently, muscle hypertrophy in response to androgens is augmented in Mstn-knockout mice. Our finding that androgens induce Mstn signaling to restrain their own anabolic actions has implications for the treatment of muscle wasting disorders.-Dubois, V., Laurent, M. R., Sinnesael, M., Cielen, N., Helsen, C., Clinckemalie, L., Spans, L., Gayan-Ramirez, G., Deldicque, L., Hespel, P., Carmeliet, G., Vanderschueren, D., and Claessens, F. A satellite cell-specific knockout of the androgen receptor reveals myostatin as a direct androgen target in skeletal muscle.

  6. Comparison of the effect of cortisol on aromatase activity and androgen metabolism in two human fibroblast cell lines derived from the same individual

    DEFF Research Database (Denmark)

    Svenstrup, B; Brünner, N; Dombernowsky, P

    1990-01-01

    The effect of preincubation with cortisol on estrogen and androgen metabolism was investigated in human fibroblast monolayers grown from biopsies of genital and non-genital skin of the same person. The activity in the cells of aromatase, 5 alpha-reductase, 17 beta-hydroxysteroid oxidoreductase.......5-1.0 x 10(-6) M in both cell lines. When preincubation with cortisol was omitted no estrogen synthesis was detected. The formation of androgen was not altered after preincubation with cortisol. Pronounced differences were found in estrogen and in androgen metabolism in the two cell lines suggesting...... a local regulation of the hormonal environment. The aromatase activity, which is low in many tissues could be stimulated by cortisol without altering the androgen metabolism was found to be a suitable system for investigations of the cellular interconversion of androgens and estrogens...

  7. Posttranslational modification of the androgen receptor in prostate cancer.

    Science.gov (United States)

    van der Steen, Travis; Tindall, Donald J; Huang, Haojie

    2013-07-16

    The androgen receptor (AR) is important in the development of the prostate by regulating transcription, cellular proliferation, and apoptosis. AR undergoes posttranslational modifications that alter its transcription activity, translocation to the nucleus and stability. The posttranslational modifications that regulate these events are of utmost importance to understand the functional role of AR and its activity. The majority of these modifications occur in the activation function-1 (AF1) region of the AR, which contains the transcriptional activation unit 1 (TAU1) and 5 (TAU5). Identification of the modifications that occur to these regions may increase our understanding of AR activation in prostate cancer and the role of AR in the progression from androgen-dependent to castration-resistant prostate cancer (CRPC). Most of the posttranslational modifications identified to date have been determined using the full-length AR in androgen dependent cells. Further investigations into the role of posttranslational modifications in androgen-independent activation of full-length AR and constitutively active splicing variants are warranted, findings from which may provide new therapeutic options for CRPC.

  8. PDE7B is involved in nandrolone decanoate hydrolysis in liver cytosol and its transcription is up-regulated by androgens in HepG2

    Directory of Open Access Journals (Sweden)

    Emmanuel eStrahm

    2014-05-01

    Full Text Available Most androgenic drugs are available as esters for a prolonged depot action. However the enzymes involved in the hydrolysis of the esters have not been identified. There is one study indicating that PDE7B may be involved in the activation of testosterone enanthate. The aims are to identify the cellular compartments where the hydrolysis of testosterone enanthate and nandrolone decanoate occurs, and to investigate the involvement of PDE7B in the activation. We also determined if testosterone and nandrolone affect the expression of the PDE7B gene. The hydrolysis studies were performed in isolated human liver cytosolic and microsomal preparations with and without specific PDE7B inhibitor. The gene expression was studied in human hepatoma cells (HepG2 exposed to testosterone and nandrolone. We show that PDE7B serves as a catalyst of the hydrolysis of testosterone enanthate and nandrolone decanoate in liver cytosol. The gene expression of PDE7B was significantly induced 3- and 5- fold after 2 hours exposure to 1 µM testosterone enanthate and nandrolone decanoate, respectively. These results show that PDE7B is involved in the activation of esterified nandrolone and testosterone and that the gene expression of PDE7B is induced by supra-physiological concentrations of androgenic drugs.

  9. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region

    Science.gov (United States)

    Kassotis, Christopher D.; Tillitt, Donald E.; Davis, J. Wade; Hormann, Anette M.; Nagel, Susan C.

    2014-01-01

    The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesized thataselected subset of chemicalsusedin natural gas drilling operationsandalso surface and ground water samples collected in a drilling-dense region of Garfield County, Colorado, would exhibit estrogen and androgen receptor activities. Water samples were collected, solid-phase extracted, and measured for estrogen and androgen receptor activities using reporter gene assays in human cell lines. Of the 39 unique water samples, 89%, 41%, 12%, and 46% exhibited estrogenic, antiestrogenic, androgenic, and antiandrogenic activities, respectively. Testing of a subset of natural gas drilling chemicals revealed novel antiestrogenic, novel antiandrogenic, and limited estrogenic activities. The Colorado River, the drainage basin for this region, exhibited moderate levels of estrogenic, antiestrogenic, and antiandrogenic activities, suggesting that higher localized activity at sites with known natural gas–related spills surrounding the river might be contributing to the multiple receptor activities observed in this water source. The majority of water samples collected from sites in a drilling-dense region of Colorado exhibited more estrogenic, antiestrogenic, or antiandrogenic activities than reference sites with limited nearby drilling operations. Our data suggest that natural gas drilling operationsmayresult in elevated endocrine-disrupting chemical activity in surface and ground water.

  10. Acidic-phosphoprotein phosphatase activity of rat ventral prostate nuclei: apparent lack of effect of androgens.

    Science.gov (United States)

    Wilson, M J; Ahmed, K; Fischbach, T J

    1978-08-01

    A protein phosphatase activity has been demonstrated in nuclei of rat ventral prostate utilizing 32P-labelled phosvitin as a model acidic phosphoprotein substrate. This phosphoprotein phosphatase has a pH optimum of 6.7, is unaffected by the sulphydryl protecting agent 2-mercaptoethanol, and requires a divalent cation for maximal activity. Of the various divalent cations tested, Mg2+ is the most effective in reactivating the EDTA-inhibited enzyme. The phosphatase is inhibited by sodium flouride, sodium oxalate, N-ethylmaleimide, ATP and ADP but is relatively insensitive to ammonium molybdate. Increased ionic strength of the reaction medium also causes a reduction in the enzyme activity, e.g., by 48% at 200 mM sodium chloride. The activity of the acidic phosphoprotein phosphatase did not change significantly at 48 h or 96 h post-orchiectomy when expressed per unit of nuclear protein. However, it is reduced by approx. 30% at these times after castration if based on DNA content. The decline in activity per nucleus reflects the decrease in the realtive nuclear protein content observed at 48 h or 96 h post-orchiectomy. This suggests that the decline in the phosphorylation of prostatic nuclear acidic proteins which occurs upon androgen withdrawal is not due to increased nuclear phosphatase activity.

  11. Androgens regulate gene expression in avian skeletal muscles.

    Directory of Open Access Journals (Sweden)

    Matthew J Fuxjager

    Full Text Available Circulating androgens in adult reproductively active male vertebrates influence a diversity of organ systems and thus are considered costly. Recently, we obtained evidence that androgen receptors (AR are expressed in several skeletal muscles of three passeriform birds, the golden-collared manakin (Manacus vitellinus, zebra finch (Taenopygia guttata, and ochre-bellied flycatcher (Mionectes oleagieus. Because skeletal muscles that control wing movement make up the bulk of a bird's body mass, evidence for widespread effects of androgen action on these muscles would greatly expand the functional impact of androgens beyond their well-characterized effects on relatively discrete targets throughout the avian body. To investigate this issue, we use quantitative PCR (qPCR to determine if androgens alter gene mRNA expression patterns in wing musculature of wild golden-collared manakins and captive zebra finches. In manakins, the androgen testosterone (T up-regulated expression of parvalbumin (PV and insulin-like growth factor I (IGF-I, two genes whose products enhance cellular Ca(2+ cycling and hypertrophy of skeletal muscle fibers. In T-treated zebra finches, the anti-androgen flutamide blunted PV and IGF-I expression. These results suggest that certain transcriptional effects of androgen action via AR are conserved in passerine skeletal muscle tissue. When we examined wing muscles of manakins, zebra finches and ochre-bellied flycatchers, we found that expression of PV and IGF-I varied across species and in a manner consistent with a function for AR-dependent gene regulation. Together, these findings imply that androgens have the potential to act on avian muscle in a way that may enhance the physicality required for successful reproduction.

  12. RNase L Suppresses Androgen Receptor Signaling, Cell Migration and Matrix Metalloproteinase Activity in Prostate Cancer Cells.

    Science.gov (United States)

    Dayal, Shubham; Zhou, Jun; Manivannan, Praveen; Siddiqui, Mohammad Adnan; Ahmad, Omaima Farid; Clark, Matthew; Awadia, Sahezeel; Garcia-Mata, Rafael; Shemshedini, Lirim; Malathi, Krishnamurthy

    2017-03-01

    The interferon antiviral pathways and prostate cancer genetics converge on a regulated endoribonuclease, RNase L. Positional cloning and linkage studies mapped Hereditary Prostate Cancer 1 (HPC1) to RNASEL. To date, there is no correlation of viral infections with prostate cancer, suggesting that RNase L may play additional roles in tumor suppression. Here, we demonstrate a role of RNase L as a suppressor of androgen receptor (AR) signaling, cell migration and matrix metalloproteinase activity. Using RNase L mutants, we show that its nucleolytic activity is dispensable for both AR signaling and migration. The most prevalent HPC1-associated mutations in RNase L, R462Q and E265X, enhance AR signaling and cell migration. RNase L negatively regulates cell migration and attachment on various extracellular matrices. We demonstrate that RNase L knockdown cells promote increased cell surface expression of integrin β1 which activates Focal Adhesion Kinase-Sarcoma (FAK-Src) pathway and Ras-related C3 botulinum toxin substrate 1-guanosine triphosphatase (Rac1-GTPase) activity to increase cell migration. Activity of matrix metalloproteinase (MMP)-2 and -9 is significantly increased in cells where RNase L levels are ablated. We show that mutations in RNase L found in HPC patients may promote prostate cancer by increasing expression of AR-responsive genes and cell motility and identify novel roles of RNase L as a prostate cancer susceptibility gene.

  13. Testicular steroidogenesis is locally regulated by androgen via suppression of Nur77.

    Science.gov (United States)

    Song, Chin-Hee; Gong, Eun-Yeung; Park, Ji soo; Lee, Keesook

    2012-06-01

    Steroidogenesis in the testis is regulated by a negative feedback mechanism through the hypothalamus-pituitary-testis axis. Recent studies suggest that besides this long-loop regulation, testicular steroidogenesis is also locally regulated by androgen. However, the molecular mechanism behind this additional regulatory pathway has been poorly addressed. In the present study, we demonstrate that liganded androgen receptor (AR) suppresses the transcriptional activity of Nur77 on steroidogenic enzyme gene promoters, affecting testicular steroidogenesis. AR physically interacts and colocalizes with Nur77 in the nucleus in the presence of androgen. AR inhibits Nur77 transactivation by competing mainly with coactivators such as SRC-1 for Nur77 binding. These results suggest that androgen, through binding to AR, directly acts as a signal inhibiting the expression of steroidogenic enzyme genes in Leydig cells, eventually resulting in decreased testicular steroidogenesis. These findings strongly support the hypothesis that androgen acts locally to regulate testicular steroidogenesis, and may provide its action mechanism.

  14. Aberrant E2F activation by polyglutamine expansion of androgen receptor in SBMA neurotoxicity.

    Science.gov (United States)

    Suzuki, Eriko; Zhao, Yue; Ito, Saya; Sawatsubashi, Shun; Murata, Takuya; Furutani, Takashi; Shirode, Yuko; Yamagata, Kaoru; Tanabe, Masahiko; Kimura, Shuhei; Ueda, Takashi; Fujiyama, Sally; Lim, Jinseon; Matsukawa, Hiroyuki; Kouzmenko, Alexander P; Aigaki, Toshiro; Tabata, Tetsuya; Takeyama, Ken-ichi; Kato, Shigeaki

    2009-03-10

    Spinal and bulbar muscular atrophy (SBMA) is a neurodegenerative disorder caused by a polyglutamine repeat (polyQ) expansion within the human androgen receptor (AR). Unlike other neurodegenerative diseases caused by abnormal polyQ expansion, the onset of SBMA depends on androgen binding to mutant human polyQ-AR proteins. This is also observed in Drosophila eyes ectopically expressing the polyQ-AR mutants. We have genetically screened mediators of androgen-induced neurodegeneration caused by polyQ-AR mutants in Drosophila eyes. We identified Rbf (Retinoblastoma-family protein), the Drosophila homologue of human Rb (Retinoblastoma protein), as a neuroprotective factor. Androgen-dependent association of Rbf or Rb with AR was remarkably potentiated by aberrant polyQ expansion. Such potentiated Rb association appeared to attenuate recruitment of histone deacetyltransferase 1 (HDAC1), a corepressor of E2F function. Either overexpression of Rbf or E2F deficiency in fly eyes reduced the neurotoxicity of the polyQ-AR mutants. Induction of E2F function by polyQ-AR-bound androgen was suppressed by Rb in human neuroblastoma cells. We conclude that abnormal expansion of polyQ may potentiate innate androgen-dependent association of AR with Rb. This appears to lead to androgen-dependent onset of SBMA through aberrant E2F transactivation caused by suppressed histone deacetylation.

  15. Enhanced evaluation of selective androgen receptor modulators in vivo.

    Science.gov (United States)

    Otto-Duessel, M; He, M; Adamson, T W; Jones, J O

    2013-01-01

    Selective androgen receptor modulators (SARMs) are a class of drugs that control the activity of the androgen receptor (AR), which mediates the response to androgens, in a tissue-selective fashion. They are specifically designed to reduce the possible complications that result from the systemic inhibition or activation of AR in patients with diseases that involve androgen signalling. However, there are no ideal in vivo models for evaluating candidate SARMs. Therefore, we created a panel of androgen-responsive genes in clinically relevant AR expressing tissues including prostate, skin, bone, fat, muscle, brain and kidney. We used select genes from this panel to compare transcriptional changes in response to the full agonist dihydrotestosterone (DHT) and the SARM bolandiol at 16 h and 6 weeks. We identified several genes in each tissue whose expression at each of these time points correlates with the known tissue-specific effects of these compounds. For example, in the prostate we found four genes whose expression was much lower in animals treated with bolandiol compared with animals treated with DHT for 6 weeks, which correlated well with differences in prostate weight. We demonstrate that adding molecular measurements (androgen-regulated gene expression) to the traditional physiological measurements (tissue weights, etc.) makes the evaluation of potential SARMs more accurate, thorough and perhaps more rapid by allowing measurement of selectivity after only 16 h of drug treatment.

  16. [The Effect of Transcription on Enhancer Activity in Drosophila melanogaster].

    Science.gov (United States)

    Erokhin, M M; Davydova, A I; Lomaev, D V; Georgiev, P G; Chetverina, D A

    2016-01-01

    In higher eukaryotes, the level of gene transcription is under the control of DNA regulatory elements, such as promoter, from which transcription is initiated with the participation of RNA polymerase II and general transcription factors, as well as the enhancer, which increase the rate of transcription with the involvement of activator proteins and cofactors. It was demonstrated that enhancers are often located in the transcribed regions of the genome. We showed earlier that transcription negatively affected the activity of enhancers in Drosophila in model transgenic systems. In this study, we tested the effect of the distance between the leading promoter, enhancer, and target promoter on the inhibitory effect of transcriptions of different strengths. It was demonstrated that the negative effect of transcription remained, but weakened with increased distance between the leading promoter and enhancer and with decreased distance between the enhancer and target promoter. Thus, transcription can modulate the activity of enhancers by controlling its maximum level.

  17. Effects of nutrition relevant mixtures of phytoestrogens on steroidogenesis, aromatase, estrogen, and androgen activity.

    Science.gov (United States)

    Taxvig, Camilla; Elleby, Anders; Sonne-Hansen, Katrine; Bonefeld-Jørgensen, Eva C; Vinggaard, Anne Marie; Lykkesfeldt, Anne E; Nellemann, Christine

    2010-01-01

    Phytoestrogens (PEs) are naturally occurring plant components produced in a large range of plants. They can induce biologic responses in vertebrates by mimicking or modulating the action or production of endogenous hormones. This study examined mixtures of 12 food relevant PEs for effects on steroid hormone production, aromatase activity, estrogenic activity, and for interaction with the androgen receptor. The results show that a mixture of all tested PEs increased estradiol production and decreased testosterone production in H295R human adrenal corticocarcinoma cells, indicating an induced aromatase activity. Furthermore, exposure of the H295R cells to isoflavonoids caused a decrease in testosterone production, and various mixtures of PEs significantly stimulated MCF-7 human breast adenocarcinoma cell growth and induced aromatase activity in JEG-3 choriocarcinoma cells. The estrogenic effect in the MCF7 cells of the isoflavonoid mixture and coumestrol was supported by an observed increase in progesterone receptor protein expression as well as a decreased ERalpha expression. Overall, the results support that nutrition-relevant concentrations of PEs both alone and in mixtures possess various endocrine disrupting effects, all of which need to be considered when assessing the effects on human health.

  18. A Combined Quantitative Structure-Activity Relationship Research of Quinolinone Derivatives as Androgen Receptor Antagonists.

    Science.gov (United States)

    Wang, Yuwei; Bai, Fang; Cao, Hong; Li, Jiazhong; Liu, Huanxiang; Gramatica, Paola

    2015-01-01

    Antiandrogens bicalutamide, flutamide and enzalutamide etc. have been used in clinical trials to treat prostate cancer by binding to and antagonizing androgen receptor (AR). Although initially effective, the drug resistance problem will emerge eventually, which results in a high medical need for novel AR antagonist exploitation. Here in this work, to facilitate the rational design of novel AR antagonists, we studied the structure-activity relationships of a series of 2-quinolinone derivatives and investigated the structural requirements for their antiandrogenic activities. Different modeling methods, including 2D MLR, 3D CoMFA and CoMSIA, were implemented to evolve QSAR models. All these models, thoroughly validated, demonstrated satisfactory results especially for the good predictive abilities. The contour maps from 3D CoMFA and CoMSIA models provide visualized explanation of key structural characteristics relevant to the antiandrogenic activities, which is summarized to a position-specific conclusion at the end. The obtained results from this research are practically useful for rational design and screening of promising chemicals with high antiandrogenic activities.

  19. Human cytomegalovirus IE2 protein interacts with transcription activating factors

    Institute of Scientific and Technical Information of China (English)

    XU; Jinping(徐进平); YE; Linbai(叶林柏)

    2002-01-01

    The human cytomegalovirus (HCMV) IE86 Cdna was cloned into Pgex-2T and fusion protein GST-IE86 was expressed in E. Coli. SDS-PAGE and Western blot assay indicated that fusion protein GST-IE86 with molecular weight of 92 ku is soluble in the supernatant of cell lysate. Protein GST and fusion protein GST-IE86 were purified by affinity chromatography. The technology of co-separation and specific affinity chromatography was used to study the interactions of HCMV IE86 protein with some transcriptional regulatory proteins and transcriptional factors. The results indicated that IE86 interacts separately with transcriptional factor TFIIB and promoter DNA binding transcription trans-activating factors SP1, AP1 and AP2 to form a heterogenous protein complex. These transcriptional trans-activating factors, transcriptional factor and IE86 protein were adsorbed and retained in the affinity chromatography simultaneously. But IE86 protein could not interact with NF-Кb, suggesting that the function of IE86 protein that can interact with transcriptional factor and transcriptional trans-activating factors has no relevance to protein glycosylation. IE86 protein probably has two domains responsible for binding transcriptional trans-activating regulatory proteins and transcriptional factors respectively, thus activating the transcription of many genes. The interactions accelerated the assembly of the transcriptional initiation complexes.

  20. Changes in neuronal activation patterns in response to androgen deprivation therapy: a pilot study

    Directory of Open Access Journals (Sweden)

    Shelton Amy L

    2010-01-01

    Full Text Available Abstract Background A common treatment option for men with prostate cancer is androgen deprivation therapy (ADT. However, men undergoing ADT may experience physical side effects, changes in quality of life and sometimes psychiatric and cognitive side effects. Methods In this study, hormone naïve patients without evidence of metastases with a rising PSA were treated with nine months of ADT. Functional magnetic resonance imaging (fMRI of the brain during three visuospatial tasks was performed at baseline prior to treatment and after nine months of ADT in five subjects. Seven healthy control patients, underwent neuroimaging at the same time intervals. Results ADT patients showed reduced, task-related BOLD-fMRI activation during treatment that was not observed in control subjects. Reduction in activation in right parietal-occipital regions from baseline was observed during recall of the spatial location of objects and mental rotation. Conclusions Findings, while preliminary, suggest that ADT reduces task-related neural activation in brain regions that are involved in mental rotation and accurate recall of spatial information.

  1. [Myoanabolic steroids and selective androgen receptor modulators: mechanism of action and perspectives].

    Science.gov (United States)

    Tóth, Miklós

    2009-11-01

    Interest in anabolic steroids has been renewed in the last decade with the discovery of tissue-selective androgen receptor modulators exhibiting high myotropic and small androgenic activity. An explanation put forward by us in 1982 for the mechanism of the preferential myotropic effect of nandrolone (19-nortestosterone) exploits the fundamental difference between the 5alpha-reductase concentrations in skeletal muscle and androgenic target tissue. In androgenic tissue, testosterone is converted to the more potent 5alpha-dihydrotestosterone whereas nandrolone is converted to a less potent derivative. As 5alpha-reduction is negligible in skeletal muscle, this explains why nandrolone shows a greater myotropic to androgenic ratio when compared with testosterone. Anabolic steroids that do not undergo 5alpha-reduction exert myotropic-androgenic dissociation because their effect in androgenic tissues is not amplified by 5alpha-reduction. Tissue selectivity by receptor modulators may be achieved by inducing specific conformational changes of the androgen receptor that affect its interaction with transcriptional coregulators. Anabolic activity is mediated by the stimulation of ribosomal RNA synthesis therefore regulation of this synthesis by anabolic steroids would deserve detailed studies.

  2. Promoter proximal polyadenylation sites reduce transcription activity

    DEFF Research Database (Denmark)

    Andersen, Pia Kjølhede; Lykke-Andersen, Søren; Jensen, Torben Heick

    2012-01-01

    on transcription requires promoter proximity, as demonstrated using artificial constructs and supported by a genome-wide data set. Importantly, transcription down-regulation can be recapitulated in a gene context devoid of splice sites by placing a functional bona fide pA site/transcription terminator within ∼500...... base pairs of the promoter. In contrast, promoter-proximal positioning of a pA site-independent histone gene terminator supports high transcription levels. We propose that optimal communication between a pA site-dependent gene terminator and its promoter critically depends on gene length and that short...

  3. Screening of 397 chemicals and development of a quantitative structure-activity relationship model for androgen receptor antagonism

    DEFF Research Database (Denmark)

    Vinggaard, Annemarie; Niemelä, Jay Russell; Wedebye, Eva Bay;

    2008-01-01

    We have screened 397 chemicals for human androgen receptor (AR) antagonism by a sensitive reporter gene assay to generate data for the development of a quantitative structure-activity relationship (QSAR) model. A total of 523 chemicals comprising data on 292 chemicals from our laboratory and data...... by the synthetic androgen R1881. The MultiCASE expert system was used to construct a QSAR model for AR antagonizing potential. A "5 Times, 2-Fold 50% Cross Validation" of the model showed a sensitivity of 64%, a specificity of 84%, and a concordance of 76%. Data for 102 chemicals were generated for an external...... validation of the model resulting in a sensitivity of 57%, a specificity of 98%, and a concordance of 92% of the model. The model was run on a set of 176103 chemicals, and 47% were within the domain of the model. Approximately 8% of chemicals was predicted active for AR antagonism. We conclude...

  4. Plant NAC-type transcription factor proteins contain a NARD domain for repression of transcriptional activation.

    Science.gov (United States)

    Hao, Yu-Jun; Song, Qing-Xin; Chen, Hao-Wei; Zou, Hong-Feng; Wei, Wei; Kang, Xu-Sheng; Ma, Biao; Zhang, Wan-Ke; Zhang, Jin-Song; Chen, Shou-Yi

    2010-10-01

    Plant-specific transcription factor NAC proteins play essential roles in many biological processes such as development, senescence, morphogenesis, and stress signal transduction pathways. In the NAC family, some members function as transcription activators while others act as repressors. In the present study we found that though the full-length GmNAC20 from soybean did not have transcriptional activation activity, the carboxy-terminal activation domain of GmNAC20 had high transcriptional activation activity in the yeast assay system. Deletion experiments revealed an active repression domain with 35 amino acids, named NARD (NAC Repression Domain), in the d subdomain of NAC DNA-binding domain. NARD can reduce the transcriptional activation ability of diverse transcription factors when fused to either the amino-terminal or the carboxy-terminal of the transcription factors. NARD-like sequences are also present in other NAC family members and they are functional repression domain when fused to VP16 in plant protoplast assay system. Mutation analysis of conserved amino acid residues in NARD showed that the hydrophobic LVFY motif may partially contribute to the repression function. It is hypothesized that the interactions between the repression domain NARD and the carboxy-terminal activation domain may finally determine the ability of NAC family proteins to regulate downstream gene expressions.

  5. Neural Activation During Mental Rotation in Complete Androgen Insensitivity Syndrome: The Influence of Sex Hormones and Sex Chromosomes.

    Science.gov (United States)

    van Hemmen, Judy; Veltman, Dick J; Hoekzema, Elseline; Cohen-Kettenis, Peggy T; Dessens, Arianne B; Bakker, Julie

    2016-03-01

    Sex hormones, androgens in particular, are hypothesized to play a key role in the sexual differentiation of the human brain. However, possible direct effects of the sex chromosomes, that is, XX or XY, have not been well studied in humans. Individuals with complete androgen insensitivity syndrome (CAIS), who have a 46,XY karyotype but a female phenotype due to a complete androgen resistance, enable us to study the separate effects of gonadal hormones versus sex chromosomes on neural sex differences. Therefore, in the present study, we compared 46,XY men (n = 30) and 46,XX women (n = 29) to 46,XY individuals with CAIS (n = 21) on a mental rotation task using functional magnetic resonance imaging. Previously reported sex differences in neural activation during mental rotation were replicated in the control groups, with control men showing more activation in the inferior parietal lobe than control women. Individuals with CAIS showed a female-like neural activation pattern in the parietal lobe, indicating feminization of the brain in CAIS. Furthermore, this first neuroimaging study in individuals with CAIS provides evidence that sex differences in regional brain function during mental rotation are most likely not directly driven by genetic sex, but rather reflect gonadal hormone exposure.

  6. In vitro metabolism of cis- and trans-permethrin by rat liver microsomes, and its effect on estrogenic and anti-androgenic activities.

    Science.gov (United States)

    Tange, Satoko; Fujimoto, Nariaki; Uramaru, Naoto; Sugihara, Kazumi; Ohta, Shigeru; Kitamura, Shigeyuki

    2014-05-01

    Permethrin is a widely applied broad-spectrum pyrethroid insecticide that consists of a mixture of cis- and trans-isomers. We examined the changes of estrogenic and anti-androgenic activities resulting from metabolism of the isomers. Both cis- and trans-permethrin were hydrolyzed to 3-phenoxybenzyl alcohol (PBAlc) by rat liver microsomes, but the extent of hydrolysis of trans-permethrin was much greater than that of the cis-isomer. In the presence of NADPH, PBAlc was further transformed to 4'-hydroxylated PBAlc (4'-OH PBAlc), 3-phenoxybenzaldehyde (PBAld) and 3-phenoxybenzoic acid (PBAcid). cis-Permethrin, but not trans-permethrin, also afforded its 4'-hydroxylated derivative (4'-OH cis-permethrin). trans-Permethrin was an anti-androgen, but also showed weak estrogenic activity, while cis-permethrin was a weak estrogen and a weak anti-androgen. After incubation with rat liver microsomes in the presence of NADPH, cis-permethrin but not trans-permethrin was metabolically activated for estrogenic activity. On the other hand, estrogenic activity of trans-permethrin was not changed, but its anti-androgenic activity was enhanced after incubation. 4'-OH PBAlc and PBAlc showed estrogenic activity, while PBAld and PBAlc showed anti-androgenic activity. PBAcid showed neither activity. 4'-OH cis-permethrin showed both estrogenic and anti-androgenic activities. Overall, our results indicate that permethrin is metabolically activated for estrogenic and anti-androgen activities, and the microsomal transformation of permethrin to 4'-OH cis-permethrin, 4'-OH PBAlc and PBAlc contributes to the both metabolic activations.

  7. IκB Kinases Modulate the Activity of the Androgen Receptor in Prostate Carcinoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Garima Jain

    2012-03-01

    Full Text Available Enhanced nuclear localization of nuclear factor κB (NF-κB in prostate cancer (PCa samples and constitutive NF-κB signaling in a class of PCa cell lines with low androgen receptor (AR expression (PC3 and DU-145 imply an important role of the IκB kinase (IKK/NF-κB system in PCa. However, most PCa and PCa cell lines depend on the activity of the AR, and the role of NF-κB in these AR-expressing PCa remains unclear. Here, we demonstrate that inhibition of NF-κB signaling by the IKK inhibitor BMS345541 reduced proliferation and increased apoptosis in AR-expressing PCa cell lines. Furthermore, AR activity and target gene expression were distinctively reduced, whereas AR protein levels remained unaltered on BMS345541 treatment. Similar effects were observed particularly after small interfering RNA (siRNA-mediated knockdown of IKK1, but not by siRNA-mediated suppression of IKK2. Moreover, IKK1 overexpression augmented 5α-dihydrotestosterone-induced nuclear AR translocation, whereas nuclear AR was reduced by IKK1 knockdown or BMS345541. However, because IKK1 also enhances the activity of a chronically nuclear AR mutant, modulation of the subcellular distribution seems not to be the only mechanism by which IKK1 enhances AR activity. Finally, reduced in vivo AR phosphorylation after BMS345541 treatment and in vitro AR phosphorylation by IKK1 or IKK2 imply that AR constitutes a novel IKK target. Taken together, our data identify IKK1 as a potentially target structure for future therapeutic intervention in PCa.

  8. Microarray analysis of androgen-regulated gene expression in testis: the use of the androgen-binding protein (ABP-transgenic mouse as a model

    Directory of Open Access Journals (Sweden)

    Grossman Gail

    2005-12-01

    Full Text Available Abstract Background Spermatogenesis is an androgen-dependent process, yet the molecular mechanisms of androgens' actions in testis are poorly understood. Transgenic mice overexpressing rat androgen-binding protein (ABP in their testes have reduced levels of intratesticular androgens and, as a result, show a progressive impairment of spermatogenesis. We used this model to characterize changes in global gene expression in testis in response to reduced bioavailability of androgens. Methods Total RNA was extracted from testes of 30-day old transgenic and wild-type control mice, converted to cRNA, labeled with biotin, and hybridized to oligonucleotide microarrays. Microarray results were confirmed by real-time reverse transcription polymerase chain reaction. Results Three-hundred-eighty-one genes (3.05% of all transcripts represented on the chips were up-regulated and 198 genes (1.59% were down-regulated by at least a factor of 2 in the androgen-deficient animals compared to controls. Genes encoding membrane proteins, intracellular signaling molecules, enzymes, proteins participating in the immune response, and those involved in cytoskeleton organization were significantly overrepresented in the up-regulated group. Among the down-regulated transcripts, those coding for extracellular proteins were overrepresented most dramatically, followed by those related to proteolysis, cell adhesion, immune response, and growth factor, cytokine, and ion channel activities. Transcripts with the greatest potential impact on cellular activities included several transcription factors, intracellular signal transducers, secreted signaling molecules and enzymes, and various cell surface molecules. Major nodes in the up-regulated network were IL-6, AGT, MYC, and A2M, those in the down-regulated network were IL-2, -4, and -10, MAPK8, SOCS1, and CREB1. Conclusion Microarray analysis followed by gene ontology profiling and connectivity analysis identified several functional

  9. Evaluation of RU58841 as an anti-androgen in prostate PC3 cells and a topical anti-alopecia agent in the bald scalp of stumptailed macaques.

    Science.gov (United States)

    Pan, H J; Wilding, G; Uno, H; Inui, S; Goldsmith, L; Messing, E; Chang, C

    1998-08-01

    The effect of androgen receptor transcriptional activation by RU58841, a nonsteroidal anti-androgen, was studied in the human prostate cancer PC3 cell line by cotransfection with wild-type androgen receptor (wt AR) and an androgen-responsive reporter (MMTV-ARE-CAT) construct. Anti-and rogens, hydroxyflutamide, and Casodex, and the antiestrogen, genistein, were studied in parallel for comparison with RU58841. The wt AR was activated only by the androgen dihydrotestosterone (DHT). Neither the anti-androgens nor antiestrogen can enhance AR transcriptional activity at 10(-11)-10(-7)M in PC3 cells. Hydroxyflutamide, RU58841, and Casodex, but not genistein, displayed competitively suppressive effects on DHT activation of wt AR. The potency of RU58841 was comparable to that of hydroxyflutamide. From this result, topical application of RU58841, which is considered to be a potential therapy for skin diseases, may induce systemic side effects. However, RU58841, on topical application, revealed a potent increase in density, thickening, and length of hair in the macaque model of androgenetic alopecia, whereas no systemic effects were detected. Together our results suggest that RU58841 may have potent antagonism to the wt AR and could be considered as a topically applied active anti-androgen for the treatment of androgen-dependent skin disorders, such as acne, androgenetic alopecia, and hirsutism.

  10. 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene stimulates androgen independence in prostate cancer cells through combinatorial activation of mutant androgen receptor and mitogen-activated protein kinase pathways.

    Science.gov (United States)

    Shah, Supriya; Hess-Wilson, Janet K; Webb, Siobhan; Daly, Hannah; Godoy-Tundidor, Sonia; Kim, Jae; Boldison, Joanne; Daaka, Yehia; Knudsen, Karen E

    2008-09-01

    Therapy resistance represents a major clinical challenge in disseminated prostate cancer for which only palliative treatment is available. One phenotype of therapy-resistant tumors is the expression of somatic, gain-of-function mutations of the androgen receptor (AR). Such mutant receptors can use noncanonical endogenous ligands (e.g., estrogen) as agonists, thereby promoting recurrent tumor formation. Additionally, selected AR mutants are sensitized to the estrogenic endocrine-disrupting compound (EDC) bisphenol A, present in the environment. Herein, screening of additional EDCs revealed that multiple tumor-derived AR mutants (including T877A, H874Y, L701H, and V715M) are sensitized to activation by the pesticide 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE), thus indicating that this agent may impinge on AR signaling in cancer cells. Further investigation showed that DDE induced mutant AR recruitment to the prostate-specific antigen regulatory region, concomitant with an enhancement of target gene expression, and androgen-independent proliferation. By contrast, neither AR activation nor altered cellular proliferation was observed in cells expressing wild-type AR. Activation of signal transduction pathways was also observed based on rapid phosphorylation of mitogen-activated protein kinase (MAPK) and vasodilator-stimulated phosphoprotein, although only MAPK activation was associated with DDE-induced cellular proliferation. Functional analyses showed that both mutant AR and MAPK pathways contribute to the proliferative action of DDE, as evidenced through selective abrogation of each pathway. Together, these data show that exposure to environmentally relevant doses of EDCs can promote androgen-independent cellular proliferation in tumor cells expressing mutant AR and that DDE uses both mutant AR and MAPK pathways to exert its mitogenic activity.

  11. Estrogenic and androgenic activities of TBBA and TBMEPH, metabolites of novel brominated flame retardants, and selected bisphenols, using the XenoScreen XL YES/YAS assay.

    Science.gov (United States)

    Fic, Anja; Žegura, Bojana; Gramec, Darja; Mašič, Lucija Peterlin

    2014-10-01

    The present study investigated and compared the estrogenic and androgenic activities of the three different classes of environmental pollutants and their metabolites using the XenoScreen XL YES/YAS assay, which has advantages compared with the original YES/YAS protocol. Contrary to the parent brominated flame retardants TBB and TBPH, which demonstrated no or very weak (anti)estrogenic or (anti)androgenic activities, their metabolites, TBBA and TBMEPH, exhibited anti-estrogenic (IC50 for TBBA=31.75 μM and IC50 for TBMEPH=0.265 μM) and anti-androgenic (IC50 for TBBA=73.95 μM and IC50 for TBMEPH=2.92 μM) activities. These results reveal that metabolism can enhance the anti-estrogenic and anti-androgenic effects of these two novel brominated flame retardants. Based on the activities of BPAF, BPF, BPA and MBP, we can conclude that the XenoScreen XL YES/YAS assay gives comparable results to the (anti)estrogenic or (anti)androgenic assays that are reported in the literature. For BPA, it was confirmed previously that the metabolite formed after an ipso-reaction (hydroxycumyl alcohol) exhibited higher estrogenic activity compared with the parent BPA, but this was not confirmed for BPAF and BPF ipso-metabolites, which were not active in the XenoScreen YES/YAS assay. Among the substituted BPA analogues, bis-GMA exhibited weak anti-estrogenic activity, BADGE demonstrated weak anti-estrogenic and anti-androgenic activities (IC50=13.73 μM), and the hydrolysed product BADGE·2H2O demonstrated no (anti)estrogenic or (anti)androgenic activities.

  12. Identification of androgen-responsive genes that are alternatively regulated in androgen-dependent and androgen-independent rat prostate tumors.

    NARCIS (Netherlands)

    Pfundt, R.; Smit, F.P.; Jansen, Corine; Aalders, T.W.; Straatman, H.M.P.M.; Vliet, W. van der; Isaacs, J.; Geurts van Kessel, A.H.M.; Schalken, J.A.

    2005-01-01

    The vast majority of androgen-dependent prostate tumors progress toward incurable, androgen-independent tumors. The identification of androgen-responsive genes, which are still actively transcribed in the tumors of patients who have undergone androgen ablation, may shed light on the molecular mechan

  13. Disruption of androgen and estrogen receptor activity in prostate cancer by a novel dietary diterpene carnosol: implications for chemoprevention

    Science.gov (United States)

    Johnson, Jeremy J.; Syed, Deeba N.; Suh, Yewseok; Heren, Chenelle R.; Saleem, Mohammad; Siddiqui, Imtiaz A.; Mukhtar, Hasan

    2010-01-01

    Emerging data is suggesting that estrogens, in addition to androgens, may also be contributing to the development of prostate cancer (PCa). In view of this notion agents that target estrogens, in addition to androgens, may be a novel approach for PCa chemoprevention and treatment. Thus, the identification and development of non-toxic dietary agents capable of disrupting androgen receptor (AR) in addition to estrogen receptor (ER) could be extremely useful in the management of PCa. Through molecular modeling we found carnosol, a dietary diterpene fits within the ligand binding domain of both AR and ER-α. Using a TR-FRET assay we found that carnosol interacts with both AR and ER-α and additional experiments confirmed that it functions as a receptor antagonist with no agonist effects. LNCaP, 22Rv1, and MCF7 cells treated with carnosol (20–40 µM) showed decreased protein expression of AR and ER-α. Oral administration of carnosol at 30 mg/kg five days weekly for 28 days to 22Rv1 PCa xenografted mice suppressed tumor growth by 36% (p = 0.028) and was associated with a decrease in serum PSA by 26% (p=0.0042). These properties make carnosol unique to any known anti-androgen or anti-estrogen investigated so far for the simultaneous disruption of AR and ER-α. We suggest that carnosol may be developed or chemically modified through more rigorous structure activity relationship studies for a new class of investigational agents - a dual AR/ER modulator. PMID:20736335

  14. Effects of androgen and leptin on behavioral and cellular responses in female rats.

    Science.gov (United States)

    Feng, Yi; Shao, Ruijin; Weijdegård, Birgitta; Wang, Tienpei; Johansson, Julia; Sun, Shan; Wang, Wei; Egecioglu, Emil; Billig, Håkan; Stener-Victorin, Elisabet

    2011-09-01

    The causes of anxiety and depression in women with polycystic ovary syndrome (PCOS) remain elusive. To identify steps linking androgen signaling to the regulation of affective symptoms in vivo, we compared behavioral responses in female rats continuously exposed to DHT from puberty (a model of DHT-induced PCOS) and in rats exposed to DHT for 1week. Continuous and 1week of DHT exposure resulted in a general decrease in locomotor activity and time spent on the open arms in the elevated plus maze, indicating anxiety-like behavior. Rats with DHT-induced PCOS have increases in adiposity and circulating leptin levels accompanied by leptin resistance. One week of DHT exposure decreased androgen receptor (AR) expression in the hypothalamus and leptin synthesis and function in adipocytes; it also inhibited signal transducer and activator of transcription 3 (STAT3) and attenuated leptin activity by increasing levels of soluble leptin receptor, a leptin-binding protein, in the hypothalamus. This may affect the androgen-induced anxiety-related behavior in female rats. In conclusion, our results highlight the central role of androgens in behavioral function in female rats and suggest that androgens directly regulate the AR by decreasing its hypothalamic expression. Androgens also increase leptin synthesis in adipocytes, which drives central leptin signaling, and may regulate anxiety-related behaviors. Elucidating mechanisms by which androgens modulate female anxiety-like behavior may uncover useful approaches for treating women with PCOS who have symptoms of anxiety.

  15. A new type of NtrC transcriptional activator.

    OpenAIRE

    Foster-Hartnett, D; Cullen, P. J.; Monika, E M; Kranz, R G

    1994-01-01

    The enteric NtrC (NRI) protein has been the paradigm for a class of bacterial enhancer-binding proteins (EBPs) that activate transcription of RNA polymerase containing the sigma 54 factor. Activators in the NtrC class are characterized by essentially three properties: (i) they bind to sites distant from the promoters that they activate (> 100 bp upstream of the transcriptional start site), (ii) they contain a conserved nucleotide-binding fold and exhibit ATPase activity that is required for a...

  16. In vivo modulation of androgen receptor by androgens

    Institute of Scientific and Technical Information of China (English)

    V·L·Kumar; V·Kumar

    2002-01-01

    Aim:To study the effect of androgen and antiandrogen on the level of androgen receptor(AR)mRNA.Methods:The totalRNA was extracted from the prostate and analyzed by slot blot analysis,The blots were hybrid-ized with ARcDNA probe and 1Aprobe(internal control)and autoradionraphy was performed.The intensity of signal was measured with a densitometer and the ratio of AR RNAand1ARNAwas calculated.Results:Androgenic deprivation produced by castration decreased the weight of the prostate and increased the levels of ARmRNA.Treatment of the castrated rats with testostrone increased the weight of prostate and decreased the levels of ARmRNA.Treatment of normal rats with flutamide decreased the weight of the gland and increased the levels of AR mRNA.Conclusion:Androgens produce proliferative effect on the prostate and negatively regulate the AR transcription.

  17. Conazole fungicides inhibit Leydig cell testosterone secretion and androgen receptor activation in vitro

    NARCIS (Netherlands)

    Roelofs, Maarke J.E.; Temming, A. Roberto; Piersma, Aldert H.; van den Berg, Martin; van Duursen, Majorie B.M.

    2014-01-01

    Abstract Conazole fungicides are widely used in agriculture despite their suspected endocrine disrupting properties. In this study, the potential (anti-)androgenic effects of ten conazoles were assessed and mutually compared with existing data. Effects of cyproconazole (CYPRO), fluconazole (FLUC), f

  18. A study of the prostate, androgens and sexual activity of male rats

    Directory of Open Access Journals (Sweden)

    Garcia Luis I

    2007-03-01

    Full Text Available Abstract Background The prostate is a sexual gland that produces important substances for the potency of sperm to fertilize eggs within the female reproductive tract, and is under complex endocrine control. Taking advantage of the peculiar behavioral pattern of copulating male rats, we developed experimental paradigms to determine the influence of sexual behavior on the level of serum testosterone, prostate androgen receptors, and mRNA for androgen receptors in male rats displaying up to four consecutive ejaculations. Methods The effect of four consecutive ejaculations was investigated by determining levels of (i testosterone in serum by solid phase RIA, (ii androgen receptors at the ventral prostate with Western Blots, and (iii androgen receptors-mRNA with RT-PCR. Data were analyzed with a one-way ANOVA followed by a post hoc application of Dunnett's test if required. Results The constant execution of sexual behavior did not produce any change in the weight of the ventral prostate. Serum testosterone increased after the second ejaculation, and remained elevated even after four ejaculations. The androgen receptor at the ventral prostate was higher after the first to third ejaculations, but returned suddenly to baseline levels after the fourth ejaculation. The level of mRNA increased after the first ejaculation, continued to increase after the second, and reached the highest peak after the third ejaculation; however, it returned suddenly to baseline levels after the fourth ejaculation. Conclusion Four consecutive ejaculations by sexually experienced male rats had important effects on the physiological responses of the ventral prostate. Fast responses were induced as a result of sexual behavior that involved an increase and decrease in androgen receptors after one and four ejaculations, respectively. However, a progressive response was observed in the elevation of mRNA for androgen receptors, which also showed a fast decrease after four

  19. Sediment contaminated with the Azo Dye disperse yellow 7 alters cellular stress- and androgen-related transcription in Silurana tropicalis larvae.

    Science.gov (United States)

    Mathieu-Denoncourt, Justine; Martyniuk, Christopher J; de Solla, Shane R; Balakrishnan, Vimal K; Langlois, Valérie S

    2014-01-01

    Azo dyes are the most commonly used type of dye, accounting for 60-70% of all organic dye production worldwide. They are used as direct dyes in the textile, leather, printing ink, and cosmetic industries. The aim of this study was to assess the lethal and sublethal effects of the disazo dye Disperse Yellow 7 (DY7) in frogs to address a knowledge gap regarding mechanisms of toxicity and the potential for endocrine disrupting properties. Larvae of Silurana tropicalis (Western clawed frog) were exposed to DY7-contaminated water (0 to 22 μg/L) and sediment (0 to 209 μg/g) during early larval development. The concentrations used included the range of similar azo dyes found in surface waters in Canada. A significant decrease in tadpole survivorship was observed at 209 μg/g while there was a significant increase in malformations at the two highest concentrations tested in sediment. In the 209 μg/g treatment, DY7 significantly induced hsp70 (2.5-fold) and hsp90 (2.4-fold) mRNA levels, suggesting that cells required oxidative protection. The same treatment also altered the expression of two androgen-related genes: decreased ar (2-fold) and increased srd5a2 (2.6-fold). Furthermore, transcriptomics generated new hypotheses regarding the mechanisms of toxic action of DY7. Gene network analysis revealed that high concentrations of DY7 in sediment induced cellular stress-related gene transcription and affected genes associated with necrotic cell death, chromosome condensation, and mRNA processing. This study is the first to report on sublethal end points for azo dyes in amphibians, a growing environmental pollutant of concern for aquatic species.

  20. Transcriptional activators enhance polyadenylation of mRNA precursors

    OpenAIRE

    Nagaike, Takashi; Manley, James L.

    2011-01-01

    3′ processing of mRNA precursors is frequently coupled to transcription by RNA polymerase II (RNAP II). This coupling is well known to involve the C-terminal domain of the RNAP II largest subunit, but a variety of other transcription-associated factors have also been suggested to mediate coupling. Our recent studies have provided direct evidence that transcriptional activators can enhance the efficiency of transcription-coupled 3′ processing. In this point-of-view, we discuss the mechanisms t...

  1. Human mediator subunit MED15 promotes transcriptional activation.

    Science.gov (United States)

    Nakatsubo, Takuya; Nishitani, Saori; Kikuchi, Yuko; Iida, Satoshi; Yamada, Kana; Tanaka, Aki; Ohkuma, Yoshiaki

    2014-10-01

    In eukaryotes, the Mediator complex is an essential transcriptional cofactor of RNA polymerase II (Pol II). In humans, it contains up to 30 subunits and consists of four modules: head, middle, tail, and CDK/Cyclin. One of the subunits, MED15, is located in the tail module, and was initially identified as Gal11 in budding yeast, where it plays an essential role in the transcriptional regulation of galactose metabolism with the potent transcriptional activator Gal4. For this reason, we investigated the function of the human MED15 subunit (hMED15) in transcriptional activation. First, we measured the effect of hMED15 knockdown on cell growth in HeLa cells. The growth rate was greatly reduced. By immunostaining, we observed the colocalization of hMED15 with the general transcription factors TFIIE and TFIIH in the nucleus. We measured the effects of siRNA-mediated knockdown of hMED15 on transcriptional activation using two different transcriptional activators, VP16 and SREBP1a. Treatment with siRNAs reduced transcriptional activation, and this reduction could be rescued by overexpression of HA/Flag-tagged, wild-type hMED15. To investigate hMED15 localization, we treated human MCF-7 cells with the MDM2 inhibitor Nutlin-3, thus inducing p21 transcription. We found that hMED15 localized to both the p53 binding site and the p21 promoter region, along with TFIIE and TFIIH. These results indicate that hMED15 promotes transcriptional activation.

  2. CHD8, A Novel Beta-Catenin Associated Chromatin Remodeling Enzyme, Regulates Androgen Receptor Mediated Gene Transcription

    Science.gov (United States)

    2010-03-01

    NP- 40 , Nonidet P - 40 ; PPAR, peroxisome prolif- erator-activated receptor; PSA, prostate-specific antigen; SDS, sodium dodecyl sulfate; siRNA, small... Nonidet P - 40 (NP- 40 ). Cell lysates were cleared by centrifugation at 20,800 g for 10 min at 4 C and used for protein interaction studies as...or therapeutic target in prostate cancer. REFERENCES 1. Mulholland, D. J., Cheng, H., Reid, K., Rennie, P . S., and Nelson, C. C. (2002) J Biol

  3. Regulation of human androgen receptor by corepressors and signal transduction in prostate cancer

    OpenAIRE

    2006-01-01

    The thesis primarily addresses the role of transcriptional corepressor and signal transduction cascades in regulating androgen receptor (AR) activity. AR is a ligand-activated transcription factor and is important for the development of male phenotype. Malfunctioning of AR function has been implicated in the progression of the prostate cancer (CaP). Clinical management of the CaP most often involves the administration of anti-hormones (Cas, CPA) that bind to AR and turn it transcr...

  4. Loss of exogenous androgen dependence by prostate tumor cells is associated with elevated glucuronidation potential

    Science.gov (United States)

    Zimmer, Brenna M.; Howell, Michelle E.; Wei, Qin; Ma, Linlin; Romsdahl, Trevor; Loughman, Eileen G.; Markham, Jonathan E.; Seravalli, Javier; Barycki, Joseph J.; Simpson, Melanie A.

    2016-01-01

    Prostate epithelial cells control the potency and availability of androgen hormones in part by inactivation and elimination. UDP-glucose dehydrogenase (UGDH) catalyzes the NAD+-dependent oxidation of UDP-glucose to UDP-glucuronate, an essential precursor for androgen inactivation by the prostate glucuronidation enzymes UGT2B15 and UGT2B17. UGDH expression is androgen stimulated, which increases the production of UDP-glucuronate, and fuels UGT-catalyzed glucuronidation. In this study, we compared the glucuronidation potential and its impact on androgen-mediated gene expression in an isogenic LNCaP model for androgen dependent versus castration resistant prostate cancer. Despite significantly lower androgen-glucuronide output, LNCaP 81 castration resistant tumor cells expressed higher levels of UGDH, UGT2B15, and UGT2B17. However, the magnitude of androgen-activated UGDH and PSA expression, as well as the AR-dependent repression of UGT2B15 and UGT2B17, was blunted several-fold in these cells. Consistent with these results, the ligand-activated binding of AR to the PSA promoter and subsequent transcriptional activation were also significantly reduced in castration resistant cells. Analysis of the UDP-sugar pools and flux through pathways downstream of UDP-glucuronate production revealed that these glucuronidation precursor metabolites were channeled through proteoglycan and glycosaminoglycan biosynthetic pathways, leading to increased surface expression of Notch 1. Knockdown of UGDH diminished Notch1 and increased glucuronide output. Overall, these results support a model in which the aberrant partitioning of UDP-glucuronate and other UDP-sugars into alternative pathways during androgen deprivation contributes to the loss of prostate tumor cell androgen sensitivity by promoting altered cell surface proteoglycan expression. PMID:27307252

  5. Antiandrogens act as selective androgen receptor modulators at the proteome level in prostate cancer cells.

    Science.gov (United States)

    Brooke, Greg N; Gamble, Simon C; Hough, Michael A; Begum, Shajna; Dart, D Alwyn; Odontiadis, Michael; Powell, Sue M; Fioretti, Flavia M; Bryan, Rosie A; Waxman, Jonathan; Wait, Robin; Bevan, Charlotte L

    2015-05-01

    Current therapies for prostate cancer include antiandrogens, inhibitory ligands of the androgen receptor, which repress androgen-stimulated growth. These include the selective androgen receptor modulators cyproterone acetate and hydroxyflutamide and the complete antagonist bicalutamide. Their activity is partly dictated by the presence of androgen receptor mutations, which are commonly detected in patients who relapse while receiving antiandrogens, i.e. in castrate-resistant prostate cancer. To characterize the early proteomic response to these antiandrogens we used the LNCaP prostate cancer cell line, which harbors the androgen receptor mutation most commonly detected in castrate-resistant tumors (T877A), analyzing alterations in the proteome, and comparing these to the effect of these therapeutics upon androgen receptor activity and cell proliferation. The majority are regulated post-transcriptionally, possibly via nongenomic androgen receptor signaling. Differences detected between the exposure groups demonstrate subtle changes in the biological response to each specific ligand, suggesting a spectrum of agonistic and antagonistic effects dependent on the ligand used. Analysis of the crystal structures of the AR in the presence of cyproterone acetate, hydroxyflutamide, and DHT identified important differences in the orientation of key residues located in the AF-2 and BF-3 protein interaction surfaces. This further implies that although there is commonality in the growth responses between androgens and those antiandrogens that stimulate growth in the presence of a mutation, there may also be influential differences in the growth pathways stimulated by the different ligands. This therefore has implications for prostate cancer treatment because tumors may respond differently dependent upon which mutation is present and which ligand is activating growth, also for the design of selective androgen receptor modulators, which aim to elicit differential proteomic

  6. Transcriptional Activation of the Zygotic Genome in Drosophila.

    Science.gov (United States)

    Harrison, Melissa M; Eisen, Michael B

    2015-01-01

    During the first stages of metazoan development, the genomes of the highly specified sperm and egg must unite and be reprogrammed to allow for the generation of a new organism. This process is controlled by maternally deposited products. Initially, the zygotic genome is largely transcriptionally quiescent, and it is not until hours later that the zygotic genome takes control of development. The transcriptional activation of the zygotic genome is tightly coordinated with the degradation of the maternal products. Here, we review the current understanding of the processes that mediate the reprogramming of the early embryonic genome and facilitate transcriptional activation during the early stages of Drosophila development.

  7. Sumoylation delays the ATF7 transcription factor subcellular localization and inhibits its transcriptional activity.

    Science.gov (United States)

    Hamard, Pierre-Jacques; Boyer-Guittaut, Michaël; Camuzeaux, Barbara; Dujardin, Denis; Hauss, Charlotte; Oelgeschläger, Thomas; Vigneron, Marc; Kedinger, Claude; Chatton, Bruno

    2007-01-01

    Over the past few years, small ubiquitin-like modifier (SUMO) modification has emerged as an important regulator of diverse pathways and activities including protein localization and transcriptional regulation. We identified a consensus sumoylation motif (IKEE), located within the N-terminal activation domain of the ATF7 transcription factor and thus investigated the role of this modification. ATF7 is a ubiquitously expressed transcription factor, homologous to ATF2, that binds to CRE elements within specific promoters. This protein is able to heterodimerize with Jun or Fos proteins and its transcriptional activity is mediated by interaction with TAF12, a subunit of the general transcription factor TFIID. In the present article, we demonstrate that ATF7 is sumoylated in vitro (using RanBP2 as a E3-specific ligase) and in vivo. Moreover, we show that ATF7 sumoylation affects its intranuclear localization by delaying its entry into the nucleus. Furthermore, SUMO conjugation inhibits ATF7 transactivation activity by (i) impairing its association with TAF12 and (ii) blocking its binding-to-specific sequences within target promoters.

