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1.
Am J Hum Genet ; 104(2): 319-330, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30639322

RESUMO

ZMIZ1 is a coactivator of several transcription factors, including p53, the androgen receptor, and NOTCH1. Here, we report 19 subjects with intellectual disability and developmental delay carrying variants in ZMIZ1. The associated features include growth failure, feeding difficulties, microcephaly, facial dysmorphism, and various other congenital malformations. Of these 19, 14 unrelated subjects carried de novo heterozygous single-nucleotide variants (SNVs) or single-base insertions/deletions, 3 siblings harbored a heterozygous single-base insertion, and 2 subjects had a balanced translocation disrupting ZMIZ1 or involving a regulatory region of ZMIZ1. In total, we identified 13 point mutations that affect key protein regions, including a SUMO acceptor site, a central disordered alanine-rich motif, a proline-rich domain, and a transactivation domain. All identified variants were absent from all available exome and genome databases. In vitro, ZMIZ1 showed impaired coactivation of the androgen receptor. In vivo, overexpression of ZMIZ1 mutant alleles in developing mouse brains using in utero electroporation resulted in abnormal pyramidal neuron morphology, polarization, and positioning, underscoring the importance of ZMIZ1 in neural development and supporting mutations in ZMIZ1 as the cause of a rare neurodevelopmental syndrome.


Assuntos
Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Mutação Puntual , Fatores de Transcrição/genética , Alelos , Animais , Criança , Pré-Escolar , Deficiências do Desenvolvimento/patologia , Feminino , Humanos , Lactente , Deficiência Intelectual/patologia , Masculino , Camundongos , Síndrome , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
2.
Oncotarget ; 8(42): 72008-72020, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-29069764

RESUMO

Constitutively active androgen receptor (AR) variants have been involved in the expression of mesenchymal markers such as N-cadherin in prostate cancer (PCa). However, the underlying molecular mechanisms remain elusive. It remains unclear, whether N-cadherin gene (CDH2) is a direct transcriptional target of AR variants or whether the observed upregulation is due to indirect effects through additional regulatory factors. Moreover, the specific contribution of full-length AR and AR variants in N-cadherin regulation in PCa has never been explored deeply. To investigate this, we artificially mimicked the co-expression of AR variants together with a full-length AR and performed miRNA-seq, RNA-seq and ChIP assays. Our results were in favor of a direct AR variants action on CDH2. Our data also revealed a distinctive mode of action between full-length AR and AR variants to regulate N-cadherin expression. Both wild type AR and AR variants could interact with a regulatory element in intron 1 of CDH2. However, a higher histone H4 acetylation in this genomic region was only observed with AR variants. This suggests that full-length AR may play an occluding function to impede CDH2 upregulation. Our data further highlighted a negative effect of AR variants on the expression of the endogenous full-length AR in LNCaP. These differences in the mode of action of AR variants and full-length AR for the control of one key gene for prostate cancer progression could be worth considering for targeting AR variants in PCa.

3.
Med Sci (Paris) ; 33(8-9): 758-764, 2017 Aug-Sep.
Artigo em Francês | MEDLINE | ID: mdl-28945566

RESUMO

Prostate cancer is a public health concern as it currently represents the most frequent malignancy in men in Europe. Progression of this hormone-dependent cancer is driven by androgens. Thus, the most common treatment for patients with advanced prostate cancer consists in an androgen ablation by castration therapy. However, the majority of patients relapses and develops a castration-resistant prostate cancer. This failure of androgen deprivation is related to the emergence of mutant and splice variants of the androgen receptor. Indeed, androgen receptor variants are ligand-independent, constitutively active and thus able to induce resistance to castration. This review focuses on AR variants signaling pathways and their role in resistance to castration and prostate cancer progression.


