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1.
Sci Rep ; 10(1): 3217, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-32081956

RESUMO

Standard of care diagnostic procedure for suspected skin cancer is microscopic examination of hematoxylin & eosin stained tissue by a pathologist. Areas of high inter-pathologist discordance and rising biopsy rates necessitate higher efficiency and diagnostic reproducibility. We present and validate a deep learning system which classifies digitized dermatopathology slides into 4 categories. The system is developed using 5,070 images from a single lab, and tested on an uncurated set of 13,537 images from 3 test labs, using whole slide scanners manufactured by 3 different vendors. The system's use of deep-learning-based confidence scoring as a criterion to consider the result as accurate yields an accuracy of up to 98%, and makes it adoptable in a real-world setting. Without confidence scoring, the system achieved an accuracy of 78%. We anticipate that our deep learning system will serve as a foundation enabling faster diagnosis of skin cancer, identification of cases for specialist review, and targeted diagnostic classifications.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Patologia/métodos , Reconhecimento Automatizado de Padrão , Neoplasias Cutâneas/diagnóstico por imagem , Algoritmos , Calibragem , Proliferação de Células , Simulação por Computador , Aprendizado Profundo , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Melanócitos/citologia , Redes Neurais de Computação , Estudos Prospectivos , Curva ROC , Reprodutibilidade dos Testes , Carga de Trabalho
2.
Lancet Oncol ; 16(6): 676-85, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25979595

RESUMO

BACKGROUND: The likelihood of tumour recurrence after nephrectomy in localised clear cell renal cell carcinoma is well characterised by clinical and pathological parameters. However, these assessments can be improved and personalised by the addition of molecular characteristics of each patient's tumour. We aimed to develop and validate a prognostic multigene signature to improve prediction of recurrence risk in clear cell renal cell carcinoma. METHODS: In the development stage, we investigated the association between expression of 732 genes, measured by reverse-transcription PCR, and clinical outcome in 942 patients with stage I-III clear cell renal cell carcinoma who had undergone a nephrectomy at the Cleveland Clinic (OH, USA). 516 genes were associated with recurrence-free interval. 11 of these genes were selected by further statistical analyses, and were combined with five reference genes (ie, 16 genes in total), from which a recurrence score algorithm was developed. The recurrence score was then validated in an independent cohort of 626 patients from France with stage I-III clear cell renal cell carcinoma who had also undergone nephrectomy. The association between the recurrence score and the risk of recurrence and cancer-specific survival in the first 5 years after surgery was assessed using Cox proportional hazard regression, stratified by tumour stage (stage I vs stage II vs III). FINDINGS: In our primary univariate analysis, the continuous recurrence score (median 37, IQR 31-45) was significantly associated with recurrence-free interval (hazard ratio 3·91 [95% CI 2·63-5·79] for a 25-unit increase in score, p<0·0001). In multivariable analyses, the recurrence score was significantly associated with the risk of tumour recurrence (hazard ratio per 25-unit increase in the score 3·37 [95% CI 2·23-5·08], p<0·0001) after stratification by stage and adjustment for tumour size, grade, or Leibovich score. The recurrence score was able to identify a clinically significant number of both high-risk stage I and low-risk stage II-III patients. A heterogeneity study on separate samples showed little to no intratumoural variability among the 16 genes. INTERPRETATION: Our findings validate the recurrence score as a predictor of clinical outcome in patients with stage I-III clear cell renal cell carcinoma, providing a more accurate and individualised risk assessment beyond existing clinical and pathological parameters. FUNDING: Genomic Health Inc and Pfizer Inc.