  8. The EDLL motif: a potent plant transcriptional activation domain from AP2/ERF transcription factors.

    Science.gov (United States)

    Tiwari, Shiv B; Belachew, Alemu; Ma, Siu Fong; Young, Melinda; Ade, Jules; Shen, Yu; Marion, Colleen M; Holtan, Hans E; Bailey, Adina; Stone, Jeffrey K; Edwards, Leslie; Wallace, Andreah D; Canales, Roger D; Adam, Luc; Ratcliffe, Oliver J; Repetti, Peter P

    2012-06-01

    In plants, the ERF/EREBP family of transcriptional regulators plays a key role in adaptation to various biotic and abiotic stresses. These proteins contain a conserved AP2 DNA-binding domain and several uncharacterized motifs. Here, we describe a short motif, termed 'EDLL', that is present in AtERF98/TDR1 and other clade members from the same AP2 sub-family. We show that the EDLL motif, which has a unique arrangement of acidic amino acids and hydrophobic leucines, functions as a strong activation domain. The motif is transferable to other proteins, and is active at both proximal and distal positions of target promoters. As such, the EDLL motif is able to partly overcome the repression conferred by the AtHB2 transcription factor, which contains an ERF-associated amphiphilic repression (EAR) motif. We further examined the activation potential of EDLL by analysis of the regulation of flowering time by NF-Y (nuclear factor Y) proteins. Genetic evidence indicates that NF-Y protein complexes potentiate the action of CONSTANS in regulation of flowering in Arabidopsis; we show that the transcriptional activation function of CONSTANS can be substituted by direct fusion of the EDLL activation motif to NF-YB subunits. The EDLL motif represents a potent plant activation domain that can be used as a tool to confer transcriptional activation potential to heterologous DNA-binding proteins.

  9. Dataset of transcriptional landscape of B cell early activation

    Directory of Open Access Journals (Sweden)

    Alexander S. Garruss

    2015-09-01

    Full Text Available Signaling via B cell receptors (BCR and Toll-like receptors (TLRs result in activation of B cells with distinct physiological outcomes, but transcriptional regulatory mechanisms that drive activation and distinguish these pathways remain unknown. At early time points after BCR and TLR ligand exposure, 0.5 and 2 h, RNA-seq was performed allowing observations on rapid transcriptional changes. At 2 h, ChIP-seq was performed to allow observations on important regulatory mechanisms potentially driving transcriptional change. The dataset includes RNA-seq, ChIP-seq of control (Input, RNA Pol II, H3K4me3, H3K27me3, and a separate RNA-seq for miRNA expression, which can be found at Gene Expression Omnibus Dataset GSE61608. Here, we provide details on the experimental and analysis methods used to obtain and analyze this dataset and to examine the transcriptional landscape of B cell early activation.

  10. Heterogeneity of Calcium Channel/cAMP-Dependent Transcriptional Activation.

    Science.gov (United States)

    Kobrinsky, Evgeny

    2015-01-01

    The major function of the voltage-gated calcium channels is to provide the Ca(2+) flux into the cell. L-type voltage-gated calcium channels (Cav1) serve as voltage sensors that couple membrane depolarization to many intracellular processes. Electrical activity in excitable cells affects gene expression through signaling pathways involved in the excitation-transcription (E-T) coupling. E-T coupling starts with activation of the Cav1 channel and results in initiation of the cAMP-response element binding protein (CREB)-dependent transcription. In this review we discuss the new quantitative approaches to measuring E-T signaling events. We describe the use of wavelet transform to detect heterogeneity of transcriptional activation in nuclei. Furthermore, we discuss the properties of discovered microdomains of nuclear signaling associated with the E-T coupling and the basis of the frequency-dependent transcriptional regulation.

  11. AOP description: Androgen receptor agonism leading to reproductive dysfunction (in fish)

    Science.gov (United States)

    This adverse outcome pathway details the linkage between binding and activation of androgen receptor as a nuclear transcription factor in females and the adverse effect of reduced cumulative fecundity in repeat-spawning fish species. Cumulative fecundity is the most apical endpoi...

  12. Potential Role of Activating Transcription Factor 5 during Osteogenesis

    Directory of Open Access Journals (Sweden)

    Luisa Vicari

    2016-01-01

    Full Text Available Human adipose-derived stem cells are an abundant population of stem cells readily isolated from human adipose tissue that can differentiate into connective tissue lineages including bone, cartilage, fat, and muscle. Activating transcription factor 5 is a transcription factor of the ATF/cAMP response element-binding protein (CREB family. It is transcribed in two types of mRNAs (activating transcription factor 5 isoform 1 and activating transcription factor 5 isoform 2, encoding the same single 30-kDa protein. Although it is well demonstrated that it regulates the proliferation, differentiation, and apoptosis, little is known about its potential role in osteogenic differentiation. The aim of this study was to evaluate the expression levels of the two isoforms and protein during osteogenic differentiation of human adipose-derived stem cells. Our data indicate that activating transcription factor 5 is differentially expressed reaching a peak of expression at the stage of bone mineralization. These findings suggest that activating transcription factor 5 could play an interesting regulatory role during osteogenesis, which would provide a powerful tool to study bone physiology.

  13. Fungal mediator tail subunits contain classical transcriptional activation domains.

    Science.gov (United States)

    Liu, Zhongle; Myers, Lawrence C

    2015-04-01

    Classical activation domains within DNA-bound eukaryotic transcription factors make weak interactions with coactivator complexes, such as Mediator, to stimulate transcription. How these interactions stimulate transcription, however, is unknown. The activation of reporter genes by artificial fusion of Mediator subunits to DNA binding domains that bind to their promoters has been cited as evidence that the primary role of activators is simply to recruit Mediator. We have identified potent classical transcriptional activation domains in the C termini of several tail module subunits of Saccharomyces cerevisiae, Candida albicans, and Candida dubliniensis Mediator, while their N-terminal domains are necessary and sufficient for their incorporation into Mediator but do not possess the ability to activate transcription when fused to a DNA binding domain. This suggests that Mediator fusion proteins actually are functioning in a manner similar to that of a classical DNA-bound activator rather than just recruiting Mediator. Our finding that deletion of the activation domains of S. cerevisiae Med2 and Med3, as well as C. dubliniensis Tlo1 (a Med2 ortholog), impairs the induction of certain genes shows these domains function at native promoters. Activation domains within coactivators are likely an important feature of these complexes and one that may have been uniquely leveraged by a common fungal pathogen.

  14. Stimulatory effects of androgens on normal children's bone marrow in culture: effects on BFU-E, CFU-E, and uroporphyrinogen I synthase activity.

    Science.gov (United States)

    Claustres, M; Sultan, C

    1986-01-01

    We studied the effect of natural and synthetic androgens on children's erythropoietic precursor cells in culture. Cultures of normal marrow were carried out according to a miniaturized methylcellulose method in the presence of erythropoietin. We then evaluated the effects of testosterone, nortestosterone, fluoxymesterone and etiocholanolone (10(-9)-10(-6) M) on erythroid colony-forming units (CFU-E) and burst-forming units (BFU-E). Androgen-induced growth of erythroid progenitors was quantified by directly scoring colonies and by a biochemical determination of the uroporphyrinogen I synthase activity (UROS). We observed a significant increase (p less than or equal to 0.05) in the number of CFU-E and BFU-E and in the UROS activity of derived colonies in the presence of androgens (10(-8) or 10(-7)M). This microculture assay could be useful not only to study the effect of androgens on erythroid progenitor cells in culture, but also to predict the best androgenic treatment of anemia in children and adults.

  15. Reinforcing aspects of androgens.

    Science.gov (United States)

    Wood, Ruth I

    2004-11-15

    Are androgens reinforcing? Androgenic-anabolic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, often with negative long-term health consequences. As a result, in 1991, testosterone was declared a controlled substance. Recently, Brower [K.J. Brower, Anabolic steroid abuse and dependence. Curr. Psychiatry Rep. 4 (2002) 377-387.] proposed a two-stage model of AAS dependence. Users initiate steroid use for their anabolic effects on muscle growth. With continued exposure, dependence on the psychoactive effects of AAS develops. However, it is difficult in humans to separate direct psychoactive effects of AAS from the user's psychological dependence on the anabolic effects of AAS. Thus, studies in laboratory animals are useful to explore androgen reinforcement. Testosterone induces a conditioned place preference in rats and mice, and is voluntarily consumed through oral, intravenous, and intracerebroventricular self-administration in hamsters. Active, gonad-intact male and female hamsters will deliver 1 microg/microl testosterone into the lateral ventricles. Indeed, some individuals self-administer testosterone intracerebroventricularly to the point of death. Male rats develop a conditioned place preference to testosterone injections into the nucleus accumbens, an effect blocked by dopamine receptor antagonists. These data suggest that androgen reinforcement is mediated by the brain. Moreover, testosterone appears to act through the mesolimbic dopamine system, a common substrate for drugs of abuse. Nonetheless, androgen reinforcement is not comparable to that of cocaine or heroin. Instead, testosterone resembles other mild reinforcers, such as caffeine, nicotine, or benzodiazepines. The potential for androgen addiction remains to be determined.

  16. A Recurrent Germline Mutation in the 5'UTR of the Androgen Receptor Causes Complete Androgen Insensitivity by Activating Aberrant uORF Translation.

    Science.gov (United States)

    Hornig, Nadine C; de Beaufort, Carine; Denzer, Friederike; Cools, Martine; Wabitsch, Martin; Ukat, Martin; Kulle, Alexandra E; Schweikert, Hans-Udo; Werner, Ralf; Hiort, Olaf; Audi, Laura; Siebert, Reiner; Ammerpohl, Ole; Holterhus, Paul-Martin

    2016-01-01

    A subset of patients with monogenic disorders lacks disease causing mutations in the protein coding region of the corresponding gene. Here we describe a recurrent germline mutation found in two unrelated patients with complete androgen insensitivity syndrome (CAIS) generating an upstream open reading frame (uORF) in the 5' untranslated region (5'-UTR) of the androgen receptor (AR) gene. We show in patient derived primary genital skin fibroblasts as well as in cell-based reporter assays that this mutation severely impacts AR function by reducing AR protein levels without affecting AR mRNA levels. Importantly, the newly generated uORF translates into a polypeptide and the expression level of this polypeptide inversely correlates with protein translation from the primary ORF of the AR thereby providing a model for AR-5'UTR mediated translational repression. Our findings not only add a hitherto unrecognized genetic cause to complete androgen insensitivity but also underline the importance of 5'UTR mutations affecting uORFs for the pathogenesis of monogenic disorders in general.

  17. A Recurrent Germline Mutation in the 5'UTR of the Androgen Receptor Causes Complete Androgen Insensitivity by Activating Aberrant uORF Translation.

    Directory of Open Access Journals (Sweden)

    Nadine C Hornig

    Full Text Available A subset of patients with monogenic disorders lacks disease causing mutations in the protein coding region of the corresponding gene. Here we describe a recurrent germline mutation found in two unrelated patients with complete androgen insensitivity syndrome (CAIS generating an upstream open reading frame (uORF in the 5' untranslated region (5'-UTR of the androgen receptor (AR gene. We show in patient derived primary genital skin fibroblasts as well as in cell-based reporter assays that this mutation severely impacts AR function by reducing AR protein levels without affecting AR mRNA levels. Importantly, the newly generated uORF translates into a polypeptide and the expression level of this polypeptide inversely correlates with protein translation from the primary ORF of the AR thereby providing a model for AR-5'UTR mediated translational repression. Our findings not only add a hitherto unrecognized genetic cause to complete androgen insensitivity but also underline the importance of 5'UTR mutations affecting uORFs for the pathogenesis of monogenic disorders in general.

  18. A Recurrent Germline Mutation in the 5’UTR of the Androgen Receptor Causes Complete Androgen Insensitivity by Activating Aberrant uORF Translation

    Science.gov (United States)

    Hornig, Nadine C.; de Beaufort, Carine; Denzer, Friederike; Cools, Martine; Wabitsch, Martin; Ukat, Martin; Kulle, Alexandra E.; Schweikert, Hans-Udo; Werner, Ralf; Hiort, Olaf; Audi, Laura; Siebert, Reiner; Ammerpohl, Ole; Holterhus, Paul-Martin

    2016-01-01

    A subset of patients with monogenic disorders lacks disease causing mutations in the protein coding region of the corresponding gene. Here we describe a recurrent germline mutation found in two unrelated patients with complete androgen insensitivity syndrome (CAIS) generating an upstream open reading frame (uORF) in the 5’ untranslated region (5’-UTR) of the androgen receptor (AR) gene. We show in patient derived primary genital skin fibroblasts as well as in cell-based reporter assays that this mutation severely impacts AR function by reducing AR protein levels without affecting AR mRNA levels. Importantly, the newly generated uORF translates into a polypeptide and the expression level of this polypeptide inversely correlates with protein translation from the primary ORF of the AR thereby providing a model for AR-5′UTR mediated translational repression. Our findings not only add a hitherto unrecognized genetic cause to complete androgen insensitivity but also underline the importance of 5′UTR mutations affecting uORFs for the pathogenesis of monogenic disorders in general. PMID:27110943

  19. First Exon Length Controls Active Chromatin Signatures and Transcription

    Directory of Open Access Journals (Sweden)

    Nicole I. Bieberstein

    2012-07-01

    Full Text Available Here, we explore the role of splicing in transcription, employing both genome-wide analysis of human ChIP-seq data and experimental manipulation of exon-intron organization in transgenic cell lines. We show that the activating histone modifications H3K4me3 and H3K9ac map specifically to first exon-intron boundaries. This is surprising, because these marks help recruit general transcription factors (GTFs to promoters. In genes with long first exons, promoter-proximal levels of H3K4me3 and H3K9ac are greatly reduced; consequently, GTFs and RNA polymerase II are low at transcription start sites (TSSs and exhibit a second, promoter-distal peak from which transcription also initiates. In contrast, short first exons lead to increased H3K4me3 and H3K9ac at promoters, higher expression levels, accuracy in TSS usage, and a lower frequency of antisense transcription. Therefore, first exon length is predictive for gene activity. Finally, splicing inhibition and intron deletion reduce H3K4me3 levels and transcriptional output. Thus, gene architecture and splicing determines transcription quantity and quality as well as chromatin signatures.

  20. Inhibition of the Androgen Receptor by Antiandrogens in Spinobulbar Muscle Atrophy.

    Science.gov (United States)

    Baniahmad, Aria

    2016-03-01

    Spinal-bulbar muscle atrophy (SBMA) or also named Kennedy's Disease is caused by a polyglutamine expansion (PolyQ) of the coding region of the androgen receptor (AR). The AR is a ligand-controlled transcription factor and member of the nuclear hormone receptor superfamily. The central characteristics of the SBMA pathogenicity are muscle weakness, the loss of motoneurons and the occurrence of AR-containing protein aggregates that are observed in spinal cord motoneurons and skeletal muscles induced by the AR-PolyQ expansion in the presence of androgens. The PolyQ triggers a misfolding in the AR-PolyQ and leads to protein aggregation in spinal cord motoneurons and muscle cells. The AR-PolyQ toxicity is activated by the AR ligand testosterone and dihydrotestosterone that activate the receptor and triggers nuclear toxicity by inducing AR nuclear translocation. In line with this, androgen treatment of SBMA patients worsened the SBMA symptoms. SBMA has been modeled in AR-overexpressing and AR-PolyQ-knock-in animals, but precisely how the PolyQ expansion leads to neurodegeneration is unclear. The androgen-induced toxicity and androgen-dependent nuclear accumulation of AR-PolyQ protein seems to be central to the pathogenesis. Therefore, the inhibition of the androgen-activated AR-PolyQ might be a therapeutic option. Here the use of AR antagonists for treatment option of SBMA will be reviewed and discussed.

  1. Resveratrol regulates gene transcription via activation of stimulus-responsive transcription factors.

    Science.gov (United States)

    Thiel, Gerald; Rössler, Oliver G

    2017-03-01

    Resveratrol (trans-3,4',5-trihydroxystilbene), a polyphenolic phytoalexin of grapes and other fruits and plants, is a common constituent of our diet and of dietary supplements. Many health-promoting benefits have been connected with resveratrol in the treatment of cardiovascular diseases, cancer, diabetes, inflammation, neurodegeneration, and diseases connected with aging. To explain the pleiotropic effects of resveratrol, the molecular targets of this compound have to be identified on the cellular level. Resveratrol induces intracellular signal transduction pathways which ultimately lead to changes in the gene expression pattern of the cells. Here, we review the effect of resveratrol on the activation of the stimulus-responsive transcription factors CREB, AP-1, Egr-1, Elk-1, and Nrf2. Following activation, these transcription factors induce transcription of delayed response genes. The gene products of these delayed response genes are ultimately responsible for the changes in the biochemistry and physiology of resveratrol-treated cells. The activation of stimulus-responsive transcription factors may explain many of the intracellular activities of resveratrol. However, results obtained in vitro may not easily be transferred to in vivo systems.

  2. Characterization of niphatenones that inhibit androgen receptor N-terminal domain.

    Directory of Open Access Journals (Sweden)

    Carmen A Banuelos

    Full Text Available Androgen ablation therapy causes a temporary reduction in tumor burden in patients with advanced prostate cancer. Unfortunately the malignancy will return to form lethal castration-recurrent prostate cancer (CRPC. The androgen receptor (AR remains transcriptionally active in CRPC in spite of castrate levels of androgens in the blood. AR transcriptional activity resides in its N-terminal domain (NTD. Possible mechanisms of continued AR transcriptional activity may include, at least in part, expression of constitutively active splice variants of AR that lack the C-terminal ligand-binding domain (LBD. Current therapies that target the AR LBD, would not be effective against these AR variants. Currently no drugs are clinically available that target the AR NTD which should be effective against these AR variants as well as full-length AR. Niphatenones were originally isolated and identified in active extracts from Niphates digitalis marine sponge. Here we begin to characterize the mechanism of niphatenones in blocking AR transcriptional activity. Both enantiomers had similar IC50 values of 6 µM for inhibiting the full-length AR in a functional transcriptional assay. However, (S-niphatenone had significantly better activity against the AR NTD compared to (R-niphatenone. Consistent with niphatenones binding to and inhibiting transactivation of AR NTD, niphatenones inhibited AR splice variant. Niphatenone did not affect the transcriptional activity of the related progesterone receptor, but slightly decreased glucocorticoid receptor (GR activity and covalently bound to GR activation function-1 (AF-1 region. Niphatenone blocked N/C interactions of AR without altering either AR protein levels or its intracellular localization in response to androgen. Alkylation with glutathione suggests that niphatenones are not a feasible scaffold for further drug development.

  3. Wild-type and specific mutant androgen receptor mediates transcription via 17β-estradiol in sex hormone-sensitive cancer cells.

    Science.gov (United States)

    Susa, Takao; Ikaga, Reina; Kajitani, Takashi; Iizuka, Masayoshi; Okinaga, Hiroko; Tamamori-Adachi, Mimi; Okazaki, Tomoki

    2015-07-01

    We previously encountered regulatory processes wherein dihydrotestosterone (DHT) exerted its inhibitory effect on parathyroid hormone-related protein (PTHrP) gene repression through the estrogen receptor (ER)α, but not the androgen receptor (AR), in breast cancer MCF-7 cells. Here, we investigated whether such aberrant ligand-nuclear receptor (NR) interaction is present in prostate cancer LNCaP cells. First, we confirmed that LNCaP cells expressed large amounts of AR at negligible levels of ERα/β or progesterone receptor. Both suppression of PTHrP and activation of prostate-specific antigen genes were observed after independent administration of 17β-estradiol (E2), DHT, or R5020. Consistent with the notion that the LNCaP AR lost its ligand specificity due to a mutation (Thr-Ala877), experiments with siRNA targeting the respective NR revealed that the AR monopolized the role of the mediator of shared hormone-dependent regulation, which was invariably associated with nuclear translocation of this mutant AR. Microarray analysis of gene regulation by DHT, E2, or R5020 disclosed that more than half of the genes downstream of the AR (Thr-Ala877) overlapped in the LNCaP cells. Of particular interest, we realized that the AR (wild-type [wt]) and AR (Thr-Ala877) were equally responsible for the E2-AR interactions. Fluorescence microscopy experiments demonstrated that both EGFP-AR (wt) and EGFP-AR (Thr-Ala877) were exclusively localized within the nucleus after E2 or DHT treatment. Furthermore, reporter assays revealed that some other cancer cells exhibited aberrant E2-AR (wt) signaling similar to that in the LNCaP cells. We herein postulate the presence of entangled interactions between wt AR and E2 in certain hormone-sensitive cancer cells.

  4. Transcriptional activity of transposable elements in coelacanth.

    Science.gov (United States)

    Forconi, Mariko; Chalopin, Domitille; Barucca, Marco; Biscotti, Maria Assunta; De Moro, Gianluca; Galiana, Delphine; Gerdol, Marco; Pallavicini, Alberto; Canapa, Adriana; Olmo, Ettore; Volff, Jean-Nicolas

    2014-09-01

    The morphological stasis of coelacanths has long suggested a slow evolutionary rate. General genomic stasis might also imply a decrease of transposable elements activity. To evaluate the potential activity of transposable elements (TEs) in "living fossil" species, transcriptomic data of Latimeria chalumnae and its Indonesian congener Latimeria menadoensis were compared through the RNA-sequencing mapping procedures in three different organs (liver, testis, and muscle). The analysis of coelacanth transcriptomes highlights a significant percentage of transcribed TEs in both species. Major contributors are LINE retrotransposons, especially from the CR1 family. Furthermore, some particular elements such as a LF-SINE and a LINE2 sequences seem to be more expressed than other elements. The amount of TEs expressed in testis suggests possible transposition burst in incoming generations. Moreover, significant amount of TEs in liver and muscle transcriptomes were also observed. Analyses of elements displaying marked organ-specific expression gave us the opportunity to highlight exaptation cases, that is, the recruitment of TEs as new cellular genes, but also to identify a new Latimeria-specific family of Short Interspersed Nuclear Elements called CoeG-SINEs. Overall, transcriptome results do not seem to be in line with a slow-evolving genome with poor TE activity.

  5. Genome-wide signatures of transcription factor activity: connecting transcription factors, disease, and small molecules.

    Directory of Open Access Journals (Sweden)

    Jing Chen

    Full Text Available Identifying transcription factors (TF involved in producing a genome-wide transcriptional profile is an essential step in building mechanistic model that can explain observed gene expression data. We developed a statistical framework for constructing genome-wide signatures of TF activity, and for using such signatures in the analysis of gene expression data produced by complex transcriptional regulatory programs. Our framework integrates ChIP-seq data and appropriately matched gene expression profiles to identify True REGulatory (TREG TF-gene interactions. It provides genome-wide quantification of the likelihood of regulatory TF-gene interaction that can be used to either identify regulated genes, or as genome-wide signature of TF activity. To effectively use ChIP-seq data, we introduce a novel statistical model that integrates information from all binding "peaks" within 2 Mb window around a gene's transcription start site (TSS, and provides gene-level binding scores and probabilities of regulatory interaction. In the second step we integrate these binding scores and regulatory probabilities with gene expression data to assess the likelihood of True REGulatory (TREG TF-gene interactions. We demonstrate the advantages of TREG framework in identifying genes regulated by two TFs with widely different distribution of functional binding events (ERα and E2f1. We also show that TREG signatures of TF activity vastly improve our ability to detect involvement of ERα in producing complex diseases-related transcriptional profiles. Through a large study of disease-related transcriptional signatures and transcriptional signatures of drug activity, we demonstrate that increase in statistical power associated with the use of TREG signatures makes the crucial difference in identifying key targets for treatment, and drugs to use for treatment. All methods are implemented in an open-source R package treg. The package also contains all data used in the analysis

  6. Exploring cellular memory molecules marking competent and active transcriptions

    Directory of Open Access Journals (Sweden)

    Liu De-Pei

    2007-05-01

    Full Text Available Abstract Background Development in higher eukaryotes involves programmed gene expression. Cell type-specific gene expression is established during this process and is inherited in succeeding cell cycles. Higher eukaryotes have evolved elegant mechanisms by which committed gene-expression states are transmitted through numerous cell divisions. Previous studies have shown that both DNase I-sensitive sites and the basal transcription factor TFIID remain on silenced mitotic chromosomes, suggesting that certain trans-factors might act as bookmarks, maintaining the information and transmitting it to the next generation. Results We used the mouse globin gene clusters as a model system to examine the retention of active information on M-phase chromosomes and its contribution to the persistence of transcriptional competence of these gene clusters in murine erythroleukemia cells. In cells arrested in mitosis, the erythroid-specific activator NF-E2p45 remained associated with its binding sites on the globin gene loci, while the other major erythroid factor, GATA-1, was removed from chromosome. Moreover, despite mitotic chromatin condensation, the distant regulatory regions and promoters of transcriptionally competent globin gene loci are marked by a preserved histone code consisting in active histone modifications such as H3 acetylation, H3-K4 dimethylation and K79 dimethylation. Further analysis showed that other active genes are also locally marked by the preserved active histone code throughout mitotic inactivation of transcription. Conclusion Our results imply that certain kinds of specific protein factors and active histone modifications function as cellular memory markers for both competent and active genes during mitosis, and serve as a reactivated core for the resumption of transcription when the cells exit mitosis.

  7. Chromatin looping and eRNA transcription precede the transcriptional activation of gene in the β-globin locus.

    Science.gov (United States)

    Kim, Yea Woon; Lee, Sungkung; Yun, Jangmi; Kim, AeRi

    2015-03-18

    Enhancers are closely positioned with actively transcribed target genes by chromatin looping. Non-coding RNAs are often transcribed on active enhancers, referred to as eRNAs (enhancer RNAs). To explore the kinetics of enhancer-promoter looping and eRNA transcription during transcriptional activation, we induced the β-globin locus by chemical treatment and analysed cross-linking frequency between the β-globin gene and locus control region (LCR) and the amount of eRNAs transcribed on the LCR in a time course manner. The cross-linking frequency was increased after chemical induction but before the transcriptional activation of gene in the β-globin locus. Transcription of eRNAs was increased in concomitant with the increase in cross-linking frequency. These results show that chromatin looping and eRNA transcription precedes the transcriptional activation of gene. Concomitant occurrence of the two events suggests functional relationship between them.

  8. Neural Activation During Mental Rotation in Complete Androgen Insensitivity Syndrome : The Influence of Sex Hormones and Sex Chromosomes

    NARCIS (Netherlands)

    van Hemmen, Judy; Veltman, Dick J; Hoekzema, Elseline; Cohen-Kettenis, Peggy T; Dessens, Arianne B; Bakker, J.

    2016-01-01

    Sex hormones, androgens in particular, are hypothesized to play a key role in the sexual differentiation of the human brain. However, possible direct effects of the sex chromosomes, that is, XX or XY, have not been well studied in humans. Individuals with complete androgen insensitivity syndrome (CA

  9. Bidirectional Transcription Arises from Two Distinct Hubs of Transcription Factor Binding and Active Chromatin.

    Science.gov (United States)

    Scruggs, Benjamin S; Gilchrist, Daniel A; Nechaev, Sergei; Muse, Ginger W; Burkholder, Adam; Fargo, David C; Adelman, Karen

    2015-06-18

    Anti-sense transcription originating upstream of mammalian protein-coding genes is a well-documented phenomenon, but remarkably little is known about the regulation or function of anti-sense promoters and the non-coding RNAs they generate. Here we define at nucleotide resolution the divergent transcription start sites (TSSs) near mouse mRNA genes. We find that coupled sense and anti-sense TSSs precisely define the boundaries of a nucleosome-depleted region (NDR) that is highly enriched in transcription factor (TF) motifs. Notably, as the distance between sense and anti-sense TSSs increases, so does the size of the NDR, the level of signal-dependent TF binding, and gene activation. We further discover a group of anti-sense TSSs in macrophages with an enhancer-like chromatin signature. Interestingly, this signature identifies divergent promoters that are activated during immune challenge. We propose that anti-sense promoters serve as platforms for TF binding and establishment of active chromatin to further regulate or enhance sense-strand mRNA expression.

  10. The transcriptionally active regions in the genome of Bacillus subtilis

    DEFF Research Database (Denmark)

    Rasmussen, Simon; Nielsen, Henrik Bjørn; Jarmer, Hanne Østergaard

    2009-01-01

    The majority of all genes have so far been identified and annotated systematically through in silico gene finding. Here we report the finding of 3662 strand-specific transcriptionally active regions (TARs) in the genome of Bacillus subtilis by the use of tiling arrays. We have measured the genome...

  11. [Transcription activator-like effectors(TALEs)based genome engineering].

    Science.gov (United States)

    Zhao, Mei-Wei; Duan, Cheng-Li; Liu, Jiang

    2013-10-01

    Systematic reverse-engineering of functional genome architecture requires precise modifications of gene sequences and transcription levels. The development and application of transcription activator-like effectors(TALEs) has created a wealth of genome engineering possibilities. TALEs are a class of naturally occurring DNA-binding proteins found in the plant pathogen Xanthomonas species. The DNA-binding domain of each TALE typically consists of tandem 34-amino acid repeat modules rearranged according to a simple cipher to target new DNA sequences. Customized TALEs can be used for a wide variety of genome engineering applications, including transcriptional modulation and genome editing. Such "genome engineering" has now been established in human cells and a number of model organisms, thus opening the door to better understanding gene function in model organisms, improving traits in crop plants and treating human genetic disorders.

  12. Role of the HSP90-associated cochaperone p23 in enhancing activity of the androgen receptor and significance for prostate cancer.

    Science.gov (United States)

    Reebye, Vikash; Querol Cano, Laia; Lavery, Derek N; Brooke, Greg N; Powell, Sue M; Chotai, Deepa; Walker, Marjorie M; Whitaker, Hayley C; Wait, Robin; Hurst, Helen C; Bevan, Charlotte L

    2012-10-01

    Prostate tumor growth initially depends on androgens, which act via the androgen receptor (AR). Despite androgen ablation therapy, tumors eventually progress to a castrate-resistant stage in which the AR remains active. The mechanisms are poorly understood but it may be that changes in levels or activity of AR coregulators affect trafficking and activation of the receptor. A key stage in AR signaling occurs in the cytoplasm, where unliganded receptor is associated with the heat shock protein (HSP)90 foldosome complex. p23, a key component of this complex, is best characterized as a cochaperone for HSP90 but also has HSP90-independent activity and has been reported as having differential effects on the activity of different steroid receptors. Here we report that p23 increases activity of the AR, and this appears to involve steps both in the cytoplasm (increasing ligand-binding capacity, possibly via direct interaction with AR) and the nucleus (enhancing AR occupancy at target promoters). We show, for the first time, that AR and p23 can interact, perhaps directly, when HSP90 is not present in the same complex. The effects of p23 on AR activity are at least partly HSP90 independent because a mutant form of p23, unable to bind HSP90, nevertheless increases AR activity. In human prostate tumors, nuclear p23 was higher in malignant prostate cells compared with benign/normal cells, supporting the utility of p23 as a therapeutic target in prostate cancer.

  13. Human DJ-1-specific Transcriptional Activation of Tyrosine Hydroxylase Gene*

    Science.gov (United States)

    Ishikawa, Shizuma; Taira, Takahiro; Takahashi-Niki, Kazuko; Niki, Takeshi; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M. M.

    2010-01-01

    Loss-of-function mutation in the DJ-1 gene causes a subset of familial Parkinson disease. The mechanism underlying DJ-1-related selective vulnerability in the dopaminergic pathway is, however, not known. DJ-1 has multiple functions, including transcriptional regulation, and one of transcriptional target genes for DJ-1 is the tyrosine hydroxylase (TH) gene, the product of which is a key enzyme for dopamine biosynthesis. It has been reported that DJ-1 is a neuroprotective transcriptional co-activator that sequesters a transcriptional co-repressor polypyrimidine tract-binding protein-associated splicing factor (PSF) from the TH gene promoter. In this study, we found that knockdown of human DJ-1 by small interference RNA in human dopaminergic cell lines attenuated TH gene expression and 4-dihydroxy-l-phenylalanine production but that knockdown or knock-out of mouse DJ-1 in mouse cell lines or in mice did not affect such expression and TH activity. In reporter assays using the human TH gene promoter linked to the luciferase gene, stimulation of TH promoter activity was observed in human cells, but not mouse cells, that had been transfected with DJ-1. Although human DJ-1 and mouse DJ-1 were associated either with human or with mouse PSF, TH promoter activity inhibited by PSF was restored by human DJ-1 but not by mouse DJ-1. Chromatin immunoprecipitation assays revealed that the complex of PSF with DJ-1 bound to the human but not the mouse TH gene promoter. These results suggest a novel species-specific transcriptional regulation of the TH promoter by DJ-1 and one of the mechanisms for no reduction of TH in DJ-1-knock-out mice. PMID:20938049

  14. Intratumoral de novo steroid synthesis activates androgen receptor in castration-resistant prostate cancer and is upregulated by treatment with CYP17A1 inhibitors.

    Science.gov (United States)

    Cai, Changmeng; Chen, Sen; Ng, Patrick; Bubley, Glenn J; Nelson, Peter S; Mostaghel, Elahe A; Marck, Brett; Matsumoto, Alvin M; Simon, Nicholas I; Wang, Hongyun; Chen, Shaoyong; Balk, Steven P

    2011-10-15

    Relapse of castration-resistant prostate cancer (CRPC) that occurs after androgen deprivation therapy of primary prostate cancer can be mediated by reactivation of the androgen receptor (AR). One important mechanism mediating this AR reactivation is intratumoral conversion of the weak adrenal androgens DHEA and androstenedione into the AR ligands testosterone and dihydrotestosterone. DHEA and androstenedione are synthesized by the adrenals through the sequential actions of the cytochrome P450 enzymes CYP11A1 and CYP17A1, so that CYP17A1 inhibitors such as abiraterone are effective therapies for CRPC. However, the significance of intratumoral CYP17A1 and de novo androgen synthesis from cholesterol in CRPC, and the mechanisms contributing to CYP17A1 inhibitor resistance/relapse, remain to be determined. We report that AR activity in castration-resistant VCaP tumor xenografts can be restored through CYP17A1-dependent de novo androgen synthesis, and that abiraterone treatment of these xenografts imposes selective pressure for increased intratumoral expression of CYP17A1, thereby generating a mechanism for development of resistance to CYP17A1 inhibitors. Supporting the clinical relevance of this mechanism, we found that intratumoral expression of CYP17A1 was markedly increased in tumor biopsies from CRPC patients after CYP17A1 inhibitor therapy. We further show that CRPC cells expressing a progesterone responsive T877A mutant AR are not CYP17A1 dependent, but that AR activity in these cells is still steroid dependent and mediated by upstream CYP11A1-dependent intraturmoral pregnenolone/progesterone synthesis. Together, our results indicate that CRPCs resistant to CYP17A1 inhibition may remain steroid dependent and therefore responsive to therapies that can further suppress de novo intratumoral steroid synthesis.

  15. Validation and application of reporter gene assays for the determination of estrogenic and androgenic endocrine disruptor activity in sport supplements.

    Science.gov (United States)

    Plotan, Monika; Elliott, Christopher T; Oplatowska, Michalina; Connolly, Lisa

    2012-07-01

    Previously developed estrogen and androgen mammalian reporter gene assays (RGAs) were assessed for their potential use as a quantitative screening method in the detection of estrogenic and androgenic endocrine disruptors (EDs) in sport supplements. The validation of both RGAs coupled with dispersive solid phase extraction (dSPE) was performed in accordance with European Commission Decision EC/2002/6579 for biological screening methods. Decision limits (CCα) and detection capabilities (CCβ) were established for both the estrogen and androgen RGAs. All samples were compliant with CCα and CCβ in both bioassays. Recovery rates were 96 % for 17β-estradiol and 115 % for dihydrotestosterone as obtained in their corresponding RGA. Both estrogens and androgens were stable in samples for more than 3 weeks, when stored at -20 °C. Specificity, good repeatability (coefficients of variation (CV), 12-25 %), reproducibility and robustness of both bioassays were also observed. Four different ED modes of action were determined for estrogens and androgens in 53 sport supplements, using the validated RGAs. This study revealed that 89 % of the investigated sport supplements contained estrogenic EDs and 51 % contained androgenic compounds. In conclusion, both bioassays are suitable for sport supplement screening of estrogenic and androgenic EDs.

  16. Selective androgen receptor modulators: in pursuit of tissue-selective androgens.

    Science.gov (United States)

    Omwancha, Josephat; Brown, Terry R

    2006-10-01

    The androgen receptor mediates the androgenic and anabolic activity of the endogenous steroids testosterone and 5alpha-dihydrotestosterone. Current knowledge of the androgen receptor protein structure, and the molecular mechanisms surrounding the binding properties and activities of agonists and antagonists has led to the design and development of novel nonsteroidal ligands with selected tissue-specific androgen receptor agonist and antagonist activities. The activity of these compounds, termed selective androgen receptor modulators (SARMs), is directed toward the maintenance or enhancement of anabolic effects on bone and muscle with minimal androgenic effects on prostate growth. SARMs are of potential therapeutic value in the treatment of male hypogonadism, osteoporosis, frailty and muscle wasting, burn injury and would healing, anemia, mood and depression, benign prostatic hyperplasia and prostate cancer.

  17. A transcription activator-like effector toolbox for genome engineering.

    Science.gov (United States)

    Sanjana, Neville E; Cong, Le; Zhou, Yang; Cunniff, Margaret M; Feng, Guoping; Zhang, Feng

    2012-01-05

    Transcription activator-like effectors (TALEs) are a class of naturally occurring DNA-binding proteins found in the plant pathogen Xanthomonas sp. The DNA-binding domain of each TALE consists of tandem 34-amino acid repeat modules that can be rearranged according to a simple cipher to target new DNA sequences. Customized TALEs can be used for a wide variety of genome engineering applications, including transcriptional modulation and genome editing. Here we describe a toolbox for rapid construction of custom TALE transcription factors (TALE-TFs) and nucleases (TALENs) using a hierarchical ligation procedure. This toolbox facilitates affordable and rapid construction of custom TALE-TFs and TALENs within 1 week and can be easily scaled up to construct TALEs for multiple targets in parallel. We also provide details for testing the activity in mammalian cells of custom TALE-TFs and TALENs using quantitative reverse-transcription PCR and Surveyor nuclease, respectively. The TALE toolbox described here will enable a broad range of biological applications.

  18. Activating transcription factor 4 regulates osteoclast differentiation in mice.

    Science.gov (United States)

    Cao, Huiling; Yu, Shibing; Yao, Zhi; Galson, Deborah L; Jiang, Yu; Zhang, Xiaoyan; Fan, Jie; Lu, Binfeng; Guan, Youfei; Luo, Min; Lai, Yumei; Zhu, Yibei; Kurihara, Noriyoshi; Patrene, Kenneth; Roodman, G David; Xiao, Guozhi

    2010-08-01

    Activating transcription factor 4 (ATF4) is a critical transcription factor for osteoblast (OBL) function and bone formation; however, a direct role in osteoclasts (OCLs) has not been established. Here, we targeted expression of ATF4 to the OCL lineage using the Trap promoter or through deletion of Atf4 in mice. OCL differentiation was drastically decreased in Atf4-/- bone marrow monocyte (BMM) cultures and bones. Coculture of Atf4-/- BMMs with WT OBLs or a high concentration of RANKL failed to restore the OCL differentiation defect. Conversely, Trap-Atf4-tg mice displayed severe osteopenia with dramatically increased osteoclastogenesis and bone resorption. We further showed that ATF4 was an upstream activator of the critical transcription factor Nfatc1 and was critical for RANKL activation of multiple MAPK pathways in OCL progenitors. Furthermore, ATF4 was crucial for M-CSF induction of RANK expression on BMMs, and lack of ATF4 caused a shift in OCL precursors to macrophages. Finally, ATF4 was largely modulated by M-CSF signaling and the PI3K/AKT pathways in BMMs. These results demonstrate that ATF4 plays a direct role in regulating OCL differentiation and suggest that it may be a therapeutic target for treating bone diseases associated with increased OCL activity.

  19. Assembly of a Notch transcriptional activation complex requires multimerization.

    Science.gov (United States)

    Vasquez-Del Carpio, Rodrigo; Kaplan, Fred M; Weaver, Kelly L; VanWye, Jeffrey D; Alves-Guerra, Marie-Clotilde; Robbins, David J; Capobianco, Anthony J

    2011-04-01

    Notch transmembrane receptors direct essential cellular processes, such as proliferation and differentiation, through direct cell-to-cell interactions. Inappropriate release of the intracellular domain of Notch (N(ICD)) from the plasma membrane results in the accumulation of deregulated nuclear N(ICD) that has been linked to human cancers, notably T-cell acute lymphoblastic leukemia (T-ALL). Nuclear N(ICD) forms a transcriptional activation complex by interacting with the coactivator protein Mastermind-like 1 and the DNA binding protein CSL (for CBF-1/Suppressor of Hairless/Lag-1) to regulate target gene expression. Although it is well understood that N(ICD) forms a transcriptional activation complex, little is known about how the complex is assembled. In this study, we demonstrate that N(ICD) multimerizes and that these multimers function as precursors for the stepwise assembly of the Notch activation complex. Importantly, we demonstrate that the assembly is mediated by N(ICD) multimers interacting with Skip and Mastermind. These interactions form a preactivation complex that is then resolved by CSL to form the Notch transcriptional activation complex on DNA.

  20. Activating transcription factor 4 regulates osteoclast differentiation in mice

    Science.gov (United States)

    Cao, Huiling; Yu, Shibing; Yao, Zhi; Galson, Deborah L.; Jiang, Yu; Zhang, Xiaoyan; Fan, Jie; Lu, Binfeng; Guan, Youfei; Luo, Min; Lai, Yumei; Zhu, Yibei; Kurihara, Noriyoshi; Patrene, Kenneth; Roodman, G. David; Xiao, Guozhi

    2010-01-01

    Activating transcription factor 4 (ATF4) is a critical transcription factor for osteoblast (OBL) function and bone formation; however, a direct role in osteoclasts (OCLs) has not been established. Here, we targeted expression of ATF4 to the OCL lineage using the Trap promoter or through deletion of Atf4 in mice. OCL differentiation was drastically decreased in Atf4–/– bone marrow monocyte (BMM) cultures and bones. Coculture of Atf4–/– BMMs with WT OBLs or a high concentration of RANKL failed to restore the OCL differentiation defect. Conversely, Trap-Atf4-tg mice displayed severe osteopenia with dramatically increased osteoclastogenesis and bone resorption. We further showed that ATF4 was an upstream activator of the critical transcription factor Nfatc1 and was critical for RANKL activation of multiple MAPK pathways in OCL progenitors. Furthermore, ATF4 was crucial for M-CSF induction of RANK expression on BMMs, and lack of ATF4 caused a shift in OCL precursors to macrophages. Finally, ATF4 was largely modulated by M-CSF signaling and the PI3K/AKT pathways in BMMs. These results demonstrate that ATF4 plays a direct role in regulating OCL differentiation and suggest that it may be a therapeutic target for treating bone diseases associated with increased OCL activity. PMID:20628199

  1. Engineering prokaryotic transcriptional activators as metabolite biosensors in yeast

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise; Snoek, Tim; Kildegaard, Kanchana Rueksomtawin

    2016-01-01

    Whole-cell biocatalysts have proven a tractable path toward sustainable production of bulk and fine chemicals. Yet the screening of libraries of cellular designs to identify best-performing biocatalysts is most often a low-throughput endeavor. For this reason, the development of biosensors enabling...... real-time monitoring of production has attracted attention. Here we applied systematic engineering of multiple parameters to search for a general biosensor design in the budding yeast Saccharomyces cerevisiae based on small-molecule binding transcriptional activators from the prokaryote superfamily...... of LysR-type transcriptional regulators (LTTRs). We identified a design supporting LTTR-dependent activation of reporter gene expression in the presence of cognate small-molecule inducers. As proof of principle, we applied the biosensors for in vivo screening of cells producing naringenin or cis...

  2. Prostate specific antigen gene expression in androgen insensitive prostate carcinoma subculture cell line.

    Science.gov (United States)

    Tsui, Ke-Hung; Feng, Tsui-Hsia; Chung, Li-Chuan; Chao, Chun-Hsiang; Chang, Phei-Lang; Juang, Horng-Heng

    2008-01-01

    A novel prostate cancer cell line (PC-J) was isolated from an androgen independent non-prostate specific antigen (non-PSA) producing carcinoma cell line. The homologous correlation between PC-J and PC-3 was determined by short tandem repeat analysis. The PSA promoter activity was detected by transient expression assay in the PC-J and LNCaP cells but not in androgen insensitive PC-3 cells. When the PC-J cells were cotransfected with androgen receptor, androgen receptor coactivators and PSA reporter vector cells, the reporter assays indicated that nuclear receptor coactivator 4 (NCOA4) but not androgen receptor activator 24 (ARA24) increased the sensitivity and maximum stimulation of dihydrotestosterone (DHT)-inducing PSA promoter activity. The RT-PCR assays revealed that the expression of several tumor markers, including interleukin-6, prostate stem cell antigen (PSCA), prostate epithelium-specific Ets transcription factor (PDEF) and matriptase, was lower in the PC-J cells than in the PC-3 cells. This cell model elucidated the regulation of PSA expression and enabled comparison of the gene profile at different stages of metastasis in prostatic carcinoma.

  3. A new highly specific and robust yeast androgen bioassay for the detection of agonists and antagonists.

    Science.gov (United States)

    Bovee, Toine F H; Helsdingen, Richard J R; Hamers, Astrid R M; van Duursen, Majorie B M; Nielen, Michel W F; Hoogenboom, Ron L A P

    2007-11-01

    Public concern about the presence of natural and anthropogenic compounds which affect human health by modulating normal endocrine functions is continuously growing. Fast and simple high-throughput screening methods for the detection of hormone activities are thus indispensable. During the last two decades, a panel of different in vitro assays has been developed, mainly for compounds with an estrogenic mode of action. Here we describe the development of an androgen transcription activation assay that is easy to use in routine screening. Recombinant yeast cells were constructed that express the human androgen receptor and yeast enhanced green fluorescent protein (yEGFP), the latter in response to androgens. Compared with other reporters, the yEGFP reporter protein is very convenient because it is directly measurable in intact living cells, i.e., cell wall disruption and the addition of a substrate are not needed. When yeast was exposed to 17beta-testosterone, the concentration where half-maximal activation is reached (EC(50)) was 50 nM. The relative androgenic potencies, defined as the ratio between the EC(50) of 17beta-testosterone and the EC(50) of the compound, of 5alpha-dihydrotestosterone, methyltrienolone, and 17beta-boldenone are 2.3, 1.4, and 0.15 respectively. The results presented in this paper demonstrate that this new yeast androgen bioassay is fast, sensitive, and very specific and also suited to detect compounds that have an antiandrogenic mode of action.

  4. Oncogenes Activate an Autonomous Transcriptional Regulatory Circuit That Drives Glioblastoma

    Directory of Open Access Journals (Sweden)

    Dinesh K. Singh

    2017-01-01

    Full Text Available Efforts to identify and target glioblastoma (GBM drivers have primarily focused on receptor tyrosine kinases (RTKs. Clinical benefits, however, have been elusive. Here, we identify an SRY-related box 2 (SOX2 transcriptional regulatory network that is independent of upstream RTKs and capable of driving glioma-initiating cells. We identified oligodendrocyte lineage transcription factor 2 (OLIG2 and zinc-finger E-box binding homeobox 1 (ZEB1, which are frequently co-expressed irrespective of driver mutations, as potential SOX2 targets. In murine glioma models, we show that different combinations of tumor suppressor and oncogene mutations can activate Sox2, Olig2, and Zeb1 expression. We demonstrate that ectopic co-expression of the three transcription factors can transform tumor-suppressor-deficient astrocytes into glioma-initiating cells in the absence of an upstream RTK oncogene. Finally, we demonstrate that the transcriptional inhibitor mithramycin downregulates SOX2 and its target genes, resulting in markedly reduced proliferation of GBM cells in vivo.

  5. Oncogenes Activate an Autonomous Transcriptional Regulatory Circuit That Drives Glioblastoma.

    Science.gov (United States)

    Singh, Dinesh K; Kollipara, Rahul K; Vemireddy, Vamsidara; Yang, Xiao-Li; Sun, Yuxiao; Regmi, Nanda; Klingler, Stefan; Hatanpaa, Kimmo J; Raisanen, Jack; Cho, Steve K; Sirasanagandla, Shyam; Nannepaga, Suraj; Piccirillo, Sara; Mashimo, Tomoyuki; Wang, Shan; Humphries, Caroline G; Mickey, Bruce; Maher, Elizabeth A; Zheng, Hongwu; Kim, Ryung S; Kittler, Ralf; Bachoo, Robert M

    2017-01-24

    Efforts to identify and target glioblastoma (GBM) drivers have primarily focused on receptor tyrosine kinases (RTKs). Clinical benefits, however, have been elusive. Here, we identify an SRY-related box 2 (SOX2) transcriptional regulatory network that is independent of upstream RTKs and capable of driving glioma-initiating cells. We identified oligodendrocyte lineage transcription factor 2 (OLIG2) and zinc-finger E-box binding homeobox 1 (ZEB1), which are frequently co-expressed irrespective of driver mutations, as potential SOX2 targets. In murine glioma models, we show that different combinations of tumor suppressor and oncogene mutations can activate Sox2, Olig2, and Zeb1 expression. We demonstrate that ectopic co-expression of the three transcription factors can transform tumor-suppressor-deficient astrocytes into glioma-initiating cells in the absence of an upstream RTK oncogene. Finally, we demonstrate that the transcriptional inhibitor mithramycin downregulates SOX2 and its target genes, resulting in markedly reduced proliferation of GBM cells in vivo.

  6. Bipartite functions of the CREB co-activators selectively direct alternative splicing or transcriptional activation.

    Science.gov (United States)

    Amelio, Antonio L; Caputi, Massimo; Conkright, Michael D

    2009-09-16

    The CREB regulated transcription co-activators (CRTCs) regulate many biological processes by integrating and converting environmental inputs into transcriptional responses. Although the mechanisms by which CRTCs sense cellular signals are characterized, little is known regarding how CRTCs contribute to the regulation of cAMP inducible genes. Here we show that these dynamic regulators, unlike other co-activators, independently direct either pre-mRNA splice-site selection or transcriptional activation depending on the cell type or promoter context. Moreover, in other scenarios, the CRTC co-activators coordinately regulate transcription and splicing. Mutational analyses showed that CRTCs possess distinct functional domains responsible for regulating either pre-mRNA splicing or transcriptional activation. Interestingly, the CRTC1-MAML2 oncoprotein lacks the splicing domain and is incapable of altering splice-site selection despite robustly activating transcription. The differential usage of these distinct domains allows CRTCs to selectively mediate multiple facets of gene regulation, indicating that co-activators are not solely restricted to coordinating alternative splicing with increase in transcriptional activity.

  7. Development of an androgen reporter gene assay (AR-LUX) utilizing a human cell line with an endogenously regulated androgen receptor.

    Science.gov (United States)

    Blankvoort, B M; de Groene, E M; van Meeteren-Kreikamp, A P; Witkamp, R F; Rodenburg, R J; Aarts, J M

    2001-11-01

    The aim of the work described in this report is to develop and characterize a cell-based androgen reporter assay. For this purpose, the androgen receptor (AR) expressing human breast cancer cell line T47D was stably transfected with a luciferase gene under transcriptional control of the PB-ARE-2 androgen response element. The application of this cell line in an endogenous Androgen Receptor-mediated LUciferase eXpression assay (AR-LUX) was validated. An EC50 value of 86 pM was determined for the standard androgen R1881 with a detection limit of 46 pM. Other androgens like dihydrotestosterone, 17beta-trenbolone, and bolasterone also induced luciferase expression, while anti-androgens suppressed these responses. As expected, AR-mediated responses were also elicited by high concentrations of the steroids progesterone, 17beta-estradiol, d-aldosterone, and dexamethasone, with observed EC50 values 10 to 350,000 times higher than that for R1881. A unique feature of the AR-LUX assay is that effects on modulation of active endogenous AR-levels are reliably reflected in the luciferase induction response, as exemplified by vitamin D, all-trans-retinoic acid, epigallocatechin gallate, and forskolin. This feature is especially useful when assessing complex mixtures, e.g., environmental samples or natural compound libraries. From these data it is concluded that the AR-LUX assay is a reliable in vitro test system for the detection and quantification of AR-mediated biological effects. The 96-well plate format makes the assay particularly suitable for high-throughput screening.

  8. Aberrant activation of the androgen receptor by NF-kappaB2/p52 in prostate cancer cells.

    Science.gov (United States)

    Nadiminty, Nagalakshmi; Lou, Wei; Sun, Meng; Chen, Jun; Yue, Jiao; Kung, Hsing-Jien; Evans, Christopher P; Zhou, Qinghua; Gao, Allen C

    2010-04-15

    Prostate cancer initiation and progression are uniquely dependent on the androgen receptor (AR). Even when the cancer progresses to a castration-resistant stage, AR signaling remains active via a variety of mechanisms. In the present study, we showed that NF-kappaB/p52 can activate the AR, resulting in increased transactivation of AR-responsive genes, such as PSA and NKX3.1, in a ligand-independent manner. NF-kappaB2/p52 enhances nuclear translocation and activation of AR by interacting with its NH(2)-terminal domain and enhances the recruitment of coactivators such as p300 to the promoters of AR-dependent genes. These results were confirmed in three different prostate cancer cell lines: LAPC-4 (wild-type AR), LNCaP (mutant AR), and C4-2 (castration resistant). Transfection of p52 into LAPC-4 and LNCaP cells (which express low levels of p52) showed increased activation of the endogenous AR. Downregulation of endogenous p52 in C4-2 cells resulted in abrogation of AR constitutive activation. Comparison of the relative effects of p52 and p65 (RelA) showed that p52, but not p65, could activate the AR. Collectively, these findings, together with previous reports that the levels of NF-kappaB2/p52 are elevated in prostate cancer cells and that active NF-kappaB2/p52 promotes prostate cancer cell growth in vitro and in vivo, suggest that NF-kappaB2/p52 may play a critical role in the progression of castration-resistant prostate cancer.

  9. Androgen Receptor Antagonists and Anti-Prostate Cancer Activities of Some Newly Synthesized Substituted Fused Pyrazolo-, Triazolo- and Thiazolo-Pyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Saleh A. Bahashwan

    2014-11-01

    Full Text Available A series of substituted pyrazole, triazole and thiazole derivatives (2–13 were synthesized from 1-(naphtho[1,2-d]thiazol-2-ylhydrazine as starting material and evaluated as androgen receptor antagonists and anti-prostate cancer agents. The newly synthesized compounds showed potent androgen receptor antagonists and anti-prostate cancer activities with low toxicity (lethal dose 50 (LD50 comparable to Bicalutamide as reference drug. The structures of newly synthesized compounds were confirmed by IR, 1H-NMR, 13C-NMR, and MS spectral data and elemental analysis. The detailed synthesis, spectroscopic data, LD50 values and pharmacological activities of the synthesized compounds are reported.

  10. Adenylyl cyclase activating polypeptide reduces phosphorylation and toxicity of the polyglutamine-expanded androgen receptor in spinobulbar muscular atrophy.

    Science.gov (United States)

    Polanco, Maria Josè; Parodi, Sara; Piol, Diana; Stack, Conor; Chivet, Mathilde; Contestabile, Andrea; Miranda, Helen C; Lievens, Patricia M-J; Espinoza, Stefano; Jochum, Tobias; Rocchi, Anna; Grunseich, Christopher; Gainetdinov, Raul R; Cato, Andrew C B; Lieberman, Andrew P; La Spada, Albert R; Sambataro, Fabio; Fischbeck, Kenneth H; Gozes, Illana; Pennuto, Maria

    2016-12-21

    Spinobulbar muscular atrophy (SBMA) is an X-linked neuromuscular disease caused by polyglutamine (polyQ) expansion in the androgen receptor (AR) gene. SBMA belongs to the family of polyQ diseases, which are fatal neurodegenerative disorders mainly caused by protein-mediated toxic gain-of-function mechanisms and characterized by deposition of misfolded proteins in the form of aggregates. The neurotoxicity of the polyQ proteins can be modified by phosphorylation at specific sites, thereby providing the rationale for the development of disease-specific treatments. We sought to identify signaling pathways that modulate polyQ-AR phosphorylation for therapy development. We report that cyclin-dependent kinase 2 (CDK2) phosphorylates polyQ-AR specifically at Ser(96) Phosphorylation of polyQ-AR by CDK2 increased protein stabilization and toxicity and is negatively regulated by the adenylyl cyclase (AC)/protein kinase A (PKA) signaling pathway. To translate these findings into therapy, we developed an analog of pituitary adenylyl cyclase activating polypeptide (PACAP), a potent activator of the AC/PKA pathway. Chronic intranasal administration of the PACAP analog to knock-in SBMA mice reduced Ser(96) phosphorylation, promoted polyQ-AR degradation, and ameliorated disease outcome. These results provide proof of principle that noninvasive therapy based on the use of PACAP analogs is a therapeutic option for SBMA.

  11. A new highly specific and robust yeast androgen bioassay for the detection of agonists and antagonists

    OpenAIRE

    Bovee, T. F. H.; Helsdingen, J.R.; Hamers, A.R.M.; Duursen, van, M.; Nielen, M. W. F.; Hoogenboom, L.A.P.