Assuntos
Polimorfismo Genético , Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Castração , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Masculino , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/terapia , Transdução de Sinais/genética
5.
Ann Biol Clin (Paris) ; 74(2): 227-32, 2016 Mar-Apr.
Artigo em Francês | MEDLINE | ID: mdl-27029727

RESUMO

To systematically review the evidence for the use of PSA and other biomarkers in the early detection of prostate cancer, we searched PubMed for clinical trials and studies assessing PSA and other biomarkers in the early detection of prostate cancer, published between 2000 and May 2013 that included >200 subjects. The level of evidence (LOE) for clinical utility was evaluated using the tumor marker utility grading system. A total of 84 publications, corresponding to 70 trials and studies were selected for inclusion in this review. We attributed a level of evidence (LoE) of IA to PSA for early PCa detection, but we do not recommend its use in mass screening. Emerging biomarkers were assessed in prospective case-control and cohort studies: PCA3 (n=3); kallikreins (n=3); [-2]proPSA (n=5); fusion oncogenes (n=2). These studies used biopsy results for prostate cancer to determine specificity and sensitivity, but they did not assess the effect on PCa mortality. The LoE attributed was III-C. PSA can be used for early prostate cancer detection but mass screening is not recommended. Studies on other biomarkers suggest that they could be used, individually or in combination, to improve the selection of patients with elevated PSA levels for biopsy, but RCTs assessing their impact on prostate cancer management and mortality are needed. A better use of available tests is possible for men at risk in order to maximize the risk-benefit ratio.


Assuntos
Biomarcadores Tumorais/análise , Detecção Precoce de Câncer/métodos , Neoplasias da Próstata/diagnóstico , Biomarcadores Tumorais/sangue , Detecção Precoce de Câncer/normas , Humanos , Masculino , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Antígeno Prostático Específico/análise , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/epidemiologia , Sensibilidade e Especificidade
6.
Oncotarget ; 7(43): 69397-69411, 2016 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-26993766

RESUMO

Despite the advent of several new treatment options over the past years, advanced/metastatic prostate carcinoma (PCa) still remains incurable, which justifies the search for novel targets and therapeutic molecules. Nucleophosmin (NPM1) is a shuttling nucleoprotein involved in tumor growth and its targeting could be a potential approach for cancer therapy. We previously demonstrated that the multivalent pseudopeptide N6L binds to NPM1 potently affecting in vitro and in vivo tumor cell growth of various tumor types as well as angiogenesis. Furthermore, NPM1 binds to androgen receptor (AR) and modulate its activity. In this study, we first investigated the implication of the NPM1 and its Thr199 and Thr234/237 phosphorylated forms in PCa. We showed that phosphorylated forms of NPM1 interact with androgen receptor (AR) in nucleoplasm. N6L treatment of prostate tumor cells led to inhibition of NPM1 phosphorylation in conjunction with inhibition of AR activity. We also found that total and phosphorylated NPM1 were overexpressed in castration-resistant PCa. Assessment of the potential therapeutic role of N6L in PCa indicated that N6L inhibited tumor growth both in vitro and in vivo when used either alone or in combination with the standard-of-care first- (hormonotherapy) and second-line (docetaxel) treatments for advanced PCa. Our findings reveal the role of Thr199 and Thr234/237 phosphorylated NPM1 in PCa progression and define N6L as a new drug candidate for PCa therapy.


Assuntos
Proteínas Nucleares/metabolismo , Nucleoproteínas/antagonistas & inibidores , Peptídeos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Docetaxel , Humanos , Masculino , Camundongos Nus , Nucleoproteínas/metabolismo , Peptídeos/metabolismo , Fosforilação/efeitos dos fármacos , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Ligação Proteica , Receptores Androgênicos/metabolismo , Taxoides/farmacologia , Treonina/metabolismo , Carga Tumoral/efeitos dos fármacos
7.
Mol Cell Endocrinol ; 422: 182-191, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26586211

