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1.
Nucleic Acids Res ; 45(19): 11056-11069, 2017 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-28977491

RESUMEN

Cancer genome sequencing has implicated the cytosine deaminase activity of apolipoprotein B mRNA editing enzyme catalytic polypeptide-like (APOBEC) genes as an important source of mutations in diverse cancers, with APOBEC3B (A3B) expression especially correlated with such cancer mutations. To better understand the processes directing A3B over-expression in cancer, and possible therapeutic avenues for targeting A3B, we have investigated the regulation of A3B gene expression. Here, we show that A3B expression is inversely related to p53 status in different cancer types and demonstrate that this is due to a direct and pivotal role for p53 in repressing A3B expression. This occurs through the induction of p21 (CDKN1A) and the recruitment of the repressive DREAM complex to the A3B gene promoter, such that loss of p53 through mutation, or human papilloma virus-mediated inhibition, prevents recruitment of the complex, thereby causing elevated A3B expression and cytosine deaminase activity in cancer cells. As p53 is frequently mutated in cancer, our findings provide a mechanism by which p53 loss can promote cancer mutagenesis.


Asunto(s)
Citidina Desaminasa/genética , Regulación Neoplásica de la Expresión Génica , Antígenos de Histocompatibilidad Menor/genética , Proteína p53 Supresora de Tumor/genética , Línea Celular , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Citidina Desaminasa/metabolismo , Células HCT116 , Humanos , Immunoblotting , Antígenos de Histocompatibilidad Menor/metabolismo , Mutación , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patología , Interferencia de ARN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína p53 Supresora de Tumor/metabolismo
2.
Nucleic Acids Res ; 44(2): 582-94, 2016 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-26400164

RESUMEN

Liver receptor homologue 1 (LRH-1) is an orphan nuclear receptor that has been implicated in the progression of breast, pancreatic and colorectal cancer (CRC). To determine mechanisms underlying growth promotion by LRH-1 in CRC, we undertook global expression profiling following siRNA-mediated LRH-1 knockdown in HCT116 cells, which require LRH-1 for growth and in HT29 cells, in which LRH-1 does not regulate growth. Interestingly, expression of the cell cycle inhibitor p21 (CDKN1A) was regulated by LRH-1 in HCT116 cells. p21 regulation was not observed in HT29 cells, where p53 is mutated. p53 dependence for the regulation of p21 by LRH-1 was confirmed by p53 knockdown with siRNA, while LRH-1-regulation of p21 was not evident in HCT116 cells where p53 had been deleted. We demonstrate that LRH-1-mediated p21 regulation in HCT116 cells does not involve altered p53 protein or phosphorylation, and we show that LRH-1 inhibits p53 recruitment to the p21 promoter, likely through a mechanism involving chromatin remodelling. Our study suggests an important role for LRH-1 in the growth of CRC cells that retain wild-type p53.


Asunto(s)
Proliferación Celular/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Regulación Neoplásica de la Expresión Génica , Receptores Citoplasmáticos y Nucleares/genética , Proteína p53 Supresora de Tumor/genética , Sitios de Unión , Ensamble y Desensamble de Cromatina , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Eliminación de Gen , Células HCT116 , Células HT29 , Humanos , Mutación , Especificidad de Órganos , Fosforilación , Regiones Promotoras Genéticas , Unión Proteica , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Transducción de Señal , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/metabolismo
3.
Breast Cancer Res Treat ; 159(2): 215-27, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27514395

RESUMEN

Differential prognostic roles of Androgen Receptor (AR) have been proposed in breast cancer (BC) depending on tumour oestrogen receptor (ER) status. This study aimed to evaluate the prognostic and/or predictive significance of AR expression in invasive BC. In this study AR expression was studied on a large (n = 1141) consecutive series of early-stage (I-III) BC using tissue microarray and immunohistochemistry (IHC). AR mRNA expression was assessed in a subset of cases. The prognostic impact of AR mRNA expression was externally validated using the online BC gene expression data sets (n = 25 data sets, 4078 patients). Nuclear AR IHC expression was significantly associated with features of good prognosis including older age, smaller tumour size, lower grade and lobular histology particularly in the ER-positive tumours. AR was associated with ER-related markers GATA3, FOXa1, RERG and BEX1. Negative association was observed with HER2, p53, Ki67, TK1, CD71 and AGTR1. AR Overexpression was associated with longer survival (p < 0.001), independent of tumour size, grade, stage [p = 0.033, hazard ratio (HR) = 0.80 95 % CI = 0.64-0.98]. Similar associations were maintained in ER+ tumours in univariate and multivariate analysis (p < 0.01) both in patients with and without adjuvant endocrine or chemotherapy. AR mRNA expression showed significant association with tumour grade, molecular subtypes, and longer 10 and 15 years survival in luminal BC. In the external validation cohorts, AR gene expression data were associated with improved patients' outcome (p < 0.001, HR = 0.84, 95 % CI 0.79-0.90). AR is not only an independent prognostic factor in ER-positive luminal BC but is also expressed in ER-negative tumours. AR could act as a molecular target in patients with ER-positive disease predicting response to adjuvant therapy.