    2007-01-01

    Public concern about the presence of natural and anthropogenic compounds which affect human health by modulating normal endocrine functions is continuously growing. Fast and simple high-throughput screening methods for the detection of hormone activities are thus indispensable. During the last two decades, a panel of different in vitro assays has been developed, mainly for compounds with an estrogenic mode of action. Here we describe the development of an androgen transcription activation ass...

  12. New Insights into the Androgen-Targeted Therapies and Epigenetic Therapies in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Abhijit M. Godbole

    2011-01-01

    Full Text Available Prostate cancer is the most common cancer in men in the United States, and it is the second leading cause of cancer-related death in American men. The androgen receptor (AR, a receptor of nuclear family and a transcription factor, is the most important target in this disease. While most efforts in the clinic are currently directed at lowering levels of androgens that activate AR, resistance to androgen deprivation eventually develops. Most prostate cancer deaths are attributable to this castration-resistant form of prostate cancer (CRPC. Recent work has shed light on the importance of epigenetic events including facilitation of AR signaling by histone-modifying enzymes, posttranslational modifications of AR such as sumoylation. Herein, we provide an overview of the structure of human AR and its key structural domains that can be used as targets to develop novel antiandrogens. We also summarize recent findings about the antiandrogens and the epigenetic factors that modulate the action of AR.

  13. Transcriptional activation of TFEB/ZKSCAN3 target genes underlies enhanced autophagy in spinobulbar muscular atrophy.

    Science.gov (United States)

    Chua, Jason P; Reddy, Satya L; Merry, Diane E; Adachi, Hiroaki; Katsuno, Masahisa; Sobue, Gen; Robins, Diane M; Lieberman, Andrew P

    2014-03-01

    Spinobulbar muscular atrophy (SBMA) is an inherited neuromuscular disorder caused by the expansion of a CAG repeat encoding a polyglutamine tract in exon 1 of the androgen receptor (AR) gene. SBMA demonstrates androgen-dependent toxicity due to unfolding and aggregation of the mutant protein. There are currently no disease-modifying therapies, but of increasing interest for therapeutic targeting is autophagy, a highly conserved cellular process mediating protein quality control. We have previously shown that genetic manipulations inhibiting autophagy diminish skeletal muscle atrophy and extend the lifespan of AR113Q knock-in mice. In contrast, manipulations inducing autophagy worsen muscle atrophy, suggesting that chronic, aberrant upregulation of autophagy contributes to pathogenesis. Since the degree to which autophagy is altered in SBMA and the mechanisms responsible for such alterations are incompletely defined, we sought to delineate autophagic status in SBMA using both cellular and mouse models. Here, we confirm that autophagy is induced in cellular and knock-in mouse models of SBMA and show that the transcription factors transcription factor EB (TFEB) and ZKSCAN3 operate in opposing roles to underlie these changes. We demonstrate upregulation of TFEB target genes in skeletal muscle from AR113Q male mice and SBMA patients. Furthermore, we observe a greater response in AR113Q mice to physiological stimulation of autophagy by both nutrient starvation and exercise. Taken together, our results indicate that transcriptional signaling contributes to autophagic dysregulation and provides a mechanistic framework for the pathologic increase of autophagic responsiveness in SBMA.

  14. Identification of Post-Transcriptional Modulators of Breast Cancer Transcription Factor Activity Using MINDy

    Science.gov (United States)

    Campbell, Thomas M.; Castro, Mauro A. A.; Ponder, Bruce A. J.

    2016-01-01

    We have recently identified transcription factors (TFs) that are key drivers of breast cancer risk. To better understand the pathways or sub-networks in which these TFs mediate their function we sought to identify upstream modulators of their activity. We applied the MINDy (Modulator Inference by Network Dynamics) algorithm to four TFs (ESR1, FOXA1, GATA3 and SPDEF) that are key drivers of estrogen receptor-positive (ER+) breast cancer risk, as well as cancer progression. Our computational analysis identified over 500 potential modulators. We assayed 189 of these and identified 55 genes with functional characteristics that were consistent with a role as TF modulators. In the future, the identified modulators may be tested as potential therapeutic targets, able to alter the activity of TFs that are critical in the development of breast cancer. PMID:27997592

  15. Post-translational regulation of Oct4 transcriptional activity.

    Directory of Open Access Journals (Sweden)

    Jonathan P Saxe

    Full Text Available Oct4 is a key component of the molecular circuitry which regulates embryonic stem cell proliferation and differentiation. It is essential for maintenance of undifferentiated, pluripotent cell populations, and accomplishes these tasks by binding DNA in multiple heterodimer and homodimer configurations. Very little is known about how formation of these complexes is regulated, or the mechanisms through which Oct4 proteins respond to complex extracellular stimuli which regulate pluripotency. Here, we provide evidence for a phosphorylation-based mechanism which regulates specific Oct4 homodimer conformations. Point mutations of a putative phosphorylation site can specifically abrogate transcriptional activity of a specific homodimer assembly, with little effect on other configurations. Moreover, we performed bioinformatic predictions to identify a subset of Oct4 target genes which may be regulated by this specific assembly, and show that altering Oct4 protein levels affects transcription of Oct4 target genes which are regulated by this assembly but not others. Finally, we identified several signaling pathways which may mediate this phosphorylation and act in combination to regulate Oct4 transcriptional activity and protein stability. These results provide a mechanism for rapid and reversible alteration of Oct4 transactivation potential in response to extracellular signals.

  16. Thioredoxin interacting protein inhibits hypoxia-inducible factor transcriptional activity

    Science.gov (United States)

    Farrell, Michael R; Rogers, Lynette K; Liu, Yusen; Welty, Stephen E; Tipple, Trent E

    2010-01-01

    Vascular endothelial growth factor (VEGF) is required for proper lung development and is transcriptionally regulated in alveolar epithelial cells by hypoxia inducible factor (HIF). Previous findings in a newborn mouse model of bronchopulmonary dysplasia (BPD) suggest that thioredoxin interacting protein (Txnip) is a novel regulator of VEGF expression. The present studies were designed to test the hypothesis that Txnip negatively regulates VEGF through effects on HIF-mediated gene expression. To test this hypothesis, we first examined the levels of VEGF and Txnip protein in the lungs of 1 day-old newborn and E19 embryos and detected a significant inverse correlation. To elucidate the mechanisms underlying this relationship, we studied the effects of Txnip overexpression on HIF-mediated transcription using murine lung epithelial (MLE-12) cells. Overexpression of Txnip inhibited HIF-mediated reporter activity in both hypoxia and room air. Suppression of HIF activity by Txnip appeared to be independent of the ability of Txnip to bind to thioredoxin. Thus, our studies support a model in which Txnip is a potentially critical regulator of HIF-mediated gene transcription in the murine lung. Alterations in Txnip expression could alter lung VEGF expression in prematurely born human infants and contribute to the development of BPD. PMID:20692333

  17. In Vitro Androgen Bioassays as a Detection Method for Designer Androgens

    Directory of Open Access Journals (Sweden)

    Alison K. Heather

    2013-02-01

    Full Text Available Androgens are the class of sex steroids responsible for male sexual characteristics, including increased muscle mass and decreased fat mass. Illicit use of androgen doping can be an attractive option for those looking to enhance sporting performance and/or physical appearance. The use of in vitro bioassays to detect androgens, especially designer or proandrogens, is becoming increasingly important in combating androgen doping associated with nutritional supplements. The nutritional sports supplement market has grown rapidly throughout the past decade. Many of these supplements contain androgens, designer androgens or proandrogens. Many designer or proandrogens cannot be detected by the standard highly-sensitive screening methods such as gas chromatography-mass spectrometry because their chemical structure is unknown. However, in vitro androgen bioassays can detect designer and proandrogens as these assays are not reliant on knowing the chemical structure but instead are based on androgen receptor activation. For these reasons, it may be advantageous to use routine androgen bioassay screening of nutraceutical samples to help curb the increasing problem of androgen doping.

  18. Looking beyond Androgen Receptor Signaling in the Treatment of Advanced Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Benjamin Sunkel

    2014-01-01

    Full Text Available This review will provide a description of recent efforts in our laboratory contributing to a general goal of identifying critical determinants of prostate cancer growth in both androgen-dependent and -independent contexts. Important outcomes to date have indicated that the sustained activation of AR transcriptional activity in castration-resistant prostate cancer (CRPC cells results in a gene expression profile separate from the androgen-responsive profile of androgen-dependent prostate cancer (ADPC cells. Contributing to this reprogramming is enhanced FoxA1 recruitment of AR to G2/M phase target gene loci and the enhanced chromatin looping of CRPC-specific gene regulatory elements facilitated by PI3K/Akt-phosphorylated MED1. We have also observed a role for FoxA1 beyond AR signaling in driving G1/S phase cell cycle progression that relies on interactions with novel collaborators MYBL2 and CREB1. Finally, we describe an in-depth mechanism of GATA2-mediated androgen-responsive gene expression in both ADPC and CRPC cells. Altogether these efforts provide evidence to support the development of novel prostate cancer therapeutics that address downstream targets of AR activity as well as AR-independent drivers of disease-relevant transcription programs.

  19. An Ikaros Promoter Element with Dual Epigenetic and Transcriptional Activities.

    Science.gov (United States)

    Perotti, Elizabeth A; Georgopoulos, Katia; Yoshida, Toshimi

    2015-01-01

    Ikaros DNA binding factor plays critical roles in lymphocyte development. Changes in Ikaros expression levels during lymphopoiesis are controlled by redundant but also unique regulatory elements of its locus that are critical for this developmental process. We have recently shown that Ikaros binds its own locus in thymocytes in vivo. Here, we evaluated the role of an Ikaros binding site within its major lympho-myeloid promoter. We identified an Ikaros/Ets binding site within a promoter sub-region that was highly conserved in mouse and human. Deletion of this binding site increased the percentage of the reporter-expressing mouse lines, indicating that its loss provided a more permissive chromatin environment. However, once transcription was established, the lack of this site decreased transcriptional activity. These findings implicate a dual role for Ikaros/Ets1 binding on Ikzf1 expression that is exerted at least through its promoter.

  20. An Ikaros Promoter Element with Dual Epigenetic and Transcriptional Activities.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Perotti

    Full Text Available Ikaros DNA binding factor plays critical roles in lymphocyte development. Changes in Ikaros expression levels during lymphopoiesis are controlled by redundant but also unique regulatory elements of its locus that are critical for this developmental process. We have recently shown that Ikaros binds its own locus in thymocytes in vivo. Here, we evaluated the role of an Ikaros binding site within its major lympho-myeloid promoter. We identified an Ikaros/Ets binding site within a promoter sub-region that was highly conserved in mouse and human. Deletion of this binding site increased the percentage of the reporter-expressing mouse lines, indicating that its loss provided a more permissive chromatin environment. However, once transcription was established, the lack of this site decreased transcriptional activity. These findings implicate a dual role for Ikaros/Ets1 binding on Ikzf1 expression that is exerted at least through its promoter.

  1. In vitro evaluation of oestrogenic/androgenic activity of the serum organochlorine pesticide mixtures previously described in a breast cancer case–control study

    Energy Technology Data Exchange (ETDEWEB)

    Rivero, Javier; Luzardo, Octavio P., E-mail: octavio.perez@ulpgc.es; Henríquez-Hernández, Luis A.; Machín, Rubén P.; Pestano, José; Zumbado, Manuel; Boada, Luis D.; Camacho, María; Valerón, Pilar F.

    2015-12-15

    Some organochlorine pesticides (OCs) have been individually linked to breast cancer (BC) because they exert oestrogenic effects on mammary cells. However, humans are environmentally exposed to more or less complex mixtures of these organochlorines, and the biological effects of these mixtures must be elucidated. In this work we evaluated the in vitro effects exerted on human BC cells by the OC mixtures that were most frequently detected in two groups of women who participated in a BC case–control study developed in Spain: healthy women and women diagnosed with BC. The cytotoxicity, oestrogenicity, and androgenicity of the most prevalent OC mixtures found in healthy women (H-mixture) and in BC patients (BC-mixture) were tested at concentrations that resembled those found in the serum of the evaluated women. Our results showed that both OC mixtures presented a similar oestrogenic activity and effect on cell viability, but BC-mixture showed an additional anti-androgenic effect. These results indicate that although the proliferative effect exerted by these mixtures on human breast cells seems to depend mainly on their oestrogenic action, the BC-mixture might additionally induce cell proliferation due to its anti-androgenic activity, therefore increasing the carcinogenic potential of this mixture. The findings of this study demonstrate that subtle variations in the composition of a mixture may induce relevant changes in its biological action. - Highlights: • E-screen and A-screen of two mixtures of organochlorine pesticides (OCP) • Assay concentrations based on a previous breast cancer case–control study • Only non-cytotoxic concentrations assayed • Both OCP mixtures induce proliferation mediated by oestrogen receptor. • OCP mixture of breast cancer patients exhibits additional androgenic activity.

  2. Male-dominant activation of rat renal organic anion transporter 1 (Oat1 and 3 (Oat3 expression by transcription factor BCL6.

    Directory of Open Access Journals (Sweden)

    Waja Wegner

    Full Text Available BACKGROUND: Organic anion transporters 1 (Oat1 and 3 (Oat3 mediate the transport of organic anions, including frequently prescribed drugs, across cell membranes in kidney proximal tubule cells. In rats, these transporters are known to be male-dominant and testosterone-dependently expressed. The molecular mechanisms that are involved in the sex-dependent expression are unknown. Our aim was to identify genes that show a sex-dependent expression and could be involved in male-dominant regulation of Oat1 and Oat3. METHODOLOGY/PRINCIPAL FINDINGS: Promoter activities of Oat1 and Oat3 were analyzed using luciferase assays. Expression profiling was done using a SurePrint G3 rat GE 8 × 60K microarray. RNA was isolated from renal cortical slices of four adult rats per sex. To filter the achieved microarray data for genes expressed in proximal tubule cells, transcription database alignment was carried out. We demonstrate that predicted androgen response elements in the promoters of Oat1 and Oat3 are not functional when the promoters were expressed in OK cells. Using microarray analyses we analyzed 17,406 different genes. Out of these genes, 56 exhibit a sex-dependent expression in rat proximal tubule cells. As genes potentially involved in the regulation of Oat1 and Oat3 expression, we identified, amongst others, the male-dominant hydroxysteroid (17-beta dehydrogenase 1 (Hsd17b1, B-cell CLL/lymphoma 6 (BCL6, and polymerase (RNA III (DNA directed polypeptide G (Polr3g. Moreover, our results revealed that the transcription factor BCL6 activates promoter constructs of Oat1 and Oat3. CONCLUSION: The results indicate that the male-dominant expression of both transporters, Oat1 and Oat3, is possibly not directly regulated by the classical androgen receptor mediated transcriptional pathway but appears to be regulated by the transcription factor BCL6.

  3. Peroxisome proliferator-activated receptor gamma (PPARγ) in brown trout: Interference of estrogenic and androgenic inputs in primary hepatocytes.

    Science.gov (United States)

    Lopes, Célia; Madureira, Tânia Vieira; Ferreira, Nádia; Pinheiro, Ivone; Castro, L Filipe C; Rocha, Eduardo

    2016-09-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) is a pivotal regulator of lipid and glucose metabolism in vertebrates. Here, we isolated and characterized for the first time the PPARγ gene from brown trout (Salmo trutta f. fario). Hormones have been reported to interfere with the regulatory function of PPARγ in various organisms, albeit with little focus on fish. Thus, primary hepatocytes isolated from juveniles of brown trout were exposed to 1, 10 and 50μM of ethinylestradiol (EE2) or testosterone (T). A significant (3 fold) decrease was obtained in response to 50μM of EE2 and to 10 and 50μM of T (13 and 14 folds), while a 3 fold increase was observed at 1μM of EE2. Therefore, trout PPARγ seems a target for natural/synthetic compounds with estrogenic or androgenic properties and so, we advocate considering PPARγ as another alert sensor gene when assessing the effects of sex-steroid endocrine disruptors.

  4. Brachyury as a potential modulator of androgen receptor activity and a key player in therapy resistance in prostate cancer

    Science.gov (United States)

    Pinto, Filipe; Pértega-Gomes, Nelma; Vizcaíno, José R.; Andrade, Raquel P.; Cárcano, Flavio M.; Reis, Rui Manuel

    2016-01-01

    Prostate cancer (PCa) is the most commonly diagnosed neoplasm and the second leading cause of cancer-related deaths in men. Acquisition of resistance to conventional therapy is a major problem for PCa patient management. Several mechanisms have been described to promote therapy resistance in PCa, such as androgen receptor (AR) activation, epithelial-to-mesenchymal transition (EMT), acquisition of stem cell properties and neuroendocrine transdifferentiation (NEtD). Recently, we identified Brachyury as a new biomarker of PCa aggressiveness and poor prognosis. In the present study we aimed to assess the role of Brachyury in PCa therapy resistance. We showed that Brachyury overexpression in prostate cancer cells lines increased resistance to docetaxel and cabazitaxel drugs, whereas Brachyury abrogation induced decrease in therapy resistance. Through ChiP-qPCR assays we further demonstrated that Brachyury is a direct regulator of AR expression as well as of the biomarker AMACR and the mesenchymal markers Snail and Fibronectin. Furthermore, in vitro Brachyury was also able to increase EMT and stem properties. By in silico analysis, clinically human Brachyury-positive PCa samples were associated with biomarkers of PCa aggressiveness and therapy resistance, including PTEN loss, and expression of NEtD markers, ERG and Bcl-2. Taken together, our results indicate that Brachyury contributes to tumor chemotherapy resistance, constituting an attractive target for advanced PCa patients. PMID:27049720

  5. Characterization of the transcriptional activation domains of human TEF3-1 (transcription enhancer factor 3 isoform 1).

    Science.gov (United States)

    Qiao, Cheng; Jiang, Yajie; Deng, Cuilan; Huang, Zebo; Teng, Kaixuan; Chen, Lan; Liu, Xin

    2015-03-01

    TEF3-1 (transcription enhancer factor 3 isoform 1) is a human transcriptional factor, which has a N-terminal TEA/ATTS domain supposedly for DNA binding and C-terminal PRD and STY domains for transcriptional activation. Taking advantage of the efficient reporter design of yeast two-hybrid system, we characterized the TEF3-1 domains in activating gene expression. Previously study usually mentioned that the C-terminal domain of TEF3-1 has the transcriptional activity, however, our data shows that the peptides TEF3-11-66 and TEF3-1197-434 functioned as two independent activation domains, suggesting that N-terminal domain of TEF3-1 also has transcriptional activation capacity. Additionally, more deletions of amino acids 197-434 showed that only the peptides TEF3-1197-265 contained the minimum sequences for the C-terminal transcriptional activation domain. The protein structure is predicted to contain a helix-turn-helix structure in TEF3-11-66 and four β sheets in TEF3-1197-265. Finally, after the truncated fragments of TEF3-1 were expressed in HUVEC cells, the whole TEF3-1 and the two activation domains could increase F-actin stress fiber, cell proliferation, migration and targeted gene expression. Further analysis and characterization of the activation domains in TEF3-1 may broaden our understanding of the gene involved in angiogenesis and other pathological processes.

  6. Synergic prodegradative activity of Bicalutamide and trehalose on the mutant androgen receptor responsible for spinal and bulbar muscular atrophy.

    Science.gov (United States)

    Giorgetti, Elisa; Rusmini, Paola; Crippa, Valeria; Cristofani, Riccardo; Boncoraglio, Alessandra; Cicardi, Maria E; Galbiati, Mariarita; Poletti, Angelo

    2015-01-01

    Spinal and bulbar muscular atrophy (SBMA) is an X-linked motoneuron disease due to a CAG triplet-repeat expansion in the androgen receptor (AR) gene, which is translated into an elongated polyglutamine (polyQ) tract in AR protein (ARpolyQ). ARpolyQ toxicity is activated by the AR ligand testosterone (or dihydrotestosterone), and the polyQ triggers ARpolyQ misfolding and aggregation in spinal cord motoneurons and muscle cells. In motoneurons, testosterone triggers nuclear toxicity by inducing AR nuclear translocation. Thus, (i) prevention of ARpolyQ nuclear localization, combined with (ii) an increased ARpolyQ cytoplasmic clearance, should reduce its detrimental activity. Using the antiandrogen Bicalutamide (Casodex(®)), which slows down AR activation and nuclear translocation, and the disaccharide trehalose, an autophagy activator, we found that, in motoneurons, the two compounds together reduced ARpolyQ insoluble forms with higher efficiency than that obtained with single treatments. The ARpolyQ clearance was mediated by trehalose-induced autophagy combined with the longer cytoplasmic retention of ARpolyQ bound to Bicalutamide. This allows an increased recognition of misfolded species by the autophagic system prior to their migration into the nucleus. Interestingly, the combinatory use of trehalose and Bicalutamide was also efficient in the removal of insoluble species of AR with a very long polyQ (Q112) tract, which typically aggregates into the cell nuclei. Collectively, these data suggest that the combinatory use of Bicalutamide and trehalose is a novel approach to facilitate ARpolyQ clearance that has to be tested in other cell types target of SBMA (i.e. muscle cells) and in vivo in animal models of SBMA.

  7. Activating transcription factor 6 derepression mediates neuroprotection in Huntington disease.

    Science.gov (United States)

    Naranjo, José R; Zhang, Hongyu; Villar, Diego; González, Paz; Dopazo, Xose M; Morón-Oset, Javier; Higueras, Elena; Oliveros, Juan C; Arrabal, María D; Prieto, Angela; Cercós, Pilar; González, Teresa; De la Cruz, Alicia; Casado-Vela, Juan; Rábano, Alberto; Valenzuela, Carmen; Gutierrez-Rodriguez, Marta; Li, Jia-Yi; Mellström, Britt

    2016-02-01

    Deregulated protein and Ca2+ homeostasis underlie synaptic dysfunction and neurodegeneration in Huntington disease (HD); however, the factors that disrupt homeostasis are not fully understood. Here, we determined that expression of downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, is reduced in murine in vivo and in vitro HD models and in HD patients. DREAM downregulation was observed early after birth and was associated with endogenous neuroprotection. In the R6/2 mouse HD model, induced DREAM haplodeficiency or blockade of DREAM activity by chronic administration of the drug repaglinide delayed onset of motor dysfunction, reduced striatal atrophy, and prolonged life span. DREAM-related neuroprotection was linked to an interaction between DREAM and the unfolded protein response (UPR) sensor activating transcription factor 6 (ATF6). Repaglinide blocked this interaction and enhanced ATF6 processing and nuclear accumulation of transcriptionally active ATF6, improving prosurvival UPR function in striatal neurons. Together, our results identify a role for DREAM silencing in the activation of ATF6 signaling, which promotes early neuroprotection in HD.

  8. Computational Investigation on the Allosteric Modulation of Androgen Receptor

    Institute of Scientific and Technical Information of China (English)

    OU Min-Rui; LI Jun-Qian

    2012-01-01

    Androgens have similar structures with different biological activities. To identify molecular determinants responsible for the activity difference, we have docked six steroidal androgens to the binding site or the surface of androgen receptor by using molecular docking with computational investigation. The energy was calculated respectively based on the QM (quantum mechanics) and MM (molecular mechanics) methods. The result shows that the allosteric modulation of androgen receptor plays an important role in the binding process between androgens and receptor. The open state receptor is less stable than the close state one, but the latter is more favorable for binding with androgens. It is worthy of note that when the androgen receptors binding or without binding with androgen are in close state, they are difficult to return to their open state. This phenomenon is an exception of the well known two-state model theory in which the two states are reversible. Whether the internal of close state androgen receptor has a combination of androgen or not, the androgen receptor surface can be combined with another androgen, and their surface binding energies could be very close. The result is consistent with the experimental observations, but this phenomenon of continuous combination from open state is also an exception of the two-state model theory.

  9. Ovarian overproduction of androgens

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001165.htm Ovarian overproduction of androgens To use the sharing features on this page, please enable JavaScript. Ovarian overproduction of androgens is a condition in which the ...

  10. Distinct regulatory mechanisms of eukaryotic transcriptional activation by SAGA and TFIID.

    Science.gov (United States)

    Bhaumik, Sukesh R

    2011-02-01

    A growing number of human diseases are linked to abnormal gene expression which is largely controlled at the level of transcriptional initiation. The gene-specific activator promotes the initiation of transcription through its interaction with one or more components of the transcriptional initiation machinery, hence leading to stimulated transcriptional initiation or activation. However, all activator proteins do not target the same component(s) of the transcriptional initiation machinery. Rather, they can have different target specificities, and thus, can lead to distinct mechanisms of transcriptional activation. Two such distinct mechanisms of transcriptional activation in yeast are mediated by the SAGA (Spt-Ada-Gcn5-Acetyltransferase) and TFIID (Transcription factor IID) complexes, and are termed as "SAGA-dependent" and "TFIID-dependent" transcriptional activation, respectively. SAGA is the target of the activator in case of SAGA-dependent transcriptional activation, while the targeting of TFIID by the activator leads to TFIID-dependent transcriptional activation. Both the SAGA and TFIID complexes are highly conserved from yeast to human, and play crucial roles in gene activation among eukaryotes. The regulatory mechanisms of eukaryotic transcriptional activation by SAGA and TFIID are discussed here. This article is part of a Special Issue entitled The 26S Proteasome: When degradation is just not enough!

  11. Differential effects of genistein on prostate cancer cells depend on mutational status of the androgen receptor.

    Directory of Open Access Journals (Sweden)

    Abeer M Mahmoud

    Full Text Available Blocking the androgen receptor (AR activity is the main goal of therapies for advanced prostate cancer (PCa. However, relapse with a more aggressive, hormone refractory PCa arises, which harbors restored AR activity. One mechanism of such reactivation occurs through acquisition of AR mutations that enable its activation by various steroidal and non-steroidal structures. Thus, natural and chemical compounds that contribute to inappropriate (androgen-independent activation of the AR become an area of intensive research. Here, we demonstrate that genistein, a soy phytoestrogen binds to both the wild and the Thr877Ala (T877A mutant types of AR competitively with androgen, nevertheless, it exerts a pleiotropic effect on PCa cell proliferation and AR activity depending on the mutational status of the AR. Genistein inhibited, in a dose-dependent way, cell proliferation and AR nuclear localization and expression in LAPC-4 cells that have wild AR. However, in LNCaP cells that express the T877A mutant AR, genistein induced a biphasic effect where physiological doses (0.5-5 µmol/L stimulated cell growth and increased AR expression and transcriptional activity, and higher doses induced inhibitory effects. Similar biphasic results were achieved in PC-3 cells transfected with AR mutants; T877A, W741C and H874Y. These findings suggest that genistein, at physiological concentrations, potentially act as an agonist and activate the mutant AR that can be present in advanced PCa after androgen ablation therapy.

  12. Differential effects of genistein on prostate cancer cells depend on mutational status of the androgen receptor.

    Science.gov (United States)

    Mahmoud, Abeer M; Zhu, Tian; Parray, Aijaz; Siddique, Hifzur R; Yang, Wancai; Saleem, Mohammad; Bosland, Maarten C

    2013-01-01

    Blocking the androgen receptor (AR) activity is the main goal of therapies for advanced prostate cancer (PCa). However, relapse with a more aggressive, hormone refractory PCa arises, which harbors restored AR activity. One mechanism of such reactivation occurs through acquisition of AR mutations that enable its activation by various steroidal and non-steroidal structures. Thus, natural and chemical compounds that contribute to inappropriate (androgen-independent) activation of the AR become an area of intensive research. Here, we demonstrate that genistein, a soy phytoestrogen binds to both the wild and the Thr877Ala (T877A) mutant types of AR competitively with androgen, nevertheless, it exerts a pleiotropic effect on PCa cell proliferation and AR activity depending on the mutational status of the AR. Genistein inhibited, in a dose-dependent way, cell proliferation and AR nuclear localization and expression in LAPC-4 cells that have wild AR. However, in LNCaP cells that express the T877A mutant AR, genistein induced a biphasic effect where physiological doses (0.5-5 µmol/L) stimulated cell growth and increased AR expression and transcriptional activity, and higher doses induced inhibitory effects. Similar biphasic results were achieved in PC-3 cells transfected with AR mutants; T877A, W741C and H874Y. These findings suggest that genistein, at physiological concentrations, potentially act as an agonist and activate the mutant AR that can be present in advanced PCa after androgen ablation therapy.

  13. Rethinking transcriptional activation in the Arabidopsis circadian clock.

    Directory of Open Access Journals (Sweden)

    Karl Fogelmark

    2014-07-01

    Full Text Available Circadian clocks are biological timekeepers that allow living cells to time their activity in anticipation of predictable daily changes in light and other environmental factors. The complexity of the circadian clock in higher plants makes it difficult to understand the role of individual genes or molecular interactions, and mathematical modelling has been useful in guiding clock research in model organisms such as Arabidopsis thaliana. We present a model of the circadian clock in Arabidopsis, based on a large corpus of published time course data. It appears from experimental evidence in the literature that most interactions in the clock are repressive. Hence, we remove all transcriptional activation found in previous models of this system, and instead extend the system by including two new components, the morning-expressed activator RVE8 and the nightly repressor/activator NOX. Our modelling results demonstrate that the clock does not need a large number of activators in order to reproduce the observed gene expression patterns. For example, the sequential expression of the PRR genes does not require the genes to be connected as a series of activators. In the presented model, transcriptional activation is exclusively the task of RVE8. Predictions of how strongly RVE8 affects its targets are found to agree with earlier interpretations of the experimental data, but generally we find that the many negative feedbacks in the system should discourage intuitive interpretations of mutant phenotypes. The dynamics of the clock are difficult to predict without mathematical modelling, and the clock is better viewed as a tangled web than as a series of loops.

  14. Rethinking transcriptional activation in the Arabidopsis circadian clock.

    Science.gov (United States)

    Fogelmark, Karl; Troein, Carl

    2014-07-01

    Circadian clocks are biological timekeepers that allow living cells to time their activity in anticipation of predictable daily changes in light and other environmental factors. The complexity of the circadian clock in higher plants makes it difficult to understand the role of individual genes or molecular interactions, and mathematical modelling has been useful in guiding clock research in model organisms such as Arabidopsis thaliana. We present a model of the circadian clock in Arabidopsis, based on a large corpus of published time course data. It appears from experimental evidence in the literature that most interactions in the clock are repressive. Hence, we remove all transcriptional activation found in previous models of this system, and instead extend the system by including two new components, the morning-expressed activator RVE8 and the nightly repressor/activator NOX. Our modelling results demonstrate that the clock does not need a large number of activators in order to reproduce the observed gene expression patterns. For example, the sequential expression of the PRR genes does not require the genes to be connected as a series of activators. In the presented model, transcriptional activation is exclusively the task of RVE8. Predictions of how strongly RVE8 affects its targets are found to agree with earlier interpretations of the experimental data, but generally we find that the many negative feedbacks in the system should discourage intuitive interpretations of mutant phenotypes. The dynamics of the clock are difficult to predict without mathematical modelling, and the clock is better viewed as a tangled web than as a series of loops.

  15. Expanding the therapeutic use of androgens via selective androgen receptor modulators (SARMs).

    Science.gov (United States)

    Gao, Wenqing; Dalton, James T

    2007-03-01

    Selective androgen receptor modulators (SARMs) are a novel class of androgen receptor (AR) ligands that might change the future of androgen therapy dramatically. With improved pharmacokinetic characteristics and tissue-selective pharmacological activities, SARMs are expected to greatly extend the clinical applications of androgens to osteoporosis, muscle wasting, male contraception and diseases of the prostate. Mechanistic studies with currently available SARMs will help to define the contributions of differential tissue distribution, tissue-specific expression of 5alpha-reductase, ligand-specific regulation of gene expression and AR interactions with tissue-specific coactivators to their observed tissue selectivity, and lead to even greater expansion of selective anabolic therapies.

  16. Synaptic long-term potentiation and depression in the rat medial vestibular nuclei depend on neural activation of estrogenic and androgenic signals.

    Directory of Open Access Journals (Sweden)

    Mariangela Scarduzio

    Full Text Available Estrogenic and androgenic steroids can be synthesised in the brain and rapidly modulate synaptic transmission and plasticity through direct interaction with membrane receptors for estrogens (ERs and androgens (ARs. We used whole cell patch clamp recordings in brainstem slices of male rats to explore the influence of ER and AR activation and local synthesis of 17β-estradiol (E2 and 5α-dihydrotestosterone (DHT on the long-term synaptic changes induced in the neurons of the medial vestibular nucleus (MVN. Long-term depression (LTD and long-term potentiation (LTP caused by different patterns of high frequency stimulation (HFS of the primary vestibular afferents were assayed under the blockade of ARs and ERs or in the presence of inhibitors for enzymes synthesizing DHT (5α-reductase and E2 (P450-aromatase from testosterone (T. We found that LTD is mediated by interaction of locally produced androgens with ARs and LTP by interaction of locally synthesized E2 with ERs. In fact, the AR block with flutamide prevented LTD while did not affect LTP, and the blockade of ERs with ICI 182,780 abolished LTP without influencing LTD. Moreover, the block of P450-aromatase with letrozole not only prevented the LTP induction, but inverted LTP into LTD. This LTD is likely due to the local activation of androgens, since it was abolished under blockade of ARs. Conversely, LTD was still induced in the presence of finasteride the inhibitor of 5α-reductase demonstrating that T is able to activate ARs and induce LTD even when DHT is not synthesized. This study demonstrates a key and opposite role of sex neurosteroids in the long-term synaptic changes of the MVN with a specific role of T-DHT for LTD and of E2 for LTP. Moreover, it suggests that different stimulation patterns can lead to LTD or LTP by specifically activating the enzymes involved in the synthesis of androgenic or estrogenic neurosteroids.

  17. Antioxidants Abrogate Alpha-Tocopherylquinone-Mediated Down-Regulation of the Androgen Receptor in Androgen-Responsive Prostate Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Alexandra M Fajardo

    Full Text Available Tocopherylquinone (TQ, the oxidation product of alpha-tocopherol (AT, is a bioactive molecule with distinct properties from AT. In this study, AT and TQ are investigated for their comparative effects on growth and androgenic activity in prostate cancer cells. TQ potently inhibited the growth of androgen-responsive prostate cancer cell lines (e.g., LAPC4 and LNCaP cells, whereas the growth of androgen-independent prostate cancer cells (e.g., DU145 cells was not affected by TQ. Due to the growth inhibitory effects induced by TQ on androgen-responsive cells, the anti-androgenic properties of TQ were examined. TQ inhibited the androgen-induced activation of an androgen-responsive reporter and inhibited the release of prostate specific antigen from LNCaP cells. TQ pretreatment was also found to inhibit AR activation as measured using the Multifunctional Androgen Receptor Screening assay. Furthermore, TQ decreased androgen-responsive gene expression, including TM4SF1, KLK2, and PSA over 5-fold, whereas AT did not affect the expression of androgen-responsive genes. Of importance, the antiandrogenic effects of TQ on prostate cancer cells were found to result from androgen receptor protein down-regulation produced by TQ that was not observed with AT treatment. Moreover, none of the androgenic endpoints assessed were affected by AT. The down-regulation of androgen receptor protein by TQ was abrogated by co-treatment with antioxidants. Overall, the biological actions of TQ were found to be distinct from AT, where TQ was found to be a potent inhibitor of cell growth and androgenic activity in androgen-responsive prostate cancer cells.

  18. p21-Activated kinase 6 (PAK6) inhibits prostate cancer growth via phosphorylation of androgen receptor and tumorigenic E3 ligase murine double minute-2 (Mdm2).

    Science.gov (United States)

    Liu, Tong; Li, Yang; Gu, Hui; Zhu, Ge; Li, Jiabin; Cao, Liu; Li, Feng

    2013-02-01

    The androgen receptor (AR) signaling pathway plays a crucial role in the development and growth of prostate malignancies. Regulation of AR homeostasis in prostate tumorigenesis has not yet been fully characterized. In this study, we demonstrate that p21-activated kinase 6 (PAK6) inhibits prostate tumorigenesis by regulating AR homeostasis. First, we demonstrated that in normal prostate epithelium, AR co-localizes with PAK6 in the cytoplasm and translocates into the nucleus in malignant prostate. Furthermore, AR phosphorylation at Ser-578 by PAK6 promotes AR-E3 ligase murine double minute-2 (Mdm2) association, causing AR degradation upon androgen stimuli. We also showed that PAK6 phosphorylates Mdm2 on Thr-158 and Ser-186, which is critical for AR ubiquitin-mediated degradation. Moreover, we found that Thr-158 collaborates with Ser-186 for AR-Mdm2 association and AR ubiquitin-mediated degradation as it facilitates PAK6-mediated AR homeostasis. PAK6 knockdown promotes prostate tumor growth in vivo. Interestingly, we found a strong inverse correlation between PAK6 and AR expression in the cytoplasm of prostate cancer cells. These observations indicate that PAK6 may be important for the maintenance of androgen-induced AR signaling homeostasis and in prostate malignancy, as well as being a possible new therapeutic target for AR-positive and hormone-sensitive prostate cancer.

  19. Analyzing phosphorylation-dependent regulation of subcellular localization and transcriptional activity of transcriptional coactivator NT-PGC-1α.

    Science.gov (United States)

    Chang, Ji Suk; Gettys, Thomas W

    2013-01-01

    Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is a nuclear transcriptional coactivator that regulates the genes involved in energy metabolism. Recent evidence has been provided that alternative splicing of PPARGC1A gene produces a functional but predominantly cytosolic isoform of PGC-1α (NT-PGC-1α). We have demonstrated that transcriptional coactivation capacity of NT-PGC-1α is directly correlated with its nuclear localization in a PKA phosphorylation-dependent manner. In this chapter, we describe quantitative imaging analysis methods that are developed to measure the relative fluorescence intensity of the protein of interest in the nucleus and cytoplasm in a single cell and the frequency distribution of nuclear/cytoplasmic intensity ratios in the population of cells, respectively. This chapter also describes transient cotransfection and dual-luciferase reporter gene assay that examine the ability of coactivators to activate the transcriptional activity of transcription factors.

  20. Dehydroepiandrosterone Activation of G-protein-coupled Estrogen Receptor Rapidly Stimulates MicroRNA-21 Transcription in Human Hepatocellular Carcinoma Cells.

    Science.gov (United States)

    Teng, Yun; Radde, Brandie N; Litchfield, Lacey M; Ivanova, Margarita M; Prough, Russell A; Clark, Barbara J; Doll, Mark A; Hein, David W; Klinge, Carolyn M

    2015-06-19

    Little is known about the regulation of the oncomiR miR-21 in liver. Dehydroepiandrosterone (DHEA) regulates gene expression as a ligand for a G-protein-coupled receptor and as a precursor for steroids that activate nuclear receptor signaling. We report that 10 nm DHEA increases primary miR-21 (pri-miR-21) transcription and mature miR-21 expression in HepG2 cells in a biphasic manner with an initial peak at 1 h followed by a second, sustained response from 3-12 h. DHEA also increased miR-21 in primary human hepatocytes and Hep3B cells. siRNA, antibody, and inhibitor studies suggest that the rapid DHEA-mediated increase in miR-21 involves a G-protein-coupled estrogen receptor (GPER/GPR30), estrogen receptor α-36 (ERα36), epidermal growth factor receptor-dependent, pertussis toxin-sensitive pathway requiring activation of c-Src, ERK1/2, and PI3K. GPER antagonist G-15 attenuated DHEA- and BSA-conjugated DHEA-stimulated pri-miR-21 transcription. Like DHEA, GPER agonists G-1 and fulvestrant increased pri-miR-21 in a GPER- and ERα36-dependent manner. DHEA, like G-1, increased GPER and ERα36 mRNA and protein levels. DHEA increased ERK1/2 and c-Src phosphorylation in a GPER-responsive manner. DHEA increased c-Jun, but not c-Fos, protein expression after 2 h. DHEA increased androgen receptor, c-Fos, and c-Jun recruitment to the miR-21 promoter. These results suggest that physiological concentrations of DHEA activate a GPER intracellular signaling cascade that increases pri-miR-21 transcription mediated at least in part by AP-1 and androgen receptor miR-21 promoter interaction.

  1. NCOA4 transcriptional coactivator inhibits activation of DNA replication origins.

    Science.gov (United States)

    Bellelli, Roberto; Castellone, Maria Domenica; Guida, Teresa; Limongello, Roberto; Dathan, Nina Alayne; Merolla, Francesco; Cirafici, Anna Maria; Affuso, Andrea; Masai, Hisao; Costanzo, Vincenzo; Grieco, Domenico; Fusco, Alfredo; Santoro, Massimo; Carlomagno, Francesca

    2014-07-01

    NCOA4 is a transcriptional coactivator of nuclear hormone receptors that undergoes gene rearrangement in human cancer. By combining studies in Xenopus laevis egg extracts and mouse embryonic fibroblasts (MEFs), we show here that NCOA4 is a minichromosome maintenance 7 (MCM7)-interacting protein that is able to control DNA replication. Depletion-reconstitution experiments in Xenopus laevis egg extracts indicate that NCOA4 acts as an inhibitor of DNA replication origin activation by regulating CMG (CDC45/MCM2-7/GINS) helicase. NCOA4(-/-) MEFs display unscheduled origin activation and reduced interorigin distance; this results in replication stress, as shown by the presence of fork stalling, reduction of fork speed, and premature senescence. Together, our findings indicate that NCOA4 acts as a regulator of DNA replication origins that helps prevent inappropriate DNA synthesis and replication stress.

  2. Dehydroepiandrosterone sulfate mediates activation of transcription factors CREB and ATF-1 via a Gα11-coupled receptor in the spermatogenic cell line GC-2.

    Science.gov (United States)

    Shihan, Mazen; Kirch, Ulrike; Scheiner-Bobis, Georgios

    2013-12-01

    Dehydroepiandrosterone sulfate (DHEAS) is a circulating steroid produced in the adrenal cortex, brain, and gonads. Whereas a series of investigations attest to neuroprotective effects of the steroid in the brain, surprisingly little is known about the physiological effects of DHEAS on cells of the reproductive system. Here we demonstrate that DHEAS acting on the spermatogenic cell line GC-2 induces a time- and concentration-dependent phosphorylation of c-Src and Erk1/2 and activates the transcription factors activating transforming factor-1 (ATF-1) and cyclic AMP-responsive element binding protein (CREB). These actions are consistent with the non-classical signaling pathway of testosterone and suggest that DHEAS is a pro-androgen that is converted into testosterone in order to exert its biological activity. The fact, however, that steroid sulfatase mRNA was not detected in the GC-2 cells and the clear demonstration of DHEAS-induced activation of Erk1/2, ATF-1 and CREB after silencing the androgen receptor by small interfering RNA (siRNA) clearly contradict this assumption and make it appear unlikely that DHEAS has to be converted in the cytosol into a different steroid in order to activate the kinases and transcription factors mentioned. Instead, it is likely that the DHEAS-induced signaling is mediated through the interaction of the steroid with a membrane-bound G-protein-coupled receptor, since silencing of Guanine nucleotide-binding protein subunit alpha-11 (Gnα11) leads to the abolition of the DHEAS-induced stimulation of Erk1/2, ATF-1, and CREB. The investigation presented here shows a hormone-like activity of DHEAS on a spermatogenic cell line. Since DHEAS is produced in male and female reproductive organs, these findings could help to define new roles for DHEAS in the physiology of reproduction.

  3. Androgen receptor-dependent transactivation of growth arrest-specific gene 6 mediates inhibitory effects of testosterone on vascular calcification.

    Science.gov (United States)

    Son, Bo-Kyung; Akishita, Masahiro; Iijima, Katsuya; Ogawa, Sumito; Maemura, Koji; Yu, Jing; Takeyama, Kenichi; Kato, Shigeaki; Eto, Masato; Ouchi, Yasuyoshi

    2010-03-05

    Recent epidemiological studies have found that androgen deficiency is associated with a higher incidence of cardiovascular disease in men. However, little is known about the mechanism underlying the cardioprotective effects of androgens. Here we show the inhibitory effects of testosterone on vascular calcification and a critical role of androgen receptor (AR)-dependent transactivation of growth arrest-specific gene 6 (Gas6), a key regulator of inorganic phosphate (P(i))-induced calcification of vascular smooth muscle cells (VSMC). Testosterone and nonaromatizable androgen dihydrotestosterone inhibited P(i)-induced calcification of human aortic VSMC in a concentration-dependent manner. Androgen inhibited P(i)-induced VSMC apoptosis, an essential process for VSMC calcification. The effects on VSMC calcification were mediated by restoration of P(i)-induced down-regulation of Gas6 expression and a subsequent reduction of Akt phosphorylation. These effects of androgen were blocked by an AR antagonist, flutamide, but not by an estrogen receptor antagonist, ICI 182,780. We then explored the mechanistic role of the AR in Gas6 expression and found an abundant expression of AR predominantly in the nucleus of VSMC and two consensus ARE sequences in the Gas6 promoter region. Dihydrotestosterone stimulated Gas6 promoter activity, and this effect was abrogated by flutamide and by AR siRNA. Site-specific mutation revealed that the proximal ARE was essential for androgen-dependent transactivation of Gas6. Furthermore, chromatin immunoprecipitation assays demonstrated ligand-dependent binding of the AR to the proximal ARE of Gas6. These results indicate that AR signaling directly regulates Gas6 transcription, which leads to inhibition of vascular calcification, and provides a mechanistic insight into the cardioprotective action of androgens.

  4. Active transcription and ultrastructural changes during Trypanosoma cruzi metacyclogenesis

    Directory of Open Access Journals (Sweden)

    Ludmila R.P. Ferreira

    2008-03-01

    Full Text Available The differentiation of proliferating epimastigote forms of Trypanosoma cruzi , the protozoan parasite that causes Chagas’ disease, into the infective and non-proliferating metacyclic forms can be reproduced in the laboratory by incubating the cells in a chemically-defined medium that mimics the urine of the insect vector. Epimastigotes have a spherical nucleus, a flagellum protruding from the middle of the protozoan cell, and a disk-shaped kinetoplast - an organelle that corresponds to the mitochondrial DNA. Metacyclic trypomastigotes have an elongated shape with the flagellum protruding from the posterior portion of the cell and associated with a spherical kinetoplast. Here we describe the morphological events of this transformation and characterize a novel intermediate stage by three-dimensional reconstruction of electron microscope serial sections. This new intermediate stage is characterized by a kinetoplast compressing an already elongated nucleus, indicating that metacyclogenesis involves active movements of the flagellar structure relative to the cell body. As transcription occurs more intensely in proliferating epimastigotes than in metacyclics, we also examined the presence of RNA polymerase II and measured transcriptional activity during the differentiation process. Both the presence of the enzyme and transcriptional activity remain unchanged during all steps of metacyclogenesis. RNA polymerase II levels and transcriptional activity only decrease after metacyclics are formed. We suggest that transcription is required during the epimastigote-to-metacyclic trypomastigote differentiation process, until the kinetoplast and flagellum reach the posterior position of the parasites in the infective form.A diferenciação de formas epimastigotas (proliferativas do Trypanosoma cruzi, parasita protozoário causador da doença de Chagas, em formas metacíclicas tripomastigotas (infectivas e não proliferativas, pode ser reproduzida em laborat

  5. Effect of highly bioaccumulated polychlorinated biphenyl congeners on estrogen and androgen receptor activity

    DEFF Research Database (Denmark)

    Bonefeld-Jørgensen, E.C.; Andersen, H. R.; Rasmussen, T.H.;

    2001-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous environmental persistent contaminants giving rise to potential health hazard. Some PCBs exert dioxin-like activities mediated through the aryl hydrocarbon receptor. Although reports on interaction with other nuclear receptors are sparce, some...

  6. Piperine, a Bioactive Component of Pepper Spice Exerts Therapeutic Effects on Androgen Dependent and Androgen Independent Prostate Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Abhilash Samykutty

    Full Text Available Prostate cancer is the most common solid malignancy in men, with 32,000 deaths annually. Piperine, a major alkaloid constituent of black pepper, has previously been reported to have anti-cancer activity in variety of cancer cell lines. The effect of piperine against prostate cancer is not currently known. Therefore, in this study, we investigated the anti-tumor mechanisms of piperine on androgen dependent and androgen independent prostate cancer cells. Here, we show that piperine inhibited the proliferation of LNCaP, PC-3, 22RV1 and DU-145 prostate cancer cells in a dose dependent manner. Furthermore, Annexin-V staining demonstrated that piperine treatment induced apoptosis in hormone dependent prostate cancer cells (LNCaP. Using global caspase activation assay, we show that piperine-induced apoptosis resulted in caspase activation in LNCaP and PC-3 cells. Further studies revealed that piperine treatment resulted in the activation of caspase-3 and cleavage of PARP-1 proteins in LNCaP, PC-3 and DU-145 prostate cancer cells. Piperine treatment also disrupted androgen receptor (AR expression in LNCaP prostate cancer cells. Our evaluations further show that there is a significant reduction of Prostate Specific Antigen (PSA levels following piperine treatment in LNCaP cells. NF-kB and STAT-3 transcription factors have previously been shown to play a role in angiogenesis and invasion of prostate cancer cells. Interestingly, treatment of LNCaP, PC-3 and DU-145 prostate cancer cells with piperine resulted in reduced expression of phosphorylated STAT-3 and Nuclear factor-κB (NF-kB transcription factors. These results correlated with the results of Boyden chamber assay, wherein piperine treatment reduced the cell migration of LNCaP and PC-3 cells. Finally, we show that piperine treatment significantly reduced the androgen dependent and androgen independent tumor growth in nude mice model xenotransplanted with prostate cancer cells. Taken together, these

  7. Early androgens, activity levels and toy choices of children in the second year of life.

    Science.gov (United States)

    Alexander, Gerianne M; Saenz, Janet

    2012-09-01

    The hypothesis that stronger preferences for active play styles contribute to stronger preferences for male-typical toys was examined in 47 boys and 37 girls at 19-months of age using ambulatory monitoring technology (i.e., actigraphy) to measure activity levels during contact with male-typical, female-typical, and gender-neutral toys. Digit ratios and salivary testosterone levels were measured earlier in children at 3-4 months of age. There were no significant sex differences in digit ratios, salivary testosterone levels, or overall activity levels during toy play. In contrast, contact times showed large sex differences in infants' toy preferences. The within-sex comparisons showed that infant girls had significant preferences for female-typical toys over male-typical toys, whereas infant boys showed only a small preference for male-typical toys over female-typical toys. More male-typical digit ratios in early infancy predicted higher activity counts during toy play and less female-typical toy preferences in girls. However, in both sexes, activity levels were unrelated to toy preferences suggesting that factors other than activity level preferences contribute to the early emergence of gender-linked toy preferences.

  8. Activator protein 1 promotes the transcriptional activation of IRAK-M.

    Science.gov (United States)

    Jin, Peipei; Bo, Lulong; Liu, Yongjian; Lu, Wenbin; Lin, Shengwei; Bian, Jinjun; Deng, Xiaoming

    2016-10-01

    Interleukin-1 receptor-associated kinase M (IRAK-M) is a well-known negative regulator for Toll-like receptor signaling, which can regulate immune homeostasis and tolerance in a number of pathological settings. However, the mechanism for IRAK-M regulation at transcriptional level remains largely unknown. In this study, a 1.4kb upstream sequence starting from the major IRAK-M transcriptional start site was cloned into luciferase reporter vector pGL3-basic to construct the full-length IRAK-M promoter. Luciferase reporter plasmids harboring the full-length and the deletion mutants of IRAK-M were transfected into 293T and A549 cells, and their relative luciferase activity was measured. The results demonstrated that activator protein 1(AP-1) cis-element plays a crucial role in IRAK-M constitutive gene transcription. Silencing of c-Fos and/or c-Jun expression suppressed the IRAK-M promoter activity as well as its mRNA and protein expressions. As a specific inhibitor for AP-1 activation, SP600125 also significantly suppressed the basal transcriptional activity of IRAK-M, the binding activity of c-Fos/c-Jun with IRAK-M promoter, and IRAK-M protein expression. Taken together, the result of this study highlights the importance of AP-1 in IRAK-M transcription, which offers more information on the role of IRAK-M in infectious and non-infectious diseases.

  9. Screening of synthetic and plant-derived compounds for (anti)estrogenic and (anti)androgenic activities

    NARCIS (Netherlands)

    Bovee, T.F.H.; Schoonen, W.G.E.J.; Hamers, A.R.M.; Bento, M.J.; Peijnenburg, A.A.C.M.

    2008-01-01

    Recently we constructed yeast cells that either express the human estrogen receptor ¿ or the human androgen receptor in combination with a consensus ERE or ARE repeat in the promoter region of a green fluorescent protein (yEGFP) read-out system. These bioassays were proven to be highly specific for

  10. The metabolic activator FOXO1 binds hepatitis B virus DNA and activates its transcription

    Energy Technology Data Exchange (ETDEWEB)

    Shlomai, Amir, E-mail: amirsh@tasmc.health.gov.il [Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100 (Israel); Institute for Gastroenterology and Liver disease, Tel-Aviv Sourasky Medical Center, 6 Weizmann street, Tel-Aviv (Israel); Shaul, Yosef [Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2009-04-17

    Hepatitis B virus (HBV) is a small DNA virus that targets the liver and infects humans worldwide. Recently we have shown that the metabolic regulator PGC-1{alpha} coactivates HBV transcription thereby rendering the virus susceptible to fluctuations in the nutritional status of the liver. PGC-1{alpha} coactivation of HBV is mediated through the liver-enriched nuclear receptor HNF4{alpha} and through another yet unknown transcription factor(s). Here we show that the forkhead transcription factor FOXO1, a known target for PGC-1{alpha} coactivation and a central mediator of glucose metabolism in the liver, binds HBV core promoter and activates its transcription. This activation is further enhanced in the presence of PGC-1{alpha}, implying that FOXO1 is a target for PGC-1{alpha} coactivation of HBV transcription. Thus, our results identify another key metabolic regulator as an activator of HBV transcription, thereby supporting the principle that HBV gene expression is regulated in a similar way to key hepatic metabolic genes.

  11. WRKY Transcription Factors Involved in Activation of SA Biosynthesis Genes

    Directory of Open Access Journals (Sweden)

    Bol John F

    2011-05-01

    Full Text Available Abstract Background Increased defense against a variety of pathogens in plants is achieved through activation of a mechanism known as systemic acquired resistance (SAR. The broad-spectrum resistance brought about by SAR is mediated through salicylic acid (SA. An important step in SA biosynthesis in Arabidopsis is the conversion of chorismate to isochorismate through the action of isochorismate synthase, encoded by the ICS1 gene. Also AVRPPHB SUSCEPTIBLE 3 (PBS3 plays an important role in SA metabolism, as pbs3 mutants accumulate drastically reduced levels of SA-glucoside, a putative storage form of SA. Bioinformatics analysis previously performed by us identified WRKY28 and WRKY46 as possible regulators of ICS1 and PBS3. Results Expression studies with ICS1 promoter::β-glucuronidase (GUS genes in Arabidopsis thaliana protoplasts cotransfected with 35S::WRKY28 showed that over expression of WRKY28 resulted in a strong increase in GUS expression. Moreover, qRT-PCR analyses indicated that the endogenous ICS1 and PBS3 genes were highly expressed in protoplasts overexpressing WRKY28 or WRKY46, respectively. Electrophoretic mobility shift assays indentified potential WRKY28 binding sites in the ICS1 promoter, positioned -445 and -460 base pairs upstream of the transcription start site. Mutation of these sites in protoplast transactivation assays showed that these binding sites are functionally important for activation of the ICS1 promoter. Chromatin immunoprecipitation assays with haemagglutinin-epitope-tagged WRKY28 showed that the region of the ICS1 promoter containing the binding sites at -445 and -460 was highly enriched in the immunoprecipitated DNA. Conclusions The results obtained here confirm results from our multiple microarray co-expression analyses indicating that WRKY28 and WRKY46 are transcriptional activators of ICS1 and PBS3, respectively, and support this in silico screening as a powerful tool for identifying new components of stress

  12. Large-scale transcriptome data reveals transcriptional activity of fission yeast LTR retrotransposons

    DEFF Research Database (Denmark)

    Mourier, Tobias; Willerslev, Eske

    2010-01-01

    transcriptional activity from Long Terminal Repeat (LTR) retrotransposons. LTR retrotransposons are normally flanked by two LTR sequences. However, the majority of LTR sequences in S. pombe exist as solitary LTRs, i.e. as single terminal repeat sequences not flanking a retrotransposon. Transcriptional activity...... of transcriptional activity are observed from both strands of solitary LTR sequences. Transcriptome data collected during meiosis suggests that transcription of solitary LTRs is correlated with the transcription of nearby protein-coding genes. CONCLUSIONS: Presumably, the host organism negatively regulates...... proliferation of LTR retrotransposons. The finding of considerable transcriptional activity of retrotransposons suggests that part of this regulation is likely to take place at a posttranscriptional level. Alternatively, the transcriptional activity may signify a hitherto unrecognized activity level...