Assuntos
Carcinoma de Células Renais/genética , Proteínas de Neoplasias/biossíntese , Recidiva Local de Neoplasia/genética , Prognóstico , Idoso , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/cirurgia , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Estadiamento de Neoplasias , Nefrectomia
3.
Nature ; 485(7396): 55-61, 2012 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-22367541

RESUMO

The mammalian target of rapamycin (mTOR) kinase is a master regulator of protein synthesis that couples nutrient sensing to cell growth and cancer. However, the downstream translationally regulated nodes of gene expression that may direct cancer development are poorly characterized. Using ribosome profiling, we uncover specialized translation of the prostate cancer genome by oncogenic mTOR signalling, revealing a remarkably specific repertoire of genes involved in cell proliferation, metabolism and invasion. We extend these findings by functionally characterizing a class of translationally controlled pro-invasion messenger RNAs that we show direct prostate cancer invasion and metastasis downstream of oncogenic mTOR signalling. Furthermore, we develop a clinically relevant ATP site inhibitor of mTOR, INK128, which reprograms this gene expression signature with therapeutic benefit for prostate cancer metastasis, for which there is presently no cure. Together, these findings extend our understanding of how the 'cancerous' translation machinery steers specific cancer cell behaviours, including metastasis, and may be therapeutically targeted.


Assuntos
Metástase Neoplásica , Neoplasias da Próstata/patologia , Biossíntese de Proteínas , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Benzoxazóis/farmacologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , Fatores de Iniciação em Eucariotos/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Genoma/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Invasividade Neoplásica/genética , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/genética , Fosfoproteínas/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Pirimidinas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidores
4.
BJU Int ; 110(1): 50-5, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22077660

RESUMO

UNLABELLED: Study Type - Diagnostic (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? The widespread use of serum PSA testing followed by TRUS-guided biopsy have resulted in profound prostate cancer stage migration with many patients presenting with focal rather than multifocal disease. There is increasing interest in the use of focal rather than whole-gland treatment. However, current biopsy schemes may still miss cancer or, even when cancer is identified, its extent or grade might not be accurately characterized. In order for focal therapy to be effective, the area of highest tumour volume and/or grade needs to localized accurately. The aim of this study was to assess how well biopsy, as currently performed, locates the focus of highest prostate cancer volume and/or grade. OBJECTIVE: To evaluate the ability of transrectal ultrasonography (TRUS)-guided extended core biopsy to identify the dominant tumour accurately in men with early stage prostate cancer. PATIENTS AND METHODS: Patients with early stage, low-risk prostate cancer who subsequently underwent radical prostatectomy (RP) and had complete surgical specimens were identified. Re-review was performed by a single uropathologist using ImageJ software to identify tumour location, dominant grade (DG) and dominant volume (DV). Pathology findings were then compared with biopsy results. RESULTS: A total of 51 men with early stage, low-risk prostate cancer, who had undergone RP, had complete specimens for review and a median of 15 biopsy cores taken for diagnosis and grading. Sixteen men had a single diagnostic biopsy, 21 had one repeat biopsy, and 14 had two or more repeat biopsies. Compared with surgical findings, biopsy correctly identified the sextant with the largest tumour volume in 55% (95% CI 0.5-0.6) of specimens and the highest grade in 37% (95 CI 0.3-0.5). No demographic or clinical factors were significantly associated with identification of DG. Interval between last biopsy and RP, total tissue length taken and total length of tumour identified were significantly associated with correct identification of DV. CONCLUSIONS: Our findings show that TRUS-guided biopsy detects and localizes DV better than it does DG. Even with an extended scheme, TRUS-guided biopsy does not reliably identify dominant cancer location in this low-risk cohort of men with early stage prostate cancer. TRUS-guided biopsy may perform better in similar men with low stage, but higher volume disease.


Assuntos
Biópsia por Agulha , Próstata/patologia , Neoplasias da Próstata/diagnóstico , Ultrassonografia de Intervenção , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Prostatectomia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Sensibilidade e Especificidade , Carga Tumoral
5.
J Radiol Case Rep ; 6(7): 23-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23365709

RESUMO

Ureteral polyps are rare causes of ureteropelvic junction (UPJ) obstruction, particularly in children. We report a nine year-old boy with UPJ obstruction initially suggestive of an obstructive urinary stone. CT showed intraureteral calcification at the UPJ and hydronephrosis. A retrograde pyelogram showed narrowing at the UPJ and partial obstruction that was found to be a ureteral polyp. This case illustrates a rare cause of UPJ obstruction that should be considered when the imaging findings and presentation are atypical for more common etiologies of ureteral obstruction.