RESUMO

The skeleton is the preferred site for prostate cancer (PC) metastasis leading to incurable castration-resistant disease. The increased expression of genes encoding steroidogenic enzymes found in bone metastatic tissue from patients suggests that up-regulated steroidogenesis might contribute to tumor growth at the metastatic site. Because of the overall sclerotic phenotype, we hypothesize that osteoblasts regulate the intratumoral steroidogenesis of castration resistant prostate cancer (CRPC) in bone. We here show that osteoblasts alter the steroidogenic transcription program in CRPC cells, closely mimicking the gene expression pattern described in CRPC. Osteoblast-stimulated LNCaP-19 cells displayed an increased expression of genes encoding for steroidogenic enzymes (CYP11A1, HSD3B1, and AKR1C3), estrogen signaling-related genes (CYP19A1, and ESR2), and genes for DHT-inactivating enzymes (UGT2B7, UGT2B15, and UGT2B17). The observed osteoblast-induced effect was exclusive to osteogenic CRPC cells (LNCaP-19) in contrast to osteolytic PC-3 and androgen-dependent LNCaP cells. The altered steroid enzymatic pattern was specific for the intratibial tumors and verified by immunohistochemistry in tissue specimens from LNCaP-19 xenograft tumors. Additionally, the overall steroidogenic effect was reflected by corresponding levels of progesterone and testosterone in serum from castrated mice with intratibial xenografts. A bi-directional interplay was demonstrated since both proliferation and Esr2 expression of osteoblasts were induced by CRPC cells in steroid-depleted conditions. Together, our results demonstrate that osteoblasts are important mediators of the intratumoral steroidogenesis of CRPC and for castration-resistant growth in bone. Targeting osteoblasts may therefore be important in the development of new therapeutic approaches.


Assuntos
Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Osteoblastos/citologia , Neoplasias de Próstata Resistentes à Castração/patologia , Esteroides/biossíntese , Androgênios/metabolismo , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Proliferação de Células , Meios de Cultivo Condicionados/química , Receptor beta de Estrogênio/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Células NIH 3T3 , Transplante de Neoplasias , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/metabolismo
8.
Chembiochem ; 15(16): 2370-3, 2014 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-25212277

RESUMO

Most of the biological effects of androgen hormones are mediated through an intracellular transcription factor, the androgen receptor (AR). This protein presents a long disordered N-terminal domain (NTD), known to aggregates into amyloid fibers.1 This aggregation property is usually associated with the presence of a poly-glutamine tract (polyQ), known to be involved in several pathologies.2 The NTD has gain interest recently because potential anti-prostate-cancer molecules could target this domain.3 Here, we characterize a conserved region of the NTD (distal from polyQ); it promotes the formation of amyloid fibers under mild oxidative conditions. Unlike most fibrils, which are irreversibly aggregated, the free peptides can be restored from the fibril by the addition of a reducing agent.


Assuntos
Amiloide/química , Receptores Androgênicos/química , Sequência de Aminoácidos , Dicroísmo Circular , Dimerização , Humanos , Masculino , Microscopia Eletrônica , Dados de Sequência Molecular , Peptídeos/química , Estrutura Secundária de Proteína , Receptores Androgênicos/metabolismo
9.
Neoplasia ; 15(7): 761-72, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23814488

RESUMO

Castration-resistant prostate cancers (CRPCs) that relapse after androgen deprivation therapies (ADTs) are responsible for the majority of mortalities from prostate cancer (PCa). While mechanisms enabling recurrent activity of androgen receptor (AR) are certainly involved in the development of CRPC, there may be factors that contribute to the process including acquired neuroendocrine (NE) cell-like behaviors working through alternate (non-AR) cell signaling systems or AR-dependent mechanisms. In this study, we explore the potential relationship between the AR axis and a novel putative marker of NE differentiation, the human male protocadherin-PC (PCDH-PC), in vitro and in human situations. We found evidence for an NE transdifferentiation process and PCDH-PC expression as an early-onset adaptive mechanism following ADT and elucidate AR as a key regulator of PCDH-PC expression. PCDH-PC overexpression, in turn, attenuates the ligand-dependent activity of the AR, enabling certain prostate tumor clones to assume a more NE phenotype and promoting their survival under diverse stress conditions. Acquisition of an NE phenotype by PCa cells positively correlated with resistance to cytotoxic agents including docetaxel, a taxane chemotherapy approved for the treatment of patients with metastatic CRPC. Furthermore, knockdown of PCDH-PC in cells that have undergone an NE transdifferentiation partially sensitized cells to docetaxel. Together, these results reveal a reciprocal regulation between the AR axis and PCDH-PC signals, observed both in vitro and in vivo, with potential implications in coordinating NE transdifferentiation processes and progression of PCa toward hormonal and chemoresistance.