Asunto(s)
Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Núcleo Celular , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Clasificación del Tumor , Pronóstico , Receptores de Estrógenos/metabolismo , Estudios Retrospectivos , Análisis de Supervivencia , Análisis de Matrices Tisulares , Carga Tumoral
4.
Breast Cancer Res Treat ; 150(3): 511-22, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25794775

RESUMEN

Peroxisome proliferator-activated receptor-gamma (PPARγ) is an adopted orphan receptor that belongs to the nuclear receptor superfamily of transcription factors. PPARγ is regarded as a differentiation factor and it plays an important role in regulating adipogenesis, cell growth, proliferation and tumour progression. In breast cancer (BC), PPARγ agonists were reported to inhibit proliferation and growth invasion and promote phenotypic changes associated with a less malignant and more differentiated status. This study aims to assess the prognostic and biological roles of PPARγ protein expression in a large cohort of BC patients (n = 1100) with emphasis on the luminal oestrogen receptor (ER) positive class. Immunohistochemistry was used to assess the levels of PPARγ expression in BC series prepared as tissue microarrays (TMAs). PPARγ antibody specificity was confirmed using Western blotting. PPARγ nuclear expression was detected in 79 % of the cases and its expression was positively correlated with the hormonal receptors (ER, progesterone receptor and androgen receptor). PPARγ levels were significantly higher in tumours with lobular subtype, smaller size and lower grade, while HER2-positive, ductal or medullary tumours were associated with lower PPARγ levels. Survival analysis showed that PPARγ is associated with better outcome in the whole series as well as in luminal ER-positive class. Cox regression model showed that PPARγ is an independent predictor of outcome. Higher PPARγ was associated with longer survival in patients with ER-positive tumours who did not receive hormone therapy. PPARγ is a good prognostic marker associated with hormone receptors. In patients with luminal BCs, PPARγ is a marker of better prognosis and is associated with longer survival.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , PPAR gamma/metabolismo , Neoplasias de la Mama/metabolismo , Núcleo Celular/metabolismo , Femenino , Humanos , Persona de Mediana Edad , Clasificación del Tumor , Pronóstico , Receptores de Estrógenos/metabolismo , Análisis de Supervivencia , Análisis de Matrices Tisulares
5.
Nucleic Acids Res ; 41(22): 10228-40, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24049078

RESUMEN

Oestrogen receptor α (ERα) is a nuclear receptor that is the driving transcription factor expressed in the majority of breast cancers. Recent studies have demonstrated that the liver receptor homolog-1 (LRH-1), another nuclear receptor, regulates breast cancer cell proliferation and promotes motility and invasion. To determine the mechanisms of LRH-1 action in breast cancer, we performed gene expression microarray analysis following RNA interference for LRH-1. Interestingly, gene ontology (GO) category enrichment analysis of LRH-1-regulated genes identified oestrogen-responsive genes as the most highly enriched GO categories. Remarkably, chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) to identify genomic targets of LRH-1 showed LRH-1 binding at many ERα binding sites. Analysis of select binding sites confirmed regulation of ERα-regulated genes by LRH-1 through binding to oestrogen response elements, as exemplified by the TFF1/pS2 gene. Finally, LRH-1 overexpression stimulated ERα recruitment, while LRH-1 knockdown reduced ERα recruitment to ERα binding sites. Taken together, our findings establish a key role for LRH-1 in the regulation of ERα target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERα at oestrogen response elements controls the expression of oestrogen-responsive genes.