Assuntos
Calcinose/diagnóstico por imagem , Hidronefrose/diagnóstico por imagem , Pelve Renal/diagnóstico por imagem , Pólipos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Obstrução Ureteral/diagnóstico por imagem , Calcinose/patologia , Criança , Humanos , Pelve Renal/patologia , Masculino , Pólipos/complicações , Pólipos/patologia , Resultado do Tratamento , Obstrução Ureteral/etiologia , Obstrução Ureteral/patologia
6.
J Urol ; 186(2): 465-9, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21679996

RESUMO

PURPOSE: We evaluated the reproducibility of Gleason grading as relevant to the clinical treatment of men on active surveillance. MATERIALS AND METHODS: Three sets of digital images of prostatic adenocarcinoma in biopsies were reviewed and assigned Gleason scores by a total of 11 pathologists from 7 institutions. Interobserver and intra-observer reproducibility were assessed for assignment of the highest Gleason pattern (3 vs 4 or higher). We also identified 97 consecutive patients on active surveillance. Prostate biopsy glass slides from 82 of the patients were available for re-review and the frequency of carcinoma requiring the distinction of tangentially sectioned Gleason pattern 3 from 4 was determined. RESULTS: Interobserver reproducibility for classic Gleason patterns was substantial (Light's κ 0.76). Interobserver reproducibility for the histological distinction of tangentially sectioned Gleason pattern 3 from Gleason pattern 4 was only fair (Light's κ 0.27). Intra-observer reproducibility ranged from 65% to 100% (mean 81.5%). Of the 82 patients on active surveillance 61 had carcinoma and 15 (24.5%) had a set of biopsies with at least 1 focus in which the distinction between tangentially sectioned Gleason pattern 3 and poorly formed pattern 4 glands had to be considered. CONCLUSIONS: The reproducibility of grading classic Gleason patterns is high. However, variability in grading occurred when distinguishing between tangentially sectioned pattern 3 glands and the poorly formed gland subset of pattern 4. Developing universally accepted histological and/or molecular criteria to distinguish these patterns and subsequently characterizing their natural history would be useful when treating patients on active surveillance.


Assuntos
Adenocarcinoma/patologia , Neoplasias da Próstata/patologia , Adenocarcinoma/terapia , Biópsia por Agulha/estatística & dados numéricos , Humanos , Masculino , Estadiamento de Neoplasias , Variações Dependentes do Observador , Vigilância da População , Neoplasias da Próstata/terapia , Reprodutibilidade dos Testes
7.
Prostate ; 65(2): 141-50, 2005 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-15924336

RESUMO

BACKGROUND: The present study was designed to determine if estrogens change microtubule polymerization and modulate cell cycle progression in vitro, related to modulation of tubulin expression and to determine if estrogens had antagonistic or synergistic effects with microtubule active agents. METHODS: cDNA array analysis of LNCaP cells treated with the estrogens, estradiol, estrone, diethylstilbestrol (DES), and 2-methoxyestradiol (2-ME) was carried out and the results confirmed by PCR and Western blotting. Microtubule arrays in cells treated with estrogens were assessed using indirect immunofluorescence. The effects of combining estrogens with taxane was assessed by MTT assay and flow cytometry for cell cycle kinetics. Human prostate cancer xenografts were treated with DES and docetaxel to assess the effects of combining estrogens and taxane in vivo. RESULTS: Treatment of LNCaP cells with DES and 2-ME suppressed transcripts and protein for beta-tubulin isotype IVa. This effect on tubulin synthesis was not blocked by estrogen or androgen receptor modulators. Other estrogens had no effect on beta-tubulin expression. 2-ME and DES decreased the density of microtubules. The administration of DES or 2-ME with paclitaxel enhanced cytotoxicity and G(2)-M arrest in vitro. DES enhanced tumor suppression in a human prostate cancer xenograft model when combined with the taxane docetaxel. CONCLUSION: The use of DES and 2-ME enhances the effects of taxanes and may be a novel and important means of increasing therapeutic efficacy of cytotoxic chemotherapy against prostate carcinoma.