Assuntos
Caderinas/metabolismo , Transdiferenciação Celular , Resistencia a Medicamentos Antineoplásicos , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Androgênios/metabolismo , Antineoplásicos/farmacologia , Caderinas/genética , Linhagem Celular Tumoral , Transdiferenciação Celular/genética , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Ligantes , Masculino , Fenótipo , Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Ativação Transcricional
10.
PLoS One ; 8(5): e63466, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23658830

RESUMO

Androgen receptor (AR) signaling pathway remains the foremost target of novel therapeutics for castration-resistant prostate cancer (CRPC). However, the expression of constitutively active AR variants lacking the carboxy-terminal region in CRPC may lead to therapy inefficacy. These AR variants are supposed to support PCa cell growth in an androgen-depleted environment, but their mode of action still remains unresolved. Moreover, recent studies indicate that constitutively active AR variants are expressed in primary prostate tumors and may contribute to tumor progression. The aim of this study was to investigate the impact of constitutively active AR variants on the expression of tumor progression markers. N-cadherin expression was analyzed in LNCaP cells overexpressing the wild type AR or a constitutively active AR variant by qRT-PCR, Western blot and immunofluorescence. We showed here for the first time that N-cadherin expression was increased in the presence of constitutively active AR variants. These results were confirmed in C4-2B cells overexpressing these AR variants. Although N-cadherin expression is often associated with a downregulation of E-cadherin, this phenomenon was not observed in our model. Nevertheless, in addition to the increased expression of N-cadherin, an upregulation of other mesenchymal markers expression such as VIMENTIN, SNAIL and ZEB1 was observed in the presence of constitutively active variants. In conclusion, our findings highlight novel consequences of constitutively active AR variants on the regulation of mesenchymal markers in prostate cancer.


Assuntos
Biomarcadores Tumorais/genética , Variação Genética , Mesoderma/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/genética , Regulação para Cima , Caderinas/genética , Linhagem Celular Tumoral , Progressão da Doença , Proteínas de Homeodomínio/genética , Humanos , Masculino , Fatores de Transcrição/genética , Vimentina/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco
11.
Cell Biol Int ; 37(5): 464-70, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23418075

RESUMO

We have investigated the expression of prostate-specific membrane antigen (PSMA) and prostate-specific antigen (PSA) transcripts in androgen-dependent (LNCaP) and androgen-independent (22Rv1) prostate cancer cell lines. We also enquired whether Q640X CTE-truncated androgen receptor (AR) has an impact on transcription of mRNA for PSMA and PSA in transfected androgen-sensitive prostate cancer LNCaP cells. Wild type LNCaP, 22Rv1 prostate cancer cells, prostate stromal cells (PrSC) and LNCaP cells transfected with p-Q640X AR, p-WT AR or p-C3 empty plasmids were studied. The expression of PSMA and PSA were detected by real-time PCR after transfection for 4 and 7 days. Expression of mRNAs for PSA was sixfold greater than PSMA in wild type LNCaP cells. In contrast, the wild type androgen refractory 22Rv1 cell line reacted almost exactly the opposite way reverse to LNCaP cells, since the transcription of mRNA for PSMA almost twofold greater than PSA. Non-transfected human PrSC responded similarly to PSMA mRNA and PSA mRNA was not detected in these cells. Q640X AR transfected LNCaP cells downregulated the expression of PSMA and PSA genes after 7 days. Our results demonstrate that Q640X mutated AR may have an important regulatory role in mediating the PSMA and PSA genes expression during the progression of prostate cancer from androgen-dependence to androgen-independence. Understanding their functional properties and mechanisms by which ARs involved in regulation of PSMA and PSA expression will allow the identification of new target therapies for the treatment of hormone-resistant prostate cancer.


Assuntos
Antígenos de Superfície/metabolismo , Glutamato Carboxipeptidase II/metabolismo , Antígeno Prostático Específico/metabolismo , Receptores Androgênicos/metabolismo , Substituição de Aminoácidos , Antígenos de Superfície/genética , Linhagem Celular Tumoral , Regulação para Baixo , Glutamato Carboxipeptidase II/genética , Humanos , Masculino , Mutação , Fosforilação , Antígeno Prostático Específico/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , RNA Mensageiro/metabolismo , Receptores Androgênicos/genética , Transcrição Genética
12.
PLoS One ; 7(8): e42252, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22879924

