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1.
Cell ; 141(1): 69-80, 2010 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-20371346

RESUMEN

Accumulating evidence implicates heterogeneity within cancer cell populations in the response to stressful exposures, including drug treatments. While modeling the acute response to various anticancer agents in drug-sensitive human tumor cell lines, we consistently detected a small subpopulation of reversibly "drug-tolerant" cells. These cells demonstrate >100-fold reduced drug sensitivity and maintain viability via engagement of IGF-1 receptor signaling and an altered chromatin state that requires the histone demethylase RBP2/KDM5A/Jarid1A. This drug-tolerant phenotype is transiently acquired and relinquished at low frequency by individual cells within the population, implicating the dynamic regulation of phenotypic heterogeneity in drug tolerance. The drug-tolerant subpopulation can be selectively ablated by treatment with IGF-1 receptor inhibitors or chromatin-modifying agents, potentially yielding a therapeutic opportunity. Together, these findings suggest that cancer cell populations employ a dynamic survival strategy in which individual cells transiently assume a reversibly drug-tolerant state to protect the population from eradication by potentially lethal exposures.


Asunto(s)
Resistencia a Antineoplásicos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Línea Celular Tumoral , Cromatina/metabolismo , Cromatina/patología , Daño del ADN , Inhibidores de Histona Desacetilasas/farmacología , Histona Demetilasas/metabolismo , Humanos , Histona Demetilasas con Dominio de Jumonji/antagonistas & inhibidores , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Neoplasias/metabolismo , Receptor IGF Tipo 1/metabolismo
2.
J Proteome Res ; 19(4): 1533-1547, 2020 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-32159963

RESUMEN

Acquisition of drug resistance remains a chief impediment to successful cancer therapy, and we previously described a transient drug-tolerant cancer cell population (DTPs) whose survival is in part dependent on the activities of the histone methyltransferases G9a/EHMT2 and EZH2, the latter being the catalytic component of the polycomb repressive complex 2 (PRC2). Here, we apply multiple proteomic techniques to better understand the role of these histone methyltransferases (HMTs) in the establishment of the DTP state. Proteome-wide comparisons of lysine methylation patterns reveal that DTPs display an increase in methylation on K116 of PRC member Jarid2, an event that helps stabilize and recruit PRC2 to chromatin. We also find that EZH2, in addition to methylating histone H3K27, also can methylate G9a at K185, and that methylated G9a better recruits repressive complexes to chromatin. These complexes are similar to complexes recruited by histone H3 methylated at K9. Finally, a detailed histone post-translational modification (PTM) analysis shows that EZH2, either directly or through its ability to methylate G9a, alters H3K9 methylation in the context of H3 serine 10 phosphorylation, primarily in a cancer cell subpopulation that serves as DTP precursors. We also show that combinations of histone PTMs recruit a different set of complexes to chromatin, shedding light on the temporal mechanisms that contribute to drug tolerance.


Asunto(s)
Neoplasias , Proteómica , Tolerancia a Medicamentos , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Histonas/metabolismo , Metilación , Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismo
3.
Nat Chem Biol ; 12(7): 531-8, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27214401

RESUMEN

The KDM5 family of histone demethylases catalyzes the demethylation of histone H3 on lysine 4 (H3K4) and is required for the survival of drug-tolerant persister cancer cells (DTPs). Here we report the discovery and characterization of the specific KDM5 inhibitor CPI-455. The crystal structure of KDM5A revealed the mechanism of inhibition of CPI-455 as well as the topological arrangements of protein domains that influence substrate binding. CPI-455 mediated KDM5 inhibition, elevated global levels of H3K4 trimethylation (H3K4me3) and decreased the number of DTPs in multiple cancer cell line models treated with standard chemotherapy or targeted agents. These findings show that pretreatment of cancer cells with a KDM5-specific inhibitor results in the ablation of a subpopulation of cancer cells that can serve as the founders for therapeutic relapse.


Asunto(s)
Antineoplásicos/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Proteína 2 de Unión a Retinoblastoma/antagonistas & inhibidores , Antineoplásicos/química , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/química , Humanos , Modelos Moleculares , Estructura Molecular , Proteína 2 de Unión a Retinoblastoma/metabolismo , Relación Estructura-Actividad
4.
Bioorg Med Chem Lett ; 27(13): 2974-2981, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28512031