Assuntos
Estrogênios/farmacologia , Neoplasias da Próstata/patologia , Taxoides/efeitos adversos , Tubulina (Proteína)/biossíntese , Western Blotting , Ciclo Celular/fisiologia , Citometria de Fluxo , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Transcrição Gênica/efeitos dos fármacos , Células Tumorais Cultivadas
8.
Clin Cancer Res ; 11(10): 3905-14, 2005 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-15897592

RESUMO

PURPOSE: Botanical preparations are widely used by patients with prostate cancer. Scutellaria baicalensis, a botanical with a long history of medicinal use in China, was a constituent of the herbal mixture PC-SPES, a product that inhibited prostate cancer growth in both laboratory and clinical studies. Due to the difficulties encountered when evaluating the efficacy of complex natural products, we sought to identify active chemical constituents within Scutellaria and determine their mechanisms of action. EXPERIMENTAL DESIGN AND RESULTS: We used high-performance liquid chromatography to fractionate S. baicalensis and identified four compounds capable of inhibiting prostate cancer cell proliferation; baicalein, wogonin, neobaicalein, and skullcapflavone. Comparisons of the cellular effects induced by the entire extract versus the four-compound combination produced comparable cell cycle changes, levels of growth inhibition, and global gene expression profiles (r(2) = 0.79). Individual compounds exhibited antiandrogenic activities with reduced expression of the androgen receptor and androgen-regulated genes. In vivo, baicalein (20 mg/kg/d p.o.) reduced the growth of prostate cancer xenografts in nude mice by 55% at 2 weeks compared with placebo and delayed the average time for tumors to achieve a volume of approximately 1,000 mm(3) from 16 to 47 days (P < 0.001). CONCLUSIONS: Most of the anticancer activities of S. baicalensis can be recapitulated with four purified constituents that function in part through inhibition of the androgen receptor signaling pathway. We conclude that clinical studies evaluating the efficacy of these agents in the context of chemoprevention or the treatment of prostate cancer are warranted.


Assuntos
Carcinoma/patologia , Extratos Vegetais/farmacologia , Neoplasias da Próstata/patologia , Receptores Androgênicos/efeitos dos fármacos , Scutellaria baicalensis/química , Animais , Ciclo Celular/efeitos dos fármacos , Proliferação de Células , Cromatografia Líquida de Alta Pressão , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Extratos Vegetais/análise , Neoplasias da Próstata/veterinária , Receptores Androgênicos/fisiologia , Transdução de Sinais , Transplante Heterólogo , Células Tumorais Cultivadas
9.
Fungal Genet Biol ; 38(1): 85-97, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12553939

RESUMO

Geotrichum candidum is unusual among reported hyphal ascomycetes in that its hyphae readily stain with phalloidin to reveal actin concentrated in the Spitzenkörper (SPK) and plaques associated with the plasma membrane (PM). Loss of SPK actin, but not the PM plaques, following latrunculin B treatment produces tip swelling, consistent with actin restraining tip morphology or localizing vesicle exocytosis. Tip morphogenesis may also involve a spectrin-like protein which concentrates at the apical PM in plaques unassociated with the actin plaques. Branch formation occurs with growth rates initially about 20% those of leading tips, and does not involve a morphologically detectable SPK, nor SPK-like actin ensembles, indicating the dispensibility of this structure in tip growth. Surprisingly, new tubular tips can form in the continued presence of latrunculin, consistent with alternative cellular systems, such as the spectrin-like protein, substituting for actin's critical functions.