RESUMO

Almost all prostate cancers respond to androgen deprivation treatment but many recur. We postulated that risk of hormone escape--frequency and delay--are influenced by hormone therapy modalities. More, hormone therapies induce crucial biological changes involving androgen receptors; some might be targets for escape prevention. We investigated the relationship between the androgen deprivation treatment and the risk of recurrence using nude mice bearing the high grade, hormone-dependent human prostate cancer xenograft PAC120. Tumor-bearing mice were treated by Luteinizing-Hormone Releasing Hormone (LHRH) antagonist alone, continuous or intermittent regimen, or combined with androgen receptor (AR) antagonists (bicalutamide or flutamide). Tumor growth was monitored. Biological changes were studied as for genomic alterations, AR mutations and protein expression in a large series of recurrent tumors according to hormone therapy modalities. Therapies targeting Her-2 or AKT were tested in combination with castration. All statistical tests were two-sided. Tumor growth was inhibited by continuous administration of the LH-RH antagonist degarelix (castration), but 40% of tumors recurred. Intermittent castration or complete blockade induced by degarelix and antiandrogens combination, inhibited tumor growth but increased the risk of recurrence (RR) as compared to continuous castration (RR(intermittent): 14.5, RR(complete blockade): 6.5 and 1.35). All recurrent tumors displayed new quantitative genetic alterations and AR mutations, whatever the treatment modalities. AR amplification was found after complete blockade. Increased expression of Her-2/neu with frequent ERK/AKT activation was detected in all variants. Combination of castration with a Her-2/neu inhibitor decreased recurrence risk (0.17) and combination with an mTOR inhibitor prevented it. Anti-hormone treatments influence risk of recurrence although tumor growth inhibition was initially similar. Recurrent tumors displayed genetic instability, AR mutations, and alterations of phosphorylation pathways. We postulated that Her-2/AKT pathways allowed salvage of tumor cells under castration and we demonstrated that their inhibition prevented tumor recurrence in our model.


Assuntos
Androgênios/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/enzimologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto , Androgênios/deficiência , Animais , Sequência de Bases , Castração , Análise por Conglomerados , Terapia Combinada , Intervalo Livre de Doença , Dosagem de Genes/genética , Humanos , Masculino , Camundongos , Mutação/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Tirosina Quinases/metabolismo , Receptor ErbB-2/genética , Receptores Androgênicos/genética
13.
Oncology ; 80(1-2): 1-11, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21577012

RESUMO

Although advanced prostate cancer patients respond very well to front-line androgen deprivation, failure to hormonal therapy most often occurs after a median time of 18-24 months. The care of castration-resistant prostate cancer (CRPC) has significantly evolved over the past decade, with the onset of first-line therapy with docetaxel. Although numerous therapy schedules have been investigated alongside docetaxel, in either first-line or salvage therapy, results were dismal. However, CRPC chemotherapy is currently evolving, with, on the one hand, new agents targeting androgen metabolism and, on the other hand, significant progress in chemotherapy drugs, particularly for second-line therapy. The aim of the present review is to describe the current treatments for CRPC chemotherapy alongside their challengers that might shortly become new standards. In this article, we discuss the most recent data from clinical trials to provide the reader with a comprehensive, state-of-the-art overview of CRPC chemotherapy and hormonal therapy.


Assuntos
Antineoplásicos/uso terapêutico , Terapia de Alvo Molecular , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Taxoides/uso terapêutico , Docetaxel , Humanos , Masculino , Neoplasias Hormônio-Dependentes/metabolismo , Orquiectomia , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores
14.
Endocrinology ; 152(6): 2174-83, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21486935