Asunto(s)
Neoplasias de la Mama/genética , Receptor alfa de Estrógeno/metabolismo , Regulación Neoplásica de la Expresión Génica , Receptores Citoplasmáticos y Nucleares/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Células COS , Chlorocebus aethiops , Femenino , Células MCF-7 , Elementos de Respuesta
6.
Pflugers Arch ; 466(7): 1421-35, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24114173

RESUMEN

The endogenous lipid agent N-arachidonoylethanolamine (anandamide), among other effects, has been shown to be involved in nociceptive processing both in the central and peripheral nervous systems. Anandamide is thought to be synthesised by several enzymatic pathways both in a Ca(2+)-sensitive and Ca(2+)-insensitive manner, and rat primary sensory neurons produce anandamide. Here, we show for the first time, that cultured rat primary sensory neurons express at least four of the five known Ca(2+)-insensitive enzymes implicated in the synthesis of anandamide, and that application of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-arachidonoyl, the common substrate of the anandamide-synthesising pathways, results in anandamide production which is not changed by the removal of extracellular Ca(2+). We also show that anandamide, which has been synthesised in primary sensory neurons following the application of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-arachidonoyl induces a transient receptor potential vanilloid type 1 ion channel-mediated excitatory effect that is not inhibited by concomitant activation of the cannabinoid type 1 receptor. Finally, we show that sub-populations of transient receptor potential vanilloid type 1 ion channel-expressing primary sensory neurons also express some of the putative Ca(2+)-insensitive anandamide-synthesising enzymes. Together, these findings indicate that anandamide synthesised by primary sensory neuron via a Ca(2+)-insensitive manner has an excitatory rather than an inhibitory role in primary sensory neurons and that excitation is mediated predominantly through autocrine signalling. Regulation of the activity of the Ca(2+)-insensitive anandamide-synthesising enzymes in these neurons may be capable of regulating the activity of these cells, with potential relevance to controlling nociceptive processing.


Asunto(s)
Potenciales de Acción , Ácidos Araquidónicos/metabolismo , Calcio/metabolismo , Endocannabinoides/metabolismo , Fosfatidiletanolaminas/farmacología , Alcamidas Poliinsaturadas/metabolismo , Células Receptoras Sensoriales/metabolismo , Animales , Ácidos Araquidónicos/biosíntesis , Células Cultivadas , Endocannabinoides/biosíntesis , Ganglios Espinales/citología , Ganglios Espinales/enzimología , Ganglios Espinales/metabolismo , Fosfolipasas A2 Grupo IB/genética , Fosfolipasas A2 Grupo IB/metabolismo , Lisofosfolipasa/genética , Lisofosfolipasa/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Fosfatidiletanolaminas/química , Hidrolasas Diéster Fosfóricas/genética , Hidrolasas Diéster Fosfóricas/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 22/metabolismo , Ratas , Ratas Sprague-Dawley , Células Receptoras Sensoriales/enzimología , Células Receptoras Sensoriales/fisiología , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismo
7.
Cancer Res ; 2024 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-39356622

RESUMEN

Resistance to endocrine therapies (ET) is common in estrogen receptor (ER) positive breast cancer, and most relapsed patients die with ET-resistant disease. While genetic mutations provide explanations for some relapses, mechanisms of resistance remain undefined in many cases. Drug-induced epigenetic reprogramming has been shown to provide possible routes to resistance. By analyzing histone H3 lysine 27 acetylation (H3K27ac) profiles and transcriptional reprogramming in models of ET resistance, we discovered that selective ER degraders (SERDs), such as fulvestrant, promote expression of VGLL1, a co-activator for TEAD transcription factors. VGLL1, acting via TEADs, promoted expression of genes that drive growth of fulvestrant-resistant breast cancer cells. Pharmacological disruption of VGLL1/TEAD4 interaction inhibited VGLL1/TEAD-induced transcriptional programs to prevent growth of resistant cells. EGFR was among the VGLL1/TEAD-regulated genes, and VGLL1-directed EGFR upregulation sensitized fulvestrant-resistant breast cancer cells to EGFR inhibitors. Taken together, these findings identify VGLL1 as a transcriptional driver in ET resistance and advance therapeutic possibilities for relapsed ER+ breast cancer patients.