Assuntos
Actinas/fisiologia , Membrana Celular/metabolismo , Geotrichum/crescimento & desenvolvimento , Hifas/crescimento & desenvolvimento , Actinas/metabolismo , Sequência de Aminoácidos , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Proteínas do Citoesqueleto/análise , Geotrichum/química , Geotrichum/metabolismo , Geotrichum/ultraestrutura , Hifas/efeitos dos fármacos , Microtúbulos/metabolismo , Dados de Sequência Molecular , Morfogênese , Homologia de Sequência de Aminoácidos , Coloração e Rotulagem , Tiazóis/farmacologia , Tiazolidinas
10.
J Natl Cancer Inst ; 94(21): 1641-7, 2002 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-12419791

RESUMO

BACKGROUND: PC-SPES is a botanical preparation shown to have efficacy in patients with androgen-dependent and androgen-independent prostate carcinoma. Several herbal constituents in PC-SPES inhibit tumor growth through cell cycle arrest and apoptosis, although the mechanisms of these activities are poorly defined. We sought to identify PC-SPES-induced changes in gene expression, specifically in those genes encoding cytoskeletal proteins that could be associated with PC-SPES-induced cytoxicity. METHODS: LNCaP prostate carcinoma cells were treated with PC-SPES, and changes in gene expression were determined by complementary DNA (cDNA) microarray hybridization and northern blot analyses. PC-SPES and paclitaxel, a microtubule-stabilizing drug, effects on microtubules were assessed by immunofluorescence of treated cells and by in vitro tubulin polymerization assays. In vivo effects of PC-SPES and paclitaxel were assessed using CWR22R androgen-independent prostate cancer xenografts. All statistical tests were two-sided. RESULTS: PC-SPES treatment of LNCaP cells for 24 hours altered the expression of 17 cytoskeletal genes. mRNA levels of alpha-tubulin decreased sevenfold. Although paclitaxel stabilized and PC-SPES treatment disrupted microtubule architecture in LNCaP cells, the combination of both agents had an intermediate effect. PC-SPES inhibited tubulin polymerization in vitro, even in the presence of paclitaxel. Compared with tumors in control mice (mean tumor volume = 2983 mm(3), 95% confidence interval [CI] = 2380 to 3586 mm(3)), tumors were statistically significantly smaller in mice that received PC-SPES (mean tumor volume = 2018 mm(3), 95% CI = 1450 to 2568 mm(3); P =.028), paclitaxel (mean tumor volume = 1340 mm(3), 95% CI = 697 to 1983 mm(3); P<.001), or the combination of PC-SPES and paclitaxel (mean tumor volume = 1955 mm(3), 95% CI = 1260 to 2650 mm(3); P =.034). CONCLUSION: PC-SPES may interfere with microtubule polymerization. This activity has implications for the clinical management of patients with advanced prostate cancer who may be taking PC-SPES concurrently with microtubule-modulating chemotherapeutic agents, such as paclitaxel.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Divisão Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas , Microtúbulos/efeitos dos fármacos , Paclitaxel/uso terapêutico , Extratos Vegetais/uso terapêutico , Neoplasias da Próstata/patologia , Animais , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Nus , Microtúbulos/ultraestrutura , Análise de Sequência com Séries de Oligonucleotídeos , Fitoterapia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Transplante Heterólogo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Células Tumorais Cultivadas
11.
Proc Natl Acad Sci U S A ; 99(18): 11890-5, 2002 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-12185249

RESUMO

The human prostate gland is an important target organ of androgenic hormones. Testosterone and dihydrotestosterone interact with the androgen receptor to regulate vital aspects of prostate growth and function including cellular proliferation, differentiation, apoptosis, metabolism, and secretory activity. Our objective in this study was to characterize the temporal program of transcription that reflects the cellular response to androgens and to identify specific androgen-regulated genes (ARGs) or gene networks that participate in these responses. We used cDNA microarrays representing about 20,000 distinct human genes to profile androgen-responsive transcripts in the LNCaP adenocarcinoma cell line and identified 146 genes with transcript alterations more than 3-fold. Of these, 103 encode proteins with described functional roles, and 43 represent transcripts that have yet to be characterized. Temporal gene expression profiles grouped the ARGs into four distinct cohorts. Five uncharacterized ARGs demonstrated exclusive or high expression levels in the prostate relative to other tissues studied. A search of available DNA sequence upstream of 28 ARGs identified 25 with homology to the androgen response-element consensus-binding motif. These results identify previously uncharacterized and unsuspected genes whose expression levels are directly or indirectly regulated by androgens; further, they provide a comprehensive temporal view of the transcriptional program of human androgen-responsive cells.