  13. Effects of 2,4-D and DCP on the DHT-induced androgenic action in human prostate cancer cells.

    Science.gov (United States)

    Kim, Hyun-Jung; Park, Young In; Dong, Mi-Sook

    2005-11-01

    2,4-Dichlorophenoxyacetic acid (2,4-D) and its metabolite 2,4-dichlorophenol (DCP) are used extensively in agriculture as herbicides, and are suspected of potential endocrine disruptor activity. In a previous study, we showed that these compounds exhibited synergistic androgenic effects by co-treatment with testosterone in the Hershberger assay. To elucidate the mechanisms of the synergistic effects of these compounds on the androgenicity of testosterone, the androgenic action of 2,4-D and DCP was characterized using a mammalian detection system in prostate cancer cell lines. In in vitro assay systems, while 2,4-D or DCP alone did not show androgenic activity, 2,4-D or DCP with 5alpha-dihydroxytestosterone (DHT) exhibited synergistic androgenic activities. Co-treatment of 10 nM 2,4-D or DCP with 10 nM DHT was shown to stimulate the cell proliferation by 1.6-fold, compared to 10 nM DHT alone. In addition, in transient transfection assays, androgen-induced transactivation was also increased to a maximum of 32-fold or 1.28-fold by co-treatment of 2,4-D or DCP with DHT, respectively. However, 2,4-D and DCP exerted no effects on either mRNA or protein levels of AR. In a competitive AR binding assay, 2,4-D and DCP inhibited androgen binding to AR, up to 50% at concentrations of approximately 0.5 microM for both compounds. The nuclear translocation of green fluorescent protein-AR fusion protein in the presence of DHT was promoted as the result of the addition of 2,4-D and DCP. Collectively, these results that 2,4-D and DCP enhanced DHT-induced AR transcriptional activity might be attributable, at least in part, to the promotion of AR nuclear translocation.

  14. Androgen receptor modulators: a marriage of chemistry and biology.

    Science.gov (United States)

    McEwan, Iain J

    2013-06-01

    Androgenic steroids are important for male development in utero and secondary sexual characteristics at puberty. In addition, androgens play a role in non-reproductive tissues, such as bone and muscle in both sexes. The actions of the androgens testosterone and dihydrotestosterone are mediated by a single receptor protein, the androgen receptor. Over the last 60-70 years there has been considerable research interest in the development of inhibitors of androgen receptor for the management of diseases such as prostate cancer. However, more recently, there is also a growing appreciation of the need for selective androgen modulators that would demonstrate tissue-selective agonist or antagonist activity. The chemistry and biology of selective agonists, antagonists and selective androgen receptor modulators will be discussed in this review.

  15. The Role of Stat3 Activation in Androgen Receptor Signaling and Prostate Cancer

    Science.gov (United States)

    2006-07-01

    0.1% SDS and 0.1 SSC, 0.1% SDS. Radioactivity in the membranes was analyzed with a Molecular Imager FX System (Bio-Rad, Hercules, CA). Electromobility ...Pierce). Electromobility Shift Assay After transfection with either Stat3 siRNA expres- sion vector or negative control plasmid, nuclear ex- tracts...were prepared and electromobility shift assay (EMSA) was performed as described previously [10]. For determination of the Stat3 DNA binding activity

  16. Berberine Suppresses Adipocyte Differentiation via Decreasing CREB Transcriptional Activity.

    Directory of Open Access Journals (Sweden)

    Juan Zhang

    Full Text Available Berberine, one of the major constituents of Chinese herb Rhizoma coptidis, has been demonstrated to lower blood glucose, blood lipid, and body weight in patients with type 2 diabetes mellitus. The anti-obesity effect of berberine has been attributed to its anti-adipogenic activity. However, the underlying molecular mechanism remains largely unknown. In the present study, we found that berberine significantly suppressed the expressions of CCAAT/enhancer-binding protein (C/EBPα, peroxisome proliferators-activated receptor γ2 (PPARγ2, and other adipogenic genes in the process of adipogenesis. Berberine decreased cAMP-response element-binding protein (CREB phosphorylation and C/EBPβ expression at the early stage of 3T3-L1 preadipocyte differentiation. In addition, CREB phosphorylation and C/EBPβ expression induced by 3-isobutyl-1-methylxanthine (IBMX and forskolin were also attenuated by berberine. The binding activities of cAMP responsive element (CRE stimulated by IBMX and forskolin were inhibited by berberine. The binding of phosphorylated CREB to the promoter of C/EBPβ was abrogated by berberine after the induction of preadipocyte differentiation. These results suggest that berberine blocks adipogenesis mainly via suppressing CREB activity, which leads to a decrease in C/EBPβ-triggered transcriptional cascades.

  17. Berberine Suppresses Adipocyte Differentiation via Decreasing CREB Transcriptional Activity.

    Science.gov (United States)

    Zhang, Juan; Tang, Hongju; Deng, Ruyuan; Wang, Ning; Zhang, Yuqing; Wang, Yao; Liu, Yun; Li, Fengying; Wang, Xiao; Zhou, Libin

    2015-01-01

    Berberine, one of the major constituents of Chinese herb Rhizoma coptidis, has been demonstrated to lower blood glucose, blood lipid, and body weight in patients with type 2 diabetes mellitus. The anti-obesity effect of berberine has been attributed to its anti-adipogenic activity. However, the underlying molecular mechanism remains largely unknown. In the present study, we found that berberine significantly suppressed the expressions of CCAAT/enhancer-binding protein (C/EBP)α, peroxisome proliferators-activated receptor γ2 (PPARγ2), and other adipogenic genes in the process of adipogenesis. Berberine decreased cAMP-response element-binding protein (CREB) phosphorylation and C/EBPβ expression at the early stage of 3T3-L1 preadipocyte differentiation. In addition, CREB phosphorylation and C/EBPβ expression induced by 3-isobutyl-1-methylxanthine (IBMX) and forskolin were also attenuated by berberine. The binding activities of cAMP responsive element (CRE) stimulated by IBMX and forskolin were inhibited by berberine. The binding of phosphorylated CREB to the promoter of C/EBPβ was abrogated by berberine after the induction of preadipocyte differentiation. These results suggest that berberine blocks adipogenesis mainly via suppressing CREB activity, which leads to a decrease in C/EBPβ-triggered transcriptional cascades.

  18. Pyridine analogues of curcumin exhibit high activity for inhibiting CWR-22Rv1 human prostate cancer cell growth and androgen receptor activation

    Science.gov (United States)

    ZHOU, DAI-YING; ZHAO, SU-QING; DU, ZHI-YUN; ZHENG, XI; ZHANG, KUN

    2016-01-01

    The concentrations required for curcumin to exert its anticancer activity (IC50, 20 µM) are difficult to achieve in the blood plasma of patients, due to the low bioavailability of the compound. Therefore, much effort has been devoted to the development of curcumin analogues that exhibit stronger anticancer activity and a lower IC50 than curcumin. The present study investigated twelve pyridine analogues of curcumin, labeled as groups AN, BN, EN and FN, to determine their effects in CWR-22Rv1 human prostate cancer cells. The inhibitory effects of these compounds on testosterone (TT)-induced androgen receptor (AR) activity was determined by performing an AR-linked luciferase assay and by TT-induced expression of prostate-specific antigen. The results of the current study suggested that the FN group of analogues had the strongest inhibitory effect of growth on CWR-22Rv1 cultured cells, and were the most potent inhibitor of AR activity compared with curcumin, and the AN, BN and EN analogues. Thus, the results of the present study indicate the inhibition of the AR pathways as a potential mechanism for the anticancer effect of curcumin analogues in human prostate cancer cells. Furthermore, curcumin analogues with pyridine as a distal ring and tetrahydrothiopyran-4-one as a linker may be good candidates for the development of novel drugs for the treatment of prostate cancer, by targeting the AR signaling pathway. PMID:27313760

  19. Inhibition of Androgen-Independent Prostate Cancer by Estrogenic Compounds Is Associated with Increased Expression of Immune-Related Genes

    Directory of Open Access Journals (Sweden)

    Ilsa M. Coleman

    2006-10-01

    Full Text Available The clinical utility of estrogens for treating prostate cancer (CaP was established in the 1940s by Huggins. The classic model of the anti-CaP activity of estrogens postulates an indirect mechanism involving the suppression of androgen production. However, clinical, preclinical studies have shown that estrogens exert growth-inhibitory effects on CaP under low-androgen conditions, suggesting additional modes whereby estrogens affect CaP cells and/or the microenvironment. Here we have investigated the activity of 17β estradiol (E2 against androgen-independent CaP, identified molecular alterations in tumors exposed to E2. E2 treatment inhibited the growth of all four androgen-independent CaP xenografts studied (LuCaP 35V, LuCaP 23.1AI, LuCaP 49, LuCaP 58 in castrated male mice. The molecular basis of growth suppression was studied by cDNA microarray analysis, which indicated that multiple pathways are altered by E2 treatment. Of particular interest are changes in transcripts encoding proteins that mediate immune responses, regulate androgen receptor signaling. In conclusion, our data show that estrogens have powerful inhibitory effects on CaP in vivo in androgendepleted environments, suggest novel mechanisms of estrogen-mediated antitumor activity. These results indicate that incorporating estrogens into CaP treatment protocols could enhance therapeutic efficacy even in cases of advanced disease.

  20. Androgens and the skeleton.

    Science.gov (United States)

    Lindberg, M K; Vandenput, L; Movèrare Skrtic, S; Vanderschueren, D; Boonen, S; Bouillon, R; Ohlsson, C

    2005-03-01

    Loss of estrogens or androgens causes bone loss by increasing the rate of bone remodeling, and also causes an imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, treatment with androgens, as well as estrogens, maintains cancellous bone mass and integrity, regardless of age or sex. Both androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs) can exert these effects, but the relative contribution of these 2 pathways remains uncertain. Androgens, like estrogens, stimulate endochondral bone formation at the start of puberty, whereas they induce epiphyseal closure at the end of puberty, thus, they have a biphasic effect. Androgen action on the growth plate is, however, clearly mediated via aromatization into estrogens and interaction with ER alpha. Androgens increase, while estrogens decrease radial growth. This differential effect of the sex steroids may be important because bone strength in males seems to be determined by higher periosteal bone formation and, therefore, greater bone dimensions. Experiments in mice suggest that both the AR and ER alpha pathways are involved in androgen action on radial bone growth. ER beta may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males. In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and expansion of cortical bone. This androgen action on bone is mediated by the AR and ER alpha.

  1. Androgen Receptor-Target Genes in African American Prostate Cancer Disparities

    Directory of Open Access Journals (Sweden)

    Bi-Dar Wang

    2013-01-01

    Full Text Available The incidence and mortality rates of prostate cancer (PCa are higher in African American (AA compared to Caucasian American (CA men. To elucidate the molecular mechanisms underlying PCa disparities, we employed an integrative approach combining gene expression profiling and pathway and promoter analyses to investigate differential transcriptomes and deregulated signaling pathways in AA versus CA cancers. A comparison of AA and CA PCa specimens identified 1,188 differentially expressed genes. Interestingly, these transcriptional differences were overrepresented in signaling pathways that converged on the androgen receptor (AR, suggesting that the AR may be a unifying oncogenic theme in AA PCa. Gene promoter analysis revealed that 382 out of 1,188 genes contained cis-acting AR-binding sequences. Chromatin immunoprecipitation confirmed STAT1, RHOA, ITGB5, MAPKAPK2, CSNK2A,1 and PIK3CB genes as novel AR targets in PCa disparities. Moreover, functional screens revealed that androgen-stimulated AR binding and upregulation of RHOA, ITGB5, and PIK3CB genes were associated with increased invasive activity of AA PCa cells, as siRNA-mediated knockdown of each gene caused a loss of androgen-stimulated invasion. In summation, our findings demonstrate that transcriptional changes have preferentially occurred in multiple signaling pathways converging (“transcriptional convergence” on AR signaling, thereby contributing to AR-target gene activation and PCa aggressiveness in AAs.

  2. Androgen and bone mass in men

    Institute of Scientific and Technical Information of China (English)

    AnnieW.C.Kung

    2003-01-01

    Androgens have multiple actions on the skeleton throughout life. Androgens promote skeletal growth and accumulation of minerals during puberty and adolescence and stimulate osteoblast but suppress osteoclast function,activity and lifespan through complex mechanisms. Also androgens increase periosteal bone apposition, resulting in larger bone size and thicker cortical bone in men. There is convincing evidence to show that aromatization to estrogens was an important pathway for mediating the action of testosterone on bone physiology. Estrogen is probably the dominant sex steroid regulating bone resorption in men, but both testosterone and estrogen are important in maintaining bone formation. ( Asian J Androl 2003 Jun; 5: 148-154)

  3. Molecular insight into the differential anti-androgenic activity of resveratrol and its natural analogs: In Silico approach to understand biological actions

    Science.gov (United States)

    The androgen receptor (AR) is a therapeutic target for the treatment of prostate cancer. Androgen receptor reactivation during the androgen-independent stage of prostate cancer is mediated by numerous mechanisms including expression of AR mutants and splice variants that become non-responsive to con...

  4. Avicequinone C Isolated from Avicennia marina Exhibits 5α-Reductase-Type 1 Inhibitory Activity Using an Androgenic Alopecia Relevant Cell-Based Assay System

    Directory of Open Access Journals (Sweden)

    Ruchy Jain

    2014-05-01

    Full Text Available Avicennia marina (AM exhibits various biological activities and has been traditionally used in Egypt to cure skin diseases. In this study, the methanolic heartwood extract of AM was evaluated for inhibitory activity against 5α-reductase (5α-R [E.C.1.3.99.5], the enzyme responsible for the over-production of 5α-dihydrotestosterone (5α-DHT causing androgenic alopecia (AGA. An AGA-relevant cell-based assay was developed using human hair dermal papilla cells (HHDPCs, the main regulator of hair growth and the only cells within the hair follicle that are the direct site of 5α-DHT action, combined with a non-radioactive thin layer chromatography (TLC detection technique. The results revealed that AM is a potent 5α-R type 1 (5α-R1 inhibitor, reducing the 5α-DHT production by 52% at the final concentration of 10 µg/mL. Activity-guided fractionation has led to the identification of avicequinone C, a furanonaphthaquinone, as a 5α-R1 inhibitor with an IC50 of 9.94 ± 0.33 µg/mL or 38.8 ± 1.29 µM. This paper is the first to report anti-androgenic activity through 5α-R1 inhibition of AM and avicequinone C.

  5. Identification of a Novel Androgen Receptor Mutation in a Family With Multiple Components Compatible With the Testicular Dysgenesis Syndrome

    DEFF Research Database (Denmark)

    Lottrup, Grete; Jørgensen, Anne; Nielsen, John E.;

    2013-01-01

    Context: Androgen signaling via the androgen receptor (AR) is essential for normal testis development and male reproductive functions. We describe a rare family with 3 males affected by a mild disorder of sex determination compatible with testicular dysgenesis syndrome (TDS), including subfertility......, cryptorchidism, hypospadias, and testicular cancer, caused by a novel AR mutation.Objective: The aim of this study was to describe the phenotype of the affected males, characterize functionally the novel AR mutation, and discuss the significance of partial androgen insufficiency in the pathogenesis of TDS...... analysis of the mutation in a gene-reporter assay showed a 50% reduction in AR-induced transcriptional activity. The affected males had elevated LH and T in accordance with decreased AR signaling. The histology and immunohistochemical profile of the testis tissue from the 2 patients with testicular cancer...

  6. DNA Topoisomerases Maintain Promoters in a State Competent for Transcriptional Activation in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Pedersen, Jakob Madsen; Fredsøe, Jacob Christian; Rødgaard, Morten Terpager;

    2012-01-01

    To investigate the role of DNA topoisomerases in transcription, we have studied global gene expression in Saccharomyces cerevisiae cells deficient for topoisomerases I and II and performed single-gene analyses to support our findings. The genome-wide studies show a general transcriptional down-re...... transcriptional activation of genes with a repressible/inducible mode of regulation....

  7. Large-scale transcriptome data reveals transcriptional activity of fission yeast LTR retrotransposons

    DEFF Research Database (Denmark)

    Mourier, Tobias; Willerslev, Eske

    2010-01-01

    of transcriptional activity are observed from both strands of solitary LTR sequences. Transcriptome data collected during meiosis suggests that transcription of solitary LTRs is correlated with the transcription of nearby protein-coding genes. CONCLUSIONS: Presumably, the host organism negatively regulates...

  8. The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells

    OpenAIRE

    2015-01-01

    The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR). TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to i...

  9. SUMO modification regulates the transcriptional activity of FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Alm-Kristiansen, Anne Hege; Norman, Ingrid Louise; Matre, Vilborg [Department of Molecular Biosciences, University of Oslo, N-0316 Oslo (Norway); Gabrielsen, Odd Stokke, E-mail: o.s.gabrielsen@imbv.uio.no [Department of Molecular Biosciences, University of Oslo, N-0316 Oslo (Norway)

    2009-09-25

    FLASH is a huge multifunctional nuclear protein that has been linked to apoptotic signalling, transcriptional control and Cajal body function. To gain further insight into the functions of the FLASH protein, we performed a yeast two-hybrid screening with FLASH as bait and identified the SUMO-conjugating enzyme Ubc9 as an interaction partner. The main interaction surface for Ubc9 was found in the C-terminal part of FLASH, which is also a target for sumoylation. We identified K1813 as the major sumoylation site in FLASH, being enhanced by the SUMO E3 ligases Pc2 and PIASy. Disruption of this SUMO-conjugation site did not change the speckled subnuclear localization of FLASH, but it caused a reduction in FLASH activity as measured in a Gal4-tethering assay. Interestingly, the SUMO-specific protease SENP1 activated FLASH in the same assay. Overall, our results point to a complex involvement of sumoylation in modulating the function of FLASH.

  10. Human transcriptional coactivator PC4 stimulates DNA end joining and activates DSB repair activity.

    Science.gov (United States)

    Batta, Kiran; Yokokawa, Masatoshi; Takeyasu, Kunio; Kundu, Tapas K

    2009-01-23

    Human transcriptional coactivator PC4 is a highly abundant nuclear protein that is involved in diverse cellular processes ranging from transcription to chromatin organization. Earlier, we have shown that PC4, a positive activator of p53, overexpresses upon genotoxic insult in a p53-dependent manner. In the present study, we show that PC4 stimulates ligase-mediated DNA end joining irrespective of the source of DNA ligase. Pull-down assays reveal that PC4 helps in the association of DNA ends through its C-terminal domain. In vitro nonhomologous end-joining assays with cell-free extracts show that PC4 enhances the joining of noncomplementary DNA ends. Interestingly, we found that PC4 activates double-strand break (DSB) repair activity through stimulation of DSB rejoining in vivo. Together, these findings demonstrate PC4 as an activator of nonhomologous end joining and DSB repair activity.

  11. Transcriptional Activation of Inflammatory Genes: Mechanistic Insight into Selectivity and Diversity.

    Science.gov (United States)

    Ahmed, Afsar U; Williams, Bryan R G; Hannigan, Gregory E

    2015-11-11

    Acute inflammation, an integral part of host defence and immunity, is a highly conserved cellular response to pathogens and other harmful stimuli. An inflammatory stimulation triggers transcriptional activation of selective pro-inflammatory genes that carry out specific functions such as anti-microbial activity or tissue healing. Based on the nature of inflammatory stimuli, an extensive exploitation of selective transcriptional activations of pro-inflammatory genes is performed by the host to ensure a defined inflammatory response. Inflammatory signal transductions are initiated by the recognition of inflammatory stimuli by transmembrane receptors, followed by the transmission of the signals to the nucleus for differential gene activations. The differential transcriptional activation of pro-inflammatory genes is precisely controlled by the selective binding of transcription factors to the promoters of these genes. Among a number of transcription factors identified to date, NF-κB still remains the most prominent and studied factor for its diverse range of selective transcriptional activities. Differential transcriptional activities of NF-κB are dictated by post-translational modifications, specificities in dimer formation, and variability in activation kinetics. Apart from the differential functions of transcription factors, the transcriptional activation of selective pro-inflammatory genes is also governed by chromatin structures, epigenetic markers, and other regulators as the field is continuously expanding.

  12. Building gene expression signatures indicative of transcription factor activation to predict AOP modulation

    Science.gov (United States)

    Building gene expression signatures indicative of transcription factor activation to predict AOP modulation Adverse outcome pathways (AOPs) are a framework for predicting quantitative relationships between molecular initiatin...

  13. Inhibitory effect of acetyl-11-keto-beta-boswellic acid on androgen receptor by interference of Sp1 binding activity in prostate cancer cells.

    Science.gov (United States)

    Yuan, Hui-Qing; Kong, Feng; Wang, Xiao-Ling; Young, Charles Y F; Hu, Xiao-Yan; Lou, Hong-Xiang

    2008-06-01

    Androgen receptor (AR)-mediated signaling is crucial for the development and progression of prostate cancer (PCa). Naturally occurring phytochemicals that target the AR signaling offer significant protection against this disease. Acetyl-11-keto-beta-boswellic acid (AKBA), a compound isolated from the gum-resin of Boswellia carterii, caused G1-phase cell cycle arrest with an induction of p21(WAF1/CIP1), and a reduction of cyclin D1 as well in prostate cancer cells. AKBA-mediated cellular proliferation inhibition was associated with a decrease of AR expression at mRNA and protein levels. Furthermore, the functional biomarkers used in evaluation of AR transactivity showed suppressions of prostate-specific antigen promoter-dependent and androgen responsive element-dependent luciferase activities. Additionally, down-regulation of an AR short promoter mainly containing a Sp1 binding site suggested the essential role of Sp1 for the reduction of AR expression in cells exposed to AKBA. Interruption effect of AKBA on Sp1 binding activity but not Sp1 protein levels was further confirmed by EMSA and transient transfection with a luciferase reporter driven by three copies of the Sp1 binding site of the AR promoter. Therefore, anti-AR properties ascribed to AKBA suggested that AKBA-containing drugs could be used for the development of novel therapeutic chemicals.

  14. Inhibition of human insulin gene transcription and MafA transcriptional activity by the dual leucine zipper kinase.

    Science.gov (United States)

    Stahnke, Marie-Jeannette; Dickel, Corinna; Schröder, Sabine; Kaiser, Diana; Blume, Roland; Stein, Roland; Pouponnot, Celio; Oetjen, Elke

    2014-09-01

    Insulin biosynthesis is an essential β-cell function and inappropriate insulin secretion and biosynthesis contribute to the pathogenesis of diabetes mellitus type 2. Previous studies showed that the dual leucine zipper kinase (DLK) induces β-cell apoptosis. Since β-cell dysfunction precedes β-cell loss, in the present study the effect of DLK on insulin gene transcription was investigated in the HIT-T15 β-cell line. Downregulation of endogenous DLK increased whereas overexpression of DLK decreased human insulin gene transcription. 5'- and 3'-deletion human insulin promoter analyses resulted in the identification of a DLK responsive element that mapped to the DNA binding-site for the β-cell specific transcription factor MafA. Overexpression of DLK wild-type but not its kinase-dead mutant inhibited MafA transcriptional activity conferred by its transactivation domain. Furthermore, in the non-β-cell line JEG DLK inhibited MafA overexpression-induced human insulin promoter activity. Overexpression of MafA and DLK or its kinase-dead mutant into JEG cells revealed that DLK but not its mutant reduced MafA protein content. Inhibition of the down-stream DLK kinase c-Jun N-terminal kinase (JNK) by SP600125 attenuated DLK-induced MafA loss. Furthermore, mutation of the serine 65 to alanine, shown to confer MafA protein stability, increased MafA-dependent insulin gene transcription and prevented DLK-induced MafA loss in JEG cells. These data suggest that DLK by activating JNK triggers the phosphorylation and degradation of MafA thereby attenuating insulin gene transcription. Given the importance of MafA for β-cell function, the inhibition of DLK might preserve β-cell function and ultimately retard the development of diabetes mellitus type 2.

  15. Enterovirus type 71 2A protease functions as a transcriptional activator in yeast

    Directory of Open Access Journals (Sweden)

    Lai Meng-Jiun

    2010-08-01

    Full Text Available Abstract Enterovirus type 71 (EV71 2A protease exhibited strong transcriptional activity in yeast cells. The transcriptional activity of 2A protease was independent of its protease activity. EV71 2A protease retained its transcriptional activity after truncation of 40 amino acids at the N-terminus but lost this activity after truncation of 60 amino acids at the N-terminus or deletion of 20 amino acids at the C-terminus. Thus, the acidic domain at the C-terminus of this protein is essential for its transcriptional activity. Indeed, deletion of amino acids from 146 to 149 (EAME in this acidic domain lost the transcriptional activity of EV71 2A protein though still retained its protease activity. EV71 2A protease was detected both in the cytoplasm and nucleus using confocal microscopy analysis. Coxsackie virus B3 2A protease also exhibited transcriptional activity in yeast cells. As expected, an acidic domain in the C-terminus of Coxsackie virus B3 2A protease was also identified. Truncation of this acidic domain resulted in the loss of transcriptional activity. Interestingly, this acidic region of poliovirus 2A protease is critical for viral RNA replication. The transcriptional activity of the EV71 or Coxsackie virus B3 2A protease should play a role in viral replication and/or pathogenesis.

  16. Study of RNA interference inhibiting rat ovarian androgen biosynthesis by depressing 17alpha-hydroxylase/17, 20-lyase activity in vivo

    Directory of Open Access Journals (Sweden)

    Yang Xing

    2009-07-01

    Full Text Available Abstract Background 17alpha-hydroxylase/17, 20-lyase encoded by CYP17 is the key enzyme in androgen biosynthesis pathway. Previous studies demonstrated the accentuation of the enzyme in patients with polycystic ovary syndrome (PCOS was the most important mechanism of androgen excess. We chose CYP17 as the therapeutic target, trying to suppress the activity of 17alpha-hydroxylase/17, 20-lyase and inhibit androgen biosynthesis by silencing the expression of CYP17 in the rat ovary. Methods Three CYP17-targeting and one negative control oligonucleotides were designed and used in the present study. The silence efficiency of lentivirus shRNA was assessed by qRT-PCR, Western blotting and hormone assay. After subcapsular injection of lentivirus shRNA in rat ovary, the delivery efficiency was evaluated by GFP fluorescence and qPCR. Total RNA was extracted from rat ovary for CYP17 mRNA determination and rat serum was collected for hormone measurement. Results In total, three CYP17-targeting lentivirus shRNAs were synthesized. The results showed that all of them had a silencing effect on CYP17 mRNA and protein. Moreover, androstenedione secreted by rat theca interstitial cells (TIC in the RNAi group declined significantly compared with that in the control group. Two weeks after rat ovarian subcapsular injection of chosen CYP17 shRNA, the GFP fluorescence of frozen ovarian sections could be seen clearly under fluorescence microscope. It also showed that the GFP DNA level increased significantly, and its relative expression level was 7.42 times higher than that in the control group. Simultaneously, shRNA treatment significantly decreased CYP17 mRNA and protein levels at 61% and 54%, respectively. Hormone assay showed that all the levels of androstenedione, 17-hydroxyprogesterone and testosterone declined to a certain degree, but progesterone levels declined significantly. Conclusion The present study proves for the first time that ovarian androgen

  17. Transcription factor PIF4 controls the thermosensory activation of flowering

    KAUST Repository

    Kumar, S. Vinod

    2012-03-21

    Plant growth and development are strongly affected by small differences in temperature. Current climate change has already altered global plant phenology and distribution, and projected increases in temperature pose a significant challenge to agriculture. Despite the important role of temperature on plant development, the underlying pathways are unknown. It has previously been shown that thermal acceleration of flowering is dependent on the florigen, FLOWERING LOCUS T (FT). How this occurs is, however, not understood, because the major pathway known to upregulate FT, the photoperiod pathway, is not required for thermal acceleration of flowering. Here we demonstrate a direct mechanism by which increasing temperature causes the bHLH transcription factor PHYTOCHROME INTERACTING FACTOR4 (PIF4) to activate FT. Our findings provide a new understanding of how plants control their timing of reproduction in response to temperature. Flowering time is an important trait in crops as well as affecting the life cycles of pollinator species. A molecular understanding of how temperature affects flowering will be important for mitigating the effects of climate change. © 2012 Macmillan Publishers Limited. All rights reserved.

  18. Androgens and the breast.

    Science.gov (United States)

    Dimitrakakis, Constantine; Bondy, Carolyn

    2009-01-01

    Androgens have important physiological effects in women while at the same time they may be implicated in breast cancer pathologies. However, data on the effects of androgens on mammary epithelial proliferation and/or breast cancer incidence are not in full agreement. We performed a literature review evaluating current clinical, genetic and epidemiological data regarding the role of androgens in mammary growth and neoplasia. Epidemiological studies appear to have significant methodological limitations and thus provide inconclusive results. The study of molecular defects involving androgenic pathways in breast cancer is still in its infancy. Clinical and nonhuman primate studies suggest that androgens inhibit mammary epithelial proliferation and breast growth while conventional estrogen treatment suppresses endogenous androgens. Abundant clinical evidence suggests that androgens normally inhibit mammary epithelial proliferation and breast growth. Suppression of androgens using conventional estrogen treatment may thus enhance estrogenic breast stimulation and possibly breast cancer risk. Addition of testosterone to the usual hormone therapy regimen may diminish the estrogen/progestin increase in breast cancer risk but the impact of this combined use on mammary gland homeostasis still needs evaluation.

  19. Androgen receptor abnormalities

    NARCIS (Netherlands)

    A.O. Brinkmann (Albert); G.G.J.M. Kuiper (George); C. Ris-Stalpers (Carolyn); H.C.J. van Rooij (Henri); G. Romalo (G.); G. Trifiro (Gianluca); E. Mulder (Eppo); L. Pinsky (L.); H.U. Schweikert (H.); J. Trapman (Jan)

    1991-01-01

    markdownabstract__Abstract__ The human androgen receptor is a member of the superfamily of steroid hormone receptors. Proper functioning of this protein is a prerequisite for normal male sexual differentiation and development. The cloning of the human androgen receptor cDNA and the elucidation of t

  20. Differential Effects of Leptin on the Invasive Potential of Androgen-Dependent and -Independent Prostate Carcinoma Cells

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    Dayanand D. Deo

    2008-01-01

    Full Text Available Obesity has been linked with an increased risk of prostate cancer. The formation of toxic free oxygen radicals has been implicated in obesity mediated disease processes. Leptin is one of the major cytokines produced by adipocytes and controls body weight homeostasis through food intake and energy expenditure. The rationale of the study was to determine the impact of leptin on the metastatic potential of androgen-sensitive (LNCaP cells as well as androgen-insensitive (PC-3 and DU-145 cells. At a concentration of 200_nm, LNCaP cells showed a significant increase (20% above control; P<.0001 in cellular proliferation without any effect on androgen-insensitive cells. Furthermore, exposure to leptin caused a significant (P<.01 to P<.0001 dose-dependent decrease in migration and invasion of PC3 and Du-145 prostate carcinoma cell lines. At the molecular level, exposure of androgen-independent prostate cancer cells to leptin stimulates the phosphorylation of MAPK at early time point as well as the transcription factor STAT3, suggesting the activation of the intracellular signaling cascade upon leptin binding to its cognate receptor. Taken together, these results suggest that leptin mediates the invasive potential of prostate carcinoma cells, and that this effect is dependent on their androgen sensitivity.

  1. Integrated expression profiling and ChIP-seq analyses of the growth inhibition response program of the androgen receptor.

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    Biaoyang Lin

    Full Text Available BACKGROUND: The androgen receptor (AR plays important roles in the development of male phenotype and in different human diseases including prostate cancers. The AR can act either as a promoter or a tumor suppressor depending on cell types. The AR proliferative response program has been well studied, but its prohibitive response program has not yet been thoroughly studied. METHODOLOGY/PRINCIPAL FINDINGS: Previous studies found that PC3 cells expressing the wild-type AR inhibit growth and suppress invasion. We applied expression profiling to identify the response program of PC3 cells expressing the AR (PC3-AR under different growth conditions (i.e. with or without androgens and at different concentration of androgens and then applied the newly developed ChIP-seq technology to identify the AR binding regions in the PC3 cancer genome. A surprising finding was that the comparison of MOCK-transfected PC3 cells with AR-transfected cells identified 3,452 differentially expressed genes (two fold cutoff even without the addition of androgens (i.e. in ethanol control, suggesting that a ligand independent activation or extremely low-level androgen activation of the AR. ChIP-Seq analysis revealed 6,629 AR binding regions in the cancer genome of PC3 cells with an FDR (false discovery rate cut off of 0.05. About 22.4% (638 of 2,849 can be mapped to within 2 kb of the transcription start site (TSS. Three novel AR binding motifs were identified in the AR binding regions of PC3-AR cells, and two of them share a core consensus sequence CGAGCTCTTC, which together mapped to 27.3% of AR binding regions (1,808/6,629. In contrast, only about 2.9% (190/6,629 of AR binding sites contains the canonical AR matrix M00481, M00447 and M00962 (from the Transfac database, which is derived mostly from AR proliferative responsive genes in androgen dependent cells. In addition, we identified four top ranking co-occupancy transcription factors in the AR binding regions, which

  2. The Three Dimensional Quantitative Structure Activity Relationships (3D-QSAR and Docking Studies of Curcumin Derivatives as Androgen Receptor Antagonists

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    Jing Yang

    2012-05-01

    Full Text Available Androgen receptor antagonists have been proved to be effective anti-prostate cancer agents. 3D-QSAR and Molecular docking methods were performed on curcumin derivatives as androgen receptor antagonists. The bioactive conformation was explored by docking the potent compound 29 into the binding site of AR. The constructed Comparative Molecular Field Analysis (CoMFA and Comparative Similarity Indices Analysis (CoMSIA models produced statistically significant results with the cross-validated correlation coefficients q2 of 0.658 and 0.567, non-cross-validated correlation coefficients r2 of 0.988 and 0.978, and predicted correction coefficients r2pred of 0.715 and 0.793, respectively. These results ensure the CoMFA and CoMSIA models as a tool to guide the design of novel potent AR antagonists. A set of 30 new analogs were proposed by utilizing the results revealed in the present study, and were predicted with potential activities in the developed models.

  3. Spi-1/PU.1 activates transcription through clustered DNA occupancy in erythroleukemia.

    Science.gov (United States)

    Ridinger-Saison, Maya; Boeva, Valentina; Rimmelé, Pauline; Kulakovskiy, Ivan; Gallais, Isabelle; Levavasseur, Benjamin; Paccard, Caroline; Legoix-Né, Patricia; Morlé, François; Nicolas, Alain; Hupé, Philippe; Barillot, Emmanuel; Moreau-Gachelin, Françoise; Guillouf, Christel

    2012-10-01

    Acute leukemias are characterized by deregulation of transcriptional networks that control the lineage specificity of gene expression. The aberrant overexpression of the Spi-1/PU.1 transcription factor leads to erythroleukemia. To determine how Spi-1 mechanistically influences the transcriptional program, we combined a ChIP-seq analysis with transcriptional profiling in cells from an erythroleukemic mouse model. We show that Spi-1 displays a selective DNA-binding that does not often cause transcriptional modulation. We report that Spi-1 controls transcriptional activation and repression partially through distinct Spi-1 recruitment to chromatin. We revealed several parameters impacting on Spi-1-mediated transcriptional activation. Gene activation is facilitated by Spi-1 occupancy close to transcriptional starting site of genes devoid of CGIs. Moreover, in those regions Spi-1 acts by binding to multiple motifs tightly clustered and with similar orientation. Finally, in contrast to the myeloid and lymphoid B cells in which Spi-1 exerts a physiological activity, in the erythroleukemic cells, lineage-specific cooperating factors do not play a prevalent role in Spi-1-mediated transcriptional activation. Thus, our work describes a new mechanism of gene activation through clustered site occupancy of Spi-1 particularly relevant in regard to the strong expression of Spi-1 in the erythroleukemic cells.

  4. Improving fold activation of small transcription activating RNAs (STARs) with rational RNA engineering strategies.

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    Meyer, Sarai; Chappell, James; Sankar, Sitara; Chew, Rebecca; Lucks, Julius B

    2016-01-01

    Regulatory RNAs have become integral components of the synthetic biology and bioengineering toolbox for controlling gene expression. We recently expanded this toolbox by creating small transcription activating RNAs (STARs) that act by disrupting the formation of a target transcriptional terminator hairpin placed upstream of a gene. While STARs are a promising addition to the repertoire of RNA regulators, much work remains to be done to optimize the fold activation of these systems. Here we apply rational RNA engineering strategies to improve the fold activation of two STAR regulators. We demonstrate that a combination of promoter strength tuning and multiple RNA engineering strategies can improve fold activation from 5.4-fold to 13.4-fold for a STAR regulator derived from the pbuE riboswitch terminator. We then validate the generality of our approach and show that these same strategies improve fold activation from 2.1-fold to 14.6-fold for an unrelated STAR regulator, opening the door to creating a range of additional STARs to use in a broad array of biotechnologies. We also establish that the optimizations preserve the orthogonality of these STARs between themselves and a set of RNA transcriptional repressors, enabling these optimized STARs to be used in sophisticated circuits.

  5. HES6 drives a critical AR transcriptional programme to induce castration-resistant prostate cancer through activation of an E2F1-mediated cell cycle network.

    Science.gov (United States)

    Ramos-Montoya, Antonio; Lamb, Alastair D; Russell, Roslin; Carroll, Thomas; Jurmeister, Sarah; Galeano-Dalmau, Nuria; Massie, Charlie E; Boren, Joan; Bon, Helene; Theodorou, Vasiliki; Vias, Maria; Shaw, Greg L; Sharma, Naomi L; Ross-Adams, Helen; Scott, Helen E; Vowler, Sarah L; Howat, William J; Warren, Anne Y; Wooster, Richard F; Mills, Ian G; Neal, David E

    2014-05-01

    Castrate-resistant prostate cancer (CRPC) is poorly characterized and heterogeneous and while the androgen receptor (AR) is of singular importance, other factors such as c-Myc and the E2F family also play a role in later stage disease. HES6 is a transcription co-factor associated with stem cell characteristics in neural tissue. Here we show that HES6 is up-regulated in aggressive human prostate cancer and drives castration-resistant tumour growth in the absence of ligand binding by enhancing the transcriptional activity of the AR, which is preferentially directed to a regulatory network enriched for transcription factors such as E2F1. In the clinical setting, we have uncovered a HES6-associated signature that predicts poor outcome in prostate cancer, which can be pharmacologically targeted by inhibition of PLK1 with restoration of sensitivity to castration. We have therefore shown for the first time the critical role of HES6 in the development of CRPC and identified its potential in patient-specific therapeutic strategies.

  6. HES6 drives a critical AR transcriptional programme to induce castration-resistant prostate cancer through activation of an E2F1-mediated cell cycle network

    Science.gov (United States)

    Ramos-Montoya, Antonio; Lamb, Alastair D; Russell, Roslin; Carroll, Thomas; Jurmeister, Sarah; Galeano-Dalmau, Nuria; Massie, Charlie E; Boren, Joan; Bon, Helene; Theodorou, Vasiliki; Vias, Maria; Shaw, Greg L; Sharma, Naomi L; Ross-Adams, Helen; Scott, Helen E; Vowler, Sarah L; Howat, William J; Warren, Anne Y; Wooster, Richard F; Mills, Ian G; Neal, David E

    2014-01-01

    Castrate-resistant prostate cancer (CRPC) is poorly characterized and heterogeneous and while the androgen receptor (AR) is of singular importance, other factors such as c-Myc and the E2F family also play a role in later stage disease. HES6 is a transcription co-factor associated with stem cell characteristics in neural tissue. Here we show that HES6 is up-regulated in aggressive human prostate cancer and drives castration-resistant tumour growth in the absence of ligand binding by enhancing the transcriptional activity of the AR, which is preferentially directed to a regulatory network enriched for transcription factors such as E2F1. In the clinical setting, we have uncovered a HES6-associated signature that predicts poor outcome in prostate cancer, which can be pharmacologically targeted by inhibition of PLK1 with restoration of sensitivity to castration. We have therefore shown for the first time the critical role of HES6 in the development of CRPC and identified its potential in patient-specific therapeutic strategies. PMID:24737870

  7. Expression and function of androgen receptor coactivator p44/Mep50/WDR77 in ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Martin Ligr

    Full Text Available Hormones, including estrogen and progesterone, and their receptors play an important role in the development and progression of ovarian carcinoma. Androgen, its receptor and coactivators have also been implicated in these processes. p44/Mep50/WDR77 was identified as a subunit of the methylosome complex and lately characterized as a steroid receptor coactivator that enhances androgen receptor as well as estrogen receptor-mediated transcriptional activity in a ligand-dependent manner. We previously described distinct expression and function of p44 in prostate, testis, and breast cancers. In this report, we examined the expression and function of p44 in ovarian cancer. In contrast to findings in prostate and testicular cancer and similar to breast cancer, p44 shows strong cytoplasmic localization in morphologically normal ovarian surface and fallopian tube epithelia, while nuclear p44 is observed in invasive ovarian carcinoma. We observed that p44 can serve as a coactivator of both androgen receptor (AR and estrogen receptor (ER in ovarian cells. Further, overexpression of nuclear-localized p44 stimulates proliferation and invasion in ovarian cancer cells in the presence of estrogen or androgen. These findings strongly suggest that p44 plays a role in mediating the effects of hormones during ovarian tumorigenesis.

  8. Hypoxia-Inducible Factor 3 Is an Oxygen-Dependent Transcription Activator and Regulates a Distinct Transcriptional Response to Hypoxia

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    Peng Zhang

    2014-03-01

    Full Text Available Hypoxia-inducible factors (HIFs play key roles in the cellular response to hypoxia. It is widely accepted that whereas HIF-1 and HIF-2 function as transcriptional activators, HIF-3 inhibits HIF-1/2α action. Contrary to this idea, we show that zebrafish Hif-3α has strong transactivation activity. Hif-3α is degraded under normoxia. Mutation of P393, P493, and L503 inhibits this oxygen-dependent degradation. Transcriptomics and chromatin immunoprecipitation analyses identify genes that are regulated by Hif-3α, Hif-1α, or both. Under hypoxia or when overexpressed, Hif-3α binds to its target gene promoters and upregulates their expression. Dominant-negative inhibition and knockdown of Hif-3α abolish hypoxia-induced Hif-3α-promoter binding and gene expression. Hif-3α not only mediates hypoxia-induced growth and developmental retardation but also possesses hypoxia-independent activities. Importantly, transactivation activity is conserved and human HIF-3α upregulates similar genes in human cells. These findings suggest that Hif-3 is an oxygen-dependent transcription factor and activates a distinct transcriptional response to hypoxia.

  9. Wnt-induced transcriptional activation is exclusively mediated by TCF/LEF

    NARCIS (Netherlands)

    Schuijers, Jurian; Mokry, Michal; Hatzis, Pantelis; Cuppen, Edwin; Clevers, Hans

    2014-01-01

    Active canonical Wnt signaling results in recruitment of β-catenin to DNA by TCF/LEF family members, leading to transcriptional activation of TCF target genes. However, additional transcription factors have been suggested to recruit β-catenin and tether it to DNA. Here, we describe the genome-wide p

  10. Preparation of cell lines for single-cell analysis of transcriptional activation dynamics.

    Science.gov (United States)

    Rafalska-Metcalf, Ilona U; Janicki, Susan M

    2013-01-01

    Imaging molecularly defined regions of chromatin in single living cells during transcriptional activation has the potential to provide new insight into gene regulatory mechanisms. Here, we describe a method for isolating cell lines with multi-copy arrays of reporter transgenes, which can be used for real-time high-resolution imaging of transcriptional activation dynamics in single cells.

  11. A modified reverse one-hybrid screen identifies transcriptional activation in Phyochrome-Interacting Factor 3

    Science.gov (United States)

    Transcriptional activation domains (TAD) are difficult to predict and identify, since they are not conserved and have little consensus. Here, we describe a yeast-based screening method that is able to identify individual amino acid residues involved in transcriptional activation in a high throughput...

  12. Development of an androgen reporter gene assay (AR-LUX) utilizing a human cell line with an endogenously regulated androgen receptor

    NARCIS (Netherlands)

    Blankvoort, B.M.G.; Groene, E.M. de; Meeteren-Kreikamp, A.P. van; Witkamp, R.F.; Rodenburg, R.J.T.; Aarts, J.M.M.J.G.

    2001-01-01

    The aim of the work described in this report is to develop and characterize a cell-based androgen reporter assay. For this purpose, the androgen receptor (AR) expressing human breast cancer cell line T47D was stably transfected with a luciferase gene under transcriptional control of the PB-ARE-2 and

  13. Metabolite Profiling and a Transcriptional Activation Assay Provide Direct Evidence of Androgen Receptor Antagonism by Bisphenol A in Fish.

    Science.gov (United States)

    Widespread environmental contamination by bisphenol A (BPA) has created the need to fully define its potential toxic mechanisms of action (MOA) to properly assess human health and ecological risks from exposure. Although long recognized as an estrogen receptor (ER) agonist, some ...

  14. Transcriptional coactivator CIITA, a functional homolog of TAF1, has kinase activity.

    Science.gov (United States)

    Soe, Katherine C; Devaiah, Ballachanda N; Singer, Dinah S

    2013-11-01

    The Major Histocompatibility Complex (MHC) class II transactivator (CIITA) mediates activated immune responses and its deficiency results in the Type II Bare Lymphocyte Syndrome. CIITA is a transcriptional co-activator that regulates γ-interferon-activated transcription of MHC class I and class II genes. It is also a functional homolog of TAF1, a component of the general transcription factor complex TFIID. TAF1 and CIITA both possess intrinsic acetyltransferase (AT) activity that is required for transcription initiation. In response to induction by γ-interferon, CIITA and it's AT activity bypass the requirement for TAF1 AT activity. TAF1 also has kinase activity that is essential for its function. However, no similar activity has been identified for CIITA thus far. Here we report that CIITA, like TAF1, is a serine-threonine kinase. Its substrate specificity parallels, but does not duplicate, that of TAF1 in phosphorylating the TFIID component TAF7, the RAP74 subunit of the general transcription factor TFIIF and histone H2B. Like TAF1, CIITA autophosphorylates, affecting its interaction with TAF7. Additionally, CIITA phosphorylates histone H2B at Ser36, a target of TAF1 that is required for transcription during cell cycle progression and stress response. However, unlike TAF1, CIITA also phosphorylates all the other histones. The identification of this novel kinase activity of CIITA further clarifies its role as a functional homolog of TAF1 which may operate during stress and γ-IFN activated MHC gene transcription.

  15. Gene expression profile of androgen modulated genes in the murine fetal developing lung

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    Côté Mélissa

    2010-01-01

    Full Text Available Abstract Background Accumulating evidences suggest that sex affects lung development. Indeed, a higher incidence of respiratory distress syndrome is observed in male compared to female preterm neonates at comparable developmental stage and experimental studies demonstrated an androgen-related delay in male lung maturation. However, the precise mechanisms underlying these deleterious effects of androgens in lung maturation are only partially understood. Methods To build up a better understanding of the effect of androgens on lung development, we analyzed by microarrays the expression of genes showing a sexual difference and those modulated by androgens. Lungs of murine fetuses resulting from a timely mating window of 1 hour were studied at gestational day 17 (GD17 and GD18, corresponding to the period of surge of surfactant production. Using injections of the antiandrogen flutamide to pregnant mice, we hunted for genes in fetal lungs which are transcriptionally modulated by androgens. Results Results revealed that 1844 genes were expressed with a sexual difference at GD17 and 833 at GD18. Many genes were significantly modulated by flutamide: 1597 at GD17 and 1775 at GD18. Datasets were analyzed by using in silico tools for reconstruction of cellular pathways. Between GD17 and GD18, male lungs showed an intensive transcriptional activity of proliferative pathways along with the onset of lung differentiation. Among the genes showing a sex difference or an antiandrogen modulation of their expression, we specifically identified androgen receptor interacting genes, surfactant related genes in particularly those involved in the pathway leading to phospholipid synthesis, and several genes of lung development regulator pathways. Among these latter, some genes related to Shh, FGF, TGF-beta, BMP, and Wnt signaling are modulated by sex and/or antiandrogen treatment. Conclusion Our results show clearly that there is a real delay in lung maturation between

  16. Refinement of the androgen response element based on ChIP-Seq in androgen-insensitive and androgen-responsive prostate cancer cell lines.

    Science.gov (United States)

    Wilson, Stephen; Qi, Jianfei; Filipp, Fabian V

    2016-09-14

    Sequence motifs are short, recurring patterns in DNA that can mediate sequence-specific binding for proteins such as transcription factors or DNA modifying enzymes. The androgen response element (ARE) is a palindromic, dihexameric motif present in promoters or enhancers of genes targeted by the androgen receptor (AR). Using chromatin immunoprecipitation sequencing (ChIP-Seq) we refined AR-binding and AREs at a genome-scale in androgen-insensitive and androgen-responsive prostate cancer cell lines. Model-based searches identified more than 120,000 ChIP-Seq motifs allowing for expansion and refinement of the ARE. We classified AREs according to their degeneracy and their transcriptional involvement. Additionally, we quantified ARE utilization in response to somatic copy number amplifications, AR splice-variants, and steroid treatment. Although imperfect AREs make up 99.9% of the motifs, the degree of degeneracy correlates negatively with validated transcriptional outcome. Weaker AREs, particularly ARE half sites, benefit from neighboring motifs or cooperating transcription factors in regulating gene expression. Taken together, ARE full sites generate a reliable transcriptional outcome in AR positive cells, despite their low genome-wide abundance. In contrast, the transcriptional influence of ARE half sites can be modulated by cooperating factors.

  17. O-GlcNAc modification of Sp3 and Sp4 transcription factors negatively regulates their transcriptional activities.

    Science.gov (United States)

    Ha, Changhoon; Lim, Kihong

    2015-11-13

    The addition of O-linked N-acetylglucosamine (O-GlcNAc) on serine or threonine modifies a myriad of proteins and regulates their function, stability and localization. O-GlcNAc modification is common among chromosome-associated proteins, such as transcription factors, suggesting its extensive involvement in gene expression regulation. In this study, we demonstrate the O-GlcNAc status of the Sp family members of transcription factors and the functional impact on their transcriptional activities. We highlight the presence of O-GlcNAc residues in Sp3 and Sp4, but not Sp2, as demonstrated by their enrichment in GlcNAc positive protein fractions and by detection of O-GlcNAc residues on Sp3 and Sp4 co-expressed in Escherichia coli together with O-GlcNAc transferase (OGT) using an O-GlcNAc-specific antibody. Deletion mutants of Sp3 and Sp4 indicate that the majority of O-GlcNAc sites reside in their N-terminal transactivation domain. Overall, using reporter gene assays and co-immunoprecipitations, we demonstrate a functional inhibitory role of O-GlcNAc modifications in Sp3 and Sp4 transcription factors. Thereby, our study strengthens the current notion that O-GlcNAc modification is an important regulator of protein interactome.

  18. Altered activities of transcription factors and their related gene expression in cardiac tissues of diabetic rats.

    Science.gov (United States)

    Nishio, Y; Kashiwagi, A; Taki, H; Shinozaki, K; Maeno, Y; Kojima, H; Maegawa, H; Haneda, M; Hidaka, H; Yasuda, H; Horiike, K; Kikkawa, R

    1998-08-01

    Gene regulation in the cardiovascular tissues of diabetic subjects has been reported to be altered. To examine abnormal activities in transcription factors as a possible cause of this altered gene regulation, we studied the activity of two redox-sensitive transcription factors--nuclear factor-kappaB (NF-kappaB) and activating protein-1 (AP-1)--and the change in the mRNA content of heme oxygenase-1, which is regulated by these transcription factors in the cardiac tissues of rats with streptozotocin-induced diabetes. Increased activity of NF-kappaB and AP-1 but not nuclear transcription-activating factor, as determined by an electrophoretic mobility shift assay, was found in the hearts of 4-week diabetic rats. Glycemic control by a subcutaneous injection of insulin prevented these diabetes-induced changes in transcription factor activity. In accordance with these changes, the mRNA content of heme oxygenase-1 was increased fourfold in 4-week diabetic rats and threefold in 24-week diabetic rats as compared with control rats (P oxidative stress is involved in the activation of the transcription factors NF-kappaB and AP-1 in the cardiac tissues of diabetic rats, and that these abnormal activities of transcription factors could be associated with the altered gene regulation observed in the cardiovascular tissues of diabetic rats.

  19. pilS loci in Neisseria gonorrhoeae are transcriptionally active

    Science.gov (United States)

    Wachter, Jenny; Masters, Thao L.; Wachter, Shaun; Mason, Joanna

    2015-01-01

    Piliation is an important virulence determinant for Neisseria gonorrhoeae. PilE polypeptide is the major protein subunit in the pilus organelle and engages in extensive antigenic variation due to recombination between pilE and a pilS locus. pilS were so-named as they are believed to be transcriptionally silent, in contrast to the pilE locus. In this study, we demonstrate the presence of a small, pil-specific RNA species. Through using a series of pilE deletion mutants, we show by Northern blotting and quantitative reverse transcriptase PCR analysis (qRT-PCR), that these smaller RNA species are not derived from the primary pilE transcript following some processing events, but rather, arose through transcription of the pilS loci. Small transcriptome analysis, in conjunction with analysis of pilS recombinants, identified both sense and anti-sense RNAs originating from most, but not all, of the pilS gene copies. Focusing on the MS11 pilS6 locus, we identified by site-directed mutagenesis a sense promoter located immediately upstream of pilS6 copy 2, as well as an anti-sense promoter immediately downstream of pilS6 copy 1. Whole transcriptome analysis also revealed the presence of pil-specific sRNA in both gonococci and meningococci. Overall, this study reveals an added layer of complexity to the pilE/pilS recombination scheme by demonstrating pil-specific transcription within genes that were previously thought to be transcriptionally silent. PMID:25701734

  20. Inferring yeast cell cycle regulators and interactions using transcription factor activities

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    Galbraith Simon J

    2005-06-01

    Full Text Available Abstract Background Since transcription factors are often regulated at the post-transcriptional level, their activities, rather than expression levels may provide valuable information for investigating functions and their interactions. The recently developed Network Component Analysis (NCA and its generalized form (gNCA provide a robust framework for deducing the transcription factor activities (TFAs from various types of DNA microarray data and transcription factor-gene connectivity. The goal of this work is to demonstrate the utility of TFAs in inferring transcription factor functions and interactions in Saccharomyces cerevisiae cell cycle regulation. Results Using gNCA, we determined 74 TFAs from both wild type and fkh1 fkh2 deletion mutant microarray data encompassing 1529 ORFs. We hypothesized that transcription factors participating in the cell cycle regulation exhibit cyclic activity profiles. This hypothesis was supported by the TFA profiles of known cell cycle factors and was used as a basis to uncover other potential cell cycle factors. By combining the results from both cluster analysis and periodicity analysis, we recovered nearly 90% of the known cell cycle regulators, and identified 5 putative cell cycle-related transcription factors (Dal81, Hap2, Hir2, Mss11, and Rlm1. In addition, by analyzing expression data from transcription factor knockout strains, we determined 3 verified (Ace2, Ndd1, and Swi5 and 4 putative interaction partners (Cha4, Hap2, Fhl1, and Rts2 of the forkhead transcription factors. Sensitivity of TFAs to connectivity errors was determined to provide confidence level of these predictions. Conclusion By subjecting TFA profiles to analyses based upon physiological signatures we were able to identify cell cycle related transcription factors consistent with current literature, transcription factors with potential cell cycle dependent roles, and interactions between transcription factors.

  1. Regulation of selected genome loci using de novo-engineered transcription activator-like effector (TALE)-type transcription factors.

    Science.gov (United States)

    Morbitzer, Robert; Römer, Patrick; Boch, Jens; Lahaye, Thomas

    2010-12-14

    Proteins that can be tailored to bind desired DNA sequences are key tools for molecular biology. Previous studies suggested that DNA-binding specificity of transcription activator-like effectors (TALEs) from the bacterial genus Xanthomonas is defined by repeat-variable diresidues (RVDs) of tandem-arranged 34/35-amino acid repeat units. We have studied chimeras of two TALEs differing in RVDs and non-RVDs and found that, in contrast to the critical contributions by RVDs, non-RVDs had no major effect on the DNA-binding specificity of the chimeras. This finding suggests that one needs only to modify the RVDs to generate designer TALEs (dTALEs) to activate transcription of user-defined target genes. We used the scaffold of the TALE AvrBs3 and changed its RVDs to match either the tomato Bs4, the Arabidopsis EGL3, or the Arabidopsis KNAT1 promoter. All three dTALEs transcriptionally activated the desired promoters in a sequence-specific manner as mutations within the targeted DNA sequences abolished promoter activation. This study is unique in showing that chromosomal loci can be targeted specifically by dTALEs. We also engineered two AvrBs3 derivatives with four additional repeat units activating specifically either the pepper Bs3 or UPA20 promoter. Because AvrBs3 activates both promoters, our data show that addition of repeat units facilitates TALE-specificity fine-tuning. Finally, we demonstrate that the RVD NK mediates specific interaction with G nucleotides that thus far could not be targeted specifically by any known RVD type. In summary, our data demonstrate that the TALE scaffold can be tailored to target user-defined DNA sequences in whole genomes.