8.
Annu Rev Med ; 62: 217-32, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21054173

RESUMEN

The identification of the link between breast cancer and estrogens has led to the development of antiestrogens, in particular tamoxifen, to inhibit the activities of estrogen receptors (ERs) in breast cancer cells. The clinical use of tamoxifen has played a major part in decreasing breast cancer mortality over the past 30 years. Though antiestrogenic in the breast, some antiestrogens have estrogen-like actions in other tissues, acting to promote bone density and protect against cardiovascular disease, thus raising the possibility of their use in counteracting the effects of estrogen loss following menopause. Moreover, antiestrogens show efficacy as chemopreventive agents in women at high risk of developing breast cancer. Thus, antiestrogens define an important and well-understood class of cancer drug, which continue to be a mainstay in breast cancer treatment.


Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Moduladores de los Receptores de Estrógeno/uso terapéutico , Densidad Ósea/efectos de los fármacos , Mama/efectos de los fármacos , Enfermedades Cardiovasculares/tratamiento farmacológico , Estrógenos/fisiología , Estrógenos/uso terapéutico , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Receptores de Estrógenos/agonistas , Receptores de Estrógenos/antagonistas & inhibidores
9.
Nat Commun ; 13(1): 2011, 2022 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-35440136

RESUMEN

Estrogen receptor alpha (ER/ESR1) is frequently mutated in endocrine resistant ER-positive (ER+) breast cancer and linked to ligand-independent growth and metastasis. Despite the distinct clinical features of ESR1 mutations, their role in intrinsic subtype switching remains largely unknown. Here we find that ESR1 mutant cells and clinical samples show a significant enrichment of basal subtype markers, and six basal cytokeratins (BCKs) are the most enriched genes. Induction of BCKs is independent of ER binding and instead associated with chromatin reprogramming centered around a progesterone receptor-orchestrated insulated neighborhood. BCK-high ER+ primary breast tumors exhibit a number of enriched immune pathways, shared with ESR1 mutant tumors. S100A8 and S100A9 are among the most induced immune mediators and involve in tumor-stroma paracrine crosstalk inferred by single-cell RNA-seq from metastatic tumors. Collectively, these observations demonstrate that ESR1 mutant tumors gain basal features associated with increased immune activation, encouraging additional studies of immune therapeutic vulnerabilities.


Asunto(s)
Neoplasias de la Mama , Receptor alfa de Estrógeno/genética , Neoplasias de la Mama/patología , Receptor alfa de Estrógeno/metabolismo , Femenino , Humanos , Mutación
10.
Cancer Res ; 82(7): 1321-1339, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35078818

RESUMEN

Constitutively active estrogen receptor α (ER/ESR1) mutations have been identified in approximately one-third of ER+ metastatic breast cancers. Although these mutations are known as mediators of endocrine resistance, their potential role in promoting metastatic disease has not yet been mechanistically addressed. In this study, we show the presence of ESR1 mutations exclusively in distant but not local recurrences in five independent breast cancer cohorts. In concordance with transcriptomic profiling of ESR1-mutant tumors, genome-edited ESR1 Y537S and D538G-mutant cell models exhibited a reprogrammed cell adhesive gene network via alterations in desmosome/gap junction genes and the TIMP3/MMP axis, which functionally conferred enhanced cell-cell contacts while decreasing cell-extracellular matrix adhesion. In vivo studies showed ESR1-mutant cells were associated with larger multicellular circulating tumor cell (CTC) clusters with increased compactness compared with ESR1 wild-type CTCs. These preclinical findings translated to clinical observations, where CTC clusters were enriched in patients with ESR1-mutated metastatic breast cancer. Conversely, context-dependent migratory phenotypes revealed cotargeting of Wnt and ER as a vulnerability in a D538G cell model. Mechanistically, mutant ESR1 exhibited noncanonical regulation of several metastatic pathways, including secondary transcriptional regulation and de novo FOXA1-driven chromatin remodeling. Collectively, these data provide evidence for ESR1 mutation-modulated metastasis and suggest future therapeutic strategies for targeting ESR1-mutant breast cancer. SIGNIFICANCE: Context- and allele-dependent transcriptome and cistrome reprogramming in mutant ESR1 cell models elicit diverse metastatic phenotypes related to cell adhesion and migration, which can be pharmacologically targeted in metastatic breast cancer.