RESUMO

The repression of the androgen receptor (AR) activity is a major objective to inhibit prostate cancer growth. One underlying mechanism for efficient hormone therapy is based on corepressors that inactivate the AR. In line with this, castration-resistant prostate cancer is associated with malfunction or reduced corepressor action. To overcome this, the overexpression of endogenous corepressors, however, affects many other transcription factors. Therefore, an AR-specific corepressor could be of advantage. Using a yeast peptide aptamer two-hybrid screen with the full-length human AR, we identified a short amino acid-stretch that binds specifically to the human AR in yeast and in mammalian cells and not to the closely related progesterone or glucocorticoid receptors. Furthermore, fused to a silencing domain, this aptamer-based corepressor (AB-CoR) exhibits corepressor activity by inhibiting both the AR-mediated transactivation and expression of the AR target gene PSA. Furthermore, stable expression of the AB-CoR inhibits growth of human LNCaP prostate cancer cells. Moreover, we generated a cell-permeable AB-CoR by fusing a protein transduction domain to establish a vector-free transport system. Treatment of LNCaP cells with the bacterially expressed and affinity-purified cell-permeable AB-CoR peptide resulted in a significant inhibition of both AR-mediated transactivation and prostate cancer cell proliferation. Thus, generation of a novel AR-specific aptamer-based corepressor may present a vector-free inhibition of AR-dependent prostate cancer growth as a novel approach.


Assuntos
Aptâmeros de Peptídeos/farmacocinética , Proliferação de Células , Proteínas Correpressoras/metabolismo , Regulação para Baixo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/fisiopatologia , Receptores Androgênicos/metabolismo , Aptâmeros de Peptídeos/síntese química , Aptâmeros de Peptídeos/genética , Aptâmeros de Peptídeos/metabolismo , Linhagem Celular Tumoral , Proteínas Correpressoras/síntese química , Proteínas Correpressoras/genética , Proteínas Correpressoras/farmacocinética , Regulação para Baixo/efeitos dos fármacos , Humanos , Masculino , Permeabilidade , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Ligação Proteica , Receptores Androgênicos/genética , Especificidade da Espécie , Ativação Transcricional/efeitos dos fármacos
15.
Cancer Res ; 70(3): 1225-35, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-20103638

RESUMO

Castration resistance in prostate cancer (PCa) constitutes an advanced, aggressive disease with poor prognosis, associated with uncontrolled cell proliferation, resistance to apoptosis, and enhanced invasive potential. The molecular mechanisms involved in the transition of PCa to castration resistance are obscure. Here, we report that the nonselective cationic channel transient receptor potential vanilloid 2 (TRPV2) is a distinctive feature of castration-resistant PCa. TRPV2 transcript levels were higher in patients with metastatic cancer (stage M1) compared with primary solid tumors (stages T2a and T2b). Previous studies of the TRPV2 channel indicated that it is primarily involved in cancer cell migration and not in cell growth. Introducing TRPV2 into androgen-dependent LNCaP cells enhanced cell migration along with expression of invasion markers matrix metalloproteinase (MMP) 9 and cathepsin B. Consistent with the likelihood that TRPV2 may affect cancer cell aggressiveness by influencing basal intracellular calcium levels, small interfering RNA-mediated silencing of TRPV2 reduced the growth and invasive properties of PC3 prostate tumors established in nude mice xenografts, and diminished expression of invasive enzymes MMP2, MMP9, and cathepsin B. Our findings establish a role for TRPV2 in PCa progression to the aggressive castration-resistant stage, prompting evaluation of TRPV2 as a potential prognostic marker and therapeutic target in the setting of advanced PCa.


Assuntos
Neoplasias da Próstata/genética , Interferência de RNA , Canais de Cátion TRPV/genética , Androgênios/metabolismo , Androgênios/farmacologia , Animais , Western Blotting , Linhagem Celular Tumoral , Movimento Celular , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Microscopia Confocal , Invasividade Neoplásica , Metástase Neoplásica , Orquiectomia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Canais de Cátion TRPV/metabolismo , Canais de Cátion TRPV/fisiologia , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Hum Mutat ; 31(1): 74-80, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19830810

RESUMO

Advanced prostate cancer (PCa) has emerged as a public health concern due to population aging. Although androgen deprivation has proven efficacy in this condition, most advanced PCa patients will have to face failure of androgen deprivation as a treatment. Mutations in the androgen receptor (AR) from tumor cells have been shown to induce androgen independency both in PCa cell lines and in the clinic. We have investigated the molecular events leading to androgen independency in the 22Rv1 cell line, a commonly used preclinical model of PCa. Besides AR mutants that have been described so far, including nonsense mutations, recent data have focused on AR pre-mRNA aberrant splicing as a new mechanism leading to constitutively active truncated AR variants. In this article, we describe two novel variants arising from aberrant splicing of AR pre-mRNA, characterized by long mRNA transcripts that encode truncated, constitutively active proteins. We also describe several new nonsense mutants that share ligand independency and transcriptional activity. Finally, we show that alongside these mutants, 22Rv1 cells also express a mutant AR lacking exon 3 tandem duplication, a major feature of this cell line. By describing unreported AR mutants in the 22Rv1 cell line, our data emphasize the complexity and heterogeneity of molecular events that occur in preclinical models, and supposedly in the clinic. Future work on the 22Rv1 cell line should take into account the concomitant expression of various AR mutants.