  2. Fur-mediated activation of gene transcription in the human pathogen Neisseria gonorrhoeae.

    Science.gov (United States)

    Yu, Chunxiao; Genco, Caroline Attardo

    2012-04-01

    It is well established that the ferric uptake regulatory protein (Fur) functions as a transcriptional repressor in diverse microorganisms. Recent studies demonstrated that Fur also functions as a transcriptional activator. In this study we defined Fur-mediated activation of gene transcription in the sexually transmitted disease pathogen Neisseria gonorrhoeae. Analysis of 37 genes which were previously determined to be iron induced and which contained putative Fur boxes revealed that only 30 of these genes exhibited reduced transcription in a gonococcal fur mutant strain. Fur-mediated activation was established by examining binding of Fur to the putative promoter regions of 16 Fur-activated genes with variable binding affinities observed. Only ∼50% of the newly identified Fur-regulated genes bound Fur in vitro, suggesting that additional regulatory circuits exist which may function through a Fur-mediated indirect mechanism. The gonococcal Fur-activated genes displayed variable transcription patterns in a fur mutant strain, which correlated with the position of the Fur box in each (promoter) region. These results suggest that Fur-mediated direct transcriptional activation is fulfilled by multiple mechanisms involving either competing with a repressor or recruiting RNA polymerase. Collectively, our studies have established that gonococcal Fur functions as an activator of gene transcription through both direct and indirect mechanisms.

  3. Distinct DNA-based epigenetic switches trigger transcriptional activation of silent genes in human dermal fibroblasts.

    Science.gov (United States)

    Pandian, Ganesh N; Taniguchi, Junichi; Junetha, Syed; Sato, Shinsuke; Han, Le; Saha, Abhijit; AnandhaKumar, Chandran; Bando, Toshikazu; Nagase, Hiroki; Vaijayanthi, Thangavel; Taylor, Rhys D; Sugiyama, Hiroshi

    2014-01-24

    The influential role of the epigenome in orchestrating genome-wide transcriptional activation instigates the demand for the artificial genetic switches with distinct DNA sequence recognition. Recently, we developed a novel class of epigenetically active small molecules called SAHA-PIPs by conjugating selective DNA binding pyrrole-imidazole polyamides (PIPs) with the histone deacetylase inhibitor SAHA. Screening studies revealed that certain SAHA-PIPs trigger targeted transcriptional activation of pluripotency and germ cell genes in mouse and human fibroblasts, respectively. Through microarray studies and functional analysis, here we demonstrate for the first time the remarkable ability of thirty-two different SAHA-PIPs to trigger the transcriptional activation of exclusive clusters of genes and noncoding RNAs. QRT-PCR validated the microarray data, and some SAHA-PIPs activated therapeutically significant genes like KSR2. Based on the aforementioned results, we propose the potential use of SAHA-PIPs as reagents capable of targeted transcriptional activation.

  4. Corepressor effect on androgen receptor activity varies with the length of the CAG encoded polyglutamine repeat and is dependent on receptor/corepressor ratio in prostate cancer cells.

    Science.gov (United States)

    Buchanan, Grant; Need, Eleanor F; Barrett, Jeffrey M; Bianco-Miotto, Tina; Thompson, Vanessa C; Butler, Lisa M; Marshall, Villis R; Tilley, Wayne D; Coetzee, Gerhard A

    2011-08-01

    The response of prostate cells to androgens reflects a combination of androgen receptor (AR) transactivation and transrepression, but how these two processes differ mechanistically and influence prostate cancer risk and disease outcome remain elusive. Given recent interest in targeting AR transrepressive processes, a better understanding of AR/corepressor interaction and responses is warranted. Here, we used transactivation and interaction assays with wild-type and mutant ARs, and deletion AR fragments, to dissect the relationship between AR and the corepressor, silencing mediator for retinoic acid and thyroid hormone receptors (SMRT). We additionally tested how these processes are influenced by AR agonist and antagonist ligands, as well as by variation in the polyglutamine tract in the AR amino terminal domain (NTD), which is encoded by a polymorphic CAG repeat in the gene. SMRT was recruited to the AR ligand binding domain by agonist ligand, and as determined by the effect of strategic mutations in activation function 2 (AF-2), requires a precise conformation of that domain. A distinct region of SMRT also mediated interaction with the AR-NTD via the transactivation unit 5 (TAU5; residues 315-538) region. The degree to which SMRT was able to repress AR increased from 17% to 56% as the AR polyglutamine repeat length was increased from 9 to 42 residues, but critically this effect could be abolished by increasing the SMRT:AR molar ratio. These data suggest that the extent to which the CAG encoded polyglutamine repeat influences AR activity represents a balance between corepressor and coactivator occupancy of the same ligand-dependent and independent AR interaction surfaces. Changes in the homeostatic relationship of AR to these molecules, including SMRT, may explain the variable penetrance of the CAG repeat and the loss of AR signaling flexibility in prostate cancer progression.

  5. Novel Role for p110β PI 3-Kinase in Male Fertility through Regulation of Androgen Receptor Activity in Sertoli Cells

    Science.gov (United States)

    Guillermet-Guibert, Julie; Smith, Lee B.; Halet, Guillaume; Whitehead, Maria A.; Pearce, Wayne; Rebourcet, Diane; León, Kelly; Crépieux, Pascale; Nock, Gemma; Strömstedt, Maria; Enerback, Malin; Chelala, Claude; Graupera, Mariona; Carroll, John; Cosulich, Sabina; Saunders, Philippa T. K.; Huhtaniemi, Ilpo; Vanhaesebroeck, Bart

    2015-01-01

    The organismal roles of the ubiquitously expressed class I PI3K isoform p110β remain largely unknown. Using a new kinase-dead knockin mouse model that mimics constitutive pharmacological inactivation of p110β, we document that full inactivation of p110β leads to embryonic lethality in a substantial fraction of mice. Interestingly, the homozygous p110β kinase-dead mice that survive into adulthood (maximum ~26% on a mixed genetic background) have no apparent phenotypes, other than subfertility in females and complete infertility in males. Systemic inhibition of p110β results in a highly specific blockade in the maturation of spermatogonia to spermatocytes. p110β was previously suggested to signal downstream of the c-kit tyrosine kinase receptor in germ cells to regulate their proliferation and survival. We now report that p110β also plays a germ cell-extrinsic role in the Sertoli cells (SCs) that support the developing sperm, with p110β inactivation dampening expression of the SC-specific Androgen Receptor (AR) target gene Rhox5, a homeobox gene critical for spermatogenesis. All extragonadal androgen-dependent functions remain unaffected by global p110β inactivation. In line with a crucial role for p110β in SCs, selective inactivation of p110β in these cells results in male infertility. Our study is the first documentation of the involvement of a signalling enzyme, PI3K, in the regulation of AR activity during spermatogenesis. This developmental pathway may become active in prostate cancer where p110β and AR have previously been reported to functionally interact. PMID:26132308

  6. Novel Role for p110β PI 3-Kinase in Male Fertility through Regulation of Androgen Receptor Activity in Sertoli Cells.

    Directory of Open Access Journals (Sweden)

    Julie Guillermet-Guibert

    2015-07-01

    Full Text Available The organismal roles of the ubiquitously expressed class I PI3K isoform p110β remain largely unknown. Using a new kinase-dead knockin mouse model that mimics constitutive pharmacological inactivation of p110β, we document that full inactivation of p110β leads to embryonic lethality in a substantial fraction of mice. Interestingly, the homozygous p110β kinase-dead mice that survive into adulthood (maximum ~26% on a mixed genetic background have no apparent phenotypes, other than subfertility in females and complete infertility in males. Systemic inhibition of p110β results in a highly specific blockade in the maturation of spermatogonia to spermatocytes. p110β was previously suggested to signal downstream of the c-kit tyrosine kinase receptor in germ cells to regulate their proliferation and survival. We now report that p110β also plays a germ cell-extrinsic role in the Sertoli cells (SCs that support the developing sperm, with p110β inactivation dampening expression of the SC-specific Androgen Receptor (AR target gene Rhox5, a homeobox gene critical for spermatogenesis. All extragonadal androgen-dependent functions remain unaffected by global p110β inactivation. In line with a crucial role for p110β in SCs, selective inactivation of p110β in these cells results in male infertility. Our study is the first documentation of the involvement of a signalling enzyme, PI3K, in the regulation of AR activity during spermatogenesis. This developmental pathway may become active in prostate cancer where p110β and AR have previously been reported to functionally interact.

  7. Signal transducer and activator of transcription 6 gene G2964A polymorphism and inflammatory bowel disease.

    NARCIS (Netherlands)

    Xia, B; Crusius, J.B.A.; Wu, J; Zwiers, A.; Bodegraven, van A.A.; Pena, A.S.

    2003-01-01

    Signal transducer and activator of transcription 6 (STAT6) is a key transcription factor involved in interleukin 4 (IL-4) and IL-13-mediated Th2 response. The STAT6 gene is located on chromosome 12q13.3-14.1 (IBD2 region) and is therefore a positional and functional candidate gene for study in infla

  8. Differential splicing of human androgen receptor pre-mRNA in X-linked reifenstein syndrome, because of a deletion involving a putative branch site

    Energy Technology Data Exchange (ETDEWEB)

    Ris-Stalpers, C.; Verleun-Mooijman, M.C.T.; Blaeij, T.J.P. de; Brinkmann, A.O.; Degenhart, H.J.; Trapman, J. (Erasmus Univ., Rotterdam (Netherlands))

    1994-04-01

    The analysis of the androgen receptor (AR) gene, mRNA, and protein in a subject with X-linked Reifenstein syndrome (partial androgen insensitivity) is reported. The presence of two mature AR transcripts in genital skin fibroblasts of the patient is established, and, by reverse transcriptase-PCR and RNase transcription analysis, the wild-type transcript and a transcript in which exon 3 sequences are absent without disruption of the translational reading frame are identified. Sequencing and hybridization analysis show a deletion of >6 kb in intron 2 of the human AR gene, starting 18 bp upstream of exon 3. The deletion includes the putative branch-point sequence (BPS) but not the acceptor splice site on the intron 2/exon 3 boundary. The deletion of the putative intron 2 BPS results in 90% inhibition of wild-type splicing. The mutant transcript encodes an AR protein lacking the second zinc finger of the DNA-binding domain. Western/immunoblotting analysis is used to show that the mutant AR protein is expressed in genital skin fibroblasts of the patient. The residual 10% wild-type transcript can be the result of the use of a cryptic BPS located 63 bp upstream of the intron 2/exon 3 boundary of the mutant AR gene. The mutated AR protein has no transcription-activating potential and does not influence the transactivating properties of the wild-type AR, as tested in cotransfection studies. It is concluded that the partial androgen-insensitivity syndrome of this patient is the consequence of the limited amount of wild-type AR protein expressed in androgen target cells, resulting from the deletion of the intron 2 putative BPS. 42 refs., 6 figs., 1 tab.

  9. ENVIRONMENTAL ANDROGENS AND ANTIANDROGENS: AN EXPANDING CHEMICAL UNIVERSE

    Science.gov (United States)

    Within the last ten years, awareness has grown about environmental chemicals that display antiandrogenic or androgenic activity. While studies in the early 1990s focused on pesticides that acted as androgen receptor (AR) antagonists, it soon became evident that this was not the ...

  10. Uncarboxylated Osteocalcin and Gprc6a Axis Produce Intratumoral Androgens in Castration-Resistant Prostate Cancer

    Science.gov (United States)

    2016-05-01

    state in the progression of prostate cancer . Recently, tumor cells have been shown to activate androgen receptor signaling via multiple pathways ...Gprc6a axis is functional in VCaP prostate cancer cells. This pathway can induce intra turmoral androgen synthesis through overexpression of...androgen biosynthetic enzyme expression. Together this pathway promotes prostate cancer bone metastasis and drive androgen receptor mediated bone tumor

  11. Synergistic cooperation of MDM2 and E2F1 contributes to TAp73 transcriptional activity

    Energy Technology Data Exchange (ETDEWEB)

    Kasim, Vivi, E-mail: vivikasim78@gmail.com [The Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Huang, Can; Zhang, Jing; Jia, Huizhen; Wang, Yunxia [The Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Yang, Li [The Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); The 111 Project Laboratory of Biomechanics and Tissue Repair, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Miyagishi, Makoto [Molecular Composite Medicine Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566 (Japan); Wu, Shourong, E-mail: shourongwu@hotmail.com [The Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); The 111 Project Laboratory of Biomechanics and Tissue Repair, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2014-07-04

    Highlights: • MDM2 is a novel positive regulator of TAp73 transcriptional activity. • MDM2 colocalizes together and physically interacts with E2F1. • Synergistic cooperation of MDM2 and E2F1 is crucial for TAp73 transcription. • MDM2 regulates TAp73 transcriptional activity in a p53-independent manner. - Abstract: TAp73, a structural homologue of p53, plays an important role in tumorigenesis. E2F1 had been reported as a transcriptional regulator of TAp73, however, the detailed mechanism remains to be elucidated. Here we reported that MDM2-silencing reduced the activities of the TAp73 promoters and the endogenous TAp73 expression level significantly; while MDM2 overexpression upregulated them. We further revealed that the regulation of TAp73 transcriptional activity occurs as a synergistic effect of MDM2 and E2F1, most probably through their physical interaction in the nuclei. Furthermore, we also suggested that MDM2 might be involved in DNA damage-induced TAp73 transcriptional activity. Finally, we elucidated that MDM2-silencing reduced the proliferation rate of colon carcinoma cells regardless of the p53 status. Our data show a synergistic effect of MDM2 and E2F1 on TAp73 transcriptional activity, suggesting a novel regulation pathway of TAp73.

  12. Development and exploitation of a novel mutant androgen receptor modelling strategy to identify new targets for advanced prostate cancer therapy.

    Science.gov (United States)

    O'Neill, Daniel; Jones, Dominic; Wade, Mark; Grey, James; Nakjang, Sirintra; Guo, Wenrui; Cork, David; Davies, Barry R; Wedge, Steve R; Robson, Craig N; Gaughan, Luke

    2015-09-22

    The persistence of androgen receptor (AR) signalling in castrate-resistant prostate cancer (CRPC) highlights the unmet clinical need for the development of more effective AR targeting therapies. A key mechanism of therapy-resistance is by selection of AR mutations that convert anti-androgens to agonists enabling the retention of androgenic signalling in CRPC. To improve our understanding of these receptors in advanced disease we developed a physiologically-relevant model to analyse the global functionality of AR mutants in CRPC. Using the bicalutamide-activated AR(W741L/C) mutation as proof of concept, we demonstrate that this mutant confers an androgenic-like signalling programme and growth promoting phenotype in the presence of bicalutamide. Transcriptomic profiling of AR(W741L) highlighted key genes markedly up-regulated by the mutant receptor, including TIPARP, RASD1 and SGK1. Importantly, SGK1 expression was found to be highly expressed in the KUCaP xenograft model and a CRPC patient biopsy sample both of which express the bicalutamide-activated receptor mutant. Using an SGK1 inhibitor, AR(W741L) transcriptional and growth promoting activity was reduced indicating that exploiting functional distinctions between receptor isoforms in our model may provide new and effective therapies for CRPC patients.

  13. SENSITIVE TO PROTON RHIZOTOXICITY1, CALMODULIN BINDING TRANSCRIPTION ACTIVATOR2, and other transcription factors are involved in ALUMINUM-ACTIVATED MALATE TRANSPORTER1 expression.

    Science.gov (United States)

    Tokizawa, Mutsutomo; Kobayashi, Yuriko; Saito, Tatsunori; Kobayashi, Masatomo; Iuchi, Satoshi; Nomoto, Mika; Tada, Yasuomi; Yamamoto, Yoshiharu Y; Koyama, Hiroyuki

    2015-03-01

    In Arabidopsis (Arabidopsis thaliana) the root apex is protected from aluminum (Al) rhizotoxicity by excretion of malate, an Al chelator, by ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (AtALMT1). AtALMT1 expression is fundamentally regulated by the SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) zinc finger protein, but other transcription factors have roles that enable Al-inducible expression with a broad dynamic range. In this study, we characterized multiple cis-elements in the AtALMT1 promoter that interact with transcription factors. In planta complementation assays of AtALMT1 driven by 5' truncated promoters of different lengths showed that the promoter region between -540 and 0 (the first ATG) restored the Al-sensitive phenotype of atalm1 and thus contains cis-elements essential for AtALMT1 expression for Al tolerance. Computation of overrepresented octamers showed that eight regions in this promoter region contained potential cis-elements involved in Al induction and STOP1 regulation. Mutation in a position around -297 from the first ATG completely inactivated AtALMT1 expression and Al response. In vitro binding assays showed that this region contained the STOP1 binding site, which accounted for the recognition by four zinc finger domains of the protein. Other positions were characterized as cis-elements that regulated expression by repressors and activators and a transcription factor that determines root tip expression of AtALMT1. From the consensus of known cis-elements, we identified CALMODULIN-BINDING TRANSCRIPTION ACTIVATOR2 to be an activator of AtALMT1 expression. Al-inducible expression of AtALMT1 changed transcription starting sites, which increased the abundance of transcripts with a shortened 5' untranslated region. The present analyses identified multiple mechanisms that regulate AtALMT1 expression.

  14. Building predictive gene signatures through simultaneous assessment of transcription factor activation and gene expression.

    Science.gov (United States)

    Building predictive gene signatures through simultaneous assessment of transcription factor activation and gene expression Exposure to many drugs and environmentally-relevant chemicals can cause adverse outcomes. These adverse outcomes, such as cancer, have been linked to mol...

  15. (-)-Epicatechin gallate (ECG) stimulates osteoblast differentiation via Runt-related transcription factor 2 (RUNX2) and transcriptional coactivator with PDZ-binding motif (TAZ)-mediated transcriptional activation.

    Science.gov (United States)

    Byun, Mi Ran; Sung, Mi Kyung; Kim, A Rum; Lee, Cham Han; Jang, Eun Jung; Jeong, Mi Gyeong; Noh, Minsoo; Hwang, Eun Sook; Hong, Jeong-Ho

    2014-04-01

    Osteoporosis is a degenerative bone disease characterized by low bone mass and is caused by an imbalance between osteoblastic bone formation and osteoclastic bone resorption. It is known that the bioactive compounds present in green tea increase osteogenic activity and decrease the risk of fracture by improving bone mineral density. However, the detailed mechanism underlying these beneficial effects has yet to be elucidated. In this study, we investigated the osteogenic effect of (-)-epicatechin gallate (ECG), a major bioactive compound found in green tea. We found that ECG effectively stimulates osteoblast differentiation, indicated by the increased expression of osteoblastic marker genes. Up-regulation of osteoblast marker genes is mediated by increased expression and interaction of the transcriptional coactivator with PDZ-binding motif (TAZ) and Runt-related transcription factor 2 (RUNX2). ECG facilitates nuclear localization of TAZ through PP1A. PP1A is essential for osteoblast differentiation because inhibition of PP1A activity was shown to suppress ECG-mediated osteogenic differentiation. Taken together, the results showed that ECG stimulates osteoblast differentiation through the activation of TAZ and RUNX2, revealing a novel mechanism for green tea-stimulated osteoblast differentiation.

  16. Two distinct domains of Flo8 activator mediates its role in transcriptional activation and the physical interaction with Mss11.

    Science.gov (United States)

    Kim, Hye Young; Lee, Sung Bae; Kang, Hyen Sam; Oh, Goo Taeg; Kim, TaeSoo

    2014-06-27

    Flo8 is a transcriptional activator essential for the inducible expression of a set of target genes such as STA1, FLO11, and FLO1 encoding an extracellular glucoamylase and two cell surface proteins, respectively. However, the molecular mechanism of Flo8-mediated transcriptional activation remains largely elusive. By generating serial deletion constructs, we revealed here that a novel transcriptional activation domain on its extreme C-terminal region plays a crucial role in activating transcription. On the other hand, the N-terminal LisH motif of Flo8 appears to be required for its physical interaction with another transcriptional activator, Mss11, for their cooperative transcriptional regulation of the shared targets. Additionally, GST pull-down experiments uncovered that Flo8 and Mss11 can directly form either a heterodimer or a homodimer capable of binding to DNA, and we also showed that this formed complex of two activators interacts functionally and physically with the Swi/Snf complex. Collectively, our findings provide valuable clues for understanding the molecular mechanism of Flo8-mediated transcriptional control of multiple targets.

  17. Double-Stranded-RNA-Activated Protein Kinase PKR Enhances Transcriptional Activation by Tumor Suppressor p53

    OpenAIRE

    1999-01-01

    The tumor suppressor p53 plays a key role in inducing G1 arrest and apoptosis following DNA damage. The double-stranded-RNA-activated protein PKR is a serine/threonine interferon (IFN)-inducible kinase which plays an important role in regulation of gene expression at both transcriptional and translational levels. Since a cross talk between IFN-inducible proteins and p53 had already been established, we investigated whether and how p53 function was modulated by PKR. We analyzed p53 function in...

  18. Gene expression profiling of aging reveals activation of a p53-mediated transcriptional program

    Directory of Open Access Journals (Sweden)

    Weindruch Richard

    2007-03-01

    Full Text Available Abstract Background Aging has been associated with widespread changes at the gene expression level in multiple mammalian tissues. We have used high density oligonucleotide arrays and novel statistical methods to identify specific transcriptional classes that may uncover biological processes that play a central role in mammalian aging. Results We identified 712 transcripts that are differentially expressed in young (5 month old and old (25-month old mouse skeletal muscle. Caloric restriction (CR completely or partially reversed 87% of the changes in expression. Examination of individual genes revealed a transcriptional profile indicative of increased p53 activity in the older muscle. To determine whether the increase in p53 activity is associated with transcriptional activation of apoptotic targets, we performed RT-PCR on four well known mediators of p53-induced apoptosis: puma, noxa, tnfrsf10b and bok. Expression levels for these proapoptotic genes increased significantly with age (P +/- and GPX4+/- mice, suggesting that oxidative stress does not induce the expression of these genes. Western blot analysis confirmed that protein levels for both p21 and GADD45a, two established transcriptional targets of p53, were higher in the older muscle tissue. Conclusion These observations support a role for p53-mediated transcriptional program in mammalian aging and suggest that mechanisms other than reactive oxygen species are involved in the age-related transcriptional activation of p53 targets.

  19. [Bone and Men's Health. Bone selective androgen receptor modulators].

    Science.gov (United States)

    Furuya, Kazuyuki

    2010-02-01

    Androgen, one of the sex steroid hormones shows various biological activities on the corresponding various tissues. Many efforts to produce novel drug materials maintaining a desired biological activity with an adequate tissue selectivity, which is so-called selective androgen receptor modulators (SARMs) , are being performed. As one of such efforts, studies on SARMs against bone tissues which possess a significant potential to stimulate a bone formation with reducing undesirable androgenic virilizing activities are in progress all over the world. This review focuses on the research and development activities of such SARMs and discuses their usefulness for the treatment of osteoporosis.

  20. Global identification and characterization of transcriptionally active regions in the rice genome.

    Directory of Open Access Journals (Sweden)

    Lei Li

    Full Text Available Genome tiling microarray studies have consistently documented rich transcriptional activity beyond the annotated genes. However, systematic characterization and transcriptional profiling of the putative novel transcripts on the genome scale are still lacking. We report here the identification of 25,352 and 27,744 transcriptionally active regions (TARs not encoded by annotated exons in the rice (Oryza. sativa subspecies japonica and indica, respectively. The non-exonic TARs account for approximately two thirds of the total TARs detected by tiling arrays and represent transcripts likely conserved between japonica and indica. Transcription of 21,018 (83% japonica non-exonic TARs was verified through expression profiling in 10 tissue types using a re-array in which annotated genes and TARs were each represented by five independent probes. Subsequent analyses indicate that about 80% of the japonica TARs that were not assigned to annotated exons can be assigned to various putatively functional or structural elements of the rice genome, including splice variants, uncharacterized portions of incompletely annotated genes, antisense transcripts, duplicated gene fragments, and potential non-coding RNAs. These results provide a systematic characterization of non-exonic transcripts in rice and thus expand the current view of the complexity and dynamics of the rice transcriptome.

  1. Characterization of identity, metabolism and androgenic activity of 17-hydroxyandrosta-3,5-diene by GC-MS and a yeast transactivation system.

    Science.gov (United States)

    Bauer, Anne; Rataj, Felicitas; Zierau, Oliver; Anielski, Patricia; Große, Joachim; Parr, Maria-Kristina; Vollmer, Günter; Thieme, Detlef

    2012-12-01

    Anabolic-androgenic steroids are frequently misused compounds in sports, and they belong to the controlled substances according to the requirements of the World Anti-Doping Agency. The classical techniques of steroid detection are mass spectrometry coupled to gas or liquid chromatography. Biological methods that base on the ability of substances to bind the steroid receptor are not applied in routine doping control procedures so far, but they appear to be useful for characterization of steroid androgenic potential. In this study we used the yeast androgen receptor reporter system (YAS), which in the past has already successfully been applied to both various androgenic substances and also urine samples. Giving attention to the androgenic potential of steroidal dietary supplements, we exemplified the analysis using both mass spectrometry techniques and the YAS-based assay on the product "Syntrax Tetrabol" which was a confiscated dietary supplement and marketed as a steroid precursor. Identification, structure and the kinetic behavior of its excreted metabolites were analyzed by NMR, GC-MS and LC-MS/MS. The androgenic potential of the parent compound as well as its metabolites in urine was evaluated with the help of the YAS. The application of urine samples with a previous deconjugation and the inclusion of urine density values were carried out and led to increased responses on the YAS. Further, the possibility of a complementary application of structure-based instrumental analysis and biological detection of androgenicity with the help of the YAS seems to be desirable and is discussed.

  2. Sequential changes in chromatin structure during transcriptional activation in the beta globin LCR and its target gene.

    Science.gov (United States)

    Kim, Kihoon; Kim, AeRi

    2010-09-01

    Chromatin structure is modulated during transcriptional activation. The changes include the association of transcriptional activators, formation of hypersensitive sites and covalent modifications of histones. To understand the order of the various changes accompanying transcriptional activation, we analyzed the mouse beta globin gene, which is transcriptionally inducible in erythroid MEL cells over a time course of HMBA treatment. Transcription of the globin genes requires the locus control region (LCR) consisting of several hypersensitive sites (HSs). Erythroid specific transcriptional activators such as NF-E2, GATA-1, TAL1 and EKLF were associated with the LCR in the uninduced state before transcriptional activation. The HSs of the LCR were formed in this state as revealed by high sensitivity to DNase I and MNase attack. However the binding of transcriptional activators and the depletion of histones were observed in the promoter of the beta globin gene only after transcriptional activation. In addition, various covalent histone modifications were sequentially detected in lysine residues of histone H3 during the activation. Acetylation of K9, K36 and K27 was notable in both LCR HSs and gene after induction but before transcriptional initiation. Inactive histone marks such as K9me2, K36me2 and K27me2 were removed coincident with transcriptional initiation in the gene region. Taken together, these results indicate that LCR has a substantially active structure in the uninduced state while transcriptional activation serially adds active marks, including histone modifications, and removes inactive marks in the target gene of the LCR.

  3. Activated AMPK inhibits PPAR-{alpha} and PPAR-{gamma} transcriptional activity in hepatoma cells.

    Science.gov (United States)

    Sozio, Margaret S; Lu, Changyue; Zeng, Yan; Liangpunsakul, Suthat; Crabb, David W

    2011-10-01

    AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-α (PPAR-α) are critical regulators of short-term and long-term fatty acid oxidation, respectively. We examined whether the activities of these molecules were coordinately regulated. H4IIEC3 cells were transfected with PPAR-α and PPAR-γ expression plasmids and a peroxisome-proliferator-response element (PPRE) luciferase reporter plasmid. The cells were treated with PPAR agonists (WY-14,643 and rosiglitazone), AMPK activators 5-aminoimidazole-4-carboxamide riboside (AICAR) and metformin, and the AMPK inhibitor compound C. Both AICAR and metformin decreased basal and WY-14,643-stimulated PPAR-α activity; compound C increased agonist-stimulated reporter activity and partially reversed the effect of the AMPK activators. Similar effects on PPAR-γ were seen, with both AICAR and metformin inhibiting PPRE reporter activity. Compound C increased basal PPAR-γ activity and rosiglitazone-stimulated activity. In contrast, retinoic acid receptor-α (RAR-α), another nuclear receptor that dimerizes with retinoid X receptor (RXR), was largely unaffected by the AMPK activators. Compound C modestly increased AM580 (an RAR agonist)-stimulated activity. The AMPK activators did not affect PPAR-α binding to DNA, and there was no consistent correlation between effects of the AMPK activators and inhibitor on PPAR and the nuclear localization of AMPK-α subunits. Expression of either a constitutively active or dominant negative AMPK-α inhibited basal and WY-14,643-stimulated PPAR-α activity and basal and rosiglitazone-stimulated PPAR-γ activity. We concluded that the AMPK activators AICAR and metformin inhibited transcriptional activities of PPAR-α and PPAR-γ, whereas inhibition of AMPK with compound C activated both PPARs. The effects of AMPK do not appear to be mediated through effects on RXR or on PPAR/RXR binding to DNA. These effects are independent of kinase activity and instead appear to

  4. A randomised controlled trial to evaluate the efficacy of a 6 month dietary and physical activity intervention for prostate cancer patients receiving androgen deprivation therapy

    Directory of Open Access Journals (Sweden)

    Haseen Farhana

    2010-08-01

    Full Text Available Abstract Background Treatment with Androgen Deprivation Therapy (ADT for prostate cancer is associated with changes in body composition including increased fat and decreased lean mass; increased fatigue, and a reduction in quality of life. No study to date has evaluated the effect of dietary and physical activity modification on the side-effects related to ADT. The aim of this study is to evaluate the efficacy of a 6-month dietary and physical activity intervention for prostate cancer survivors receiving ADT to minimise the changes in body composition, fatigue and quality of life, typically associated with ADT. Methods Men are recruited to this study if their treatment plan is to receive ADT for at least 6 months. Men who are randomised to the intervention arm receive a home-based tailored intervention to meet the following guidelines a ≥ 5 servings vegetables and fruits/day; b 30%-35% of total energy from fat, and Discussion The results of this study will provide detailed information on diet and physical activity levels in prostate cancer patients treated with ADT and will test the feasibility and efficacy of a diet and physical activity intervention which could provide essential information to develop guidelines for prostate cancer patients to minimise the side effects related to ADT. Trial registration ISRCTN trial number ISCRTN75282423

  5. Antifolate/folate-activated HGF/c-Met signalling pathways in mouse kidneys-the putative role of their downstream effectors in cross-talk with androgen receptor.

    Science.gov (United States)

    Dudkowska, Magdalena; Bajer, Seweryn; Jaworski, Tomasz; Zielińska, Joanna; Manteuffel-Cymborowska, Małgorzata; Grzelakowska-Sztabert, Barbara

    2009-03-01

    This in vivo study of mouse kidneys was focused on the identification of protein mediators involved in the cross-talk between two signalling pathways. One pathway was triggered by testosterone via an androgen receptor, AR, and the other induced by CB 3717/folate via HGF, and its membrane receptor c-Met. Sequential activation of these pathways leads to a drastic decrease of testosterone-induced ornithine decarboxylase, ODC, expression. We proved that CB 3717/folate-induced ODC expression is Akt-dependent. CB 3717/folate activates Akt and ERK1/2 kinases, PTEN phosphatase and also up-regulates cyclin D2 and PCNA, but decreases GSK3beta and cyclin D1 protein levels. Testosterone activation of AR induces GSK3beta and PTEN. Results of the sequential activation of the studied signalling pathways suggest that Akt, GSK3beta and possibly ERK1/2 kinases may participate in the negative cross-talk and attenuation of AR transactivity, while the involvement of PTEN and cyclin D1 seems to be doubtful.

  6. Evaluation and characterization of anti-estrogenic and anti-androgenic activities in soil samples along the Second Songhua River, China.

    Science.gov (United States)

    Li, Jian; Wang, Yafei; Kong, Dongdong; Wang, Jinsheng; Teng, Yanguo; Li, Na

    2015-11-01

    In the present study, re-combined estrogen receptor (ER) and androgen receptor (AR) gene yeast assays combined with a novel approach based on Monte Carlo simulation were used for evaluation and characterization of soil samples collected from Jilin along the Second Songhua River to assess their antagonist/agonist properties for ER and AR. The results showed that estrogenic activity only occurred in the soil samples collected in the agriculture area, but most soil samples showed anti-estrogenic activities, and the bioassay-derived 4-hydroxytamoxifen equivalents ranged from N.D. to 23.51 μg/g. Hydrophilic substance fractions were determined as potential contributors associated with anti-estrogenic activity in these soil samples. Moreover, none of the soil samples exhibited AR agonistic potency, whereas 54% of the soil samples exhibited AR antagonistic potency. The flutamide equivalents varied between N.D. and 178.05 μg/g. Based on Monte Carlo simulation-related mass balance analysis, the AR antagonistic activities were significantly correlated with the media polar and polar fractions. All of these results support that this novel calculation method can be adopted effectively to quantify and characterize the ER/AR agonists and antagonists of the soil samples, and these data could help provide useful information for future management and remediation efforts.

  7. N-linked glycosylation supports cross-talk between receptor tyrosine kinases and androgen receptor.

    Directory of Open Access Journals (Sweden)

    Harri M Itkonen

    Full Text Available Prostate cancer is the second most common cause of cancer-associated deaths in men and signalling via a transcription factor called androgen receptor (AR is an important driver of the disease. Androgen treatment is known to affect the expression and activity of other oncogenes including receptor tyrosine kinases (RTKs. In this study we report that AR-positive prostate cancer cell-lines express 50% higher levels of enzymes in the hexosamine biosynthesis pathway (HBP than AR-negative prostate cell-lines. HBP produces hexosamines that are used by endoplasmic reticulum and golgi enzymes to glycosylate proteins targeted to plasma-membrane and secretion. Inhibition of O-linked glycosylation by ST045849 or N-linked glycosylation with tunicamycin decreased cell viability by 20%. In addition, tunicamycin inhibited the androgen-induced expression of AR target genes KLK3 and CaMKK2 by 50%. RTKs have been shown to enhance AR activity and we used an antibody array to identify changes in the phosphorylation status of RTKs in response to androgen stimulation. Hormone treatment increased the activity of Insulin like Growth Factor 1-Receptor (IGF-1R ten-fold and this was associated with a concomitant increase in the N-linked glycosylation of the receptor, analyzed by lectin enrichment experiments. Glycosylation is known to be important for the processing and stability of RTKs. Inhibition of N-linked glycosylation resulted in accumulation of IGF-1R pro-receptor with altered mobility as shown by immunoprecipitation. Confocal imaging revealed that androgen induced plasma-membrane localization of IGF-1R was blocked by tunicamycin. In conclusion we have established that the glycosylation of IGF-1R is necessary for the full activation of the receptor in response to androgen treatment and that perturbing this process can break the feedback loop between AR and IGF-1R activation in prostate cells. Achieving similar results selectively in a clinical setting will be an

  8. Voltage-gated Na+ Channel Activity Increases Colon Cancer Transcriptional Activity and Invasion Via Persistent MAPK Signaling

    Science.gov (United States)

    House, Carrie D.; Wang, Bi-Dar; Ceniccola, Kristin; Williams, Russell; Simaan, May; Olender, Jacqueline; Patel, Vyomesh; Baptista-Hon, Daniel T.; Annunziata, Christina M.; Silvio Gutkind, J.; Hales, Tim G.; Lee, Norman H.

    2015-06-01

    Functional expression of voltage-gated Na+ channels (VGSCs) has been demonstrated in multiple cancer cell types where channel activity induces invasive activity. The signaling mechanisms by which VGSCs promote oncogenesis remain poorly understood. We explored the signal transduction process critical to VGSC-mediated invasion on the basis of reports linking channel activity to gene expression changes in excitable cells. Coincidentally, many genes transcriptionally regulated by the SCN5A isoform in colon cancer have an over-representation of cis-acting sites for transcription factors phosphorylated by ERK1/2 MAPK. We hypothesized that VGSC activity promotes MAPK activation to induce transcriptional changes in invasion-related genes. Using pharmacological inhibitors/activators and siRNA-mediated gene knockdowns, we correlated channel activity with Rap1-dependent persistent MAPK activation in the SW620 human colon cancer cell line. We further demonstrated that VGSC activity induces downstream changes in invasion-related gene expression via a PKA/ERK/c-JUN/ELK-1/ETS-1 transcriptional pathway. This is the first study illustrating a molecular mechanism linking functional activity of VGSCs to transcriptional activation of invasion-related genes.

  9. DNA Topoisomerases maintain promoters in a state competent for transcriptional activation in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Jakob Madsen Pedersen

    Full Text Available To investigate the role of DNA topoisomerases in transcription, we have studied global gene expression in Saccharomyces cerevisiae cells deficient for topoisomerases I and II and performed single-gene analyses to support our findings. The genome-wide studies show a general transcriptional down-regulation upon lack of the enzymes, which correlates with gene activity but not gene length. Furthermore, our data reveal a distinct subclass of genes with a strong requirement for topoisomerases. These genes are characterized by high transcriptional plasticity, chromatin regulation, TATA box presence, and enrichment of a nucleosome at a critical position in the promoter region, in line with a repressible/inducible mode of regulation. Single-gene studies with a range of genes belonging to this group demonstrate that topoisomerases play an important role during activation of these genes. Subsequent in-depth analysis of the inducible PHO5 gene reveals that topoisomerases are essential for binding of the Pho4p transcription factor to the PHO5 promoter, which is required for promoter nucleosome removal during activation. In contrast, topoisomerases are dispensable for constitutive transcription initiation and elongation of PHO5, as well as the nuclear entrance of Pho4p. Finally, we provide evidence that topoisomerases are required to maintain the PHO5 promoter in a superhelical state, which is competent for proper activation. In conclusion, our results reveal a hitherto unknown function of topoisomerases during transcriptional activation of genes with a repressible/inducible mode of regulation.

  10. Ataxia telangiectasia mutated activation by transcription- and topoisomerase I-induced DNA double-strand breaks.

    Science.gov (United States)

    Sordet, Olivier; Redon, Christophe E; Guirouilh-Barbat, Josée; Smith, Susan; Solier, Stéphanie; Douarre, Céline; Conti, Chiara; Nakamura, Asako J; Das, Benu B; Nicolas, Estelle; Kohn, Kurt W; Bonner, William M; Pommier, Yves

    2009-08-01

    Ataxia telangiectasia mutated (ATM), the deficiency of which causes a severe neurodegenerative disease, is a crucial mediator for the DNA damage response (DDR). As neurons have high rates of transcription that require topoisomerase I (TOP1), we investigated whether TOP1 cleavage complexes (TOP1cc)-which are potent transcription-blocking lesions-also produce transcription-dependent DNA double-strand breaks (DSBs) with ATM activation. We show the induction of DSBs and DDR activation in post-mitotic primary neurons and lymphocytes treated with camptothecin, with the induction of nuclear DDR foci containing activated ATM, gamma-H2AX (phosphorylated histone H2AX), activated CHK2 (checkpoint kinase 2), MDC1 (mediator of DNA damage checkpoint 1) and 53BP1 (p53 binding protein 1). The DSB-ATM-DDR pathway was suppressed by inhibiting transcription and gamma-H2AX signals were reduced by RNase H1 transfection, which removes transcription-mediated R-loops. Thus, we propose that Top1cc produce transcription arrests with R-loop formation and generate DSBs that activate ATM in post-mitotic cells.

  11. Enhanced osteoclastogenesis by mitochondrial retrograde signaling through transcriptional activation of the cathepsin K gene

    Science.gov (United States)

    Guha, Manti; Srinivasan, Satish; Koenigstein, Alexander; Zaidi, Mone; Avadhani, Narayan G.

    2015-01-01

    Mitochondrial dysfunction has emerged as an important factor in wide ranging human pathologies. We have previously defined a retrograde signaling pathway that originates from dysfunctional mitochondria (Mt-RS) and causes a global nuclear transcriptional reprograming as its endpoint. Mitochondrial dysfunction causing disruption of mitochondrial membrane potential and consequent increase in cytosolic calcium [Ca2](c) activates calcineurin and the transcription factors NF-κB, NFAT, CREB, and C/EBPδ. In macrophages this signaling complements receptor activator of nuclear factor kappa-B ligand (RANKL)–induced osteoclastic differentiation. Here, we show that the Mt-RS activated transcriptional coactivator heterogeneous ribonucleoprotein A2 (hnRNP A2) is induced by hypoxia in murine macrophages. We demonstrate that the cathepsin K gene (Cstk), one of the key genes upregulated during osteoclast differentiation, is transcriptionally activated by Mt-RS factors. HnRNP A2 acts as a coactivator with nuclear transcription factors, cRel, and C/EBPδ for Cstk promoter activation under hypoxic conditions. Notably, our study shows that hypoxia-induced activation of the stress target factors mediates effects similar to that of RANKL with regard to Cstk activation. We therefore suggest that mitochondrial dysfunction and activation of Mt-RS, induced by various pathophysiologic conditions, is a potential risk factor for osteoclastogenesis and bone loss. PMID:25800988

  12. Enhanced osteoclastogenesis by mitochondrial retrograde signaling through transcriptional activation of the cathepsin K gene.

    Science.gov (United States)

    Guha, Manti; Srinivasan, Satish; Koenigstein, Alexander; Zaidi, Mone; Avadhani, Narayan G

    2016-01-01

    Mitochondrial dysfunction has emerged as an important factor in wide ranging human pathologies. We have previously defined a retrograde signaling pathway that originates from dysfunctional mitochondria (Mt-RS) and causes a global nuclear transcriptional reprograming as its end point. Mitochondrial dysfunction causing disruption of mitochondrial membrane potential and consequent increase in cytosolic calcium [Ca(2) ](c) activates calcineurin and the transcription factors NF-κB, NFAT, CREB, and C/EBPδ. In macrophages, this signaling complements receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastic differentiation. Here, we show that the Mt-RS activated transcriptional coactivator heterogeneous ribonucleoprotein A2 (hnRNP A2) is induced by hypoxia in murine macrophages. We demonstrate that the cathepsin K gene (Ctsk), one of the key genes upregulated during osteoclast differentiation, is transcriptionally activated by Mt-RS factors. HnRNP A2 acts as a coactivator with nuclear transcription factors, cRel, and C/EBPδ for Ctsk promoter activation under hypoxic conditions. Notably, our study shows that hypoxia-induced activation of the stress target factors mediates effects similar to that of RANKL with regard to Ctsk activation. We therefore suggest that mitochondrial dysfunction and activation of Mt-RS, induced by various pathophysiologic conditions, is a potential risk factor for osteoclastogenesis and bone loss.

  13. Interaction of the transcription start site core region and transcription factor YY1 determine ascorbate transporter SVCT2 exon 1a promoter activity.

    Directory of Open Access Journals (Sweden)

    Huan Qiao

    Full Text Available Transcription of the ascorbate transporter, SVCT2, is driven by two distinct promoters in exon 1 of the transporter sequence. The exon 1a promoter lacks a classical transcription start site and little is known about regulation of promoter activity in the transcription start site core (TSSC region. Here we present evidence that the TSSC binds the multifunctional initiator-binding protein YY1. Electrophoresis shift assays using YY1 antibody showed that YY1 is present as one of two major complexes that specifically bind to the TSSC. The other complex contains the transcription factor NF-Y. Mutations in the TSSC that decreased YY1 binding also impaired the exon 1a promoter activity despite the presence of an upstream activating NF-Y/USF complex, suggesting that YY1 is involved in the regulation of the exon 1a transcription. Furthermore, YY1 interaction with NF-Y and/or USF synergistically enhanced the exon 1a promoter activity in transient transfections and co-activator p300 enhanced their synergistic activation. We propose that the TSSC plays a vital role in the exon 1a transcription and that this function is partially carried out by the transcription factor YY1. Moreover, co-activator p300 might be able to synergistically enhance the TSSC function via a "bridge" mechanism with upstream sequences.

  14. In Vivo Transcriptional Activation Using CRISPR/Cas9 in Drosophila.

    Science.gov (United States)

    Lin, Shuailiang; Ewen-Campen, Ben; Ni, Xiaochun; Housden, Benjamin E; Perrimon, Norbert

    2015-10-01

    A number of approaches for Cas9-mediated transcriptional activation have recently been developed, allowing target genes to be overexpressed from their endogenous genomic loci. However, these approaches have thus far been limited to cell culture, and this technique has not been demonstrated in vivo in any animal. The technique involving the fewest separate components, and therefore the most amenable to in vivo applications, is the dCas9-VPR system, where a nuclease-dead Cas9 is fused to a highly active chimeric activator domain. In this study, we characterize the dCas9-VPR system in Drosophila cells and in vivo. We show that this system can be used in cell culture to upregulate a range of target genes, singly and in multiplex, and that a single guide RNA upstream of the transcription start site can activate high levels of target transcription. We observe marked heterogeneity in guide RNA efficacy for any given gene, and we confirm that transcription is inhibited by guide RNAs binding downstream of the transcription start site. To demonstrate one application of this technique in cells, we used dCas9-VPR to identify target genes for Twist and Snail, two highly conserved transcription factors that cooperate during Drosophila mesoderm development. In addition, we simultaneously activated both Twist and Snail to identify synergistic responses to this physiologically relevant combination. Finally, we show that dCas9-VPR can activate target genes and cause dominant phenotypes in vivo, providing the first demonstration of dCas9 activation in a multicellular animal. Transcriptional activation using dCas9-VPR thus offers a simple and broadly applicable technique for a variety of overexpression studies.

  15. Update on androgenicity.

    Science.gov (United States)

    Thorneycroft, I H

    1999-02-01

    The development of a new generation of progestins deemed less androgenic than their earlier counterparts has led to a number of misconceptions regarding their possible benefits in combination oral contraceptives. All combination oral contraceptives are beneficial for treating such androgenic conditions as acne and hirsutism. The only expressed androgenic effect of some first- and second-generation combined oral contraceptives are changes in plasma lipid and lipoprotein levels. However, the overall effect of today's low-dose oral contraceptives is largely lipid neutral, and human and monkey studies have shown that oral contraceptive use is associated with reduced, not increased, atherosclerosis rates. Myocardial infarction rates are not increased among oral contraceptive users, except among those who are heavy smokers.

  16. Transcriptional regulation of the redD transcriptional activator gene accounts for growth-phase-dependent production of the antibiotic undecylprodigiosin in Streptomyces coelicolor A3(2)

    NARCIS (Netherlands)

    Takano, E.; Gramajo, H.C.; Strauch, E.; White, J.; Bibb, M.J.

    1992-01-01

    Transcription of redD, the activator gene required for production of the red-pigmented antibiotic undecylprodigiosin by Streptomyces coelicolor A3(2), showed a dramatic increase during the transition from exponential to stationary phase. The increase in redD expression was followed by transcription

  17. Targeted HIV-1 Latency Reversal Using CRISPR/Cas9-Derived Transcriptional Activator Systems.

    Directory of Open Access Journals (Sweden)

    Julia K Bialek

    Full Text Available CRISPR/Cas9 technology is currently considered the most advanced tool for targeted genome engineering. Its sequence-dependent specificity has been explored for locus-directed transcriptional modulation. Such modulation, in particular transcriptional activation, has been proposed as key approach to overcome silencing of dormant HIV provirus in latently infected cellular reservoirs. Currently available agents for provirus activation, so-called latency reversing agents (LRAs, act indirectly through cellular pathways to induce viral transcription. However, their clinical performance remains suboptimal, possibly because reservoirs have diverse cellular identities and/or proviral DNA is intractable to the induced pathways. We have explored two CRISPR/Cas9-derived activator systems as targeted approaches to induce dormant HIV-1 proviral DNA. These systems recruit multiple transcriptional activation domains to the HIV 5' long terminal repeat (LTR, for which we have identified an optimal target region within the LTR U3 sequence. Using this target region, we demonstrate transcriptional activation of proviral genomes via the synergistic activation mediator complex in various in culture model systems for HIV latency. Observed levels of induction are comparable or indeed higher than treatment with established LRAs. Importantly, activation is complete, leading to production of infective viral particles. Our data demonstrate that CRISPR/Cas9-derived technologies can be applied to counteract HIV latency and may therefore represent promising novel approaches in the quest for HIV elimination.

  18. Farnesoid X Receptor Inhibits the Transcriptional Activity of Carbohydrate Response Element Binding Protein in Human Hepatocytes

    Science.gov (United States)

    Caron, Sandrine; Huaman Samanez, Carolina; Dehondt, Hélène; Ploton, Maheul; Briand, Olivier; Lien, Fleur; Dorchies, Emilie; Dumont, Julie; Postic, Catherine; Cariou, Bertrand; Lefebvre, Philippe

    2013-01-01

    The glucose-activated transcription factor carbohydrate response element binding protein (ChREBP) induces the expression of hepatic glycolytic and lipogenic genes. The farnesoid X receptor (FXR) is a nuclear bile acid receptor controlling bile acid, lipid, and glucose homeostasis. FXR negatively regulates hepatic glycolysis and lipogenesis in mouse liver. The aim of this study was to determine whether FXR regulates the transcriptional activity of ChREBP in human hepatocytes and to unravel the underlying molecular mechanisms. Agonist-activated FXR inhibits glucose-induced transcription of several glycolytic genes, including the liver-type pyruvate kinase gene (L-PK), in the immortalized human hepatocyte (IHH) and HepaRG cell lines. This inhibition requires the L4L3 region of the L-PK promoter, known to bind the transcription factors ChREBP and hepatocyte nuclear factor 4α (HNF4α). FXR interacts directly with ChREBP and HNF4α proteins. Analysis of the protein complex bound to the L4L3 region reveals the presence of ChREBP, HNF4α, FXR, and the transcriptional coactivators p300 and CBP at high glucose concentrations. FXR activation does not affect either FXR or HNF4α binding to the L4L3 region but does result in the concomitant release of ChREBP, p300, and CBP and in the recruitment of the transcriptional corepressor SMRT. Thus, FXR transrepresses the expression of genes involved in glycolysis in human hepatocytes. PMID:23530060

  19. Advantages and Limitations of Androgen Receptor-Based Methods for Detecting Anabolic Androgenic Steroid Abuse as Performance Enhancing Drugs.

    Science.gov (United States)

    Bailey, Kathy; Yazdi, Tahmineh; Masharani, Umesh; Tyrrell, Blake; Butch, Anthony; Schaufele, Fred

    2016-01-01

    Testosterone (T) and related androgens are performance enhancing drugs (PEDs) abused by some athletes to gain competitive advantage. To monitor unauthorized androgen abuse, doping control programs use mass spectrometry (MS) to detect androgens, synthetic anabolic-androgenic steroids (AASs) and their metabolites in an athlete's urine. AASs of unknown composition will not be detected by these procedures. Since AASs achieve their anabolic effects by activating the Androgen Receptor (AR), cell-based bioassays that measure the effect of a urine sample on AR activity are under investigation as complementary, pan-androgen detection methods. We evaluated an AR BioAssay as a monitor for androgen activity in urine pre-treated with glucuronidase, which releases T from the inactive T-glucuronide that predominates in urine. AR BioAssay activity levels were expressed as 'T-equivalent' concentrations by comparison to a T dose response curve. The T-equivalent concentrations of androgens in the urine of hypogonadal participants supplemented with T (in whom all androgenic activity should arise from T) were quantitatively identical to the T measurements conducted by MS at the UCLA Olympic Analytical Laboratory (0.96 ± 0.22). All 17 AASs studied were active in the AR BioAssay; other steroids were inactive. 12 metabolites of 10 commonly abused AASs, which are used for MS monitoring of AAS doping because of their prolonged presence in urine, had reduced or no AR BioAssay activity. Thus, the AR BioAssay can accurately and inexpensively monitor T, but its ability to monitor urinary AASs will be limited to a period immediately following doping in which the active AASs remain intact.

  20. DNA double-strand breaks and ATM activation by transcription-blocking DNA lesions.

    Science.gov (United States)

    Sordet, Olivier; Nakamura, Asako J; Redon, Christophe E; Pommier, Yves

    2010-01-15

    A taxia telangiectasia mutated (ATM), the deficiency of which causes a severe neurodegenerative disease, is a crucial mediator for the DNA double-strand break (DSB) response. We recently showed that transcription-blocking topoisomerase I cleavage complexes (TOP1cc) produce DSBs related to R-loop formation and activate ATM in post-mitotic neurons and lymphocytes. Here we discuss how TOP1cc can produce transcription arrest with R-loop formation and generate DSBs that activate ATM, as well as data suggesting that those transcription-dependent DSBs tend to form at the IgH locus and at specific genomic sites. We also address the potential roles of ATM in response to transcription-blocking TOP1cc.

  1. Cyclin-dependent kinase 5 modulates STAT3 and androgen receptor activation through phosphorylation of Ser⁷²⁷ on STAT3 in prostate cancer cells.

    Science.gov (United States)

    Hsu, Fu-Ning; Chen, Mei-Chih; Lin, Kuan-Chia; Peng, Yu-Ting; Li, Pei-Chi; Lin, Eugene; Chiang, Ming-Ching; Hsieh, Jer-Tsong; Lin, Ho

    2013-10-15

    Cyclin-dependent kinase 5 (Cdk5) is known to regulate prostate cancer metastasis. Our previous results indicated that Cdk5 activates androgen receptor (AR) and supports prostate cancer growth. We also found that STAT3 is a target of Cdk5 in promoting thyroid cancer cell growth, whereas STAT3 may play a role as a regulator to AR activation under cytokine control. In this study, we investigated the regulation of Cdk5 and its activator p35 on STAT3/AR signaling in prostate cancer cells. Our results show that Cdk5 biochemically interacts with STAT3 and that this interaction depends on Cdk5 activation in prostate cancer cells. The phosphorylation of STAT3 at Ser⁷²⁷ (p-Ser⁷²⁷-STAT3) is regulated by Cdk5 in cells and xenograft tumors. The mutant of STAT3 S727A reduces its interaction with Cdk5. We further show that the nuclear distribution of p-Ser⁷²⁷-STAT3 and the expression of STAT3-regulated genes (junB, c-fos, c-myc, and survivin) are regulated by Cdk5 activation. STAT3 mutant does not further decrease cell proliferation upon Cdk5 inhibition, which implies that the role of STAT3 regulated by Cdk5 correlates to cell proliferation control. Interestingly, Cdk5 may regulate the interaction between STAT3 and AR through phosphorylation of Ser⁷²⁷-STAT3 and therefore upregulate AR protein stability and transactivation. Correspondingly, clinical evidence shows that the level of p-Ser⁷²⁷-STAT3 is significantly correlated with Gleason score and the levels of upstream regulators (Cdk5 and p35) as well as downstream protein (AR). In conclusion, this study demonstrates that Cdk5 regulates STAT3 activation through Ser⁷²⁷ phosphorylation and further promotes AR activation by protein-protein interaction in prostate cancer cells.

  2. Proximal genomic localization of STAT1 binding and regulated transcriptional activity

    Directory of Open Access Journals (Sweden)

    Smyth Gordon K

    2006-10-01

    Full Text Available Abstract Background Signal transducer and activator of transcription (STAT proteins are key regulators of gene expression in response to the interferon (IFN family of anti-viral and anti-microbial cytokines. We have examined the genomic relationship between STAT1 binding and regulated transcription using multiple tiling microarray and chromatin immunoprecipitation microarray (ChIP-chip experiments from public repositories. Results In response to IFN-γ, STAT1 bound proximally to regions of the genome that exhibit regulated transcriptional activity. This finding was consistent between different tiling microarray platforms, and between different measures of transcriptional activity, including differential binding of RNA polymerase II, and differential mRNA transcription. Re-analysis of tiling microarray data from a recent study of IFN-γ-induced STAT1 ChIP-chip and mRNA expression revealed that STAT1 binding is tightly associated with localized mRNA transcription in response to IFN-γ. Close relationships were also apparent between STAT1 binding, STAT2 binding, and mRNA transcription in response to IFN-α. Furthermore, we found that sites of STAT1 binding within the Encyclopedia of DNA Elements (ENCODE region are precisely correlated with sites of either enhanced or diminished binding by the RNA polymerase II complex. Conclusion Together, our results indicate that STAT1 binds proximally to regions of the genome that exhibit regulated transcriptional activity. This finding establishes a generalized basis for the positioning of STAT1 binding sites within the genome, and supports a role for STAT1 in the direct recruitment of the RNA polymerase II complex to the promoters of IFN-γ-responsive genes.