RESUMEN

A high-throughput screening (HTS) of the Genentech/Roche library identified a novel, uncharged scaffold as a KDM5A inhibitor. Lacking insight into the binding mode, initial attempts to improve inhibitor potency failed to improve potency, and synthesis of analogs was further hampered by the presence of a C-C bond between the pyrrolidine and pyridine. Replacing this with a C-N bond significantly simplified synthesis, yielding pyrazole analog 35, of which we obtained a co-crystal structure with KDM5A. Using structure-based design approach, we identified 50 with improved biochemical, cell potency and reduced MW and lower lipophilicity (LogD) compared with the original hit. Furthermore, 50 showed lower clearance than 9 in mice. In combination with its remarkably low plasma protein binding (PPB) in mice (40%), oral dosing of 50 at 5mg/kg resulted in unbound Cmax ∼2-fold of its cell potency (PC9 H3K4Me3 0.96µM), meeting our criteria for an in vivo tool compound from a new scaffold.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Ensayos Analíticos de Alto Rendimiento , Pirazoles/farmacología , Proteína 2 de Unión a Retinoblastoma/antagonistas & inhibidores , Administración Oral , Animales , Disponibilidad Biológica , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/química , Humanos , Ratones , Microsomas Hepáticos/química , Microsomas Hepáticos/metabolismo , Simulación del Acoplamiento Molecular , Estructura Molecular , Pirazoles/administración & dosificación , Pirazoles/química , Ratas , Proteína 2 de Unión a Retinoblastoma/metabolismo , Relación Estructura-Actividad
5.
Mol Cell Proteomics ; 14(4): 1148-58, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25680960

RESUMEN

Mass spectrometry is a powerful alternative to antibody-based methods for the analysis of histone post-translational modifications (marks). A key development in this approach was the deliberate propionylation of histones to improve sequence coverage across the lysine-rich and hydrophilic tails that bear most modifications. Several marks continue to be problematic however, particularly di- and tri-methylated lysine 4 of histone H3 which we found to be subject to substantial and selective losses during sample preparation and liquid chromatography-mass spectrometry. We developed a new method employing a "one-pot" hybrid chemical derivatization of histones, whereby an initial conversion of free lysines to their propionylated forms under mild aqueous conditions is followed by trypsin digestion and labeling of new peptide N termini with phenyl isocyanate. High resolution mass spectrometry was used to collect qualitative and quantitative data, and a novel web-based software application (Fishtones) was developed for viewing and quantifying histone marks in the resulting data sets. Recoveries of 53 methyl, acetyl, and phosphoryl marks on histone H3.1 were improved by an average of threefold overall, and over 50-fold for H3K4 di- and tri-methyl marks. The power of this workflow for epigenetic research and drug discovery was demonstrated by measuring quantitative changes in H3K4 trimethylation induced by small molecule inhibitors of lysine demethylases and siRNA knockdown of epigenetic modifiers ASH2L and WDR5.


Asunto(s)
Histonas/metabolismo , Espectrometría de Masas/métodos , Procesamiento Proteico-Postraduccional , Coloración y Etiquetado/métodos , Cromatografía Liquida , Técnicas de Silenciamiento del Gen , Células HEK293 , Células HeLa , Histona Demetilasas/metabolismo , Humanos , Lisina/metabolismo , Metilación , Péptidos/metabolismo , Propionatos/metabolismo , ARN Interferente Pequeño/metabolismo , Estándares de Referencia , Tripsina/metabolismo
6.
Bioorg Med Chem Lett ; 26(16): 4036-41, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27406798

RESUMEN

Starting with a lead [1,5-a]pyrimidin-7(4H)-one-containing molecule (1), we generated potent, selective and orally bioavailable KDM5 inhibitors. Using structure- and property-based approaches, we designed 48 with improved cell potency (PC9 H3K4Me3 EC50=0.34µM). Furthermore, 48 maintained suitable physiochemical properties and displayed an excellent pharmacokinetic (PK) profile in mice. When dosed orally in mice at 50mg/kg twice a day (BID), 48 showed an unbound maximal plasma concentration (Cmax) >15-fold over its cell EC50, thereby providing a robust chemical probe for studying KDM5 biological functions in vivo.


Asunto(s)
Pirazoles/química , Pirimidinonas/química , Proteína 2 de Unión a Retinoblastoma/antagonistas & inhibidores , Administración Oral , Animales , Sitios de Unión , Cristalografía por Rayos X , Femenino , Semivida , Histonas/metabolismo , Humanos , Hígado/metabolismo , Ratones , Microsomas Hepáticos/metabolismo , Simulación de Dinámica Molecular , Pirazoles/síntesis química , Pirazoles/farmacocinética , Pirimidinonas/sangre , Pirimidinonas/síntesis química , Pirimidinonas/farmacocinética , Ratas , Proteína 2 de Unión a Retinoblastoma/metabolismo , Relación Estructura-Actividad
7.
Nat Cell Biol ; 9(2): 225-32, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17187060

RESUMEN

The retinoblastoma protein (pRB) negatively regulates the progression from G1 to S phase of the cell cycle, in part, by repressing E2F-dependent transcription. pRB also possesses E2F-independent functions that contribute to cell-cycle control--for example, during pRB-mediated cell-cycle arrest pRB associates with Skp2, the F-box protein of the Skp1-Cullin-F-box protein (SCF) E3 ubiquitin ligase complex, and promotes the stability of the cyclin-dependent kinase-inhibitor p27(Kip1) through an unknown mechanism. Degradation of p27(Kip1) is mediated by ubiquitin-dependent targeting of p27(Kip1) by SCF -Skp2 (ref. 4). Here, we report a novel interaction between pRB and the anaphase-promoting complex/cyclosome (APC/C) that controls p27(Kip1) stability by targeting Skp2 for ubiquitin-mediated degradation. Cdh1, an activator of APC/C, not only interacts with pRB but is also required for a pRB-induced cell-cycle arrest. The results reveal an unexpected physical convergence between the pRB tumour-suppressor protein and E3 ligase complexes, and raise the possibility that pRB may direct APC/C to additional targets during pRB-mediated cell-cycle exit.