Assuntos
Processamento Alternativo , Mutação , Neoplasias Hormônio-Dependentes/genética , Neoplasias da Próstata/genética , Precursores de RNA , Receptores Androgênicos/genética , Androgênios/metabolismo , Linhagem Celular Tumoral , Éxons , Regulação Neoplásica da Expressão Gênica , Variação Genética , Humanos , Masculino , Precursores de RNA/genética , Precursores de RNA/metabolismo , Receptores Androgênicos/metabolismo
17.
Hum Mutat ; 30(2): 145-57, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18800375

RESUMO

The androgen receptor (AR) signaling pathway plays an important role during the development of the normal prostate gland, but also during the progression of prostate cancer on androgen ablation therapy. Mutations in the AR gene emerge to keep active the AR signaling pathway and to support prostate cancer cells growth and survival despite the low levels of circulating androgens. Indeed, mutations affecting the ligand binding domain (LBD) of the AR have been shown to generate so-called "promiscuous" receptors that present widened ligand specificity and allow the stimulation of these receptors by a larger spectrum of endogenous hormones. Another class of mutations, arising in the amino-terminal domain (NTD) of the receptor, modulate AR interactions with coregulators involved in cell proliferation regulation. Besides characteristics of these well-known types of mutations, the properties of other classes of AR mutants recently described in prostate cancer are currently under investigation. Most interestingly, in addition to their potential role in the mechanisms which allow prostate cancer cells to escape androgen ablation therapy, data suggest that certain AR mutations are present early in the natural history of the disease and may play a role in many aspects of prostate cancer progression. Surprisingly, singular truncated AR devoid of their carboxy-terminal end (CTE) region seem to exert specific paracrine effects and to induce a clonal cooperation with neighboring prostate cancer cells, which may facilitate both the invasion and metastasis processes. In this article, we review the functional properties of different classes of AR mutants and their potential impact on the natural history of prostate cancer. Hum Mutat 0, 1-14, 2008. (c) 2008 Wiley-Liss, Inc.


Assuntos
Proteínas Mutantes/metabolismo , Mutação/genética , Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Humanos , Masculino , Receptores Androgênicos/química
18.
Int J Cancer ; 124(5): 1103-11, 2009 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19058198

RESUMO

Lack of hormone dependency in prostate cancers is an irreversible event that occurs through generation of genomic instability induced by androgen deprivation. Indeed, the cytogenetic profile of hormone-dependent (HD) prostate cancer remains stable as long as it received a hormone supply, whereas the profile of hormone-independent (HID) variants acquired new and various alterations. This is demonstrated here using a HD xenografted model of a human prostate cancer, PAC120, transplanted for 11 years into male nude mice and 4 HID variants obtained by surgical castration. Cytogenetic analysis, done by karyotype, FISH, CGH and array-CGH, shows that PAC120 at early passage presents numerous chromosomal alterations. Very few additional alterations were found between the 5th and 47th passages, indicating the stability of the parental tumor. HID variants largely maintained the core of chromosomal alterations of PAC120 - losses at 6q, 7p, 12q, 15q and 17q sites. However, each HID variant displayed a number of new alterations, almost all being specific to each variant and very few shared by all. None of the HID had androgen receptor mutations. Our study indicates that hormone castration is responsible for genomic instability generating new cytogenetic abnormalities susceptible to alter the properties of cancer cell associated with tumor progression, such as increased cell survival and ability to metastasize.