  3. Full p53 transcriptional activation potential is dispensable for tumor suppression in diverse lineages.

    Science.gov (United States)

    Jiang, Dadi; Brady, Colleen A; Johnson, Thomas M; Lee, Eunice Y; Park, Eunice J; Scott, Matthew P; Attardi, Laura D

    2011-10-11

    Over half of all human cancers, of a wide variety of types, sustain mutations in the p53 tumor suppressor gene. Although p53 limits tumorigenesis through the induction of apoptosis or cell cycle arrest, its molecular mechanism of action in tumor suppression has been elusive. The best-characterized p53 activity in vitro is as a transcriptional activator, but the identification of numerous additional p53 biochemical activities in vitro has made it unclear which mechanism accounts for tumor suppression. Here, we assess the importance of transcriptional activation for p53 tumor suppression function in vivo in several tissues, using a knock-in mouse strain expressing a p53 mutant compromised for transcriptional activation, p53(25,26). p53(25,26) is severely impaired for the transactivation of numerous classical p53 target genes, including p21, Noxa, and Puma, but it retains the ability to activate a small subset of p53 target genes, including Bax. Surprisingly, p53(25,26) can nonetheless suppress tumor growth in cancers derived from the epithelial, mesenchymal, central nervous system, and lymphoid lineages. Therefore, full transactivation of most p53 target genes is dispensable for p53 tumor suppressor function in a range of tissue types. In contrast, a transcriptional activation mutant that is completely defective for transactivation, p53(25,26,53,54), fails to suppress tumor development. These findings demonstrate that transcriptional activation is indeed broadly critical for p53 tumor suppressor function, although this requirement reflects the limited transcriptional activity observed with p53(25,26) rather than robust transactivation of a full complement of p53 target genes.

  4. Redefining the transcriptional regulatory dynamics of classically and alternatively activated macrophages by deepCAGE transcriptomics

    KAUST Repository

    Roy, S.

    2015-06-27

    Classically or alternatively activated macrophages (M1 and M2, respectively) play distinct and important roles for microbiocidal activity, regulation of inflammation and tissue homeostasis. Despite this, their transcriptional regulatory dynamics are poorly understood. Using promoter-level expression profiling by non-biased deepCAGE we have studied the transcriptional dynamics of classically and alternatively activated macrophages. Transcription factor (TF) binding motif activity analysis revealed four motifs, NFKB1_REL_RELA, IRF1,2, IRF7 and TBP that are commonly activated but have distinct activity dynamics in M1 and M2 activation. We observe matching changes in the expression profiles of the corresponding TFs and show that only a restricted set of TFs change expression. There is an overall drastic and transient up-regulation in M1 and a weaker and more sustainable up-regulation in M2. Novel TFs, such as Thap6, Maff, (M1) and Hivep1, Nfil3, Prdm1, (M2) among others, were suggested to be involved in the activation processes. Additionally, 52 (M1) and 67 (M2) novel differentially expressed genes and, for the first time, several differentially expressed long non-coding RNA (lncRNA) transcriptome markers were identified. In conclusion, the finding of novel motifs, TFs and protein-coding and lncRNA genes is an important step forward to fully understand the transcriptional machinery of macrophage activation.

  5. Transcriptional Activity of rRNA Genes in Barley Cells after Mutagenic Treatment.

    Directory of Open Access Journals (Sweden)

    Jolanta Kwasniewska

    Full Text Available In the present study, the combination of the micronucleus test with analysis of the activity of the rRNA genes in mutagen-treated Hordeum vulgare (barley by maleic hydrazide (MH cells was performed. Simultaneously fluorescence in situ hybridization (FISH with 25S rDNA as probes and an analysis of the transcriptional activity of 35S rRNA genes with silver staining were performed. The results showed that transcriptional activity is always maintained in the micronuclei although they are eliminated during the next cell cycle. The analysis of the transcriptional activity was extended to barley nuclei. MH influenced the fusion of the nucleoli in barley nuclei. The silver staining enabled detection of the nuclear bodies which arose after MH treatment. The results confirmed the usefulness of cytogenetic techniques in the characterization of micronuclei. Similar analyses can be now extended to other abiotic stresses to study the response of plant cells to the environment.

  6. DnaA-stimulated transcriptional activation of oriλ: Escherichia coli RNA polymerase β subunit as a transcriptional activator contact site

    OpenAIRE

    Szalewska-Palasz, Agnieszka; Wegrzyn, Alicja; Blaszczak, Adam; Taylor, Karol; Wegrzyn, Grzegorz

    1998-01-01

    We present evidence that Escherichia coli RNA polymerase β subunit may be a transcriptional activator contact site. Stimulation of the activity of the pR promoter by DnaA protein is necessary for replication of plasmids derived from bacteriophage λ. We found that DnaA activates the pR promoter in vitro. Particular mutations in the rpoB gene were able to suppress negative effects that certain dnaA mutations had on the replication of λ plasmids; this suppression was allele-specific. When a pote...

  7. Design, Assembly, and Characterization of TALE-Based Transcriptional Activators and Repressors.

    Science.gov (United States)

    Thakore, Pratiksha I; Gersbach, Charles A

    2016-01-01

    Transcription activator-like effectors (TALEs) are modular DNA-binding proteins that can be fused to a variety of effector domains to regulate the epigenome. Nucleotide recognition by TALE monomers follows a simple cipher, making this a powerful and versatile method to activate or repress gene expression. Described here are methods to design, assemble, and test TALE transcription factors (TALE-TFs) for control of endogenous gene expression. In this protocol, TALE arrays are constructed by Golden Gate cloning and tested for activity by transfection and quantitative RT-PCR. These methods for engineering TALE-TFs are useful for studies in reverse genetics and genomics, synthetic biology, and gene therapy.

  8. Activity-dependent transport of the transcriptional coactivator CRTC1 from synapse to nucleus.

    Science.gov (United States)

    Ch'ng, Toh Hean; Uzgil, Besim; Lin, Peter; Avliyakulov, Nuraly K; O'Dell, Thomas J; Martin, Kelsey C

    2012-07-01

    Long-lasting changes in synaptic efficacy, such as those underlying long-term memory, require transcription. Activity-dependent transport of synaptically localized transcriptional regulators provides a direct means of coupling synaptic stimulation with changes in transcription. The CREB-regulated transcriptional coactivator (CRTC1), which is required for long-term hippocampal plasticity, binds CREB to potently promote transcription. We show that CRTC1 localizes to synapses in silenced hippocampal neurons but translocates to the nucleus in response to localized synaptic stimulation. Regulated nuclear translocation occurs only in excitatory neurons and requires calcium influx and calcineurin activation. CRTC1 is controlled in a dual fashion with activity regulating CRTC1 nuclear translocation and cAMP modulating its persistence in the nucleus. Neuronal activity triggers a complex change in CRTC1 phosphorylation, suggesting that CRTC1 may link specific types of stimuli to specific changes in gene expression. Together, our results indicate that synapse-to-nuclear transport of CRTC1 dynamically informs the nucleus about synaptic activity.

  9. Transcriptional Activity of Human Endogenous Retroviruses in Human Peripheral Blood Mononuclear Cells

    Directory of Open Access Journals (Sweden)

    Emanuela Balestrieri

    2015-01-01

    Full Text Available Human endogenous retroviruses (HERVs have been implicated in human physiology and in human pathology. A better knowledge of the retroviral transcriptional activity in the general population and during the life span would greatly help the debate on its pathologic potential. The transcriptional activity of four HERV families (H, K, W, and E was assessed, by qualitative and quantitative PCR, in PBMCs from 261 individuals aged from 1 to 80 years. Our results show that HERV-H, HERV-K, and HERV-W, but not HERV-E, are transcriptionally active in the test population already in the early childhood. In addition, the transcriptional levels of HERV-H, HERV-K, and HERV-W change significantly during the life span, albeit with distinct patterns. Our results, reinforce the hypothesis of a physiological correlation between HERVs activity and the different stages of life in humans. Studies aiming at identifying the factors, which are responsible for these changes during the individual’s life, are still needed. Although the observed phenomena are presumably subjected to great variability, the basal transcriptional activity of each individual, also depending on the different ages of life, must be carefully considered in all the studies involving HERVs as causative agents of disease.

  10. Poised transcription factories prime silent uPA gene prior to activation.

    Directory of Open Access Journals (Sweden)

    Carmelo Ferrai

    2010-01-01

    Full Text Available The position of genes in the interphase nucleus and their association with functional landmarks correlate with active and/or silent states of expression. Gene activation can induce chromatin looping from chromosome territories (CTs and is thought to require de novo association with transcription factories. We identify two types of factory: "poised transcription factories," containing RNA polymerase II phosphorylated on Ser5, but not Ser2, residues, which differ from "active factories" associated with phosphorylation on both residues. Using the urokinase-type plasminogen activator (uPA gene as a model system, we find that this inducible gene is predominantly associated with poised (S5p(+S2p(- factories prior to activation and localized at the CT interior. Shortly after induction, the uPA locus is found associated with active (S5p(+S2p(+ factories and loops out from its CT. However, the levels of gene association with poised or active transcription factories, before and after activation, are independent of locus positioning relative to its CT. RNA-FISH analyses show that, after activation, the uPA gene is transcribed with the same frequency at each CT position. Unexpectedly, prior to activation, the uPA loci internal to the CT are seldom transcriptionally active, while the smaller number of uPA loci found outside their CT are transcribed as frequently as after induction. The association of inducible genes with poised transcription factories prior to activation is likely to contribute to the rapid and robust induction of gene expression in response to external stimuli, whereas gene positioning at the CT interior may be important to reinforce silencing mechanisms prior to induction.

  11. A New Microsphere-Based Immunoassay for Measuring the Activity of Transcription Factors

    Directory of Open Access Journals (Sweden)

    Tsai Chueh-Jen

    2010-01-01

    Full Text Available Abstract There are several traditional and well-developed methods for analyzing the activity of transcription factors, such as EMSA, enzyme-linked immunosorbent assay, and reporter gene activity assays. All of these methods have their own distinct disadvantages, but none can analyze the changes in transcription factors in the few cells that are cultured in the wells of 96-well titer plates. Thus, a new microsphere-based immunoassay to measure the activity of transcription factors (MIA-TF was developed. In MIA-TF, NeutrAvidin-labeled microspheres were used as the solid phase to capture biotin-labeled double-strand DNA fragments which contain certain transcription factor binding elements. The activity of transcription factors was detected by immunoassay using a transcription factor-specific antibody to monitor the binding with the DNA probe. Next, analysis was performed by flow cytometry. The targets hypoxia-inducible factor-1α (HIF-1α and nuclear factor-kappa B (NF-κB were applied and detected in this MIA-TF method; the results that we obtained demonstrated that this method could be used to monitor the changes of NF-κB or HIF within 50 or 100 ng of nuclear extract. Furthermore, MIA-TF could detect the changes in NF-κB or HIF in cells that were cultured in wells of a 96-well plate without purification of the nuclear protein, an important consideration for applying this method to high-throughput assays in the future. The development of MIA-TF would support further progress in clinical analysis and drug screening systems. Overall, MIA-TF is a method with high potential to detect the activity of transcription factors.

  12. Partial Androgen Insensitivity Syndrome

    OpenAIRE

    Sindhu Sharma, Kuldeep Singh, Sanjay Dhar*,Yudhvir Gupta

    2010-01-01

    Androgen insensitivity syndrome (AIS) present at several differentiation from genetic defects to endorgan resistance thereby producing gender dilema dispelled by sex hormones signature.It is quite traumaticfor the patients and family of the affected baby. Extreme sensitivity and awareness on the part of thecaring doctor is necessary for early diagnosis of case of AIS &for successful outcome.

  13. Partial Androgen Insensitivity Syndrome

    Directory of Open Access Journals (Sweden)

    Sindhu Sharma, Kuldeep Singh, Sanjay Dhar*,Yudhvir Gupta

    2010-01-01

    Full Text Available Androgen insensitivity syndrome (AIS present at several differentiation from genetic defects to endorgan resistance thereby producing gender dilema dispelled by sex hormones signature.It is quite traumaticfor the patients and family of the affected baby. Extreme sensitivity and awareness on the part of thecaring doctor is necessary for early diagnosis of case of AIS &for successful outcome.

  14. Androgen insensitivity syndrome

    Science.gov (United States)

    ... syndrome URL of this page: //medlineplus.gov/ency/article/001180.htm Androgen insensitivity syndrome To use the ... a condition in which the opening of the urethra is on the underside of the penis, instead of ... they can develop cancer, just like any undescended testicle. Estrogen replacement is ...

  15. Differences in transcriptional activity of cutaneous human papillomaviruses

    DEFF Research Database (Denmark)

    Vasiljevic, Natasa; Nielsen, Lone; Doherty, Geoff;

    2008-01-01

    The interaction between UV-B irradiation and cutaneous human papillomaviruses (HPV) has been suggested to be of relevance for the development of non-melanoma skin cancers. We investigated the activity within the upstream regulatory region (URR) of the HPV types 8, 38, 92, 93 and 96, as well...... and 96 URR was up-regulated by cellular differentiation, linking the activity of these HPVs to the cellular state. UV-B irradiation activated HPV-8 but inhibited HPV-38 and HPV-93 whereas HPV-92 and 96 were not affected. As there are variable UV-B responses among the HPV types, further studies...... of interactions between UV-B and HPV need to consider the HPV type....

  16. Weak estrogenic transcriptional activities of Bisphenol A and Bisphenol S.

    Science.gov (United States)

    Grignard, Elise; Lapenna, Silvia; Bremer, Susanne

    2012-08-01

    In 2011, the European Commission has restricted the use of Bisphenol A in plastic infant feeding bottles. In a response to this restriction, Bisphenol S is now often used as a component of plastic substitutes for the production of babybottles. One of the major concerns leading to the restriction of Bisphenol A was its weak estrogenic activity. By using two highly standardised transactivation assays, we could demonstrate that the estrogenic activity of Bisphenol A and Bisphenol S is of a comparable potency. Furthermore, some insights about the structure-activity relationships of these two chemicals and their metabolites could be gained from in silico predictions of their relative estrogen receptor-binding affinities and their liver phase-I biotransformation.

  17. Mechanism of the tissue-specific action of the selective androgen receptor modulator S-101479.

    Science.gov (United States)

    Furuya, Kazuyuki; Yamamoto, Noriko; Ohyabu, Yuki; Morikyu, Teruyuki; Ishige, Hirohide; Albers, Michael; Endo, Yasuhisa

    2013-01-01

    Selective androgen receptor modulators (SARMs) comprise a new class of molecules that induce anabolic effects with fewer side effects than those of other anabolic agents. We previously reported that the novel SARM S-101479 had a tissue-selective bone anabolic effect with diminished side effects in female animals. However, the mechanism of its tissue selectivity is not well known. In this report, we show that S-101479 increased alkaline phosphatase activity and androgen receptor (AR) transcriptional activity in osteoblastic cell lines in the same manner as the natural androgen ligand dihydrotestosterone (DHT); conversely, stimulation of AR dimerization was very low compared with that of DHT (34.4%). S-101479 increased bone mineral content in ovariectomized rats without promoting endometrial proliferation. Yeast two-hybrid interaction assays revealed that DHT promoted recruitment of numerous cofactors to AR such as TIF2, SRC1, β-catenin, NCoA3, gelsolin and PROX1 in a dose-dependent manner. SARMs induced recruitment of fewer cofactors than DHT; in particular, S-101479 failed to induce recruitment of canonical p160 coactivators such as SRC1, TIF2 and notably NCoA3 but only stimulated binding of AR to gelsolin and PROX1. The results suggest that a full capability of the AR to dimerize and to effectively and unselectively recruit all canonical cofactors is not a prerequisite for transcriptional activity in osteoblastic cells and resulting anabolic effects in bone tissues. Instead, few relevant cofactors might be sufficient to promote AR activity in these tissues.

  18. Expression and Activation of STAT Transcription Factors in Breast Cancer

    Science.gov (United States)

    1998-05-08

    clinicians. J~, 273: 577-585, 1995. 183 Hundertmark 5, Buhler H, Rudolf M, Weitzel HK, Ragosch V: Inhibition of 11 beta-hydroxysteroid dehydrogenase...activated protein kinase through a Jakl-dependent pathway. Mol. Cell. Bioi., 17:3833-40, 1997. Stewart JF, Rubens RO, King RJ, Minton MJ, Steiner R

  19. Histone Acetylation Influences the Activity of Sox9-related Transcriptional Complex

    Directory of Open Access Journals (Sweden)

    Furumatsu,Takayuki

    2010-12-01

    Full Text Available Chondrocyte differentiation is the fundamental process in skeletal development. From the mesenchymal condensation of chondroprogenitors to the hypertrophic maturation of chondrocytes, chondrogenesis is sequentially regulated by cross-talk among transcription factors, growth factors, and chromatin structure. The master transcription factor Sry-type HMG box (Sox 9 has an essential role in the expression of chondrogenic genes through the association with Sox9-binding sites on its target genes. Several transcription factors and coactivators, such as Scleraxis/E47 and p300, cooperatively modulate the Sox9-dependent transcription by interacting with Sox9. The Sox9-related transcriptional apparatus activates its target gene expression through p300-mediated histone acetylation on chromatin. The transforming growth factor (TGF-β superfamily also plays a key role in chondrocyte differentiation. The TGF-β-regulated Smad3/4 complex activates Sox9-dependent transcription on chromatin by associating with Sox9 itself, and by recruiting p300 onto Sox9. These findings suggest that the epigenetic status including histone modification and chromatin structure, directly influences Sox9-regulated chondrocyte differentiation. In this article, we review the regulators of Sox9 expression itself, modulators of posttranslational Sox9 function, and Sox9-associating factors in the Sox9-dependent epigenetic regulation during chondrogenesis.

  20. Novel Chemical Strategies for Labeling Small Molecule Ligands for Androgen, Progestin, and Peroxisome Proliferator-Activated Receptors for Imaging Prostate and Breast Cancer and the Heart

    Energy Technology Data Exchange (ETDEWEB)

    Katzenellenbogen, John, A.

    2007-04-19

    Summary of Progress The specific aims of this project can be summarized as follows: • Aim 1: Prepare and evaluate radiolabeled ligands for the peroxisome proliferator-activated receptor (PPAR), a new nuclear hormone receptor target for tumor imaging and hormone therapy. • Aim 2: Prepare steroids labeled with a cyclopentadienyl tricarbonyl technetium or rhenium unit. • Aim 3: Prepare and evaluate other organometallic systems of novel design as ligand mimics and halogenated ligands for nuclear hormone receptor-based tumor imaging. As is described in detail below, we made excellent progress on all three of these aims; the highlights of our progress are the following: • we have prepared the first fluorine-18 labeled analogs of ligands for the PPAR receptor and used these in tissue distribution studies in rats • we have developed three new methods for the synthesis of cyclopentadienyltricarbonyl rhenium and technetium (CpRe(CO)3 and CpTc(CO)3) systems and we have adapted these to the synthesis of steroids labeled with these metals, as well as ligands for other receptor systems • we have prepared a number of fluorine-18 labeled steroidal and non-steroidal androgens and measured their tissue distribution in rats • we have prepared iodine and bromine-labeled progestins with high progesterone receptor binding affinity • we have prepared inorganic metal tricarbonyl complexes and steroid receptor ligands in which the metal tricarbonyl unit is an integral part off the ligand core.

  1. Nitrogen-regulated transcription and enzyme activities in continuous cultures of Saccharomyces cerevisiae.

    Science.gov (United States)

    ter Schure, E G; Silljé, H H; Raeven, L J; Boonstra, J; Verkleij, A J; Verrips, C T

    1995-05-01

    Variations in the transcription of nitrogen-regulated genes and in the activities of nitrogen-regulated enzymes of the yeast Saccharomyces cerevisiae were studied by changing the carbon and nitrogen fluxes. S. cerevisiae was grown in continuous culture at various dilution rates (D) under nitrogen limitation with NH4Cl as sole nitrogen source. With an increase in D from 0.05 to 0.29 h-1, both the glucose and the ammonia flux increased sixfold. The activities of the two ammonia-incorporating enzymes, NADPH-dependent glutamate dehydrogenase (NADPH-GDH) and glutamine synthetase (GS), encoded by GDH1 and GLN1, respectively, increased with increasing D, while the activity of the glutamate-degrading enzyme, NAD-dependent glutamate dehydrogenase (NAD-GDH), decreased. Surprisingly, no changes were observed in the transcription of GDH1 and GLN1; however increased D was accompanied by an increase in GAP1 transcription. At the metabolite level, the increase in the glucose and nitrogen flux did not result in changes in the intracellular 2-oxoglutarate, glutamate or glutamine concentrations. It is shown that growth on ammonia alone is not sufficient to cause repression of GAP1 and GLN1 transcription and that the regulation of GAP1 transcription and both NADPH-GDH and GS activity is not an on/off switch, but is gradually modulated in correlation with the ammonia concentration.

  2. The JmjC domain of Gis1 is dispensable for transcriptional activation.

    Science.gov (United States)

    Yu, Yao; Neiman, Aaron M; Sternglanz, Rolf

    2010-11-01

    Yeast Gis1 protein functions as a transcription factor after nutrient limitation and oxidative stress. In this report, we show that Gis1 also regulates the induction of several genes involved in spore wall synthesis during sporulation. Gis1 contains a JmjC domain near its N-terminus. In many proteins, JmjC domains provide histone demethylase activity. Whether the JmjC domain of Gis1 contributes to its transcriptional activation is still unknown. Here, we show that gis1 point mutations that abolish Fe (II) and α-ketoglutarate binding, known cofactors in other JmjC proteins, are still able to induce transcription normally during glucose starvation and sporulation. Even the deletion of the entire JmjC domain does not affect transcriptional activation by Gis1. Moreover, the JmjC domain is not required for the toxicity associated with Gis1 overexpression. The data demonstrate that the JmjC domain is dispensable for transcriptional activation by Gis1 during nutrient stress and sporulation.

  3. A non canonical subtilase attenuates the transcriptional activation of defence responses in Arabidopsis thaliana

    Science.gov (United States)

    Serrano, Irene; Buscaill, Pierre; Audran, Corinne; Pouzet, Cécile; Jauneau, Alain; Rivas, Susana

    2016-01-01

    Proteases play crucial physiological functions in all organisms by controlling the lifetime of proteins. Here, we identified an atypical protease of the subtilase family [SBT5.2(b)] that attenuates the transcriptional activation of plant defence independently of its protease activity. The SBT5.2 gene produces two distinct transcripts encoding a canonical secreted subtilase [SBT5.2(a)] and an intracellular protein [SBT5.2(b)]. Concomitant to SBT5.2(a) downregulation, SBT5.2(b) expression is induced after bacterial inoculation. SBT5.2(b) localizes to endosomes where it interacts with and retains the defence-related transcription factor MYB30. Nuclear exclusion of MYB30 results in its reduced transcriptional activation and, thus, suppressed resistance. sbt5.2 mutants, with abolished SBT5.2(a) and SBT5.2(b) expression, display enhanced defence that is suppressed in a myb30 mutant background. Moreover, overexpression of SBT5.2(b), but not SBT5.2(a), in sbt5.2 plants reverts the phenotypes displayed by sbt5.2 mutants. Overall, we uncover a regulatory mode of the transcriptional activation of defence responses previously undescribed in eukaryotes. DOI: http://dx.doi.org/10.7554/eLife.19755.001 PMID:27685353

  4. 1-(2-Hydroxy-2-methyl-3-phenoxypropanoyl)indoline-4-carbonitrile derivatives as potent and tissue selective androgen receptor modulators.

    Science.gov (United States)

    Piatnitski Chekler, Eugene L; Unwalla, Rayomond; Khan, Taukeer A; Tangirala, Raghuram S; Johnson, Mark; St Andre, Michael; Anderson, James T; Kenney, Thomas; Chiparri, Sue; McNally, Chris; Kilbourne, Edward; Thompson, Catherine; Nagpal, Sunil; Weber, Gregory; Schelling, Scott; Owens, Jane; Morris, Carl A; Powell, Dennis; Verhoest, Patrick R; Gilbert, Adam M

    2014-03-27

    We present a novel series of selective androgen receptor modulators (SARMs) which shows excellent biological activity and physical properties. 1-(2-Hydroxy-2-methyl-3-phenoxypropanoyl)-indoline-4-carbonitriles showed potent binding to the androgen receptor (AR) and activated AR-mediated transcription in vitro. Representative compounds demonstrated diminished activity in promoting the intramolecular interaction between the AR carboxyl (C) and amino (N) termini. This N/C-termini interaction is a biomarker assay for the undesired androgenic responses in vivo. In orchidectomized rats, daily administration of a lead compound from this series showed anabolic activity by increasing levator ani muscle weight. Importantly, minimal androgenic effects (increased tissue weights) were observed in the prostate and seminal vesicles, along with minimal repression of circulating luteinizing hormone (LH) levels and no change in the lipid and triglyceride levels. This lead compound completed a two week rat toxicology study, and was well tolerated at doses up to 100 mg/kg/day, the highest dose tested, for 14 consecutive days.

  5. MAML1 enhances the transcriptional activity of Runx2 and plays a role in bone development.

    Directory of Open Access Journals (Sweden)

    Takashi Watanabe

    Full Text Available Mastermind-like 1 (MAML1 is a transcriptional co-activator in the Notch signaling pathway. Recently, however, several reports revealed novel and unique roles for MAML1 that are independent of the Notch signaling pathway. We found that MAML1 enhances the transcriptional activity of runt-related transcription factor 2 (Runx2, a transcription factor essential for osteoblastic differentiation and chondrocyte proliferation and maturation. MAML1 significantly enhanced the Runx2-mediated transcription of the p6OSE2-Luc reporter, in which luciferase expression was controlled by six copies of the osteoblast specific element 2 (OSE2 from the Runx2-regulated osteocalcin gene promoter. Interestingly, a deletion mutant of MAML1 lacking the N-terminal Notch-binding domain also enhanced Runx2-mediated transcription. Moreover, inhibition of Notch signaling did not affect the action of MAML1 on Runx2, suggesting that the activation of Runx2 by MAML1 may be caused in a Notch-independent manner. Overexpression of MAML1 transiently enhanced the Runx2-mediated expression of alkaline phosphatase, an early marker of osteoblast differentiation, in the murine pluripotent mesenchymal cell line C3H10T1/2. MAML1(-/- embryos at embryonic day 16.5 (E16.5 had shorter bone lengths than wild-type embryos. The area of primary spongiosa of the femoral diaphysis was narrowed. At E14.5, extended zone of collagen type II alpha 1 (Col2a1 and Sox9 expression, markers of chondrocyte differentiation, and decreased zone of collagen type X alpha 1 (Col10a1 expression, a marker of hypertrophic chondrocyte, were observed. These observations suggest that chondrocyte maturation was impaired in MAML1(-/- mice. MAML1 enhances the transcriptional activity of Runx2 and plays a role in bone development.

  6. Endocrine disrupting potentials of Bisphenol A, Bisphenol A dimethacrylate, 4-n-Nonyl-phenol and 4-Octylphenol assessed in cell model systems for effects on the estrogen-, androgen-, aryl hydrocarbon-receptor and aromatase activity

    DEFF Research Database (Denmark)

    Bonefeld-Jørgensen, Eva Cecilie; Long, Manhai; Hofmeister, Marlene V;

    used as surfactants. We have investigated the effect in vitro of these four plasticizers in four cell culture model systems.The estrogenic potencies were analyzed using the stable ERE-luciferase transfected cell line MVLN measuring the relative estrogen receptor (ER) transactivated luciferase units...... in the conversion of androgens to estrogens in an array of cells, were assessed in the human choriocarcinoma JEG-3 cells using the classical [3H]2O assay. Trans-activation of the Aryl hydrocarbon receptor (AhR) was determined in the mouse hepatoma Hepa1.12cR cell line, stable transfected by an AhR-CALUX construct...... determining RLU. All four compounds elicited a response in each of the four bioassays. Thus, our in vitro data clearly indicates that the four tested plasticizers have ED potentials and that such effects can be mediated via several cellular pathway systems including the estrogen- and the androgen hormones...

  7. Nutritional conditions regulate transcriptional activity of SF-1 by controlling sumoylation and ubiquitination.

    Science.gov (United States)

    Lee, Jiwon; Yang, Dong Joo; Lee, Syann; Hammer, Gary D; Kim, Ki Woo; Elmquist, Joel K

    2016-01-11

    Steroidogenic factor 1 (SF-1) is a transcription factor expressed in the ventral medial nucleus of the hypothalamus that regulates energy homeostasis. However, the molecular mechanisms of SF-1 in the control of energy balance are largely unknown. Here, we show that nutritional conditions, such as the presence or absence of serum, affect SF-1 action. Serum starvation significantly decreased hypothalamic SF-1 levels by promoting ubiquitin-dependent degradation, and sumoylation was required for this process. SF-1 transcriptional activity was also differentially regulated by nutritional status. Under normal conditions, the transcriptional activity of hypothalamic SF-1 was activated by SUMO, but this was attenuated during starvation. Taken together, these results indicate that sumoylation and ubiquitination play crucial roles in the regulation of SF-1 function and that these effects are dependent on nutritional conditions, further supporting the importance of SF-1 in the control of energy homeostasis.

  8. Non-Canonical EZH2 Transcriptionally Activates RelB in Triple Negative Breast Cancer

    Science.gov (United States)

    Lawrence, Cortney L.; Baldwin, Albert S.

    2016-01-01

    Enhancer of zeste homology 2 (EZH2) is the methyltransferase component of the polycomb repressive complex (PRC2) which represses gene transcription via histone H3 trimethylation at lysine 23 (H3K27me3). EZH2 activity has been linked with oncogenesis where it is thought to block expression of certain tumor suppressors. Relative to a role in cancer, EZH2 functions to promote self-renewal and has been shown to be important for the tumor-initiating cell (TIC) phenotype in breast cancer. Recently a non-canonical role for EZH2 has been identified where it promotes transcriptional activation of certain genes. Here we show that EZH2, through a methyltransferase-independent mechanism, promotes the transcriptional activation of the non-canonical NF-κB subunit RelB to drive self-renewal and the TIC phenotype of triple-negative breast cancer cells. PMID:27764181

  9. Identification and characterization of the minimal androgen-regulated kidney-specific kidney androgen-regulated protein gene promoter

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The kidney androgen-regulated protein (Kap) gene is tissue specific and regulated by androgen in mouse kidney proximal tubule cells (PTCs). In the present study, we aimed to identify the minimal PTC-specific androgen-regulated Kap promoter and analyze its androgen response elements (AREs).Adeletion series of the Kap1542 promoter/luciferase constructs were assayed in opossum kidney (OK) PTCs in the presence or absence of 15 nM dihydrotestosterone (DHT). Kap 1542 and Kap637 had low activity and no androgen induction; Kap224 had a basal activity that was 4- to 5-fold higher than that of Kap 1542, but was only sfightly induced by DHT. Kap 147 had a basal activity that was 2- to 3-fold higher than that of Kap 1542 and was induced by DHT 4- to 6-fold. Kap77 abol-ished basal promoter activity but was still induced by DHT. Results showed that, in vitro, Kap147 was a minimal androgen-regulated promoter. Transient transfection in different cells demonstrated that Kap147 specifically initi-ated reporter gene expression in PTCs. Sequence analysis revealed two potential AREs located at positions -124 and -39 of Kap147. Mutational assays showed that only the ARE at -124 was involved in androgen response in OK cells. Electrophoretic mobility shift assay also verified -124 ARE bound specifically to androgen receptor. In conclusion, we defined the minimal Kap 147 promoter that may be a good model for the study of kidney PTC-specific expression and molecular mechanisms that lead to an androgen-specific responsiveness in vivo.

  10. NACK is an integral component of the Notch transcriptional activation complex and is critical for development and tumorigenesis.

    Science.gov (United States)

    Weaver, Kelly L; Alves-Guerra, Marie-Clotilde; Jin, Ke; Wang, Zhiqiang; Han, Xiaoqing; Ranganathan, Prathibha; Zhu, Xiaoxia; DaSilva, Thiago; Liu, Wei; Ratti, Francesca; Demarest, Renee M; Tzimas, Cristos; Rice, Meghan; Vasquez-Del Carpio, Rodrigo; Dahmane, Nadia; Robbins, David J; Capobianco, Anthony J

    2014-09-01

    The Notch signaling pathway governs many distinct cellular processes by regulating transcriptional programs. The transcriptional response initiated by Notch is highly cell context dependent, indicating that multiple factors influence Notch target gene selection and activity. However, the mechanism by which Notch drives target gene transcription is not well understood. Herein, we identify and characterize a novel Notch-interacting protein, Notch activation complex kinase (NACK), which acts as a Notch transcriptional coactivator. We show that NACK associates with the Notch transcriptional activation complex on DNA, mediates Notch transcriptional activity, and is required for Notch-mediated tumorigenesis. We demonstrate that Notch1 and NACK are coexpressed during mouse development and that homozygous loss of NACK is embryonic lethal. Finally, we show that NACK is also a Notch target gene, establishing a feed-forward loop. Thus, our data indicate that NACK is a key component of the Notch transcriptional complex and is an essential regulator of Notch-mediated tumorigenesis and development.

  11. Polyester monomers lack ability to bind and activate both androgenic and estrogenic receptors as determined by in vitro and in silico methods.

    Science.gov (United States)

    Osimitz, Thomas G; Welsh, William J; Ai, Ni; Toole, Colleen

    2015-01-01

    The paper presents results from the screening of seven monomers used by Eastman Chemical to make various polymers. Ethylene glycol, diethylene glycol, polytetramethylene glycol, isophthalic acid, monosodium-5-sulfoisophthalic acid, 1,4-cyclohexanedicarboxylic acid, and dimethylcyclohexanedicarboxylate were screened for potential androgenicity or estrogenicity. The following studies were conducted: QSAR for binding to the AR and ER, in vitro Androgen Receptor Binding Assay, in vitro Estrogen Receptor Binding Assays (alpha and beta isoforms), in vitro Androgen Receptor Transactivation Assay in human cells, and in vitro Estrogen Receptor Transactivation Assay in human cells. None of the QSAR models predicted that any of the monomers possessed appreciable binding affinity for either AR or ER. Binding assays showed no evidence of interaction with either the AR or the alpha or beta ER receptors. Similarly, the AR and ER transactivation assays were negative. Moreover, six of the seven monomers have been subjected to 13-week and developmental toxicity studies in rats with no androgen- or estrogen-related effects being noted. Given the negative results of the in vitro screening assays (except PMG which demonstrated cytotoxicity) as well as available repeated dose and developmental and reproductive studies, the data suggest that none of the monomers tested exhibit androgenic or estrogenic hazards.

  12. Elevated LIM kinase 1 in nonmetastatic prostate cancer reflects its role in facilitating androgen receptor nuclear translocation.

    Science.gov (United States)

    Mardilovich, Katerina; Gabrielsen, Mads; McGarry, Lynn; Orange, Clare; Patel, Rachana; Shanks, Emma; Edwards, Joanne; Olson, Michael F

    2015-01-01

    Prostate cancer affects a large proportion of the male population, and is primarily driven by androgen receptor (AR) activity. First-line treatment typically consists of reducing AR signaling by hormone depletion, but resistance inevitably develops over time. One way to overcome this issue is to block AR function via alternative means, preferably by inhibiting protein targets that are more active in tumors than in normal tissue. By staining prostate cancer tumor sections, elevated LIM kinase 1 (LIMK1) expression and increased phosphorylation of its substrate Cofilin were found to be associated with poor outcome and reduced survival in patients with nonmetastatic prostate cancer. A LIMK-selective small molecule inhibitor (LIMKi) was used to determine whether targeted LIMK inhibition was a potential prostate cancer therapy. LIMKi reduced prostate cancer cell motility, as well as inhibiting proliferation and increasing apoptosis in androgen-dependent prostate cancer cells more effectively than in androgen-independent prostate cancer cells. LIMK inhibition blocked ligand-induced AR nuclear translocation, reduced AR protein stability and transcriptional activity, consistent with its effects on proliferation and survival acting via inhibition of AR activity. Furthermore, inhibition of LIMK activity increased αTubulin acetylation and decreased AR interactions with αTubulin, indicating that the role of LIMK in regulating microtubule dynamics contributes to AR function. These results indicate that LIMK inhibitors could be beneficial for the treatment of prostate cancer both by reducing nuclear AR translocation, leading to reduced proliferation and survival, and by inhibiting prostate cancer cell dissemination.

  13. PEA3/ETV4-related transcription factors coupled with active ERK signalling are associated with poor prognosis in gastric adenocarcinoma

    LENUS (Irish Health Repository)

    Keld, R

    2011-06-28

    Background: Transcription factors often play important roles in tumourigenesis. Members of the PEA3 subfamily of ETS-domain transcription factors fulfil such a role and have been associated with tumour metastasis in several different cancers. Moreover, the activity of the PEA3 subfamily transcription factors is potentiated by Ras-ERK pathway signalling, which is itself often deregulated in tumour cells.\\r\

  14. Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment.

    Science.gov (United States)

    Mellon, S H; Wolkowitz, O M; Schonemann, M D; Epel, E S; Rosser, R; Burke, H B; Mahan, L; Reus, V I; Stamatiou, D; Liew, C-C; Cole, S W

    2016-05-24

    Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1-4 (EGR1-4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators.

  15. Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment

    Science.gov (United States)

    Mellon, S H; Wolkowitz, O M; Schonemann, M D; Epel, E S; Rosser, R; Burke, H B; Mahan, L; Reus, V I; Stamatiou, D; Liew, C -C; Cole, S W

    2016-01-01

    Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1–4 (EGR1–4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators. PMID:27187237

  16. Nucleophosmin contributes to the transcriptional activation function of the Epstein-Barr virus EBNA1 protein.

    Science.gov (United States)

    Malik-Soni, Natasha; Frappier, Lori

    2014-02-01

    The Epstein-Barr virus (EBV) EBNA1 protein plays important roles in latent infection, including transcriptional activation of EBV latency genes by binding to the family-of-repeats (FR) element. Through a proteomic approach, we previously identified an interaction between EBNA1 and the histone chaperone nucleophosmin. Here we show that the EBNA1-nucleophosmin interaction is direct and requires the Gly-Arg-rich sequences that contribute to transactivation. Additionally, nucleophosmin is recruited by EBNA1 to the FR element and is required for EBNA1-mediated transcriptional activation.

  17. Molecular Determinants for PspA-Mediated Repression of the AAA Transcriptional Activator PspF

    OpenAIRE

    Elderkin, Sarah; Bordes, Patricia; Jones, Susan; Rappas, Mathieu; Buck, Martin

    2005-01-01

    The Escherichia coli phage shock protein system (pspABCDE operon and pspG gene) is induced by numerous stresses related to the membrane integrity state. Transcription of the psp genes requires the RNA polymerase containing the σ54 subunit and the AAA transcriptional activator PspF. PspF belongs to an atypical class of σ54 AAA activators in that it lacks an N-terminal regulatory domain and is instead negatively regulated by another regulatory protein, PspA. PspA therefore represses its own exp...

  18. Antarlides: A New Type of Androgen Receptor (AR) Antagonist that Overcomes Resistance to AR-Targeted Therapy.

    Science.gov (United States)

    Saito, Shun; Fujimaki, Takahiro; Panbangred, Watanalai; Igarashi, Yasuhiro; Imoto, Masaya

    2016-02-18

    Prostate cancer is treated with androgen receptor (AR) antagonists but most patients experience disease progression after long-term treatment with these compounds. Therefore, new AR antagonists are required for patient follow-up treatment. In the course of screening for a new AR antagonist, we isolated the novel compounds antarlides A-E (1-5) from Streptomyces sp. BB47. Antarlides are mutually isomeric with respect to the double bond and have a 22-membered-ring macrocyclic structure. The full stereostructure of 1 was established by chemical modifications, including methanolysis, the Trost method, acetonide formation, and the PGME method. 1-5 inhibited the binding of androgen to ARs in vitro. In addition, 2 inhibited the transcriptional activity of not only wild-type AR but also mutant ARs, which are seen in patients with acquired resistance to clinically used AR antagonists. Therefore, antarlides are a potent new generation of AR antagonists that overcome resistance.

  19. Regulation of U6 Promoter Activity by Transcriptional Interference in Viral Vector-Based RNAi

    Institute of Scientific and Technical Information of China (English)

    Linghu Nie; Meghna Das Thakur; Yumei Wang; Qin Su; Yongliang Zhao; Yunfeng Feng

    2010-01-01

    The direct negative impact of the transcriptional activity of one component on the second one in c/s is referred to as transcriptional interference (TI).U6 is a type Ⅲ RNA polymerase Ⅲ promoter commonly used for driving small hairpin RNA (shRNA) expression in vector-based RNAi.In the design and construction of viral vectors,multiple transcription units may be arranged in close proximity in a space-limited vector.Determining if U6 promoter activity can be affected by TI is critical for the expression of target shRNA in gene therapy or loss-of-function studies.In this research,we designed and implemented a modified retroviral system where shRNA and exogenous gene expressions were driven by two independent transcriptional units.We arranged U6 promoter driving.shRNA expression and UbiC promoter in two promoter arrangements.In primary macrophages,we found U6 promoter activity was inhibited by UbiC promoter when in the divergent arrangement but not in tandem.In contrast,PKG promoter had no such negative impact.Instead of enhancing U6 promoter activity,CMV enhancer had significant negative impact on U6 promoter activity in the presence of UbiC promoter.Our results indicate that U6 promoter activity can be affected by TI in a proximal promoter-specific and arrangement-dependent manner.

  20. Estrogen receptor-mediated transcription involves the activation of multiple kinase pathways in neuroblastoma cells.

    Science.gov (United States)

    Clark, Sara; Rainville, Jennifer; Zhao, Xing; Katzenellenbogen, Benita S; Pfaff, Donald; Vasudevan, Nandini

    2014-01-01

    While many physiological effects of estrogens (E) are due to regulation of gene transcription by liganded estrogen receptors (ERs), several effects are also mediated, at least in part, by rapid non-genomic actions of E. Though the relative importance of rapid versus genomic effects in the central nervous system is controversial, we showed previously that membrane-limited effects of E, initiated by an estradiol bovine serum albumin conjugate (E2-BSA), could potentiate transcriptional effects of 17β-estradiol from an estrogen response element (ERE)-reporter in neuroblastoma cells. Here, using specific inhibitors and activators in a pharmacological approach, we show that activation of phosphatidylinositol-3-phosphate kinase (PI3K) and mitogen activated protein kinase (MAPK) pathways, dependent on a Gαq coupled receptor signaling are important in this transcriptional potentiation. We further demonstrate, using ERα phospho-deficient mutants, that E2-BSA mediated phosphorylation of ERα is one mechanism to potentiate transcription from an ERE reporter construct. This study provides a possible mechanism by which signaling from the membrane is coupled to transcription in the nucleus, providing an integrated view of hormone signaling in the brain.

  1. Model of transcriptional activation by MarA in escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Michael E [Los Alamos National Laboratory; Rosner, Judah L [NATIONAL INSTITUTE OF HEALTH; Martin, Robert G [NATIONAL INSTITUTE OF HEALTH

    2009-01-01

    The AraC family transcription factor MarA activates approximately 40 genes (the marA/soxS/rob regulon) of the Escherichia coli chromosome resulting in different levels of resistance to a wide array of antibiotics and to superoxides. Activation of marA/soxS/rob regulon promoters occurs in a well-defined order with respect to the level of MarA; however, the order of activation does not parallel the strength of MarA binding to promoter sequences. To understand this lack of correspondence, we developed a computational model of transcriptional activation in which a transcription factor either increases or decreases RNA polymerase binding, and either accelerates or retards post-binding events associated with transcription initiation. We used the model to analyze data characterizing MarA regulation of promoter activity. The model clearly explains the lack of correspondence between the order of activation and the MarA-DNA affinity and indicates that the order of activation can only be predicted using information about the strength of the full MarA-polymerase-DNA interaction. The analysis further suggests that MarA can activate without increasing polymerase binding and that activation can even involve a decrease in polymerase binding, which is opposite to the textbook model of activation by recruitment. These findings are consistent with published chromatin immunoprecipitation assays of interactions between polymerase and the E. coli chromosome. We find that activation involving decreased polymerase binding yields lower latency in gene regulation and therefore might confer a competitive advantage to cells. Our model yields insights into requirements for predicting the order of activation of a regulon and enables us to suggest that activation might involve a decrease in polymerase binding which we expect to be an important theme of gene regulation in E. coli and beyond.

  2. One and the same androgen for all? towards designer androgens

    Institute of Scientific and Technical Information of China (English)

    LouisJGGooren; NhuThanhNguyen

    1999-01-01

    The introduction of designer oestrogens as a treatment medality in hormone replacement in women has invited to consider the concept of compounds with selective androgenic effects for male honnone replacement therapy. The full spectrum of the actions of testosterone may not be necessary of even undesired for certain indications for testosterone treatment, To define for what indications certain androgenic properties are desired and undesired more insight in basic androgen (patho)physiology is required. There is convincing evidence that aromatization of androgenic compounds to nestrogens might be an advantage for maintenance of bone mass and it might also mitigate negative effects of androgens on bichemical parameters of cardiovascular risks: the potentially negative effects of oestmgens on prostate pathology in ageing men needs further elucidation. While the role of dihydro-testosterone (DHT) for the male sexual differentiation and for pubertal sexual maturation is evident, its role in mature and ageing males seems less significant or may even be harmful. It is, however, of note that a negative effect of DHT on prostate pathophysiolog~ is certainly not proven.For male contraception a progestational agent with strong androgenic properties might be an asset. For most of the androgenic actions the critical levels of androgens are not well established. The latter is relevant since the large amount of androgen molecules required for its biological actions (as compared to oestrogens) is an impediment in androgen replacement medalities. There may be room for more biopotent androgens since delivery of large amounts of androgen molecules to the circulation poses problems fur treatment modalities. ( Asian J Andro11999 Jun; 1:21 -28)

  3. Cisplatin induces cytotoxicity through the mitogen-activated protein kinase pathways and activating transcription factor 3.

    Science.gov (United States)

    St Germain, Carly; Niknejad, Nima; Ma, Laurie; Garbuio, Kyla; Hai, Tsonwin; Dimitroulakos, Jim

    2010-07-01

    The mechanisms underlying the proapoptotic effect of the chemotherapeutic agent, cisplatin, are largely undefined. Understanding the mechanisms regulating cisplatin cytotoxicity may uncover strategies to enhance the efficacy of this important therapeutic agent. This study evaluates the role of activating transcription factor 3 (ATF3) as a mediator of cisplatin-induced cytotoxicity. Cytotoxic doses of cisplatin and carboplatin treatments consistently induced ATF3 expression in five tumor-derived cell lines. Characterization of this induction revealed a p53, BRCA1, and integrated stress response-independent mechanism, all previously implicated in stress-mediated ATF3 induction. Analysis of mitogen-activated protein kinase (MAPK) pathway involvement in ATF3 induction by cisplatin revealed a MAPK-dependent mechanism. Cisplatin treatment combined with specific inhibitors to each MAPK pathway (c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38) resulted in decreased ATF3 induction at the protein level. MAPK pathway inhibition led to decreased ATF3 messenger RNA expression and reduced cytotoxic effects of cisplatin as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay. In A549 lung carcinoma cells, targeting ATF3 with specific small hairpin RNA also attenuated the cytotoxic effects of cisplatin. Similarly, ATF3-/- murine embryonic fibroblasts (MEFs) were shown to be less sensitive to cisplatin-induced cytotoxicity compared with ATF3+/+ MEFs. This study identifies cisplatin as a MAPK pathway-dependent inducer of ATF3, whose expression influences cisplatin's cytotoxic effects.

  4. PEA3activates CXCL12transcription in MCF-7breast cancer cells%PEA3 activates CXCL12 transcription in MCF-7 breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    CHEN Li; CHEN Bo-bin; LI Jun-jie; JIN Wei; SHAO Zhi-min

    2011-01-01

    Objective To explore the activity of PEA3 ( polyomavirus enhancer activator 3 ) on CXCL12 (Chemokine CXC motif ligand 12) transcription and to reveal the role of PEA3 involved in CXCL12-mediated metastasis and angiogenesis in breast cancer. Methods Methods such as cell transfection, ChIP assay (chromatin immunoprecipitation ), and siRNA (small interfering RNA) were applied to demonstrate and confirm the interaction between PEA3 and CXCL12. Results Over-expression of PEA3 could increase the CXCL12 mRNA level and the CXCL12 promoter activity in human MCF-7 breast cancer cells. ChIP assay demonstrated that PEA3 could bind to the CXCL12 promoter in the cells transfected with PEA3 expression vector. PEA3 siRNA decreased CXCL12 promoter activity and the binding of PEA3 to the CXCL12 promoter in MCF-7 cells. Conclusions PEA3 could activate CXCL12 promoter transcription. It may be a potential mechanism of tumor angiogenesis and metastasis regarding of PEA3 and CXCL12.

  5. Complete androgen insensitivity syndrome due to a new frameshift deletion in exon 4 of the androgen receptor gene: Functional analysis of the mutant receptor

    OpenAIRE

    Lobaccaro, J.M.; Lumbroso, S.; Poujol, Nicolas; Georget, V.; Brinkmann, Albert; Malpuech, Georges; Sultan, C.

    1995-01-01

    textabstractWe studied the androgen receptor gene in a large kindred with complete androgen insensitivity syndrome and negative receptor-binding activity, single-strand conformation polymorphism (SSCP) analysis and sequencing identified a 13 base pair deletion within exon 4. This was responsible for a predictive frameshift in the open reading frame and introduction of a premature stop codon at position 783 instead of 919. The deletion was reproduced in androgen receptor wildtype cDNA and tran...

  6. A novel nuclear role for the Vav3 nucleotide exchange factor in androgen receptor coactivation in prostate cancer.

    Science.gov (United States)

    Rao, S; Lyons, L S; Fahrenholtz, C D; Wu, F; Farooq, A; Balkan, W; Burnstein, K L

    2012-02-01

    Increased androgen receptor (AR) transcriptional activity mediated by coactivator proteins may drive castration-resistant prostate cancer (CRPC) growth. Vav3, a Rho GTPase guanine nucleotide exchange factor (GEF), is overexpressed in human prostate cancers, particularly in models of CRPC progression. Vav3 coactivates AR in a Vav3 pleckstrin homology (PH) domain-dependent but GEF-independent manner. Ectopic expression of Vav3 in androgen-dependent human prostate cancer cells conferred robust castration-resistant xenograft tumor growth. Vav3 but not a Vav3 PH mutant greatly stimulated interaction between the AR amino and carboxyl termini (N-C interaction), which is required for maximal receptor transcriptional activity. Vav3 was distributed between the cytoplasm and nucleus with nuclear localization-dependent on the Vav3 PH domain. Membrane targeting of Vav3 abolished Vav3 potentiation of AR activity, whereas nuclear targeting of a Vav3 PH mutant rescued AR coactivation, suggesting that nuclear localization is an important function of the Vav3 PH domain. A nuclear role for Vav3 was further demonstrated by sequential chromatin immunoprecipitation assays, which revealed that Vav3 and AR were recruited to the same transcriptional complexes of an AR target gene enhancer. These data demonstrate the importance of Vav3 in CRPC and define a novel nuclear function of Vav3 in regulating AR activity.

  7. Plants contain a novel multi-member class of heat shock factors without transcriptional activator potential.

    Science.gov (United States)

    Czarnecka-Verner, E; Yuan, C X; Scharf, K D; Englich, G; Gurley, W B

    2000-07-01

    Based on phylogeny of DNA-binding domains and the organization of hydrophobic repeats, two families of heat shock transcription factors (HSFs) exist in plants. Class A HSFs are involved in the activation of the heat shock response, but the role of class B HSFs is not clear. When transcriptional activities of full-length HSFs were monitored in tobacco protoplasts, no class B HSFs from soybean or Arabidopsis showed activity under control or heat stress conditions. Additional assays confirmed the finding that the class B HSFs lacked the capacity to activate transcription. Fusion of a heterologous activation domain from human HSF1 (AD2) to the C-terminus of GmHSFB1-34 gave no evidence of synergistic enhancement of AD2 activity, which would be expected if weak activation domains were present. Furthermore, activity of AtHSFB1-4 (class B) was not rescued by coexpression with AtHSFA4-21 (class A) indicating that the class A HSF was not able to provide a missing function required for class B activity. The transcriptional activation potential of Arabidopsis AtHSFA4-21 was mapped primarily to a 39 amino acid fragment in the C-terminus enriched in bulky hydrophobic and acidic residues. Deletion mutagenesis of the C-terminal activator regions of tomato and Arabidopsis HSFs indicated that these plant HSFs lack heat-inducible regulatory regions analogous to those of mammalian HSF1. These findings suggest that heat shock regulation in plants may differ from metazoans by partitioning negative and positive functional domains onto separate HSF proteins. Class A HSFs are primarily responsible for stress-inducible activation of heat shock genes whereas some of the inert class B HSFs may be specialized for repression, or down-regulation, of the heat shock response.

  8. A Modified Reverse One-Hybrid Screen Identifies Transcriptional Activation Domains in PHYTOCHROME-INTERACTING FACTOR 3.

    Science.gov (United States)

    Dalton, Jutta C; Bätz, Ulrike; Liu, Jason; Curie, Gemma L; Quail, Peter H

    2016-01-01

    Transcriptional activation domains (TADs) are difficult to predict and identify, since they are not conserved and have little consensus. Here, we describe a yeast-based screening method that is able to identify individual amino acid residues involved in transcriptional activation in a high throughput manner. A plant transcriptional activator, PIF3 (phytochrome interacting factor 3), was fused to the yeast GAL4-DNA-binding Domain (BD), driving expression of the URA3 (Orotidine 5'-phosphate decarboxylase) reporter, and used for negative selection on 5-fluroorotic acid (5FOA). Randomly mutagenized variants of PIF3 were then selected for a loss or reduction in transcriptional activation activity by survival on FOA. In the process, we developed a strategy to eliminate false positives from negative selection that can be used for both reverse-1- and 2-hybrid screens. With this method we were able to identify two distinct regions in PIF3 with transcriptional activation activity, both of which are functionally conserved in PIF1, PIF4, and PIF5. Both are collectively necessary for full PIF3 transcriptional activity, but neither is sufficient to induce transcription autonomously. We also found that the TAD appear to overlap physically with other PIF3 functions, such as phyB binding activity and consequent phosphorylation. Our protocol should provide a valuable tool for identifying, analyzing and characterizing novel TADs in eukaryotic transcription factors, and thus potentially contribute to the unraveling of the mechanism underlying transcriptional activation.

  9. A Modified Reverse One-Hybrid Screen Identifies Transcriptional Activation Domains in PHYTOCHROME-INTERACTING FACTOR 3

    Science.gov (United States)

    Dalton, Jutta C.; Bätz, Ulrike; Liu, Jason; Curie, Gemma L.; Quail, Peter H.

    2016-01-01

    Transcriptional activation domains (TADs) are difficult to predict and identify, since they are not conserved and have little consensus. Here, we describe a yeast-based screening method that is able to identify individual amino acid residues involved in transcriptional activation in a high throughput manner. A plant transcriptional activator, PIF3 (phytochrome interacting factor 3), was fused to the yeast GAL4-DNA-binding Domain (BD), driving expression of the URA3 (Orotidine 5′-phosphate decarboxylase) reporter, and used for negative selection on 5-fluroorotic acid (5FOA). Randomly mutagenized variants of PIF3 were then selected for a loss or reduction in transcriptional activation activity by survival on FOA. In the process, we developed a strategy to eliminate false positives from negative selection that can be used for both reverse-1- and 2-hybrid screens. With this method we were able to identify two distinct regions in PIF3 with transcriptional activation activity, both of which are functionally conserved in PIF1, PIF4, and PIF5. Both are collectively necessary for full PIF3 transcriptional activity, but neither is sufficient to induce transcription autonomously. We also found that the TAD appear to overlap physically with other PIF3 functions, such as phyB binding activity and consequent phosphorylation. Our protocol should provide a valuable tool for identifying, analyzing and characterizing novel TADs in eukaryotic transcription factors, and thus potentially contribute to the unraveling of the mechanism underlying transcriptional activation. PMID:27379152

  10. Metabolic syndrome, androgens, and hypertension.

    Science.gov (United States)

    Moulana, Mohadetheh; Lima, Roberta; Reckelhoff, Jane F

    2011-04-01

    Obesity is one of the constellation of factors that make up the definition of the metabolic syndrome. Metabolic syndrome is also associated with insulin resistance, dyslipidemia, hypertriglyceridemia, and type 2 diabetes mellitus. The presence of obesity and metabolic syndrome in men and women is also associated with increased risk of cardiovascular disease and hypertension. In men, obesity and metabolic syndrome are associated with reductions in testosterone levels. In women, obesity and metabolic syndrome are associated with increases in androgen levels. In men, reductions in androgen levels are associated with inflammation, and androgen supplements reduce inflammation. In women, increases in androgens are associated with increases in inflammatory cytokines, and reducing androgens reduces inflammation. This review discusses the possibility that the effects of androgens on metabolic syndrome and its sequelae may differ between males and females.