Asunto(s)
Neoplasias de la Mama , Receptor alfa de Estrógeno , Neoplasias Primarias Secundarias , Células Neoplásicas Circulantes , Neoplasias de la Mama/patología , Receptor alfa de Estrógeno/genética , Femenino , Humanos , Mutación
11.
Breast Cancer Res Treat ; 127(2): 385-96, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20607599

RESUMEN

Estrogen receptor-α (ER) is expressed in the great majority of breast cancers, and the inhibition of ER action is a key part of breast cancer treatment. The inhibition of ER action is achieved using anti-estrogens, primarily tamoxifen, and with aromatase inhibitors that inhibit estrogen biosynthesis, thereby preventing ER activation. However, resistance to these therapies is common. With the aim of identifying new molecular targets for breast cancer therapy, we have identified the liver receptor homolog-1 (LRH-1) as an estrogen-regulated gene. RNA interference and over-expression studies were used to investigate the role of the LRH-1 in regulating breast cancer growth and to identify the targets of an LRH-1 action. Promoter recruitment was determined using reporter gene and chromatin immunoprecipitation (ChIP) assays. We show that LRH-1 regulates breast cancer cell growth by regulating the ER expression. Reporter gene and in vitro DNA-binding assays identified an LRH-1-binding site in the ER gene promoter, and ChIP assays have demonstrated in vivo binding at this site. We also provide evidence for new LRH-1 variants in breast cancer cells arising from the use of alternative promoters. Previous studies have shown that LRH-1 functions in estrogen biosynthesis by regulating aromatase expression. Our findings extend this by highlighting LRH-1 as a key regulator of the estrogen response in breast cancer cells through the regulation of ER expression. Hence, inhibition of LRH-1 could provide a powerful new approach for the treatment of endocrine-resistant breast cancer.


Asunto(s)
Neoplasias de la Mama/fisiopatología , Regulación Neoplásica de la Expresión Génica , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores de Estrógenos/metabolismo , Secuencia de Aminoácidos , Animales , Aromatasa/metabolismo , Secuencia de Bases , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Células COS , Línea Celular Tumoral , Proliferación Celular , Chlorocebus aethiops , Femenino , Orden Génico , Células Hep G2 , Humanos , Datos de Secuencia Molecular , Regiones Promotoras Genéticas/genética , Receptores Citoplasmáticos y Nucleares/genética , Receptores de Estrógenos/genética , Alineación de Secuencia
12.
Breast Cancer Res Treat ; 128(2): 357-68, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20730598

RESUMEN

Estrogen receptor-α (ERα) positive breast cancer frequently responds to inhibitors of ERα activity, such as tamoxifen, and/or to aromatase inhibitors that block estrogen biosynthesis. However, many patients become resistant to these agents through mechanisms that remain unclear. Previous studies have shown that expression of ERα in ERα-negative breast cancer cell lines frequently inhibits their growth. In order to determine the consequence of ERα over-expression in ERα-positive breast cancer cells, we over-expressed ERα in the MCF-7 breast cancer cell line using adenovirus gene transduction. ERα over-expression led to ligand-independent expression of the estrogen-regulated genes pS2 and PR and growth in the absence of estrogen. Interestingly, prolonged culturing of these cells in estrogen-free conditions led to the outgrowth of cells capable of growth in cultures from ERα transduced, but not in control cultures. From these cultures a line, MLET5, was established which remained ERα-positive, but grew in an estrogen-independent manner. Moreover, MLET5 cells were inhibited by anti-estrogens showing that ERα remains important for their growth. Gene expression microarray analysis comparing MCF-7 cells with MLET5 highlighted apoptosis as a major functional grouping that is altered in MLET5 cells, such that cell survival would be favoured. This conclusion was further substantiated by the demonstration that MLET5 show resistance to etoposide-induced apoptosis. As the gene expression microarray analysis also shows that the apoptosis gene set differentially expressed in MLET5 is enriched for estrogen-regulated genes, our findings suggest that transient over-expression of ERα could lead to increased cell survival and the development of estrogen-independent growth, thereby contributing to resistance to endocrine therapies in breast cancer patients.