Assuntos
Androgênios/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Neoplasias da Próstata/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Transporte Biológico , Diferenciação Celular/genética , Divisão Celular/genética , Humanos , Masculino , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Células Tumorais Cultivadas
12.
Cancer Res ; 62(14): 3920-4, 2002 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-12124319

RESUMO

Clinical trials of the herbal preparation PC-SPES have demonstrated substantial responses in patients with advanced prostate cancer. Biochemical assays and clinical observations suggest that the effects of PC-SPES are mediated at least in part through estrogenic activity, although the mechanism(s) remains largely undefined. In this study, we used cDNA microarray analysis to identify gene expression changes in LNCaP prostate carcinoma cells exposed to PC-SPES and estrogenic agents including diethylstilbestrol. PC-SPES altered the expression of 156 genes after 24 h of exposure. Of particular interest, transcripts encoding cell cycle-regulatory proteins, alpha- and beta-tubulins, and the androgen receptor were down-regulated by PC-SPES. A comparison of gene expression profiles resulting from these treatments indicates that PC-SPES exhibits activities distinct from those attributable to diethylstilbestrol and suggests that alterations in specific genes involved in modulating the cell cycle, cell structure, and androgen response may be responsible for PC-SPES-mediated cytotoxicity.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Dietilestilbestrol/farmacologia , Estrogênios não Esteroides/farmacologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/biossíntese , Receptores Androgênicos/genética , Transcrição Gênica/efeitos dos fármacos , Células Tumorais Cultivadas
13.
J Biol Chem ; 277(2): 1240-8, 2002 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-11707452

RESUMO

In the prostate, androgens negatively regulate the expression of transforming growth factor-beta (TGF-beta) ligands and receptors and Smad activation through unknown mechanisms. We show that androgens (dihydrotestosterone and R1881) down-regulate TGF-beta1-induced expression of TGF-beta1, c-Fos, and Egr-1 in the human prostate adenocarcinoma cell line, LNCaP. Moreover, 5alpha-dihydrotestosterone (DHT) inhibits TGF-beta1 activation of three TGF-beta1-responsive promoter constructs, 3TP-luciferase, AP-1-luciferase, and SBE4(BV)-luciferase, in LNCaP cells either with or without enforced expression of TGF-beta receptors (TbetaRI and TbetaRII). Similarly, DHT inhibits the activation of Smad-binding element (SBE)4(BV)-luciferase by either constitutively activated TbetaRI (T204D) or constitutively activated Smad3 (S3*). Activation of SBE4(BV)-luciferase by S3* in the NRP-154 prostatic cell line, which is androgen receptor (AR)-negative but highly responsive to TGF-beta1, is blocked by co-transfection with either full-length AR or AR missing the DNA binding domain. Immunoprecipitation and GST pull-down assays show that AR directly associates with Smad3 but not Smad2 or Smad4. Electrophoretic mobility shift assays indicate that the AR ligand binding domain directly inhibits the association of Smad3 to the Smad-binding element. In conclusion, our data demonstrate for the first time that ligand-bound AR inhibits TGF-beta transcriptional responses through selectively repressing the binding of Smad3 to SBE.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Receptores Androgênicos/metabolismo , Transdução de Sinais , Transativadores/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adenocarcinoma , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Di-Hidrotestosterona/metabolismo , Proteína 1 de Resposta de Crescimento Precoce , Regulação da Expressão Gênica/efeitos dos fármacos , Genes Reporter , Humanos , Proteínas Imediatamente Precoces/metabolismo , Ligantes , Masculino , Metribolona/metabolismo , Neoplasias da Próstata , Inibidores da Síntese de Proteínas/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores Androgênicos/genética , Proteína Smad3 , Congêneres da Testosterona/metabolismo , Fatores de Transcrição/metabolismo , Transfecção , Células Tumorais Cultivadas
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