  11. Resveratrol inhibits growth of orthotopic pancreatic tumors through activation of FOXO transcription factors.

    Directory of Open Access Journals (Sweden)

    Sanjit K Roy

    Full Text Available BACKGROUND: The forkhead transcription factors of the O class (FOXO play a direct role in cellular proliferation, oxidative stress response, and tumorigenesis. The objectives of this study were to examine whether FOXOs regulate antitumor activities of resveratrol in pancreatic cancer cells in vitro and in vivo. METHODOLOGY/PRINCIPAL FINDINGS: Pancreatic cancer cell lines were treated with resveratrol. Cell viability, colony formation, apoptosis and cell cycle were measured by XTT, soft agar, TUNEL and flow cytometry assays, respectively. FOXO nuclear translocation, DNA binding and transcriptional activities were measured by fluorescence technique, gelshift and luciferase assay, respectively. Mice were orthotopically implanted with PANC1 cells and orally gavaged with resveratrol. The components of PI3K and ERK pathways, FOXOs and their target gene expressions were measured by the Western blot analysis. Resveratrol inhibited cell viability and colony formations, and induced apoptosis through caspase-3 activation in four pancreatic cancer cell lines (PANC-1, MIA PaCa-2, Hs766T, and AsPC-1. Resveratrol induced cell cycle arrest by up-regulating the expression of p21/CIP1, p27/KIP1 and inhibiting the expression of cyclin D1. Resveratrol induced apoptosis by up-regulating Bim and activating caspase-3. Resveratrol inhibited phosphorylation of FOXOs, and enhanced their nuclear translocation, FOXO-DNA binding and transcriptional activities. The inhibition of PI3K/AKT and MEK/ERK pathways induced FOXO transcriptional activity and apoptosis. Furthermore, deletion of FOXO genes abrogated resveratrol-induced cell cycle arrest and apoptosis. Finally, resveratrol-treated mice showed significant inhibition in tumor growth which was associated with reduced phosphorylation of ERK, PI3K, AKT, FOXO1 and FOXO3a, and induction of apoptosis and FOXO target genes. CONCLUSIONS: These data suggest that inhibition of ERK and AKT pathways act together to activate FOXO

  12. Role of SIRT1 and FOXO factors in eNOS transcriptional activation by resveratrol.

    Science.gov (United States)

    Xia, Ning; Strand, Susanne; Schlufter, Frank; Siuda, Daniel; Reifenberg, Gisela; Kleinert, Hartmut; Förstermann, Ulrich; Li, Huige

    2013-08-01

    Many of the cardiovascular protective effects of resveratrol are attributable to an enhanced production of nitric oxide (NO) by the endothelial NO synthase (eNOS). Resveratrol has been shown to enhance eNOS gene expression as well as eNOS enzymatic activity. The aim of the present study was to analyze the molecular mechanisms of eNOS transcriptional activation by resveratrol. Treatment of human EA.hy 926 endothelial cells with resveratrol led to a concentration-dependent upregulation of eNOS expression. In luciferase reporter gene assay, resveratrol enhanced the activity of human eNOS promoter fragments (3500, 1600, 633 and 263bp in length, respectively), indicating that the proximal promoter region is required for resveratrol-induced eNOS transcriptional activation. Knockdown of the NAD(+)-dependent protein deacetylase sirtuin 1 (SIRT1) by siRNA prevented the upregulation of eNOS mRNA and protein by resveratrol. Forkhead box O (FOXO) transcription factors are established downstream targets of SIRT1. siRNA-mediated knockdown of FOXO1 and FOXO3a abolished the effect of resveratrol on eNOS expression, indicating the involvement of these factors. Resveratrol treatment enhanced the expression of FOXO1 and FOXO3a in EA.hy 926 cells. Reporter gene assay using promoter containing forkhead response elements showed increased FOXO factor activity by resveratrol. In electrophoretic mobility shift assay, the enhanced binding of nuclear proteins to the eNOS promoter regions by resveratrol could be blocked by antibodies against FOXO1 and FOXO3a. In conclusion, resveratrol enhances the expression and activity of FOXO transcription factors. The SIRT1/FOXO factor axis is involved in resveratrol-induced eNOS transcriptional activation.

  13. Inflammatory transcription factors as activation markers and functional readouts in immune-to-brain communication.

    Science.gov (United States)

    Rummel, Christoph

    2016-05-01

    Immune-to-brain communication pathways involve humoral mediators, including cytokines, central modulation by neuronal afferents and immune cell trafficking to the brain. During systemic inflammation these pathways contribute to mediating brain-controlled sickness symptoms including fever. Experimentally, activation of these signaling pathways can be mimicked and studied when injecting animals with pathogen associated molecular patterns (PAMPS). One central component of the brain inflammatory response, which leads, for example, to fever induction, is transcriptional activation of brain cells via cytokines and PAMPS. We and others have studied the spatiotemporal activation and the physiological significance of transcription factors for the induction of inflammation within the brain and the manifestation of fever. Evidence has revealed a role of nuclear factor (NF)κB in the initiation, signal transducer and activator of transcription (STAT)3 in the maintenance and NF-interleukin (IL)6 in the maintenance or even termination of brain-inflammation and fever. Moreover, psychological stressors, such as exposure to a novel environment, leads to increased body core temperature and genomic NF-IL6-activation, suggesting a potential use of NF-IL6-immunohistochemistry as a multimodal brain cell activation marker and a role for NF-IL6 for differential brain activity. In addition, the nutritional status, as reflected by circulating levels of the cytokine-like hormone leptin, influence immune-to-brain communication and age-dependent changes in LPS-induced fever. Overall, transcription factors remain therapeutically important targets for the treatment of brain-inflammation and fever induction during infectious/non-infectious inflammatory and psychological stress. However, the exact physiological role and significance of these transcription factors requires to be further investigated.

  14. Genetic factors affecting gene transcription and catalytic activity of UDP-glucuronosyltransferases in human liver.

    Science.gov (United States)

    Liu, Wanqing; Ramírez, Jacqueline; Gamazon, Eric R; Mirkov, Snezana; Chen, Peixian; Wu, Kehua; Sun, Chang; Cox, Nancy J; Cook, Edwin; Das, Soma; Ratain, Mark J

    2014-10-15

    The aim of this study was to discover cis- and trans-acting factors significantly affecting mRNA expression and catalytic activity of human hepatic UDP-glucuronosyltransferases (UGTs). Transcription levels of five major hepatic UGT1A (UGT1A1, UGT1A3, UGT1A4, UGT1A6 and UGT1A9) and five UGT2B (UGT2B4, UGT2B7, UGT2B10, UGT2B15 and UGT2B17) genes were quantified in human liver tissue samples (n = 125) using real-time PCR. Glucuronidation activities of 14 substrates were measured in 47 livers. We genotyped 167 tagSNPs (single-nucleotide polymorphisms) in UGT1A (n = 43) and UGT2B (n = 124), as well as the known functional UGT1A1*28 and UGT2B17 CNV (copy number variation) polymorphisms. Transcription levels of 15 transcription factors (TFs) known to regulate these UGTs were quantified. We found that UGT expression and activity were highly variable among the livers (median and range of coefficient of variations: 135%, 74-217% and 52%, 39-105%, respectively). CAR, PXR and ESR1 were found to be the most important trans-regulators of UGT transcription (median and range of correlation coefficients: 46%, 6-58%; 47%, 9-58%; and 52%, 24-75%, respectively). Hepatic UGT activities were mainly determined by UGT gene transcription levels. Twenty-one polymorphisms were significantly (FDR-adjusted P transcription and testosterone glucuronidation rate, in addition to that attributable to the UGT2B17 CNV. Our study discovered novel pharmacogenetic markers and provided detailed insight into the genetic network regulating hepatic UGTs.

  15. Dynamic Effects of Topoisomerase I Inhibition on R-Loops and Short Transcripts at Active Promoters.

    Science.gov (United States)

    Marinello, Jessica; Bertoncini, Stefania; Aloisi, Iris; Cristini, Agnese; Malagoli Tagliazucchi, Guidantonio; Forcato, Mattia; Sordet, Olivier; Capranico, Giovanni

    2016-01-01

    Topoisomerase I-DNA-cleavage complexes (Top1cc) stabilized by camptothecin (CPT) have specific effects at transcriptional levels. We recently reported that Top1cc increase antisense transcript (aRNAs) levels at divergent CpG-island promoters and, transiently, DNA/RNA hybrids (R-loop) in nuclear and mitochondrial genomes of colon cancer HCT116 cells. However, the relationship between R-loops and aRNAs was not established. Here, we show that aRNAs can form R-loops in N-TERA-2 cells under physiological conditions, and that promoter-associated R-loops are somewhat increased and extended in length immediately upon cell exposure to CPT. In contrast, persistent Top1ccs reduce the majority of R-loops suggesting that CPT-accumulated aRNAs are not commonly involved in R-loops. The enhancement of aRNAs by Top1ccs is present both in human colon cancer HCT116 cells and WI38 fibroblasts suggesting a common response of cancer and normal cells. Although Top1ccs lead to DSB and DDR kinases activation, we do not detect a dependence of aRNA accumulation on ATM or DNA-PK activation. However, we showed that the cell response to persistent Top1ccs can involve an impairment of aRNA turnover rather than a higher synthesis rate. Finally, a genome-wide analysis shows that persistent Top1ccs also determine an accumulation of sense transcripts at 5'-end gene regions suggesting an increased occurrence of truncated transcripts. Taken together, the results indicate that Top1 may regulate transcription initiation by modulating RNA polymerase-generated negative supercoils, which can in turn favor R-loop formation at promoters, and that transcript accumulation at TSS is a response to persistent transcriptional stress by Top1 poisoning.

  16. Dynamic Effects of Topoisomerase I Inhibition on R-Loops and Short Transcripts at Active Promoters.

    Directory of Open Access Journals (Sweden)

    Jessica Marinello

    Full Text Available Topoisomerase I-DNA-cleavage complexes (Top1cc stabilized by camptothecin (CPT have specific effects at transcriptional levels. We recently reported that Top1cc increase antisense transcript (aRNAs levels at divergent CpG-island promoters and, transiently, DNA/RNA hybrids (R-loop in nuclear and mitochondrial genomes of colon cancer HCT116 cells. However, the relationship between R-loops and aRNAs was not established. Here, we show that aRNAs can form R-loops in N-TERA-2 cells under physiological conditions, and that promoter-associated R-loops are somewhat increased and extended in length immediately upon cell exposure to CPT. In contrast, persistent Top1ccs reduce the majority of R-loops suggesting that CPT-accumulated aRNAs are not commonly involved in R-loops. The enhancement of aRNAs by Top1ccs is present both in human colon cancer HCT116 cells and WI38 fibroblasts suggesting a common response of cancer and normal cells. Although Top1ccs lead to DSB and DDR kinases activation, we do not detect a dependence of aRNA accumulation on ATM or DNA-PK activation. However, we showed that the cell response to persistent Top1ccs can involve an impairment of aRNA turnover rather than a higher synthesis rate. Finally, a genome-wide analysis shows that persistent Top1ccs also determine an accumulation of sense transcripts at 5'-end gene regions suggesting an increased occurrence of truncated transcripts. Taken together, the results indicate that Top1 may regulate transcription initiation by modulating RNA polymerase-generated negative supercoils, which can in turn favor R-loop formation at promoters, and that transcript accumulation at TSS is a response to persistent transcriptional stress by Top1 poisoning.

  17. Transcriptional activation of human CDCA8 gene regulated by transcription factor NF-Y in embryonic stem cells and cancer cells.

    Science.gov (United States)

    Dai, Can; Miao, Cong-Xiu; Xu, Xiao-Ming; Liu, Lv-Jun; Gu, Yi-Fan; Zhou, Di; Chen, Lian-Sheng; Lin, Ge; Lu, Guang-Xiu

    2015-09-11

    The cell division cycle associated 8 (CDCA8) gene plays an important role in mitosis. Overexpression of CDCA8 was reported in some human cancers and is required for cancer growth and progression. We found CDCA8 expression was also high in human ES cells (hESCs) but dropped significantly upon hESC differentiation. However, the regulation of CDCA8 expression has not yet been studied. Here, we characterized the CDCA8 promoter and identified its cis-elements and transcription factors. Three transcription start sites were identified. Reporter gene assays revealed that the CDCA8 promoter was activated in hESCs and cancer cell lines. The promoter drove the reporter expression specifically to pluripotent cells during early mouse embryo development and to tumor tissues in tumor-bearing mice. These results indicate that CDCA8 is transcriptionally activated in hESCs and cancer cells. Mechanistically, two key activation elements, bound by transcription factor NF-Y and CREB1, respectively, were identified in the CDCA8 basic promoter by mutation analyses and electrophoretic motility shift assays. NF-Y binding is positively correlated with promoter activities in different cell types. Interestingly, the NF-YA subunit, binding to the promoter, is primarily a short isoform in hESCs and a long isoform in cancer cells, indicating a different activation mechanism of the CDCA8 transcription between hESCs and cancer cells. Finally, enhanced CDCA8 promoter activities by NF-Y overexpression and reduced CDCA8 transcription by NF-Y knockdown further verified that NF-Y is a positive regulator of CDCA8 transcription. Our study unearths the molecular mechanisms underlying the activation of CDCA8 expression in hESCs and cancer cells, which provides a better understanding of its biological functions.

  18. Transcriptional activity around bacterial cell death reveals molecular biomarkers for cell viability

    Directory of Open Access Journals (Sweden)

    Schuren Frank H

    2008-12-01

    Full Text Available Abstract Background In bacteriology, the ability to grow in selective media and to form colonies on nutrient agar plates is routinely used as a retrospective criterion for the detection of living bacteria. However, the utilization of indicators for bacterial viability-such as the presence of specific transcripts or membrane integrity-would overcome bias introduced by cultivation and reduces the time span of analysis from initiation to read out. Therefore, we investigated the correlation between transcriptional activity, membrane integrity and cultivation-based viability in the Gram-positive model bacterium Bacillus subtilis. Results We present microbiological, cytological and molecular analyses of the physiological response to lethal heat stress under accurately defined conditions through systematic sampling of bacteria from a single culture exposed to gradually increasing temperatures. We identified a coherent transcriptional program including known heat shock responses as well as the rapid expression of a small number of sporulation and competence genes, the latter only known to be active in the stationary growth phase. Conclusion The observed coordinated gene expression continued even after cell death, in other words after all bacteria permanently lost their ability to reproduce. Transcription of a very limited number of genes correlated with cell viability under the applied killing regime. The transcripts of the expressed genes in living bacteria – but silent in dead bacteria-include those of essential genes encoding chaperones of the protein folding machinery and can serve as molecular biomarkers for bacterial cell viability.

  19. Multiple transcription factor codes activate epidermal wound-response genes in Drosophila.

    Science.gov (United States)

    Pearson, Joseph C; Juarez, Michelle T; Kim, Myungjin; Drivenes, Øyvind; McGinnis, William

    2009-02-17

    Wounds in Drosophila and mouse embryos induce similar genetic pathways to repair epidermal barriers. However, the transcription factors that transduce wound signals to repair epidermal barriers are largely unknown. We characterize the transcriptional regulatory enhancers of 4 genes-Ddc, ple, msn, and kkv-that are rapidly activated in epidermal cells surrounding wounds in late Drosophila embryos and early larvae. These epidermal wound enhancers all contain evolutionarily conserved sequences matching binding sites for JUN/FOS and GRH transcription factors, but vary widely in trans- and cis-requirements for these inputs and their binding sites. We propose that the combination of GRH and FOS is part of an ancient wound-response pathway still used in vertebrates and invertebrates, but that other mechanisms have evolved that result in similar transcriptional output. A common, but largely untested assumption of bioinformatic analyses of gene regulatory networks is that transcription units activated in the same spatial and temporal patterns will require the same cis-regulatory codes. Our results indicate that this is an overly simplistic view.

  20. Distinct structural features of TFAM drive mitochondrial DNA packaging versus transcriptional activation.

    Science.gov (United States)

    Ngo, Huu B; Lovely, Geoffrey A; Phillips, Rob; Chan, David C

    2014-01-01

    TFAM (transcription factor A, mitochondrial) is a DNA-binding protein that activates transcription at the two major promoters of mitochondrial DNA (mtDNA)--the light strand promoter (LSP) and the heavy strand promoter 1 (HSP1). Equally important, it coats and packages the mitochondrial genome. TFAM has been shown to impose a U-turn on LSP DNA; however, whether this distortion is relevant at other sites is unknown. Here we present crystal structures of TFAM bound to HSP1 and to nonspecific DNA. In both, TFAM similarly distorts the DNA into a U-turn. Yet, TFAM binds to HSP1 in the opposite orientation from LSP explaining why transcription from LSP requires DNA bending, whereas transcription at HSP1 does not. Moreover, the crystal structures reveal dimerization of DNA-bound TFAM. This dimerization is dispensable for DNA bending and transcriptional activation but is important in DNA compaction. We propose that TFAM dimerization enhances mitochondrial DNA compaction by promoting looping of the DNA.

  1. An Efficient Method to Identify Conditionally Activated Transcription Factors and their Corresponding Signal Transduction Pathway Segments

    Directory of Open Access Journals (Sweden)

    Haiyan Hu

    2009-11-01

    Full Text Available A signal transduction pathway (STP is a cascade composed of a series of signal transferring steps, which often activate one or more transcription factors (TFs to control the transcription of target genes. Understanding signaling pathways is important to our understanding of the molecular mechanisms of disease. Many condition-annotated pathways have been deposited in public databases. However, condition-annotated pathways are far from complete, considering the large number of possible conditions. Computational methods to assist in the identification of conditionally activated pathways are greatly needed. In this paper, we propose an efficient method to identify conditionally activated pathway segments starting from the identification of conditionally activated TFs, by incorporating protein-DNA binding data, gene expression data and protein interaction data. Applying our methods on several microarray datasets, we have discovered many significantly activated TFs and their corresponding pathway segments, which are supported by evidence in the literature.

  2. Versatility of cooperative transcriptional activation: a thermodynamical modeling analysis for greater-than-additive and less-than-additive effects.

    Directory of Open Access Journals (Sweden)

    Till D Frank

    Full Text Available We derive a statistical model of transcriptional activation using equilibrium thermodynamics of chemical reactions. We examine to what extent this statistical model predicts synergy effects of cooperative activation of gene expression. We determine parameter domains in which greater-than-additive and less-than-additive effects are predicted for cooperative regulation by two activators. We show that the statistical approach can be used to identify different causes of synergistic greater-than-additive effects: nonlinearities of the thermostatistical transcriptional machinery and three-body interactions between RNA polymerase and two activators. In particular, our model-based analysis suggests that at low transcription factor concentrations cooperative activation cannot yield synergistic greater-than-additive effects, i.e., DNA transcription can only exhibit less-than-additive effects. Accordingly, transcriptional activity turns from synergistic greater-than-additive responses at relatively high transcription factor concentrations into less-than-additive responses at relatively low concentrations. In addition, two types of re-entrant phenomena are predicted. First, our analysis predicts that under particular circumstances transcriptional activity will feature a sequence of less-than-additive, greater-than-additive, and eventually less-than-additive effects when for fixed activator concentrations the regulatory impact of activators on the binding of RNA polymerase to the promoter increases from weak, to moderate, to strong. Second, for appropriate promoter conditions when activator concentrations are increased then the aforementioned re-entrant sequence of less-than-additive, greater-than-additive, and less-than-additive effects is predicted as well. Finally, our model-based analysis suggests that even for weak activators that individually induce only negligible increases in promoter activity, promoter activity can exhibit greater

  3. Glycogen synthase kinase3 beta phosphorylates serine 33 of p53 and activates p53's transcriptional activity

    Directory of Open Access Journals (Sweden)

    Price Brendan D

    2001-07-01

    Full Text Available Abstract Background The p53 protein is activated by genotoxic stress, oncogene expression and during senescence, p53 transcriptionally activates genes involved in growth arrest and apoptosis. p53 activation is regulated by post-translational modification, including phosphorylation of the N-terminal transactivation domain. Here, we have examined how Glycogen Synthase Kinase (GSK3, a protein kinase involved in tumorigenesis, differentiation and apoptosis, phosphorylates and regulates p53. Results The 2 isoforms of GSK3, GSK3α and GSK3β, phosphorylate the sequence Ser-X-X-X-Ser(P when the C-terminal serine residue is already phosphorylated. Several p53 kinases were examined for their ability to create GSK3 phosphorylation sites on the p53 protein. Our results demonstrate that phosphorylation of serine 37 of p53 by DNA-PK creates a site for GSK3β phosphorylation at serine 33 in vitro. GSK3α did not phosphorylate p53 under any condition. GSK3β increased the transcriptional activity of the p53 protein in vivo. Mutation of either serine 33 or serine 37 of p53 to alanine blocked the ability of GSK3β to regulate p53 transcriptional activity. GSK3β is therefore able to regulate p53 function in vivo. p53's transcriptional activity is commonly increased by DNA damage. However, GSK3β kinase activity was inhibited in response to DNA damage, suggesting that GSK3β regulation of p53 is not involved in the p53-DNA damage response. Conclusions GSK3β can regulate p53's transcriptional activity by phosphorylating serine 33. However, GSK3β does not appear to be part of the p53-DNA damage response pathway. Instead, GSK3β may provide the link between p53 and non-DNA damage mechanisms for p53 activation.

  4. Characterization of estrogen and androgen activity of food contact materials by different in vitro bioassays (YES, YAS, ERα and AR CALUX) and chromatographic analysis (GC-MS, HPLC-MS).

    Science.gov (United States)

    Mertl, Johannes; Kirchnawy, Christian; Osorio, Veronica; Grininger, Angelika; Richter, Alexander; Bergmair, Johannes; Pyerin, Michael; Washüttl, Michael; Tacker, Manfred

    2014-01-01

    Endocrine active substances (EAS) show structural similarities to natural hormones and are suspected to affect the human endocrine system by inducing hormone dependent effects. Recent studies with in vitro tests suggest that EAS can leach from packaging into food and may therefore pose a risk to human health. Sample migrates from food contact materials were tested for estrogen and androgen agonists and antagonists with different commonly used in vitro tests. Additionally, chemical trace analysis by GC-MS and HPLC-MS was used to identify potential hormone active substances in sample migrates. A GC-MS method to screen migrates for 29 known or potential endocrine active substances was established and validated. Samples were migrated according to EC 10/2011, concentrated by solid phase extraction and tested with estrogen and androgen responsive reporter gene assays based on yeast cells (YES and YAS) or human osteoblast cells (ERα and AR CALUX). A high level of agreement between the different bioassays could be observed by screening for estrogen agonists. Four out of 18 samples tested showed an estrogen activity in a similar range in both, YES and ERα CALUX. Two more samples tested positive in ERα CALUX due to the lower limits of detection in this assay. Androgen agonists could not be detected in any of the tested samples, neither with YAS nor with AR CALUX. When testing for antagonists, significant differences between yeast and human cell-based bioassays were noticed. Using YES and YAS many samples showed a strong antagonistic activity which was not observed using human cell-based CALUX assays. By GC-MS, some known or supposed EAS were identified in sample migrates that showed a biological activity in the in vitro tests. However, no firm conclusions about the sources of the observed hormone activity could be obtained from the chemical results.

  5. Diversity in the androgen receptor CAG repeat has been shaped by a multistep mutational mechanism.

    Science.gov (United States)

    Santos, Diana; Pimenta, João; Wong, Virginia C N; Amorim, António; Martins, Sandra

    2014-10-01

    The androgen receptor (AR) gene encodes a type of nuclear receptor that functions as a steroid-hormone activated transcription factor. In its coding region, AR includes a CAG repeat, which has been intensely studied due to the inverse correlation between repeat size and AR transcriptional activity. Several studies have reported different (CAG)n sizes associated with the risk of androgen-linked diseases. We aimed at clarifying the mechanisms on the origin of newly CAG sized alleles through a strategy involving the analysis of the associated haplotype diversity. We genotyped 374 control individuals of European and Asian ancestry, and reconstructed the haplotypes associated with the CAG repeat, defined by 10 SNPs and 6 flanking STRs. The most powerful SNPs to tag AR lineages are rs7061037-rs12012620 and rs34191540-rs6625187-rs2768578 in Europeans and Asians, respectively. In the most frequent AR lineage, (CAG)18 alleles seem to have been generated by a multistep mutation mechanism, most probably from longer alleles. We further noticed that the DXS1194-DXS1111 haplotype, in linkage disequilibrium with AR-(CAG)n expanded alleles responsible for spinal bulbar muscular atrophy (SBMA), is rare among our controls; however, the haplotype strategy here described may be used to clarify the origin of expansions in other populations, as in future association studies.

  6. Nonmyocytic androgen receptor regulates the sexually dimorphic development of the embryonic bulbocavernosus muscle.

    Science.gov (United States)

    Ipulan, Lerrie Ann; Suzuki, Kentaro; Sakamoto, Yuki; Murashima, Aki; Imai, Yuuki; Omori, Akiko; Nakagata, Naomi; Nishinakamura, Ryuichi; Valasek, Petr; Yamada, Gen

    2014-07-01

    The bulbocavernosus (BC) is a sexually dimorphic muscle observed only in males. Androgen receptor knockout mouse studies show the loss of BC formation. This suggests that androgen signaling plays a vital role in its development. Androgen has been known to induce muscle hypertrophy through satellite cell activation and myonuclei accretion during muscle regeneration and growth. Whether the same mechanism is present during embryonic development is not yet elucidated. To identify the mechanism of sexual dimorphism during BC development, the timing of morphological differences was first established. It was revealed that the BC was morphologically different between male and female mice at embryonic day (E) 16.5. Differences in the myogenic process were detected at E15.5. The male BC possesses a higher number of proliferating undifferentiated myoblasts. To identify the role of androgen signaling in this process, muscle-specific androgen receptor (AR) mutation was introduced, which resulted in no observable phenotypes. Hence, the expression of AR in the BC was examined and found that the AR did not colocalize with any muscle markers such as Myogenic differentiation 1, Myogenin, and paired box transcription factor 7. It was revealed that the mesenchyme surrounding the BC expressed AR and the BC started to express AR at E15.5. AR mutation on the nonmyocytic cells using spalt-like transcription factor 1 (Sall1) Cre driver mouse was performed, which resulted in defective BC formation. It was revealed that the number of proliferating undifferentiated myoblasts was reduced in the Sall1 Cre:AR(L-/Y) mutant embryos, and the adult mutants were devoid of BC. The transition of myoblasts from proliferation to differentiation is mediated by cyclin-dependent kinase inhibitors. An increased expression of p21 was observed in the BC myoblast of the Sall1 Cre:AR(L-/Y) mutant and wild-type female. Altogether this study suggests that the nonmyocytic AR may paracrinely regulate the

  7. ANDROGEN INSENSITIVITY SYNDROME

    OpenAIRE

    Kanan; Sonali

    2014-01-01

    The condition is inherited as X - linked recessive gene 1 . The underlying pathology is the inability of end organs to respond to androgens. These cases are phenotypically and psychologically female with adequate breast development , normal external genitalia , a vagina with variable depth , absent /sparse pubic hair and axillary hair. The exact incidence in India is not known but the reported incidence is 1 in 2 , 000 to 1 in 62 ,400 worldwi...

  8. Activation of TORC1 transcriptional coactivator through MEKK1-induced phosphorylation.

    Science.gov (United States)

    Siu, Yeung-Tung; Ching, Yick-Pang; Jin, Dong-Yan

    2008-11-01

    CREB is a prototypic bZIP transcription factor and a master regulator of glucose metabolism, synaptic plasticity, cell growth, apoptosis, and tumorigenesis. Transducers of regulated CREB activity (TORCs) are essential transcriptional coactivators of CREB and an important point of regulation on which various signals converge. In this study, we report on the activation of TORC1 through MEKK1-mediated phosphorylation. MEKK1 potently activated TORC1, and this activation was independent of downstream effectors MEK1/MEK2, ERK2, JNK, p38, protein kinase A, and calcineurin. MEKK1 induced phosphorylation of TORC1 both in vivo and in vitro. Expression of the catalytic domain of MEKK1 alone in cultured mammalian cells sufficiently caused phosphorylation and subsequent activation of TORC1. MEKK1 physically interacted with TORC1 and stimulated its nuclear translocation. An activation domain responsive to MEKK1 stimulation was mapped to amino acids 431-650 of TORC1. As a physiological activator of CREB, interleukin 1alpha triggered MEKK1-dependent phosphorylation of TORC1 and its consequent recruitment to the cAMP response elements in the interleukin 8 promoter. Taken together, our findings suggest a new mechanism for regulated activation of TORC1 transcriptional coactivator and CREB signaling.

  9. Activation of transcriptional activity of HSE by a novel mouse zinc finger protein ZNFD specifically expressed in testis.

    Science.gov (United States)

    Xu, Fengqin; Wang, Weiping; Lei, Chen; Liu, Qingmei; Qiu, Hao; Muraleedharan, Vinaydhar; Zhou, Bin; Cheng, Hongxia; Huang, Zhongkai; Xu, Weian; Li, Bichun; Wang, Minghua

    2012-04-01

    Zinc finger proteins (ZFPs) that contain multiple cysteine and/or histidine residues perform important roles in various cellular functions, including transcriptional regulation, cell proliferation, differentiation, and apoptosis. The Cys-Cys-His-His (C(2)H(2)) type of ZFPs are the well-defined members of this super family and are the largest and most complex proteins in eukaryotic genomes. In this study, we identified a novel C(2)H(2) type of zinc finger gene ZNFD from mice which has a 1,002 bp open reading frame and encodes a protein with 333 amino acid residues. The predicted 37.4 kDa protein contains a C(2)H(2) zinc finger domain. ZNFD gene is located on chromosome 18qD1. RT-PCR analysis revealed that the ZNFD gene was specifically expressed in mouse testis but not in other tissues. Subcellular localization analysis demonstrated that ZNFD was localized in the nucleus. Reporter gene assays showed that overexpression of ZNFD in the COS7 cells activates the transcriptional activities of heat shock element (HSE). Overall, these results suggest that ZNFD is a member of the zinc finger transcription factor family and it participates in the transcriptional regulation of HSE. Many heat shock proteins regulated by HSE are involved in testicular development. Therefore, our results suggest that ZNFD may probably participate in the development of mouse testis and function as a transcription activator in HSE-mediated gene expression and signaling pathways.

  10. Effect of nitrate on activities and transcript levels of nitrate reductase and glutamine synthetase in rice

    Institute of Scientific and Technical Information of China (English)

    CAO Yun; FAN Xiao-Rong; SUN Shu-Bin; XU Guo-Hua; HU Jiang; SHEN Qi-Rong

    2008-01-01

    Real-time polymerase chain reaction analysis was used to compare the effect of NO-3 on the activities of nitrate reductase (NR) and glutamine synthetase (GS),and the transcript levels of two NR genes,OsNia1 and OsNia2,two cytceolic GS1 genes,OsGln1;1 and OsGln1;2,and one plastid GS2 gene OsGln2,in two rice (Oryza sativa L.) cultivars Nanguang (NG) and Yunjing (YJ).Both cultivars achieved greater biomass and higher total N concentration when grown in a mixed N supply than in sole NH+ nutrition.Supply of NO-3 increased NR activity in both leaves and roots.Expression of both NR genes was also substantially enhanced and transcript levels of OsNia2 were significantly higher than those of OsNia1.NO-3 also caused an increase in GS activity,but had a complex effect on the expression of the three GS genes.In roots,the OsGln1;1 transcript increased,but OsGln1;2 decreased.In leaves,NO-3 had no effect on the GS1 expression,but the transcript for OsGln2 increased both in the leaves and roots of rice with a mixed supply of N.These results suggested that the increase in GS activity might be a result of the complicated regulation of the various GS genes.In addition,the NO-3 induced increase of biomass,NR activity,GS activity,and the transcript levels of NR and GS genes were proportionally higher in NG than in YJ,indicating a stronger response of NG to NO-3 nutrition than YJ.

  11. Coregulator control of androgen receptor action by a novel nuclear receptor-binding motif.

    Science.gov (United States)

    Jehle, Katja; Cato, Laura; Neeb, Antje; Muhle-Goll, Claudia; Jung, Nicole; Smith, Emmanuel W; Buzon, Victor; Carbó, Laia R; Estébanez-Perpiñá, Eva; Schmitz, Katja; Fruk, Ljiljana; Luy, Burkhard; Chen, Yu; Cox, Marc B; Bräse, Stefan; Brown, Myles; Cato, Andrew C B

    2014-03-28

    The androgen receptor (AR) is a ligand-activated transcription factor that is essential for prostate cancer development. It is activated by androgens through its ligand-binding domain (LBD), which consists predominantly of 11 α-helices. Upon ligand binding, the last helix is reorganized to an agonist conformation termed activator function-2 (AF-2) for coactivator binding. Several coactivators bind to the AF-2 pocket through conserved LXXLL or FXXLF sequences to enhance the activity of the receptor. Recently, a small compound-binding surface adjacent to AF-2 has been identified as an allosteric modulator of the AF-2 activity and is termed binding function-3 (BF-3). However, the role of BF-3 in vivo is currently unknown, and little is understood about what proteins can bind to it. Here we demonstrate that a duplicated GARRPR motif at the N terminus of the cochaperone Bag-1L functions through the BF-3 pocket. These findings are supported by the fact that a selective BF-3 inhibitor or mutations within the BF-3 pocket abolish the interaction between the GARRPR motif(s) and the BF-3. Conversely, amino acid exchanges in the two GARRPR motifs of Bag-1L can impair the interaction between Bag-1L and AR without altering the ability of Bag-1L to bind to chromatin. Furthermore, the mutant Bag-1L increases androgen-dependent activation of a subset of AR targets in a genome-wide transcriptome analysis, demonstrating a repressive function of the GARRPR/BF-3 interaction. We have therefore identified GARRPR as a novel BF-3 regulatory sequence important for fine-tuning the activity of the AR.

  12. Nuclear transportation of exogenous epidermal growth factor receptor and androgen receptor via extracellular vesicles.

    Science.gov (United States)

    Read, Jolene; Ingram, Alistair; Al Saleh, Hassan A; Platko, Khrystyna; Gabriel, Kathleen; Kapoor, Anil; Pinthus, Jehonathan; Majeed, Fadwa; Qureshi, Talha; Al-Nedawi, Khalid

    2017-01-01

    Epidermal growth factor receptor (EGFR) plays a central role in the progression of several human malignancies. Although EGFR is a membrane receptor, it undergoes nuclear translocation, where it has a distinct signalling pathway. Herein, we report a novel mechanism by which cancer cells can directly transport EGFR to the nucleus of other cells via extracellular vesicles (EVs). The transported receptor is active and stimulates the nuclear EGFR pathways. Interestingly, the translocation of EGFR via EVs occurs independently of the nuclear localisation sequence that is required for nuclear translocation of endogenous EGFR. Also, we found that the mutant receptor EGFRvIII could be transported to the nucleus of other cells via EVs. To assess the role of EVs in the regulation of an actual nuclear receptor, we studied the regulation of androgen receptor (AR). We found that full-length AR and mutant variant ARv7 are secreted in EVs derived from prostate cancer cell lines and could be transported to the nucleus of AR-null cells. The EV-derived AR was able to bind the androgen-responsive promoter region of prostate specific antigen, and recruit RNA Pol II, an indication of active transcription. The nuclear-translocated AR via EVs enhanced the proliferation of acceptor cells in the absence of androgen. Finally, we provide evidence that nuclear localisation of AR could occur in vivo via orthotopically-injected EVs in male SCID mice prostate glands. To our knowledge, this is the first study showing the nuclear translocation of nuclear receptors via EVs, which significantly extends the role of EVs as paracrine transcriptional regulators.

  13. Interaction with general transcription factor IIF (TFIIF) is required for the suppression of activated transcription by RPB5-mediating protein(RMP)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    RMP was reported to regulate transcription via competing with HBx to bind the general transcription factor IIB (TFIIB) and interacting with RPB5 subunit of RNA polymerase Ⅱ as a corepressor of transcription regulator. However, our present research uncovered that RMP also regulates the transcription through interaction with the general transcription factors IIF (TFIIF), which assemble in the preinitiation complex and function in both transcription initiation and elongation. With in vitro pull-down assay and Far-Western analysis, we demonstrated that RMP could bind with bacterially expressed recombinant RAP30 and RAP74of TFIIF subunits. In the immunoprecipitation assay in COS 1 cells cotransfected with FLAG-tagged RMP or its mutants, GST-fused RAP30 and RAP74 were co-immunoprecipitated with RMP in approximately equal molar ratio, which suggests that RAP30 and RAP74 interact with RMP as a TFIIF complex. Interestingly both RAP30 and RAP74 interact with the same domain (D5) of the C-terminal RMP of 118-amino-acid residuals which overlaps with its TFIIB-binding domain. Internal deletion of D5 region of RMP abolished its binding ability with both subunits of TFIIF, while D5 domain alone was sufficient to interact with TFIIF subunits. The result of luciferase assay showed that overexpression of RMP, but not the mutant RMP lacking D5 region, suppressed the transcription activated by Gal-VP16, suggesting that interaction with TFIIF is required for RMP to suppress the activated transcription. The interaction between RMP and TFIIF may be an additional passway for RMP to regulate the transcription, or alternatively TFIIF may cooperate with RPB5 and TFIIB for the corepressor function of RMP.

  14. E2F1-mediated transcriptional inhibition of the plasminogen activator inhibitor type 1 gene

    DEFF Research Database (Denmark)

    Koziczak, M; Müller, H; Helin, K;

    2001-01-01

    -sensitive retinoblastoma protein (pRB), a shift to a permissive temperature induced PAI-1 mRNA expression. In U2OS cells stably expressing an E2F1-estrogen receptor chimeric protein that could be activated by tamoxifen, PAI-1 gene transcription was markedly reduced by tamoxifen even in the presence of cycloheximide...

  15. Analysis of the transcriptional networks underpinning the activation of murine macrophages by inflammatory mediators.

    Science.gov (United States)

    Raza, Sobia; Barnett, Mark W; Barnett-Itzhaki, Zohar; Amit, Ido; Hume, David A; Freeman, Tom C

    2014-08-01

    Macrophages respond to the TLR4 agonist LPS with a sequential transcriptional cascade controlled by a complex regulatory network of signaling pathways and transcription factors. At least two distinct pathways are currently known to be engaged by TLR4 and are distinguished by their dependence on the adaptor molecule MyD88. We have used gene expression microarrays to define the effects of each of three variables--LPS dose, LPS versus IFN-β and -γ, and genetic background--on the transcriptional response of mouse BMDMs. Analysis of correlation networks generated from the data has identified subnetworks or modules within the macrophage transcriptional network that are activated selectively by these variables. We have identified mouse strain-specific signatures, including a module enriched for SLE susceptibility candidates. In the modules of genes unique to different treatments, we found a module of genes induced by type-I IFN but not by LPS treatment, suggesting another layer of complexity in the LPS-TLR4 signaling feedback control. We also observe that the activation of the complement system, in common with the known activation of MHC class 2 genes, is reliant on IFN-γ signaling. Taken together, these data further highlight the exquisite nature of the regulatory systems that control macrophage activation, their likely relevance to disease resistance/susceptibility, and the appropriate response of these cells to proinflammatory stimuli.

  16. Comprehensive analysis of the specificity of transcription activator-like effector nucleases

    DEFF Research Database (Denmark)

    Juillerat, Alexandre; Dubois, Gwendoline; Valton, Julien;

    2014-01-01

    their target site. The ability to predict the specificity of targeting is thus highly desirable. Here, we describe the first comprehensive experimental study focused on the specificity of the four commonly used repeat variable diresidues (RVDs; NI:A, HD:C, NN:G and NG:T) incorporated in transcription activator...

  17. Transcriptional activation of the mouse obese (ob) gene by CCAAT/enhancer binding protein alpha

    DEFF Research Database (Denmark)

    Hwang, C S; Mandrup, S; MacDougald, O A

    1996-01-01

    Like other adipocyte genes that are transcriptionally activated by CCAAT/enhancer binding protein alpha (C/EBP alpha) during preadipocyte differentiation, expression of the mouse obese (ob) gene is immediately preceded by the expression of C/EBP alpha. While the 5' flanking region of the mouse ob...

  18. Analysis of the transcriptional networks underpinning the activation of murine macrophages by inflammatory mediators

    Science.gov (United States)

    Raza, Sobia; Barnett, Mark W.; Barnett-Itzhaki, Zohar; Amit, Ido; Hume, David A.; Freeman, Tom C.

    2014-01-01

    Macrophages respond to the TLR4 agonist LPS with a sequential transcriptional cascade controlled by a complex regulatory network of signaling pathways and transcription factors. At least two distinct pathways are currently known to be engaged by TLR4 and are distinguished by their dependence on the adaptor molecule MyD88. We have used gene expression microarrays to define the effects of each of three variables—LPS dose, LPS versus IFN-β and -γ, and genetic background—on the transcriptional response of mouse BMDMs. Analysis of correlation networks generated from the data has identified subnetworks or modules within the macrophage transcriptional network that are activated selectively by these variables. We have identified mouse strain-specific signatures, including a module enriched for SLE susceptibility candidates. In the modules of genes unique to different treatments, we found a module of genes induced by type-I IFN but not by LPS treatment, suggesting another layer of complexity in the LPS-TLR4 signaling feedback control. We also observe that the activation of the complement system, in common with the known activation of MHC class 2 genes, is reliant on IFN-γ signaling. Taken together, these data further highlight the exquisite nature of the regulatory systems that control macrophage activation, their likely relevance to disease resistance/susceptibility, and the appropriate response of these cells to proinflammatory stimuli. PMID:24721704

  19. Modulation of CP2 family transcriptional activity by CRTR-1 and sumoylation.

    Directory of Open Access Journals (Sweden)

    Sarah To

    Full Text Available CRTR-1 is a member of the CP2 family of transcription factors. Unlike other members of the family which are widely expressed, CRTR-1 expression shows specific spatio-temporal regulation. Gene targeting demonstrates that CRTR-1 plays a central role in the maturation and function of the salivary glands and the kidney. CRTR-1 has also recently been identified as a component of the complex transcriptional network that maintains pluripotency in embryonic stem (ES cells. CRTR-1 was previously shown to be a repressor of transcription. We examine the activity of CRTR-1 in ES and other cells and show that CRTR-1 is generally an activator of transcription and that it modulates the activity of other family members, CP2, NF2d9 and altNF2d9, in a cell specific manner. We also demonstrate that CRTR-1 activity is regulated by sumoylation at a single major site, residue K30. These findings imply that functional redundancy with other family members may mask important roles for CRTR-1 in other tissues, including the blastocyst stage embryo and embryonic stem cells.

  20. Modulation of CP2 family transcriptional activity by CRTR-1 and sumoylation.

    Science.gov (United States)

    To, Sarah; Rodda, Stephen J; Rathjen, Peter D; Keough, Rebecca A

    2010-07-22

    CRTR-1 is a member of the CP2 family of transcription factors. Unlike other members of the family which are widely expressed, CRTR-1 expression shows specific spatio-temporal regulation. Gene targeting demonstrates that CRTR-1 plays a central role in the maturation and function of the salivary glands and the kidney. CRTR-1 has also recently been identified as a component of the complex transcriptional network that maintains pluripotency in embryonic stem (ES) cells. CRTR-1 was previously shown to be a repressor of transcription. We examine the activity of CRTR-1 in ES and other cells and show that CRTR-1 is generally an activator of transcription and that it modulates the activity of other family members, CP2, NF2d9 and altNF2d9, in a cell specific manner. We also demonstrate that CRTR-1 activity is regulated by sumoylation at a single major site, residue K30. These findings imply that functional redundancy with other family members may mask important roles for CRTR-1 in other tissues, including the blastocyst stage embryo and embryonic stem cells.

  1. A do-it-yourself protocol for simple transcription activator-like effector assembly

    OpenAIRE

    Uhde-Stone Claudia; Gor Nilang; Chin Tiffany; Huang Joseph; Lu Biao

    2013-01-01

    Abstract Background TALEs (transcription activator-like effectors) are powerful molecules that have broad applications in genetic and epigenetic manipulations. The simple design of TALEs, coupled with high binding predictability and specificity, is bringing genome engineering power to the standard molecular laboratory. Currently, however, custom TALE assembly is either costly or limited to few research centers, due to complicated assembly protocols, l...

  2. IscR regulates RNase LS activity by repressing rnlA transcription.

    Science.gov (United States)

    Otsuka, Yuichi; Miki, Kumiko; Koga, Mitsunori; Katayama, Natsu; Morimoto, Wakako; Takahashi, Yasuhiro; Yonesaki, Tetsuro

    2010-07-01

    The Escherichia coli endoribonuclease LS was originally identified as a potential antagonist of bacteriophage T4. When the T4 dmd gene is defective, RNase LS cleaves T4 mRNAs and antagonizes T4 reproduction. This RNase also plays an important role in RNA metabolisms in E. coli. rnlA is an essential gene for RNase LS activity, but the transcriptional regulation of this gene remains to be elucidated. An Fe-S cluster protein, IscR, acts as a transcription factor and controls the expression of genes that are necessary for Fe-S cluster biogenesis. Here, we report that overexpression of IscR suppressed RNase LS activity, causing the loss of antagonist activity against phage T4. This suppressive effect did not require the ligation of Fe-S cluster into IscR. beta-Galactosidase reporter assays showed that transcription from an rnlA promoter increased in iscR-deleted cells compared to wild-type cells, and gel-mobility shift assays revealed specific binding of IscR to the rnlA promoter region. RT-PCR analysis demonstrated that endogenous rnlA mRNA was reduced by overexpression of IscR and increased by deletion of iscR. From these results, we conclude that IscR negatively regulates transcription of rnlA and represses RNase LS activity.

  3. RNA Polymerase II Regulates Topoisomerase 1 Activity to Favor Efficient Transcription.

    Science.gov (United States)

    Baranello, Laura; Wojtowicz, Damian; Cui, Kairong; Devaiah, Ballachanda N; Chung, Hye-Jung; Chan-Salis, Ka Yim; Guha, Rajarshi; Wilson, Kelli; Zhang, Xiaohu; Zhang, Hongliang; Piotrowski, Jason; Thomas, Craig J; Singer, Dinah S; Pugh, B Franklin; Pommier, Yves; Przytycka, Teresa M; Kouzine, Fedor; Lewis, Brian A; Zhao, Keji; Levens, David

    2016-04-01

    We report a mechanism through which the transcription machinery directly controls topoisomerase 1 (TOP1) activity to adjust DNA topology throughout the transcription cycle. By comparing TOP1 occupancy using chromatin immunoprecipitation sequencing (ChIP-seq) versus TOP1 activity using topoisomerase 1 sequencing (TOP1-seq), a method reported here to map catalytically engaged TOP1, TOP1 bound at promoters was discovered to become fully active only after pause-release. This transition coupled the phosphorylation of the carboxyl-terminal-domain (CTD) of RNA polymerase II (RNAPII) with stimulation of TOP1 above its basal rate, enhancing its processivity. TOP1 stimulation is strongly dependent on the kinase activity of BRD4, a protein that phosphorylates Ser2-CTD and regulates RNAPII pause-release. Thus the coordinated action of BRD4 and TOP1 overcame the torsional stress opposing transcription as RNAPII commenced elongation but preserved negative supercoiling that assists promoter melting at start sites. This nexus between transcription and DNA topology promises to elicit new strategies to intercept pathological gene expression.

  4. Complete androgen insensitivity syndrome

    Directory of Open Access Journals (Sweden)

    Tančić-Gajić Milina

    2015-01-01

    Full Text Available Introduction. Androgen insensitivity syndrome (AIS belongs to disorders of sex development, resulting from complete or partial resistance to the biological actions of androgens in persons who are genetically males (XY with normally developed testes and age-appropriate for males of serum testosterone concentration. Case Outline. A 21-year-old female patient was admitted at our Clinic further evaluation and treatment of testicular feminization syndrome, which was diagnosed at the age of 16 years. The patient had never menstruated. On physical examination, her external genitalia and breast development appeared as completely normal feminine structures but pubic and axillary hair was absent. Cytogenetic analysis showed a 46 XY karyotype. The values of sex hormones were as in adult males. The multisliced computed tomography (MSCT showed structures on both sides of the pelvic region, suggestive of testes. Bilateral orchiectomy was performed. Hormone replacement therapy was prescribed after gonadectomy. Vaginal dilatation was advised to avoid dyspareunia. Conclusion. The diagnosis of complete androgen insensitivity is based on clinical findigs, hormonal analysis karyotype, visualization methods and genetic analysis. Bilateral gonadectomy is generally recommended in early adulthood to avoid the risk of testicular malignancy. Vaginal length may be short requiring dilatation in an effort to avoid dyspareunia. Vaginal surgery is rarely indicated for the creation of a functional vagina. [Projekat Ministarstva nauke Republike Srbije, br. 175067

  5. Cloning and Transcriptional Activity of the Mouse Omi/HtrA2 Gene Promoter.

    Science.gov (United States)

    Liu, Dan; Liu, Xin; Wu, Ye; Wang, Wen; Ma, Xinliang; Liu, Huirong

    2016-01-16

    HtrA serine peptidase 2 (HtrA2), also named Omi, is a pro-apoptotic protein that exhibits dramatic changes in expression levels in a variety of disorders, including ischemia/reperfusion injury, cancer, and neurodegeneration. In our study, Omi/HtrA2 protein levels were high in the heart, brain, kidney and liver, with elevated heart/brain expression in aging mice. A similar expression pattern was observed at the mRNA level, which suggests that the regulation of Omi/HtrA2 is predominately transcriptional. Promoter binding by transcription factors is the main influencing factor of transcription, and to identify specific promoter elements that contribute to the differential expression of mouse Omi/HtrA2, we constructed truncated Omi/HtrA2 promoter/luciferase reporter vectors and analyzed their relative luciferase activity; it was greatest in the promoter regions at -1205~-838 bp and -146~+93 bp, with the -838~-649 bp region exhibiting negative regulatory activity. Bioinformatics analysis suggested that the Omi/HtrA2 gene promoter contains a CpG island at -709~+37 bp, and eight heat shock transcription factor 1 (HSF1) sites, two Sp1 transcription factor (SP1)sites, one activator protein (AP) site, seven p53 sites, and four YY1 transcription factor(YY1) sites were predicted in the core areas. Furthermore, we found that p53 and HSF1 specifically binds to the Omi/HtrA2 promoter using chromatin immunoprecipitation analysis. These results provide a foundation for understanding Omi/HtrA2 regulatory mechanisms, which could further understanding of HtrA-associated diseases.

  6. Regulation of androgen action during establishment of pregnancy.

    Science.gov (United States)

    Gibson, Douglas A; Simitsidellis, Ioannis; Saunders, Philippa T K

    2016-07-01

    During the establishment of pregnancy, the ovarian-derived hormones progesterone and oestradiol regulate remodelling of the endometrium to promote an environment that is able to support and maintain a successful pregnancy. Decidualisation is characterised by differentiation of endometrial stromal cells that secrete growth factors and cytokines that regulate vascular remodelling and immune cell influx. This differentiation process is critical for reproduction, and inadequate decidualisation is implicated in the aetiology of pregnancy disorders such as foetal growth restriction and preeclampsia. In contrast to progesterone and oestradiol, the role of androgens in regulating endometrial function is poorly understood. Androgen receptors are expressed in the endometrium, and androgens are reported to regulate both the transcriptome and the secretome of endometrial stromal cells. In androgen-target tissues, circulating precursors are activated to mediate local effects, and recent studies report that steroid concentrations detected in endometrial tissue are distinct to those detected in the peripheral circulation. New evidence suggests that decidualisation results in dynamic changes in the expression of androgen biosynthetic enzymes, highlighting a role for pre-receptor regulation of androgen action during the establishment of pregnancy. These results suggest that such enzymes could be future therapeutic targets for the treatment of infertility associated with endometrial dysfunction. In conclusion, these data support the hypothesis that androgens play a beneficial role in regulating the establishment and maintenance of pregnancy. Future studies should be focussed on investigating the safety and efficacy of androgen supplementation with the potential for utilisation of novel therapeutics, such as selective androgen receptor modulators, to improve reproductive outcomes in women.

  7. Elk3 from hamster-a ternary complex factor with strong transcriptional repressor activity

    DEFF Research Database (Denmark)

    Hjortoe, G.M.; Weilguny, D.; Willumsen, Berthe Marie

    2005-01-01

    the transcription of genes that are activated during entry into G1. We have isolated the Cricetulus griseus Elk3 gene from the Chinese hamster ovary (CHO) cell line and investigated the transcriptional potential of this factor. Transient transfections revealed that, in addition to its regulation of the c......-fos promoter, Elk3 from CHO cells seems to inhibit other promoters controlling expression of proteins involved in G1/S phase progression; Cyclin D1 and DHFR. As has been described for the Elk3 homologs Net (Mouse) and Sap-2 (Human), the results of the present study further indicate that hamster Elk3...

  8. Transcriptional activation of peroxisome proliferator-activated receptor-{gamma} requires activation of both protein kinase A and Akt during adipocyte differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-pil [Department of Thoracic and Cardiovascular Surgery, Pusan National University School of Medicine (Korea, Republic of); Ha, Jung Min; Yun, Sung Ji; Kim, Eun Kyoung [MRC for Ischemic Tissue Regeneration, Medical Research Institute, and Department of Pharmacology, Pusan National University School of Medicine (Korea, Republic of); Chung, Sung Woon [Department of Thoracic and Cardiovascular Surgery, Pusan National University School of Medicine (Korea, Republic of); Hong, Ki Whan; Kim, Chi Dae [MRC for Ischemic Tissue Regeneration, Medical Research Institute, and Department of Pharmacology, Pusan National University School of Medicine (Korea, Republic of); Bae, Sun Sik, E-mail: sunsik@pusan.ac.kr [MRC for Ischemic Tissue Regeneration, Medical Research Institute, and Department of Pharmacology, Pusan National University School of Medicine (Korea, Republic of)

    2010-08-13

    Research highlights: {yields} Elevated cAMP activates both PKA and Epac. {yields} PKA activates CREB transcriptional factor and Epac activates PI3K/Akt pathway via Rap1. {yields} Akt modulates PPAR-{gamma} transcriptional activity in concert with CREB. -- Abstract: Peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}) is required for the conversion of pre-adipocytes. However, the mechanism underlying activation of PPAR-{gamma} is unclear. Here we showed that cAMP-induced activation of protein kinase A (PKA) and Akt is essential for the transcriptional activation of PPAR-{gamma}. Hormonal induction of adipogenesis was blocked by a phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002), by a protein kinase A (PKA) inhibitor (H89), and by a Rap1 inhibitor (GGTI-298). Transcriptional activity of PPAR-{gamma} was markedly enhanced by 3-isobutyl-1-methylxanthine (IBMX), but not insulin and dexamethasone. In addition, IBMX-induced PPAR-{gamma} transcriptional activity was blocked by PI3K/Akt, PKA, or Rap1 inhibitors. 8-(4-Chlorophenylthio)-2'-O-methyl-cAMP (8-pCPT-2'-O-Me-cAMP) which is a specific agonist for exchanger protein directly activated by cAMP (Epac) significantly induced the activation of Akt. Furthermore, knock-down of Akt1 markedly attenuated PPAR-{gamma} transcriptional activity. These results indicate that both PKA and Akt signaling pathways are required for transcriptional activation of PPAR-{gamma}, suggesting post-translational activation of PPAR-{gamma} might be critical step for adipogenic gene expression.

  9. High resolution analysis of the human transcriptome: detection of extensive alternative splicing independent of transcriptional activity

    Directory of Open Access Journals (Sweden)

    Rouet Fabien

    2009-10-01

    transcriptional activity, indicating that the controls for transcript generation and transcription are distinct, and require novel tools in order to detect changes in specific transcript quantity. Our results demonstrate that the SpliceArray™ design will provide researchers with a robust platform to detect and quantify specific changes not only in overall gene expression, but also at the individual transcript level.

  10. Expression of androgen receptor target genes in skeletal muscle

    OpenAIRE

    2014-01-01

    We aimed to determine the mechanisms of the anabolic actions of androgens in skeletal muscle by investigating potential androgen receptor (AR)-regulated genes in in vitro and in vivo models. The expression of the myogenic regulatory factor myogenin was significantly decreased in skeletal muscle from testosterone-treated orchidectomized male mice compared to control orchidectomized males, and was increased in muscle from male AR knockout mice that lacked DNA binding activity (ARΔZF2 ) versus w...