Asunto(s)
Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Proliferación Celular , Resistencia a Antineoplásicos , Receptor alfa de Estrógeno/metabolismo , Estrógenos/farmacología , Adenoviridae/genética , Antineoplásicos Hormonales/uso terapéutico , Apoptosis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Western Blotting , Neoplasias de la Mama/genética , Ciclo Celular , Receptor alfa de Estrógeno/genética , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tamoxifeno/uso terapéutico , Células Tumorales Cultivadas
13.
Sci Rep ; 8(1): 5237, 2018 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-29568076

RESUMEN

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

14.
Mol Cancer Ther ; 17(6): 1156-1166, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29545334

RESUMEN

Recent reports indicate that some cancer types are especially sensitive to transcription inhibition, suggesting that targeting the transcriptional machinery provides new approaches to cancer treatment. Cyclin-dependent kinase (CDK)7 is necessary for transcription, and acts by phosphorylating the C-terminal domain (CTD) of RNA polymerase II (PolII) to enable transcription initiation. CDK7 additionally regulates the activities of a number of transcription factors, including estrogen receptor (ER)-α. Here we describe a new, orally bioavailable CDK7 inhibitor, ICEC0942. It selectively inhibits CDK7, with an IC50 of 40 nmol/L; IC50 values for CDK1, CDK2, CDK5, and CDK9 were 45-, 15-, 230-, and 30-fold higher. In vitro studies show that a wide range of cancer types are sensitive to CDK7 inhibition with GI50 values ranging between 0.2 and 0.3 µmol/L. In xenografts of both breast and colorectal cancers, the drug has substantial antitumor effects. In addition, combination therapy with tamoxifen showed complete growth arrest of ER-positive tumor xenografts. Our findings reveal that CDK7 inhibition provides a new approach, especially for ER-positive breast cancer and identify ICEC0942 as a prototype drug with potential utility as a single agent or in combination with hormone therapies for breast cancer. ICEC0942 may also be effective in other cancers that display characteristics of transcription factor addiction, such as acute leukaemia and small-cell lung cancer. Mol Cancer Ther; 17(6); 1156-66. ©2018 AACR.


Asunto(s)
Antineoplásicos/farmacología , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Administración Oral , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Antineoplásicos/farmacocinética , Disponibilidad Biológica , Caspasas/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Quinasas Ciclina-Dependientes/metabolismo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Humanos , Ratones , Fosforilación , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacocinética , Ensayos Antitumor por Modelo de Xenoinjerto , Quinasa Activadora de Quinasas Ciclina-Dependientes
15.
Sci Rep ; 7(1): 16115, 2017 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-29170437

RESUMEN

Polo-like kinase-1 (PLK1) plays a major role in driving mitotic events, including centrosome disjunction and separation, and is frequently over-expressed in human cancers. PLK1 inhibition is a promising therapeutic strategy and works by arresting cells in mitosis due to monopolar spindles. The p53 tumour suppressor protein is a short-lived transcription factor that can inhibit the growth, or stimulate the death, of developing cancer cells. Curiously, although p53 normally acts in an anti-cancer capacity, it can offer significant protection against inhibitors of PLK1, but the events underpinning this effect are not known. Here, we show that functional p53 reduces the sensitivity to PLK1 inhibitors by permitting centrosome separation to occur, allowing cells to traverse mitosis and re-enter cycle with a normal complement of 2N chromosomes. Protection entails the activation of p53 through the DNA damage-response enzymes, ATM and ATR, and requires the phosphorylation of p53 at the key regulatory site, Ser15. These data highlight a previously unrecognised link between p53, PLK1 and centrosome separation that has therapeutic implications for the use of PLK1 inhibitors in the clinic.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Centrosoma/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Bencimidazoles/farmacología , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas de Ciclo Celular/genética , Supervivencia Celular/efectos de los fármacos , Centrosoma/efectos de los fármacos , Técnica del Anticuerpo Fluorescente , Silenciador del Gen , Células HCT116 , Humanos , Mitosis/efectos de los fármacos , Mitosis/genética , Mitosis/fisiología , Morfolinas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/genética , Pirazinas/farmacología , Pironas/farmacología , Sulfonas/farmacología , Tiofenos/farmacología , Proteína p53 Supresora de Tumor/genética , Quinasa Tipo Polo 1
16.
Nat Commun ; 8(1): 1865, 2017 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-29192207

RESUMEN

Resistance to endocrine therapy remains a major clinical problem in breast cancer. Genetic studies highlight the potential role of estrogen receptor-α (ESR1) mutations, which show increased prevalence in the metastatic, endocrine-resistant setting. No naturally occurring ESR1 mutations have been reported in in vitro models of BC either before or after the acquisition of endocrine resistance making functional consequences difficult to study. We report the first discovery of naturally occurring ESR1 Y537C and ESR1 Y537S mutations in MCF7 and SUM44 ESR1-positive cell lines after acquisition of resistance to long-term-estrogen-deprivation (LTED) and subsequent resistance to fulvestrant (ICIR). Mutations were enriched with time, impacted on ESR1 binding to the genome and altered the ESR1 interactome. The results highlight the importance and functional consequence of these mutations and provide an important resource for studying endocrine resistance.