Assuntos
Instabilidade Genômica , Neoplasias Hormônio-Dependentes/genética , Neoplasias da Próstata/genética , Animais , Aberrações Cromossômicas , Bandeamento Cromossômico , Hibridização Genômica Comparativa , Humanos , Masculino , Camundongos , Receptores Androgênicos/genética
19.
Biol Chem ; 389(12): 1455-66, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18844449

RESUMO

Abstract Several neurodegenerative diseases, including Kennedy's disease (KD), are associated with misfolding and aggregation of polyglutamine (polyQ)-expansion proteins. KD is caused by a polyQ-expansion in the androgen receptor (AR), a key player in male sexual differentiation. Interestingly, KD patients often show signs of mild-to-moderate androgen insensitivity syndrome (AIS) resulting from AR dysfunction. Here, we used the yeast Saccharomyces cerevisiae to investigate the molecular mechanism behind AIS in KD. Upon expression in yeast, polyQ-expanded N-terminal fragments of AR lacking the hormone binding domain caused a polyQ length-dependent growth defect. Interestingly, while AR fragments with 67 Q formed large, SDS-resistant inclusions, the most pronounced toxicity was observed upon expression of 102 Q fragments which accumulated exclusively as soluble oligomers in the 100-600 kDa range. Analysis using a hormone-dependent luciferase reporter revealed that full-length polyQ-expanded AR is fully functional in transactivation, but becomes inactivated in the presence of the corresponding polyQ-expanded N-terminal fragment. Furthermore, the greatest impairment of AR activity was observed upon interaction of full-length AR with soluble AR fragments. Taken together, our results suggest that soluble polyQ-containing fragments bind to full-length AR and inactivate it, thus providing insight into the mechanism behind AIS in KD and possibly other polyglutamine diseases, such as Huntington's disease.


Assuntos
Peptídeos/metabolismo , Receptores Androgênicos/genética , Ativação Transcricional/genética , Western Blotting , Atrofia Bulboespinal Ligada ao X/genética , Atrofia Bulboespinal Ligada ao X/metabolismo , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Humanos , Imunoprecipitação , Indicadores e Reagentes , Luciferases/metabolismo , Microscopia de Fluorescência , Modelos Genéticos , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Peptídeos/toxicidade , Plasmídeos/genética , Saccharomyces cerevisiae/genética , Frações Subcelulares/metabolismo , Ácido Tricloroacético
20.
Adv Exp Med Biol ; 617: 529-34, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18497078

RESUMO

Mutations in the human androgen receptor (AR) gene that lead to C-terminus truncated AR variants are frequently detected in prostate cancer (PC). These AR variants lack both the ligand-binding domain (LBD) and the AF-2 region. The aim of this study was to delineate the alternative mechanisms that lead to the activation of such AR variants as they are unresponsive to hormone stimulation, and to outline consequences of the loss of the LBD/AF-2 region on their functional properties. By using an MMTV-luciferase reporter construct and LY294002, UO126, or ZD1839, inhibitor of PI3K, MEK1/2, and EGFR signaling pathway respectively, we demonstrated that phosphorylation was required for full transcriptional activities of one these AR variants, the Q640X mutant AR. Western-blot analyses confirmed that these inhibitors affect the phosphorylation status of this AR variant. Furthermore, studies of the intranuclear colocalization of the Q640X AR with cofactors, such as CBP, GRIP-1, and c-Jun, reveal that the transcriptional complex that forms around the mutant AR is different to that formed around the wild type AR. We demonstrated that CBP and c-Jun are highly recruited by the mutant AR, and this leads to an unexpected activation of AP-1, NFAT, and NFkappaB transcriptional activities. Similar enhanced activities of these transcription factors were not observed with the wild type AR. The importance of the LBD/AF-2 for the regulation of AR transcriptional activities, the impact of the presence of such AR variants on PC cells proliferation and survival, and on progression to androgen independence are discussed.


Assuntos
Regulação Neoplásica da Expressão Gênica , Variação Genética , Neoplasias Hormônio-Dependentes/genética , Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 2/antagonistas & inibidores , MAP Quinase Quinase 2/metabolismo , Masculino , NF-kappa B/genética , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/genética , Fatores de Transcrição NFATC/metabolismo , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias Hormônio-Dependentes/patologia , Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/metabolismo , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo , Transcrição Genética , Ativação Transcricional , Células Tumorais Cultivadas
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