  11. Fenofibrate down-regulates the expressions of androgen receptor (AR) and AR target genes and induces oxidative stress in the prostate cancer cell line LNCaP

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hu; Zhu, Chen; Qin, Chao [State Key Laboratory of Reproductive Medicine, Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing (China); Tao, Tao [Department of Neurosurgery, First Affiliated Hospital of Nanjing Medical University, Nanjing (China); Li, Jie; Cheng, Gong; Li, Pu; Cao, Qiang; Meng, Xiaoxin; Ju, Xiaobing; Shao, Pengfei; Hua, Lixin [State Key Laboratory of Reproductive Medicine, Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing (China); Gu, Min, E-mail: medzhao1980@163.com [State Key Laboratory of Reproductive Medicine, Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing (China); Yin, Changjun, E-mail: drcjyin@gmail.com [State Key Laboratory of Reproductive Medicine, Department of Urology, First Affiliated Hospital of Nanjing Medical University, Nanjing (China)

    2013-03-08

    Highlights: ► Fenofibrate induces cell cycle arrest in G1 phase and apoptosis in LNCaP cells. ► Fenofibrate reduces the expressions of androgen receptor in LNCaP cells. ► Fenofibrate induces oxidative stress in the prostate cancer cell line LNCaP. -- Abstract: Fenofibrate, a peroxisome proliferator-androgen receptor-alpha agonist, is widely used in treating different forms of hyperlipidemia and hypercholesterolemia. Recent reports have indicated that fenofibrate exerts anti-proliferative and pro-apoptotic properties. This study aims to investigate the effects of fenofibrate on the prostate cancer (PCa) cell line LNCaP. The effects of fenofibrate on LNCaP cells were evaluated by flow cytometry, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assays, Western blot analysis, and dual-luciferase reporter assay. Fenofibrate induces cell cycle arrest in G1 phase and apoptosis in LNCaP cells, reduces the expressions of androgen receptor (AR) and AR target genes (prostate-specific antigen and TMPRSS2), and inhibits Akt phosphorylation. Fenofibrate can induce the accumulation of intracellular reactive oxygen species and malondialdehyde, and decrease the activities of total anti-oxidant and superoxide dismutase in LNCaP cells. Fenofibrate exerts an anti-proliferative property by inhibiting the expression of AR and induces apoptosis by causing oxidative stress. Therefore, our data suggest fenofibrate may have beneficial effects in fenofibrate users by preventing prostate cancer growth through inhibition of androgen activation and expression.

  12. Constitutively-active androgen receptor variants function independently of the HSP90 chaperone but do not confer resistance to HSP90 inhibitors.

    Science.gov (United States)

    Gillis, Joanna L; Selth, Luke A; Centenera, Margaret M; Townley, Scott L; Sun, Shihua; Plymate, Stephen R; Tilley, Wayne D; Butler, Lisa M

    2013-05-01

    The development of lethal, castration resistant prostate cancer is associated with adaptive changes to the androgen receptor (AR), including the emergence of mutant receptors and truncated, constitutively active AR variants. AR relies on the molecular chaperone HSP90 for its function in both normal and malignant prostate cells, but the requirement for HSP90 in environments with aberrant AR expression is largely unknown. Here, we investigated the efficacy of three HSP90 inhibitors, 17-AAG, HSP990 and AUY922, against clinically-relevant AR missense mutants and truncated variants. HSP90 inhibition effectively suppressed the signaling of wild-type AR and all AR missense mutants tested. By contrast, two truncated AR variants, AR-V7 and ARv567es, exhibited marked resistance to HSP90 inhibitors. Supporting this observation, nuclear localization of the truncated AR variants was not affected by HSP90 inhibition and AR variant:HSP90 complexes could not be detected in prostate cancer cells. Interestingly, HSP90 inhibition resulted in accumulation of AR-V7 and ARv567es in both cell lines and human tumor explants. Despite the apparent independence of AR variants from HSP90 and their treatment-associated induction, the growth of cell lines with endogenous or enforced expression of AR-V7 or ARv567es remained highly sensitive to AUY922. This study demonstrates that functional AR variant signaling does not confer resistance to HSP90 inhibition, yields insight into the interaction between AR and HSP90 and provides further impetus for the clinical application of HSP90 inhibitors in advanced prostate cancer.

  13. MiR-361-5p acts as a tumor suppressor in prostate cancer by targeting signal transducer and activator of transcription-6(STAT6)

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dachuang [Department of Urology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province 210009 (China); Department of Urology, Xuzhou Central Hospital Affiliated with Southeast University, Xuzhou, Jiangsu Province 221009 (China); Surgery Central Laboratory of Southeast University, Nanjing, Jiangsu Province 210009 (China); Tao, Tao; Xu, Bin; Chen, Shuqiu; Liu, Chunhui [Department of Urology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province 210009 (China); Surgery Central Laboratory of Southeast University, Nanjing, Jiangsu Province 210009 (China); Zhang, Lei; Lu, Kai [Department of Urology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province 210009 (China); Huang, Yeqing; Jiang, Liang [Department of Urology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province 210009 (China); Surgery Central Laboratory of Southeast University, Nanjing, Jiangsu Province 210009 (China); Zhang, Xiaowen [Department of Urology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province 210009 (China); Huang, Xiaoming [Surgery Central Laboratory of Southeast University, Nanjing, Jiangsu Province 210009 (China); Zhang, Lihua [Department of Pathology, Zhongda Hospital Affiliated with Southeast University, Nanjing, Jiangsu Province 210009 (China); Han, Conghui [Department of Urology, Xuzhou Central Hospital Affiliated with Southeast University, Xuzhou, Jiangsu Province 221009 (China); Chen, Ming, E-mail: mingchenseu@gmail.com [Department of Urology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province 210009 (China); Surgery Central Laboratory of Southeast University, Nanjing, Jiangsu Province 210009 (China)

    2014-02-28

    Highlights: • The role of miR-361-5p in prostate cancer (PCa) has not been evaluated until date. • We found that the expression of miR-361-5p in CRPC was lower than in ADPC. • MiR-361-5p suppressed DU145 cell proliferation and triggered apoptosis. • STAT6 is a direct target of miR-361-5p. • STAT6 enhances the expression of Bcl-xL at the transcriptional level. - Abstract: Castration-resistant prostate cancer (CRPC), whose pathogenesis is known to be regulated by microRNAs (miRNAs), has a poor prognosis. In our present study, we found that the expression of miR-361-5p in CRPC was lower than in androgen-dependent prostate cancer (ADPC), indicating that miR-361-5p may play an important role in the progression of ADPC to CRPC. The role of miR-361-5p in prostate cancer (PCa) has not been evaluated until date. Our findings suggest that miR-361-5p is a suppressor in CRPC. Signal transducer and activator of transcription-6 (STAT6), a direct target of miR-361-5p, enhances the expression of B-cell lymphoma-extra large (Bcl-xL), while miR-361-5p inhibits its expression through STAT6. Therefore, miR-361-5p has great clinical significance in preventing the malignant progression of PCa.

  14. Calmodulin-binding transcription activators and perspectives for applications in biotechnology.

    Science.gov (United States)

    Shen, Chenjia; Yang, Yanjun; Du, Liqun; Wang, Huizhong

    2015-12-01

    In recent years, a novel family of calmodulin-binding transcription activators (CAMTAs) has been reported in various species. The CAMTAs share a conserved domain organization, with a CG-1 DNA-binding domain, a transcription factor immunoglobulin domain, several ankyrin repeats, a calmodulin-binding domain, and a varying number of IQ motifs. CAMTAs participate in transcriptional regulation by recognizing and binding to a specific cis-element: (G/A/C)CGCG(C/G/T). Plants suffer from the environmental challenges, including abiotic and biotic stresses. Investigations in various plant species indicate a broad range of CAMTA functions involved in developmental regulation, environmental stress response, and hormone cross talk. In this review, we focus on the expression patterns and biological functions of CAMTAs to explore their probable applications in biotechnology. Furthermore, the identification and phylogenetic analysis of CAMTAs in crops could open new perspectives for enhancing stress tolerance, which could lead to improved crop production.

  15. Rph1 mediates the nutrient-limitation signaling pathway leading to transcriptional activation of autophagy.

    Science.gov (United States)

    Bernard, Amélie; Klionsky, Daniel J

    2015-04-01

    To maintain proper cellular homeostasis, the magnitude of autophagy activity has to be finely tuned in response to environmental changes. Many aspects of autophagy regulation have been extensively studied: pathways integrating signals through the master regulators TORC1 and PKA lead to multiple post-translational modifications affecting the functions, protein-protein interactions, and localization of Atg proteins. The expression of several ATG genes increases sharply upon autophagy induction conditions, and defects in ATG gene expression are associated with various diseases, pointing to the importance of transcriptional regulation of autophagy. Yet, how changes in ATG gene expression affect the rate of autophagy is not well characterized, and transcriptional regulators of the autophagy pathway remain largely unknown. To identify such regulators, we analyzed the expression of several ATG genes in a library of DNA-binding protein mutants. This led to the identification of Rph1 as a master transcriptional regulator of autophagy.

  16. Regulation and function of signal transducer and activator of transcription 3

    Institute of Scientific and Technical Information of China (English)

    Qian-Rong; Qi; Zeng-Ming; Yang

    2014-01-01

    Signal transducer and activator of transcription 3(STAT3), a member of the STAT family, is a key regulator of many physiological and pathological processes. Significant progress has been made in understanding the transcriptional control, posttranslational modification, cellular localization and functional regulation of STAT3. STAT3 can translocate into the nucleus and bind to specific promoter sequences, thereby exerting transcriptional regulation. Recent studies have shown that STAT3 can also translocate into mitochondria, participating in aerobic respiration and apoptosis. In addition, STAT3 plays an important role in inflammation and tumorigenesis by regulating cell proliferation, differentiation and metabolism. Conditional knockout mouse models make it possible to study the physiological function of STAT3 in specific tissues and organs. This review summarizes the latest advances in the understanding of the expression, regulation and function of STAT3 in physiological and tumorigenic processes.

  17. A transcription activator-like effector (TALE) induction system mediated by proteolysis.

    Science.gov (United States)

    Copeland, Matthew F; Politz, Mark C; Johnson, Charles B; Markley, Andrew L; Pfleger, Brian F

    2016-04-01

    Simple and predictable trans-acting regulatory tools are needed in the fields of synthetic biology and metabolic engineering to build complex genetic circuits and optimize the levels of native and heterologous gene products. Transcription activator-like effectors (TALEs) are bacterial virulence factors that have recently gained traction in biotechnology applications owing to their customizable DNA-binding specificity. In this work we expanded the versatility of these transcription factors to create an inducible TALE system by inserting tobacco-etch virus (TEV) protease recognition sites into the TALE backbone. The resulting engineered TALEs maintain transcriptional repression of their target genes in Escherichia coli, but are degraded after induction of the TEV protease, thereby promoting expression of the previously repressed target gene of interest. This TALE-TEV technology enables both repression and induction of plasmid or chromosomal target genes in a manner analogous to traditional repressor proteins but with the added flexibility of being operator-agnostic.

  18. Cardiac hypertrophy induced by active Raf depends on Yorkie-mediated transcription

    OpenAIRE

    Yu, Lin; Daniels, Joseph P.; Wu, Huihui; Wolf, Matthew J.

    2015-01-01

    Organ hypertrophy can result from enlargement of individual cells or from cell proliferation or both. Activating mutations in the serine-threonine kinase Raf cause cardiac hypertrophy and contribute to Noonan syndrome in humans. Cardiac-specific expression of activated Raf also causes hypertrophy in Drosophila melanogaster. We found that Yorkie (Yki), a transcriptional coactivator in the Hippo pathway that regulates organ size, is required for Raf-induced cardiac hypertrophy in flies. Althoug...

  19. A central region of Gli2 regulates its localization to the primary cilium and transcriptional activity

    OpenAIRE

    Santos, Nicole; Reiter, Jeremy F.

    2014-01-01

    Signaling through vertebrate Hedgehog (Hh) proteins depends on the primary cilium. In response to Hh signals, the transcriptional activator of the pathway, Gli2, accumulates at the ciliary tip, raising the possibility that ciliary localization is important for Gli2 activation. To test this hypothesis, we used the Floxin system to create knock-in Gli2 alleles in embryonic stem cells (ESCs) to allow methodical testing of which domains and residues are essential for the ciliary localization of G...

  20. Occludin controls HIV transcription in brain pericytes via regulation of SIRT-1 activation.

    Science.gov (United States)

    Castro, Victor; Bertrand, Luc; Luethen, Mareen; Dabrowski, Sebastian; Lombardi, Jorge; Morgan, Laura; Sharova, Natalia; Stevenson, Mario; Blasig, Ingolf E; Toborek, Michal

    2016-03-01

    HIV invades the brain early after infection; however, its interactions with the cells of the blood-brain barrier (BBB) remain poorly understood. Our goal was to evaluate the role of occludin, one of the tight junction proteins that regulate BBB functions in HIV infection of BBB pericytes. We provide evidence that occludin levels largely control the metabolic responses of human pericytes to HIV. Occludin in BBB pericytes decreased by 10% during the first 48 h after HIV infection, correlating with increased nuclear translocation of the gene repressor C-terminal-binding protein (CtBP)-1 and NFκB-p65 activation. These changes were associated with decreased expression and activation of the class III histone deacetylase sirtuin (SIRT)-1. Occludin levels recovered 96 h after infection, restoring SIRT-1 and reducing HIV transcription to 20% of its highest values. We characterized occludin biochemically as a novel NADH oxidase that controls the expression and activation of SIRT-1. The inverse correlation between occludin and HIV transcription was then replicated in human primary macrophages and differentiated monocytic U937 cells, in which occludin silencing resulted in 75 and 250% increased viral transcription, respectively. Our work shows that occludin has previously unsuspected metabolic properties and is a target of HIV infection, opening the possibility of designing novel pharmacological approaches to control HIV transcription.

  1. RIT1 GTPase Regulates Sox2 Transcriptional Activity and Hippocampal Neurogenesis.

    Science.gov (United States)

    Mir, Sajad; Cai, Weikang; Andres, Douglas A

    2017-02-10

    Adult neurogenesis, the process of generating mature neurons from neuronal progenitor cells, makes critical contributions to neural circuitry and brain function in both healthy and disease states. Neurogenesis is a highly regulated process in which diverse environmental and physiological stimuli are relayed to resident neural stem cell populations to control the transcription of genes involved in self-renewal and differentiation. Understanding the molecular mechanisms governing neurogenesis is necessary for the development of translational strategies to harness this process for neuronal repair. Here we report that the Ras-related GTPase RIT1 serves to control the sequential proliferation and differentiation of adult hippocampal neural progenitor cells, with in vivo expression of active RIT1 driving robust adult neurogenesis. Gene expression profiling analysis demonstrates increased expression of a specific set of transcription factors known to govern adult neurogenesis in response to active RIT1 expression in the hippocampus, including sex-determining region Y-related HMG box 2 (Sox2), a well established regulator of stem cell self-renewal and neurogenesis. In adult hippocampal neuronal precursor cells, RIT1 controls an Akt-dependent signaling cascade, resulting in the stabilization and transcriptional activation of phosphorylated Sox2. This study supports a role for RIT1 in relaying niche-derived signals to neural/stem progenitor cells to control transcription of genes involved in self-renewal and differentiation.

  2. Wnt inhibitory factor 1 (Wif1) is regulated by androgens and enhances androgen-dependent prostate development.

    Science.gov (United States)

    Keil, Kimberly P; Mehta, Vatsal; Branam, Amanda M; Abler, Lisa L; Buresh-Stiemke, Rita A; Joshi, Pinak S; Schmitz, Christopher T; Marker, Paul C; Vezina, Chad M

    2012-12-01

    Fetal prostate development from urogenital sinus (UGS) epithelium requires androgen receptor (AR) activation in UGS mesenchyme (UGM). Despite growing awareness of sexually dimorphic gene expression in the UGS, we are still limited in our knowledge of androgen-responsive genes in UGM that initiate prostate ductal development. We found that WNT inhibitory factor 1 (Wif1) mRNA is more abundant in male vs. female mouse UGM in which its expression temporally and spatially overlaps androgen-responsive steroid 5α-reductase 2 (Srd5a2). Wif1 mRNA is also present in prostatic buds during their elongation and branching morphogenesis. Androgens are necessary and sufficient for Wif1 expression in mouse UGS explant mesenchyme, and testicular androgens remain necessary for normal Wif1 expression in adult mouse prostate stroma. WIF1 contributes functionally to prostatic bud formation. In the presence of androgens, exogenous WIF1 protein increases prostatic bud number and UGS basal epithelial cell proliferation without noticeably altering the pattern of WNT/β-catenin-responsive Axin2 or lymphoid enhancer binding factor 1 (Lef1) mRNA. Wif1 mutant male UGSs exhibit increased (Sfrp)2 and (Sfrp)3 expression and form the same number of prostatic buds as the wild-type control males. Collectively our results reveal Wif1 as one of the few known androgen-responsive genes in the fetal mouse UGM and support the hypothesis that androgen-dependent Wif1 expression is linked to the mechanism of androgen-induced prostatic bud formation.

  3. Yap5 is an iron-responsive transcriptional activator that regulates vacuolar iron storage in yeast.

    Science.gov (United States)

    Li, Liangtao; Bagley, Dustin; Ward, Diane M; Kaplan, Jerry

    2008-02-01

    The transporter Ccc1 imports iron into the vacuole, which is the major site of iron storage in fungi and plants. CCC1 mRNA is destabilized under low-iron conditions by the binding of Cth1 and Cth2 to the 3' untranslated region (S. Puig, E. Askeland, and D. J. Thiele, Cell 120:99-110, 2005). Here, we show that the transcription of CCC1 is stimulated by iron through a Yap consensus site in the CCC1 promoter. We identified YAP5 as being the iron-sensitive transcription factor and show that a yap5Delta strain is sensitive to high iron. Green fluorescent protein-tagged Yap5 is localized to the nucleus and occupies the CCC1 promoter independent of the iron concentration. Yap5 contains two cysteine-rich domains, and the mutation of the cysteines to alanines in each of the domains affects the transcription of CCC1 but not DNA binding. The fusion of the Yap5 cysteine-containing domains to a GAL4 DNA binding domain results in iron-sensitive GAL1-lacZ expression. Iron affects the sulfhydryl status of Yap5, which is indicative of the generation of intramolecular disulfide bonds. These results show that Yap5 is an iron-sensing transcription factor and that iron regulates transcriptional activation.

  4. Yap5 Is an Iron-Responsive Transcriptional Activator That Regulates Vacuolar Iron Storage in Yeast▿

    Science.gov (United States)

    Li, Liangtao; Bagley, Dustin; Ward, Diane M.; Kaplan, Jerry

    2008-01-01

    The transporter Ccc1 imports iron into the vacuole, which is the major site of iron storage in fungi and plants. CCC1 mRNA is destabilized under low-iron conditions by the binding of Cth1 and Cth2 to the 3′ untranslated region (S. Puig, E. Askeland, and D. J. Thiele, Cell 120:99-110, 2005). Here, we show that the transcription of CCC1 is stimulated by iron through a Yap consensus site in the CCC1 promoter. We identified YAP5 as being the iron-sensitive transcription factor and show that a yap5Δ strain is sensitive to high iron. Green fluorescent protein-tagged Yap5 is localized to the nucleus and occupies the CCC1 promoter independent of the iron concentration. Yap5 contains two cysteine-rich domains, and the mutation of the cysteines to alanines in each of the domains affects the transcription of CCC1 but not DNA binding. The fusion of the Yap5 cysteine-containing domains to a GAL4 DNA binding domain results in iron-sensitive GAL1-lacZ expression. Iron affects the sulfhydryl status of Yap5, which is indicative of the generation of intramolecular disulfide bonds. These results show that Yap5 is an iron-sensing transcription factor and that iron regulates transcriptional activation. PMID:18070921

  5. Activation of the SMU.1882 transcription by CovR in Streptococcus mutans.

    Directory of Open Access Journals (Sweden)

    Patrick Chong

    Full Text Available In Streptococcus mutans, the global response regulator CovR plays an important role in biofilm formation, stress-tolerance response, and caries production. We have previously shown that CovR acts as a transcriptional repressor by binding to the upstream promoter regions of its target genes. Here, we report that in vivo, CovR activates the transcription of SMU.1882, which encodes a small peptide containing a double-glycine motif. We also show that SMU.1882 is transcriptionally linked to comA that encodes a putative ABC transporter protein. Several genes from man gene clusters that encode mannose phosphotranferase system flank SMU.1882 -comA genes. Genomic comparison with other streptococci indicates that SMU.1882 is uniquely present in S. mutans, while the man operon is conserved among all streptococci, suggesting that a genetic rearrangement might have taken place at this locus. With the use of a transcriptional reporter system and semi-quantitative RT-PCR, we demonstrated the transcriptional regulation of SMU.1882 by CovR. In vitro gel shift and DNase I foot-printing analyses with purified CovR suggest that CovR binds to a large region surrounding the -10 region of the P(1882. Using this information and comparing with other CovR regulated promoters, we have developed a putative consensus binding sequence for CovR. Although CovR binds to P(1882, in vitro experiments using purified S. mutans RpoD, E. coli RNA polymerase, and CovR did not activate transcription from this promoter. Thus, we speculate that in vivo, CovR may interfere with the binding of a repressor or requires a cofactor.

  6. A central region of Gli2 regulates its localization to the primary cilium and transcriptional activity.

    Science.gov (United States)

    Santos, Nicole; Reiter, Jeremy F

    2014-04-01

    Signaling through vertebrate Hedgehog (Hh) proteins depends on the primary cilium. In response to Hh signals, the transcriptional activator of the pathway, Gli2, accumulates at the ciliary tip, raising the possibility that ciliary localization is important for Gli2 activation. To test this hypothesis, we used the Floxin system to create knock-in Gli2 alleles in embryonic stem cells (ESCs) to allow methodical testing of which domains and residues are essential for the ciliary localization of Gli2. The Gli2 zinc fingers, transcriptional activation domain, repressor domain, phosphorylation cluster and a Sufu binding motif were each dispensable for ciliary localization. Mutating residues that are required for Gli2 sumoylation and nuclear trafficking also did not abrogate ciliary localization. By contrast, several other domains restricted Gli2 nuclear localization, and a central region, distinct from previously characterized domains, was required for ciliary localization. In addition to an inability to localize to cilia, Gli2 lacking this central domain was unable to activate target genes. Thus, our systematic analysis in ESCs reveals that distinct regions of Gli2 regulate its nuclear and ciliary localization. The identification of a domain essential for both ciliary localization and transcriptional activity suggests that ciliary localization of Gli2 is required for its activation.

  7. Genome-scale transcriptional activation by an engineered CRISPR-Cas9 complex.

    Science.gov (United States)

    Konermann, Silvana; Brigham, Mark D; Trevino, Alexandro E; Joung, Julia; Abudayyeh, Omar O; Barcena, Clea; Hsu, Patrick D; Habib, Naomi; Gootenberg, Jonathan S; Nishimasu, Hiroshi; Nureki, Osamu; Zhang, Feng

    2015-01-29

    Systematic interrogation of gene function requires the ability to perturb gene expression in a robust and generalizable manner. Here we describe structure-guided engineering of a CRISPR-Cas9 complex to mediate efficient transcriptional activation at endogenous genomic loci. We used these engineered Cas9 activation complexes to investigate single-guide RNA (sgRNA) targeting rules for effective transcriptional activation, to demonstrate multiplexed activation of ten genes simultaneously, and to upregulate long intergenic non-coding RNA (lincRNA) transcripts. We also synthesized a library consisting of 70,290 guides targeting all human RefSeq coding isoforms to screen for genes that, upon activation, confer resistance to a BRAF inhibitor. The top hits included genes previously shown to be able to confer resistance, and novel candidates were validated using individual sgRNA and complementary DNA overexpression. A gene expression signature based on the top screening hits correlated with markers of BRAF inhibitor resistance in cell lines and patient-derived samples. These results collectively demonstrate the potential of Cas9-based activators as a powerful genetic perturbation technology.

  8. PARP1 orchestrates variant histone exchange in signal-mediated transcriptional activation.

    Science.gov (United States)

    O'Donnell, Amanda; Yang, Shen-Hsi; Sharrocks, Andrew D

    2013-12-01

    Transcriptional activation is accompanied by multiple molecular events that remodel the local chromatin environment in promoter regions. These molecular events are often orchestrated in response to the activation of signalling pathways, as exemplified by the response of immediate early genes such as FOS to ERK MAP kinase signalling. Here, we demonstrate that inducible NFI recruitment permits PARP1 binding to the FOS promoter by a mutually reinforcing loop. PARP1 and its poly(ADP-ribosyl)ation activity are required for maintaining FOS activation kinetics. We also show that the histone variant H2A.Z associates with the FOS promoter and acts in a transcription-suppressive manner. However, in response to ERK pathway signalling, H2A.Z is replaced by H2A; PARP1 activity is required to promote this exchange. Thus, our work has revealed an additional facet of PARP1 function in promoting dynamic remodelling of promoter-associated nucleosomes to allow transcriptional activation in response to cellular signalling.

  9. Locked and proteolysis-based transcription activator-like effector (TALE) regulation.

    Science.gov (United States)

    Lonzarić, Jan; Lebar, Tina; Majerle, Andreja; Manček-Keber, Mateja; Jerala, Roman

    2016-02-18

    Development of orthogonal, designable and adjustable transcriptional regulators is an important goal of synthetic biology. Their activity has been typically modulated through stimulus-induced oligomerization or interaction between the DNA-binding and activation/repression domain. We exploited a feature of the designable Transcription activator-like effector (TALE) DNA-binding domain that it winds around the DNA which allows to topologically prevent it from binding by intramolecular cyclization. This new approach was investigated through noncovalent ligand-induced cyclization or through a covalent split intein cyclization strategy, where the topological inhibition of DNA binding by cyclization and its restoration by a proteolytic release of the topologic constraint was expected. We show that locked TALEs indeed have diminished DNA binding and regain full transcriptional activity by stimulation with the rapamycin ligand or site-specific proteolysis of the peptide linker, with much higher level of activation than rapamycin-induced heterodimerization. Additionally, we demonstrated reversibility, activation of genomic targets and implemented logic gates based on combinations of protein cyclization, proteolytic cleavage and ligand-induced dimerization, where the strongest fold induction was achieved by the proteolytic cleavage of a repression domain from a linear TALE.

  10. Androgen receptor function links human sexual dimorphism to DNA methylation.

    Directory of Open Access Journals (Sweden)

    Ole Ammerpohl

    Full Text Available Sex differences are well known to be determinants of development, health and disease. Epigenetic mechanisms are also known to differ between men and women through X-inactivation in females. We hypothesized that epigenetic sex differences may also result from sex hormone functions, in particular from long-lasting androgen programming. We aimed at investigating whether inactivation of the androgen receptor, the key regulator of normal male sex development, is associated with differences of the patterns of DNA methylation marks in genital tissues. To this end, we performed large scale array-based analysis of gene methylation profiles on genomic DNA from labioscrotal skin fibroblasts of 8 males and 26 individuals with androgen insensitivity syndrome (AIS due to inactivating androgen receptor gene mutations. By this approach we identified differential methylation of 167 CpG loci representing 162 unique human genes. These were significantly enriched for androgen target genes and low CpG content promoter genes. Additional 75 genes showed a significant increase of heterogeneity of methylation in AIS compared to a high homogeneity in normal male controls. Our data show that normal and aberrant androgen receptor function is associated with distinct patterns of DNA-methylation marks in genital tissues. These findings support the concept that transcription factor binding to the DNA has an impact on the shape of the DNA methylome. These data which derived from a rare human model suggest that androgen programming of methylation marks contributes to sexual dimorphism in the human which might have considerable impact on the manifestation of sex-associated phenotypes and diseases.

  11. Piperine, a Bioactive Component of Pepper Spice Exerts Therapeutic Effects on Androgen Dependent and Androgen Independent Prostate Cancer Cells

    OpenAIRE

    2013-01-01

    Prostate cancer is the most common solid malignancy in men, with 32,000 deaths annually. Piperine, a major alkaloid constituent of black pepper, has previously been reported to have anti-cancer activity in variety of cancer cell lines. The effect of piperine against prostate cancer is not currently known. Therefore, in this study, we investigated the anti-tumor mechanisms of piperine on androgen dependent and androgen independent prostate cancer cells. Here, we show that piperine inhibited th...

  12. Model of Transcriptional Activation By MarA in Escherichia Coli

    Science.gov (United States)

    Wall, Michael E.; Markowitz, David A.; Rosner, Judah L.; Martin, Robert G.

    2010-01-01

    We have developed a mathematical model of transcriptional activation by MarA in Escherichia coli, and used the model to analyze measurements of MarA-dependent activity of the marRAB, sodA, and micF promoters in mar-rob- cells. The model rationalizes an unexpected poor correlation between the mid-point of in vivo promoter activity profiles and in vitro equilibrium constants for MarA binding to promoter sequences. Analysis of the promoter activity data using the model yielded the following predictions regarding activation mechanisms: (1) MarA activation of the marRAB, sodA, and micF promoters involves a net acceleration of the kinetics of transitions after RNA polymerase binding, up to and including promoter escape and message elongation; (2) RNA polymerase binds to these promoters with nearly unit occupancy in the absence of MarA, making recruitment of polymerase an insignificant factor in activation of these promoters; and (3) instead of recruitment, activation of the micF promoter might involve a repulsion of polymerase combined with a large acceleration of the kinetics of polymerase activity. These predictions are consistent with published chromatin immunoprecipitation assays of interactions between polymerase and the E. coli chromosome. A lack of recruitment in transcriptional activation represents an exception to the textbook description of activation of bacterial sigma-70 promoters. However, use of accelerated polymerase kinetics instead of recruitment might confer a competitive advantage to E. coli by decreasing latency in gene regulation.

  13. Reactive oxygen species in signalling the transcriptional activation of WIPK expression in tobacco.

    Science.gov (United States)

    Xu, Juan; Yang, Kwang-Yeol; Yoo, Seung Jin; Liu, Yidong; Ren, Dongtao; Zhang, Shuqun

    2014-07-01

    Plant mitogen-activated protein kinases represented by tobacco WIPK (wounding-induced protein kinase) and its orthologs in other species are unique in their regulation at transcriptional level in response to stress and pathogen infection. We previously demonstrated that transcriptional activation of WIPK is essential for induced WIPK activity, and activation of salicylic acid-induced protein kinase (SIPK) by the constitutively active NtMEK2(DD) is sufficient to induce WIPK gene expression. Here, we report that the effect of SIPK on WIPK gene expression is mediated by reactive oxygen species (ROS). Using a combination of pharmacological and gain-of-function transgenic approaches, we studied the relationship among SIPK activation, WIPK gene activation in response to fungal cryptogein, light-dependent ROS generation in chloroplasts, and ROS generated via NADPH oxidase. In the conditional gain-of-function GVG-NtMEK2(DD) transgenic tobacco, induction of WIPK expression is dependent on the ROS generation in chloroplasts. Consistently, methyl viologen, an inducer of ROS generation in chloroplasts, highly activated WIPK expression. In addition to chloroplast-originated ROS, H(2)O(2) generated from the cell-surface NADPH oxidase could also activate WIPK gene expression, and inhibition of cryptogein-induced ROS generation also abolished WIPK gene activation. Our data demonstrate that WIPK gene activation is mediated by ROS, which provides a mechanism by which ROS influence cellular signalling processes in plant stress/defence response.

  14. Adaptation of the Agrobacterium tumefaciens VirG response regulator to activate transcription in plants.

    Science.gov (United States)

    Czarnecka-Verner, Eva; Salem, Tarek A; Gurley, William B

    2016-02-01

    The Agrobacterium tumefaciens VirG response regulator of the VirA/VirG two-component system was adapted to function in tobacco protoplasts. The subcellular localization of VirG and VirA proteins transiently expressed in onion cells was determined using GFP fusions. Preliminary studies using Gal4DBD-VP16 fusions with VirG and Escherichia coli UhpA, and NarL response regulators indicated compatibility of these bacterial proteins with the eukaryotic transcriptional apparatus. A strong transcriptional activator based on tandem activation domains from the Drosophila fushi tarazu and Herpes simplex VP16 was created. Selected configurations of the two-site Gal4-vir box GUS reporters were activated by chimeric effectors dependent on either the yeast Gal4 DNA-binding domain or that of VirG. Transcriptional induction of the GUS reporter was highest for the VirE19-element promoter with both constitutive and wild-type VirG-tandem activation domain effectors. Multiple VirE19 elements increased the reporter activity proportionately, indicating that the VirG DNA binding domain was functional in plants. The VirG constitutive-Q-VP16 effector was more active than the VirG wild-type. In both the constitutive and wild-type forms of VirG, Q-VP16 activated transcription of the GUS reporter best when located at the C-terminus, i.e. juxtaposed to the VirG DNA binding domain. These results demonstrate the possibility of using DNA binding domains from bacterial response regulators and their cognate binding elements in the engineering of plant gene expression.

  15. Copper is required for cobalt-induced transcriptional activity of hypoxia-inducible factor-1.

    Science.gov (United States)

    Qiu, Liying; Ding, Xueqin; Zhang, Zhen; Kang, Y James

    2012-08-01

    Cobalt inhibits prolyl hydroxylases, leading to the accumulation of hypoxia-inducible factor-1α (HIF-1α) and a concomitant increase in the transcriptional activity of HIF-1. Therefore, cobalt has been under development as a drug for activating HIF-1 under some disease conditions. However, it has been shown that ischemic conditions resulted in the loss of copper, and the activation of HIF-1 would not occur unless copper was supplemented. The present study was undertaken to test the hypothesis that copper is also required for the cobalt activation of HIF-1 transcriptional activity. Human umbilical vein endothelial cells subjected to treatment with cobalt chloride (CoCl(2)) at concentrations above 25 μM for 2 h resulted in an accumulation of HIF-1α, which was determined by Western blot analysis, and an increase in the expression of vascular endothelial growth factor (VEGF), which was determined by real-time reverse transcription-polymerase chain reaction analysis for mRNA levels and enzyme-linked immunosorbent assay analysis for protein levels. The copper chelator tetraethylenepentamine at 25 μM did not significantly affect the accumulation of HIF-1α but blocked increases in VEGF mRNA and protein levels, an effect that could be reversed by the addition of 25 μM copper sulfate (CuSO(4)). In addition, gene silencing of the copper chaperone for Cu,Zn-superoxide dismutase blocked VEGF expression with little effect on cobalt-induced HIF-1α accumulation. The present study thus demonstrates that copper was required for cobalt-activated transcriptional activity of HIF-1, although copper did not affect cobalt-induced accumulation of HIF-1α in the cells.

  16. Bromodomain and extra-terminal (BET) bromodomain inhibition activate transcription via transient release of positive transcription elongation factor b (P-TEFb) from 7SK small nuclear ribonucleoprotein.

    Science.gov (United States)

    Bartholomeeusen, Koen; Xiang, Yanhui; Fujinaga, Koh; Peterlin, B Matija

    2012-10-19

    By phosphorylating elongation factors and the C-terminal domain of RNA polymerase II, the positive transcription elongation factor b (P-TEFb) is the critical kinase for transcription elongation and co-transcriptional processing of eukaryotic genes. It exists in inactive small nuclear ribonucleoprotein (7SK snRNP) and active (free P-TEFb) complexes in cells. The P-TEFb equilibrium determines the state of cellular activation, proliferation, and differentiation. Free P-TEFb, which is required for growth, can be recruited to RNA polymerase II via transcription factors, BRD4, or the super elongation complex (SEC). UV light, various signaling cascades, transcriptional blockade, or compounds such as hexamethylene bisacetamide (HMBA), suberoylanilide hydroxamic acid (SAHA), and other histone deacetylase inhibitors lead to a rapid release of free P-TEFb, followed by its reassembly into the 7SK snRNP. As a consequence, transcription of HEXIM1, a critical 7SK snRNP subunit, and HIV is induced. In this study, we found that a bromodomain and extra-terminal (BET) bromodomain inhibitor, JQ1, which inhibits BRD4 by blocking its association with chromatin, also leads to the rapid release of free P-TEFb from the 7SK snRNP. Indeed, JQ1 transiently increased levels of free P-TEFb and BRD4·P-TEFb and SEC·P-TEFb complexes in cells. As a consequence, the levels of HEXIM1 and HIV proteins rose. Importantly, the knockdown of ELL2, a subunit of the SEC, blocked the ability of JQ1 to increase HIV transcription. Finally, the effects of JQ1 and HMBA or SAHA on the P-TEFb equilibrium were cooperative. We conclude that HMBA, SAHA, and JQ1 affect transcription elongation by a similar and convergent mechanism.

  17. Androgen deprivation causes truncation of the C-terminal region of androgen receptor in human prostate cancer LNCaP cells.

    Science.gov (United States)

    Harada, Naoki; Inoue, Kaoru; Yamaji, Ryoichi; Nakano, Yoshihisa; Inui, Hiroshi

    2012-06-01

    The androgen receptor (AR) acts as a ligand-dependent transcription factor, whereas mutant AR lacking the C-terminal ligand-binding domain functions in a ligand-independent manner. In the present study we report that the C-terminal truncated AR, which we named AR-NH1 (the N-terminal fragment of AR cleaved in the neighborhood of helix 1 of the ligand-binding domain), is produced in LNCaP prostatic carcinoma cells. The AR-NH1 of ~90 kDa was observed in an androgen-independent LNCaP subline and was further accumulated by the proteasome inhibitor MG132. MG132 treatment caused the accumulation of AR-NH1 even in parent LNCaP cells. AR-NH1 was produced in the absence of ligand or in the presence of the AR antagonist bicalutamide, whereas AR agonists suppressed its production. AR-NH1 was detected with different AR antibodies recognizing amino acid residues 1-20 and 300-316 and was also generated from exogenous AR. Both siRNA-mediated AR knockdown and treatment with a serine protease inhibitor (4-(2-aminoethyl)-benzenesulfonyl fluoride) reduced AR-NH1 levels. According to the predicted cleavage site (between amino acid residues 660-685) and its nuclear localization, it is assumed that AR-NH1 functions as a constitutively active transcription factor. These data suggest that AR-NH1 is produced under hormone therapy and contributes to the development of castration-resistant prostate cancer due to its ligand-independent transcriptional activity.

  18. Resveratrol induces growth arrest and apoptosis through activation of FOXO transcription factors in prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Qinghe Chen

    Full Text Available BACKGROUND: Resveratrol, a naturally occurring phytopolyphenol compound, has attracted extensive interest in recent years because of its diverse pharmacological characteristics. Although resveratrol possesses chemopreventive properties against several cancers, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood. The present study was carried out to examine whether PI3K/AKT/FOXO pathway mediates the biological effects of resveratrol. METHODOLOGY/PRINCIPAL FINDINGS: Resveratrol inhibited the phosphorylation of PI3K, AKT and mTOR. Resveratrol, PI3K inhibitors (LY294002 and Wortmannin and AKT inhibitor alone slightly induced apoptosis in LNCaP cells. These inhibitors further enhanced the apoptosis-inducing potential of resveratrol. Overexpression of wild-type PTEN slightly induced apoptosis. Wild type PTEN and PTEN-G129E enhanced resveratrol-induced apoptosis, whereas PTEN-G129R had no effect on proapoptotic effects of resveratrol. Furthermore, apoptosis-inducing potential of resveratrol was enhanced by dominant negative AKT, and inhibited by wild-type AKT and constitutively active AKT. Resveratrol has no effect on the expression of FKHR, FKHRL1 and AFX genes. The inhibition of FOXO phosphorylation by resveratrol resulted in its nuclear translocation, DNA binding and transcriptional activity. The inhibition of PI3K/AKT pathway induced FOXO transcriptional activity resulting in induction of Bim, TRAIL, p27/KIP1, DR4 and DR5, and inhibition of cyclin D1. Similarly, resveratrol-induced FOXO transcriptional activity was further enhanced when activation of PI3K/AKT pathway was blocked. Over-expression of phosphorylation deficient mutants of FOXO proteins (FOXO1-TM, FOXO3A-TM and FOXO4-TM induced FOXO transcriptional activity, which was further enhanced by resveratrol. Inhibition of FOXO transcription factors by shRNA blocked resveratrol-induced upregulation of Bim, TRAIL, DR4, DR5, p27/KIP1 and

  19. Cisplatin Induces Cytotoxicity through the Mitogen-Activated Protein Kinase Pathways ana Activating Transcription Factor 3

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    Carly St. Germain

    2010-07-01

    Full Text Available The mechanisms underlying the proapoptotic effect of the chemotherapeutic agent, cisplatin, are largely undefined. Understanding the mechanisms regulating cisplatin cytotoxicity may uncover strategies to enhance the efficacy of this important therapeutic agent. This study evaluates the role of activating transcription factor 3 (ATF3 as a mediator of cisplatin-induced cytotoxicity. Cytotoxic doses of cisplatin and carboplatin treatments consistently induced ATF3 expression in five tumor-derived cell lines. Characterization of this induction revealed a p53, BRCA1, and integrated stress response-independent mechanism, all previously implicated in stress-mediated ATF3 induction. Analysis of mitogenactivated protein kinase (MAPK pathway involvement in ATF3 induction by cisplatin revealed a MAPK-dependent mechanism. Cisplatin treatment combined with specific inhibitors to each MAPK pathway (c-Jun N-terminal kinase, extracellularsignal-regulated kinase, and p38 resulted in decreasedATF3 induction at the protein level. MAPK pathway inhibition led to decreased ATF3 messenger RNA expression and reduced cytotoxic effects of cisplatin as measured by the 3-(4,5-dimethylthiazol-2-ylF2,5-diphenyltetrazolium bromide cell viability assay. In A549 lung carcinoma cells, targeting ATF3 with specific small hairpin RNA also attenuated the cytotoxic effects of cisplatin. Similarly, ATF3-/murine embryonic fibroblasts (MEFs were shown to be less sensitive to cisplatin-induced cytotoxicity compared with ATF3+/+ MEFs. This study identifies cisplatin as a MAPK pathway-dependent inducer of ATF3, whose expression influences cisplatin’s cytotoxic effects.

  20. Functional domains of the transcriptional activator NUC-1 in Neurospora crassa.

    Science.gov (United States)

    Kang, S

    1993-08-25

    The NUC-1 regulatory protein directly controls the transcription of these genes and how the activity enzymes in Neurospora crassa. To understand how NUC-1 regulates the transcription of these genes and how the activity of NUC-1 is modulated by other regulatory proteins, two putative functional domains of NUC-1 were analysed: the DNA-binding domain and the regulatory domain. The DNA-binding activity of NUC-1 has not been directly demonstrated; however, results of deletion analysis, sequence analysis of the nuc-1 mutant alleles, and strong sequence similarity with the Saccharomyces cerevisiae PHO4 protein strongly suggest that the basic helix-loop-helix motif of NUC-1 forms a DNA-binding domain. Deletion and mutant analyses revealed that 39 amino acid (aa) residues (aa 463 to 501), or fewer, of NUC-1 are interacting with the negative regulatory factor(s), the PREG and/or PGOV proteins.

  1. Therapeutic doses of irradiation activate viral transcription and induce apoptosis in HIV-1 infected cells

    Energy Technology Data Exchange (ETDEWEB)

    Iordanskiy, Sergey [School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110 (United States); Van Duyne, Rachel [School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110 (United States); Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Sampey, Gavin C; Woodson, Caitlin M; Fry, Kelsi; Saifuddin, Mohammed; Guo, Jia; Wu, Yuntao [School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110 (United States); Romerio, Fabio [Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Kashanchi, Fatah, E-mail: fkashanc@gmu.edu [School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110 (United States)

    2015-11-15

    The highly active antiretroviral therapy reduces HIV-1 RNA in plasma to undetectable levels. However, the virus continues to persist in the long-lived resting CD4{sup +} T cells, macrophages and astrocytes which form a viral reservoir in infected individuals. Reactivation of viral transcription is critical since the host immune response in combination with antiretroviral therapy may eradicate the virus. Using the chronically HIV-1 infected T lymphoblastoid and monocytic cell lines, primary quiescent CD4{sup +} T cells and humanized mice infected with dual-tropic HIV-1 89.6, we examined the effect of various X-ray irradiation (IR) doses (used for HIV-related lymphoma treatment and lower doses) on HIV-1 transcription and viability of infected cells. Treatment of both T cells and monocytes with IR, a well-defined stress signal, led to increase of HIV-1 transcription, as evidenced by the presence of RNA polymerase II and reduction of HDAC1 and methyl transferase SUV39H1 on the HIV-1 promoter. This correlated with the increased GFP signal and elevated level of intracellular HIV-1 RNA in the IR-treated quiescent CD4{sup +} T cells infected with GFP-encoding HIV-1. Exposition of latently HIV-1infected monocytes treated with PKC agonist bryostatin 1 to IR enhanced transcription activation effect of this latency-reversing agent. Increased HIV-1 replication after IR correlated with higher cell death: the level of phosphorylated Ser46 in p53, responsible for apoptosis induction, was markedly higher in the HIV-1 infected cells following IR treatment. Exposure of HIV-1 infected humanized mice with undetectable viral RNA level to IR resulted in a significant increase of HIV-1 RNA in plasma, lung and brain tissues. Collectively, these data point to the use of low to moderate dose of IR alone or in combination with HIV-1 transcription activators as a potential application for the “Shock and Kill” strategy for latently HIV-1 infected cells. - Highlights: • X-ray irradiation

  2. Activation of the Escherichia coli marA/soxS/rob regulon in response to transcriptional activator concentration.

    Science.gov (United States)

    Martin, Robert G; Bartlett, Emily S; Rosner, Judah L; Wall, Michael E

    2008-07-04

    The paralogous transcriptional activators MarA, SoxS, and Rob activate a common set of promoters, the marA/soxS/rob regulon of Escherichia coli, by binding a cognate site (marbox) upstream of each promoter. The extent of activation varies from one promoter to another and is only poorly correlated with the in vitro affinity of the activator for the specific marbox. Here, we examine the dependence of promoter activation on the level of activator in vivo by manipulating the steady-state concentrations of MarA and SoxS in Lon protease mutants and by measuring promoter activation using lacZ transcriptional fusions. We found that: (i) the MarA concentrations needed for half-maximal stimulation varied by at least 19-fold among the 10 promoters tested; (ii) most marboxes were not saturated when there were 24,000 molecules of MarA per cell; (iii) the correlation between the MarA concentration needed for half-maximal promoter activity in vivo and marbox binding affinity in vitro was poor; and (iv) the two activators differed in their promoter activation profiles. The marRAB and sodA promoters could both be saturated by MarA and SoxS in vivo. However, saturation by MarA resulted in greater marRAB and lesser sodA transcription than did saturation by SoxS, implying that the two activators interact with RNA polymerase in different ways at the different promoters. Thus, the concentration and nature of activator determine which regulon promoters are activated, as well as the extent of their activation.

  3. The Calmodulin-Binding Transcription Activator CAMTA1 Is Required for Long-Term Memory Formation in Mice

    Science.gov (United States)

    Bas-Orth, Carlos; Tan, Yan-Wei; Oliveira, Ana M. M.; Bengtson, C. Peter; Bading, Hilmar

    2016-01-01

    The formation of long-term memory requires signaling from the synapse to the nucleus to mediate neuronal activity-dependent gene transcription. Synapse-to-nucleus communication is initiated by influx of calcium ions through synaptic NMDA receptors and/or L-type voltage-gated calcium channels and involves the activation of transcription factors by…

  4. Androgens Regulate T47D Cells Motility and Invasion through Actin Cytoskeleton Remodeling

    Science.gov (United States)

    Montt-Guevara, Maria Magdalena; Shortrede, Jorge Eduardo; Giretti, Maria Silvia; Giannini, Andrea; Mannella, Paolo; Russo, Eleonora; Genazzani, Alessandro David; Simoncini, Tommaso

    2016-01-01

    The relationship between androgens and breast cancer is controversial. Androgens have complex effects on breast cancer progression and metastasis. Moreover, androgen receptor (AR) is expressed in approximately 70 to 90% of invasive breast carcinomas, which has prognostic relevance in basal-like cancers and in triple-negative breast cancers. Recent studies have associated the actin-binding proteins of the ezrin–radixin–moesin (ERM) family with metastasis in endocrine-sensitive cancers. We studied on T47D breast cancer cells whether androgens with different characteristics, such as testosterone (T), dihydrotestosterone (DHT), and dehydroepiandrosterone (DHEA) may regulate breast cancer cell motility and invasion through the control of actin remodeling. We demonstrate that androgens promote migration and invasion in T47D via Moesin activation. We show that T and DHEA exert their actions via the AR and estrogen receptor (ER), while the non-aromatizable androgen – DHT – only recruits AR. We further report that androgen induced significant changes in actin organization with pseudopodia along with membrane ruffles formation, and this process is mediated by Moesin. Our work identifies novel mechanisms of action of androgens on breast cancer cells. Through the modulation of Moesin, androgens alter the architecture of cytoskeleton in T47D breast cancer cell and promote cell migration and invasion. These results could help to understand the biological actions of androgens on breast cancer and, eventually, to develop new strategies for breast cancer treatment. PMID:27746764

  5. ANDROGENS REGULATE T47D CELLS MOTILITY AND INVASION THROUGH ACTIN CYTOSKELETON REMODELLING

    Directory of Open Access Journals (Sweden)

    Maria Magdalena Montt-Guevara

    2016-09-01

    Full Text Available The relationship between androgens and breast cancer is controversial. Androgens have complex effects on breast cancer progression and metastasis. Moreover, androgens receptor (AR is expressed in approximately 70% to 90% of invasive breast carcinomas, which has prognostic relevance in basal-like cancers and in triple negative breast cancers. Recent studies have associated the actin-binding proteins of the Ezrin-Radixin-Moesin (ERM family with metastasis in endocrine-sensitive cancers. We studied on T47D breast cancer cells whether androgens with different characteristics, such as testosterone (T, dihydrotestosterone (DHT and dehydroepiandrosterone (DHEA may regulate breast cancer cell motility and invasion through the control of actin remodelling. We demonstrate that androgens promote migration and invasion in T47D via Moesin activation. We show that T and DHEA exert their actions via the AR and estrogen receptor (ER, while the non aromatizable androgen – DHT only recruits AR. We further report that androgen induced significant changes in actin organization with pseudopodia along with membrane ruffles formation, and this process is mediated by Moesin. Our work identifies novel mechanisms of action of androgens on breast cancer cells. Through the modulation of Moesin, androgens alter the architecture of cytoskeleton in T47D breast cancer cell and promote cell migration and invasion. These results could help to understand the biological actions of androgens on breast cancer, and eventually to develop new strategies for treatment of breast cancer.

  6. Endocrine Activity of Bisphenol S (BPS) Using In Vitro Estrogenic/Anti-Androgenic Transcriptional Activation Assays and the In Vivo Uterotrophic Assay

    Science.gov (United States)

    Bisphenol A (BPA) is gradually being phased out of many consumer products and processes leading to potential increases in human and environmental exposures to relatively understudied replacement compounds, including Bisphenol S (BPS). Research from our lab has shown that BPA and...

  7. IQGAP1 Binds to Yes-associated Protein (YAP) and Modulates Its Transcriptional Activity.

    Science.gov (United States)

    Sayedyahossein, Samar; Li, Zhigang; Hedman, Andrew C; Morgan, Chase J; Sacks, David B

    2016-09-09

    During development, the Hippo signaling pathway regulates key physiological processes, such as control of organ size, regeneration, and stem cell biology. Yes-associated protein (YAP) is a major transcriptional co-activator of the Hippo pathway. The scaffold protein IQGAP1 interacts with more than 100 binding partners to integrate diverse signaling pathways. In this study, we report that IQGAP1 binds to YAP and modulates its activity. IQGAP1 and YAP co-immunoprecipitated from cells. In vitro analysis with pure proteins demonstrated a direct interaction between IQGAP1 and YAP. Analysis with multiple fragments of each protein showed that the interaction occurs via the IQ domain of IQGAP1 and the TEAD-binding domain of YAP. The interaction between IQGAP1 and YAP has functional effects. Knock-out of endogenous IQGAP1 significantly increased the formation of nuclear YAP-TEAD complexes. Transcription assays were performed with IQGAP1-null mouse embryonic fibroblasts and HEK293 cells with IQGAP1 knockdown by CRISPR/Cas9. Quantification demonstrated that YAP-TEAD-mediated transcription in cells lacking IQGAP1 was significantly greater than in control cells. These data reveal that IQGAP1 binds to YAP and modulates its co-transcriptional function, suggesting that IQGAP1 participates in Hippo signaling.

  8. Differential expression of two activating transcription factor 5 isoforms in papillary thyroid carcinoma

    Science.gov (United States)

    Vicari, Luisa; La Rosa, Cristina; Forte, Stefano; Calabrese, Giovanna; Colarossi, Cristina; Aiello, Eleonora; Salluzzo, Salvatore; Memeo, Lorenzo

    2016-01-01

    Background Activating transcription factor 5 (ATF5) is a member of the activating transcription/cAMP response element-binding protein family of basic leucine zipper proteins that plays an important role in cell survival, differentiation, proliferation, and apoptosis. The ATF5 gene generates two transcripts: ATF5 isoform 1 and ATF5 isoform 2. A number of studies indicate that ATF5 could be an attractive target for therapeutic intervention in several tumor types; however, so far, the role of ATF5 has not been investigated in papillary thyroid carcinoma (PTC). Methods Quantitative real-time reverse transcription polymerase chain reaction and immuno-histochemical staining were used to study ATF5 mRNA and protein expression in PTC. Results We report here that ATF5 is expressed more in PTC tissue than in normal thyroid tissue. Furthermore, this is the first study that describes the presence of both ATF5 isoforms in PTC. Conclusion These findings could provide potential applications in PTC cancer treatment.

  9. Wnt-induced transcriptional activation is exclusively mediated by TCF/LEF.

    Science.gov (United States)

    Schuijers, Jurian; Mokry, Michal; Hatzis, Pantelis; Cuppen, Edwin; Clevers, Hans

    2014-01-13

    Active canonical Wnt signaling results in recruitment of β-catenin to DNA by TCF/LEF family members, leading to transcriptional activation of TCF target genes. However, additional transcription factors have been suggested to recruit β-catenin and tether it to DNA. Here, we describe the genome-wide pattern of β-catenin DNA binding in murine intestinal epithelium, Wnt-responsive colorectal cancer (CRC) cells and HEK293 embryonic kidney cells. We identify two classes of β-catenin binding sites. The first class represents the majority of the DNA-bound β-catenin and co-localizes with TCF4, the prominent TCF/LEF family member in these cells. The second class consists of β-catenin binding sites that co-localize with a minimal amount of TCF4. The latter consists of lower affinity β-catenin binding events, does not drive transcription and often does not contain a consensus TCF binding motif. Surprisingly, a dominant-negative form of TCF4 abrogates the β-catenin/DNA interaction of both classes of binding sites, implying that the second class comprises low affinity TCF-DNA complexes. Our results indicate that β-catenin is tethered to chromatin overwhelmingly through the TCF/LEF transcription factors in these three systems.

  10. Androgen receptor and its splice variant, AR-V7, differentially regulate FOXA1 sensitive genes in LNCaP prostate cancer cells.

    Science.gov (United States)

    Krause, William C; Shafi, Ayesha A; Nakka, Manjula; Weigel, Nancy L

    2014-09-01

    Prostate cancer (PCa) is an androgen-dependent disease, and tumors that are resistant to androgen ablation therapy often remain androgen receptor (AR) dependent. Among the contributors to castration-resistant PCa are AR splice variants that lack the ligand-binding domain (LBD). Instead, they have small amounts of unique sequence derived from cryptic exons or from out of frame translation. The AR-V7 (or AR3) variant is constitutively active and is expressed under conditions consistent with CRPC. AR-V7 is reported to regulate a transcriptional program that is similar but not identical to that of AR. However, it is unknown whether these differences are due to the unique sequence in AR-V7, or simply to loss of the LBD. To examine transcriptional regulation by AR-V7, we have used lentiviruses encoding AR-V7 (amino acids 1-627 of AR with the 16 amino acids unique to the variant) to prepare a derivative of the androgen-dependent LNCaP cells with inducible expression of AR-V7. An additional cell line was generated with regulated expression of AR-NTD (amino acids 1-660 of AR); this mutant lacks the LBD but does not have the AR-V7 specific sequence. We find that AR and AR-V7 have distinct activities on target genes that are co-regulated by FOXA1. Transcripts regulated by AR-V7 were similarly regulated by AR-NTD, indicating that loss of the LBD is sufficient for the observed differences. Differential regulation of target genes correlates with preferential recruitment of AR or AR-V7 to specific cis-regulatory DNA sequences providing an explanation for some of the observed differences in target gene regulation.

  11. A co-activator of nitrogen-regulated transcription in S