Asunto(s)
Neoplasias de la Mama/genética , Resistencia a Antineoplásicos/genética , Estradiol/análogos & derivados , Antagonistas del Receptor de Estrógeno/uso terapéutico , Receptor alfa de Estrógeno/genética , Línea Celular Tumoral , Estradiol/uso terapéutico , Femenino , Fulvestrant , Humanos , Células MCF-7 , Mutación , Moduladores Selectivos de los Receptores de Estrógeno/uso terapéutico , Tamoxifeno/uso terapéutico
17.
Clin Cancer Res ; 22(23): 5929-5938, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27301701

RESUMEN

PURPOSE: CDK-activating kinase (CAK) is required for the regulation of the cell cycle and is a trimeric complex consisting of cyclin-dependent kinase 7 (CDK7), Cyclin H, and the accessory protein, MAT1. CDK7 also plays a critical role in regulating transcription, primarily by phosphorylating RNA polymerase II, as well as transcription factors such as estrogen receptor-α (ER). Deregulation of cell cycle and transcriptional control are general features of tumor cells, highlighting the potential for the use of CDK7 inhibitors as novel cancer therapeutics. EXPERIMENTAL DESIGN: mRNA and protein expression of CDK7 and its essential cofactors cyclin H and MAT1 were evaluated in breast cancer samples to determine if their levels are altered in cancer. Immunohistochemical staining of >900 breast cancers was used to determine the association with clinicopathologic features and patient outcome. RESULTS: We show that expressions of CDK7, cyclin H, and MAT1 are all closely linked at the mRNA and protein level, and their expression is elevated in breast cancer compared with the normal breast tissue. Intriguingly, CDK7 expression was inversely proportional to tumor grade and size, and outcome analysis showed an association between CAK levels and better outcome. Moreover, CDK7 expression was positively associated with ER expression and in particular with phosphorylation of ER at serine 118, a site important for ER transcriptional activity. CONCLUSIONS: Expressions of components of the CAK complex, CDK7, MAT1, and Cyclin H are elevated in breast cancer and correlate with ER. Like ER, CDK7 expression is inversely proportional to poor prognostic factors and survival. Clin Cancer Res; 22(23); 5929-38. ©2016 AACR.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Proteínas Portadoras/genética , Ciclina H/genética , Quinasas Ciclina-Dependientes/genética , Expresión Génica/genética , Receptores de Estrógenos/genética , Adulto , Proteínas de Ciclo Celular , Femenino , Humanos , Persona de Mediana Edad , Fosforilación/genética , Pronóstico , Transducción de Señal/genética , Factores de Transcripción , Transcripción Genética/genética , Quinasa Activadora de Quinasas Ciclina-Dependientes
18.
Oncogene ; 23(45): 7561-70, 2004 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-15334066

RESUMEN

The androgen receptor (AR) is a member of the nuclear receptor superfamily of ligand-activated transcription factors and plays a key role in the development and progression of prostate cancer. Current therapies include the use of antiandrogens aimed at inhibiting the transcriptional activation of AR-regulated genes by AR. Here, we explore a strategy aimed at obtaining silencing of AR-regulated genes, based on the properties of the transcriptional repressor promyelocytic leukamia zinc-finger protein (PLZF). In order to do this, we have made a fusion protein between PLZF and AR, named PLZF-AR, and show that PLZF-AR is able to bring about silencing of genomically encoded AR-regulated genes and inhibit the androgen-regulated growth of LNCaP prostate cancer cells. Together, our results show that this strategy is able to bring about potent repression of AR-regulated responses and, therefore, could be of value in the development of new therapies for prostate cancer.


Asunto(s)
Andrógenos/fisiología , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica/fisiología , Silenciador del Gen , Receptores Androgénicos/genética , Proteínas Recombinantes de Fusión/fisiología , Factores de Transcripción/genética , Animales , Secuencia de Bases , Células COS , Cartilla de ADN , Técnica del Anticuerpo Fluorescente Indirecta , Genes Reporteros , Humanos , Factores de Transcripción de Tipo Kruppel , Proteína de la Leucemia Promielocítica con Dedos de Zinc , Proteínas Recombinantes de Fusión/genética
19.
Clin Cancer Res ; 10(23): 8094-104, 2004 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-15585645

RESUMEN

PURPOSE: Estrogen receptor alpha (ERalpha)-positive breast cancer cell lines are up to 10 times more sensitive than ERalpha-negative cell lines to the antiproliferative activity of the histone deacetylase inhibitor trichostatin A (TSA). The purpose of the study was to investigate the mechanisms underlying this differential response. EXPERIMENTAL DESIGN AND RESULTS: In the ERalpha-positive MCF-7 cell line, TSA repressed ERalpha and cyclin D1 transcription and induced ubiquitin dependent proteasomal degradation of cyclin D1, leading primarily to G(1)-S-phase cell cycle arrest. By contrast, cyclin D1 degradation was enhanced but its transcription unaffected by TSA in the ERalpha-negative MDA-MB-231 cell line, which arrested in G(2)-M phase. Cyclin D1 degradation involved Skp2/p45, a regulatory component of the Skp1/Cullin/F-box complex; silencing SKP2 gene expression by RNA interference stabilized cyclin D1 and abrogated the cyclin D1 down-regulation response to TSA. CONCLUSIONS: Tamoxifen has been shown to inhibit ERalpha-mediated cyclin D1 transcription, and acquired resistance to tamoxifen is associated with a shift to ERalpha-independent cyclin D1 up-regulation. Taken together, our data show that TSA effectively induces cyclin D1 down-regulation through both ERalpha-dependent and ERalpha-independent mechanisms, providing an important new strategy for combating resistance to antiestrogens.


Asunto(s)
Neoplasias de la Mama/metabolismo , Ciclina D1/metabolismo , Receptor alfa de Estrógeno/metabolismo , Ácidos Hidroxámicos/farmacología , Transcripción Genética/efectos de los fármacos , Neoplasias Uterinas/metabolismo , Antineoplásicos Hormonales/farmacología , Neoplasias de la Mama/patología , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ciclina D1/antagonistas & inhibidores , Ciclina D1/genética , Inhibidores de Cisteína Proteinasa/farmacología , Resistencia a Antineoplásicos , Endopeptidasas/metabolismo , Receptor alfa de Estrógeno/antagonistas & inhibidores , Receptor alfa de Estrógeno/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Inhibidores de Histona Desacetilasas , Humanos , Leupeptinas/farmacología , Interferencia de ARN , Proteínas Quinasas Asociadas a Fase-S/antagonistas & inhibidores , Proteínas Quinasas Asociadas a Fase-S/genética , Tamoxifeno/farmacología , Células Tumorales Cultivadas , Neoplasias Uterinas/patología
20.
Cell Rep ; 12(5): 837-49, 2015 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-26212333

RESUMEN

LMTK3 is an oncogenic receptor tyrosine kinase (RTK) implicated in various types of cancer, including breast, lung, gastric, and colorectal cancer. It is localized in different cellular compartments, but its nuclear function has not been investigated so far. We mapped LMTK3 binding across the genome using ChIP-seq and found that LMTK3 binding events are correlated with repressive chromatin markers. We further identified KRAB-associated protein 1 (KAP1) as a binding partner of LMTK3. The LMTK3/KAP1 interaction is stabilized by PP1α, which suppresses KAP1 phosphorylation specifically at LMTK3-associated chromatin regions, inducing chromatin condensation and resulting in transcriptional repression of LMTK3-bound tumor suppressor-like genes. Furthermore, LMTK3 functions at distal regions in tethering the chromatin to the nuclear periphery, resulting in H3K9me3 modification and gene silencing. In summary, we propose a model where a scaffolding function of nuclear LMTK3 promotes cancer progression through chromatin remodeling.


Asunto(s)
Neoplasias de la Mama/metabolismo , Ensamble y Desensamble de Cromatina , Proteínas de la Membrana/metabolismo , Modelos Biológicos , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Represoras/metabolismo , Proteínas Supresoras de Tumor/biosíntesis , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Femenino , Xenoinjertos , Humanos , Células MCF-7 , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Trasplante de Neoplasias , Proteínas Serina-Treonina Quinasas/genética , Proteínas Represoras/genética , Proteínas Supresoras de Tumor/genética
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