Asunto(s)
Anafase , Proteína de Retinoblastoma/metabolismo , Complejos de Ubiquitina-Proteína Ligasa/metabolismo , Ciclosoma-Complejo Promotor de la Anafase , Cadherinas/metabolismo , Ciclo Celular , Línea Celular Tumoral , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Fase G1 , Humanos , Fase S , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Ubiquitina/metabolismo
8.
Cancer Cell ; 10(5): 425-35, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17097564

RESUMEN

"Oncogene addiction" describes an unexplained dependency of cancer cells on a particular cellular pathway for survival or proliferation. We report that differential attenuation rates of prosurvival and proapoptotic signals in oncogene-dependent cells contribute to cell death following oncogene inactivation. Src-, BCR-ABL-, and EGF receptor-dependent cells exhibit a similar profile of signal attenuation following oncogene inactivation characterized by rapid diminution of phospho-ERK, -Akt, and -STAT3/5, and a delayed accumulation of the proapoptotic effector phospho-p38 MAPK. These findings implicate a transient imbalance in survival and apoptotic oncogenic outputs in the apoptotic response to oncogene inactivation. Moreover, these observations implicate a common profile of signal attenuation for multiple oncogenes and suggest that "addiction" associated with apoptosis reflects an active rather than a passive process.


Asunto(s)
Receptores ErbB , Genes abl , Neoplasias/metabolismo , Transducción de Señal/fisiología , Familia-src Quinasas , Animales , Apoptosis/fisiología , Línea Celular Tumoral , Supervivencia Celular , Inhibidores Enzimáticos/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Ratones , Modelos Biológicos , Células 3T3 NIH , Monoéster Fosfórico Hidrolasas/metabolismo , Temperatura , Familia-src Quinasas/genética , Familia-src Quinasas/metabolismo
9.
Cell Rep ; 43(2): 113684, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38261511

RESUMEN

Viral mimicry describes the immune response induced by endogenous stimuli such as double-stranded RNA (dsRNA) from endogenous retroelements. Activation of viral mimicry has the potential to kill cancer cells or augment anti-tumor immune responses. Here, we systematically identify mechanisms of viral mimicry adaptation associated with cancer cell dependencies. Among the top hits is the RNA decay protein XRN1 as an essential gene for the survival of a subset of cancer cell lines. XRN1 dependency is mediated by mitochondrial antiviral signaling protein and protein kinase R activation and is associated with higher levels of cytosolic dsRNA, higher levels of a subset of Alus capable of forming dsRNA, and higher interferon-stimulated gene expression, indicating that cells die due to induction of viral mimicry. Furthermore, dsRNA-inducing drugs such as 5-aza-2'-deoxycytidine and palbociclib can generate a synthetic dependency on XRN1 in cells initially resistant to XRN1 knockout. These results indicate that XRN1 is a promising target for future cancer therapeutics.


Asunto(s)
Neoplasias , Retroelementos , Humanos , Línea Celular , Citosol , Decitabina , Exonucleasas , Neoplasias/genética , ARN Bicatenario , Exorribonucleasas , Proteínas Asociadas a Microtúbulos
10.
Nat Rev Cancer ; 2(12): 910-7, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12459729

RESUMEN

Since its discovery, the retinoblastoma (RB) tumour-suppressor protein has been a focal point of cancer research. Accumulating evidence indicates a complex role for RB in cell proliferation, differentiation and survival. To further complicate matters, proteins that are related to RB have redundant as well as antagonistic functions. Recent studies of knockout mice and cells that lack one or more of these proteins have begun to clarify their various context-specific functions and the unique activity of this tumour suppressor.


Asunto(s)
Genes de Retinoblastoma , Proteínas , Proteína de Retinoblastoma/metabolismo , Retinoblastoma/metabolismo , Animales , División Celular , Humanos , Ratones , Ratones Noqueados , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenotipo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Retinoblastoma/genética , Retinoblastoma/patología , Proteína de Retinoblastoma/genética , Proteína p107 Similar a la del Retinoblastoma , Proteína p130 Similar a la del Retinoblastoma , Transducción de Señal
11.
Adv Cancer Res ; 158: 1-39, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36990531

RESUMEN

The use of chemotherapeutic agents and the development of new cancer therapies over the past few decades has consequently led to the emergence of myriad therapeutic resistance mechanisms. Once thought to be explicitly driven by genetics, the coupling of reversible sensitivity and absence of pre-existing mutations in some tumors opened the way for discovery of drug-tolerant persisters (DTPs): slow-cycling subpopulations of tumor cells that exhibit reversible sensitivity to therapy. These cells confer multi-drug tolerance, to targeted and chemotherapies alike, until the residual disease can establish a stable, drug-resistant state. The DTP state can exploit a multitude of distinct, yet interlaced, mechanisms to survive otherwise lethal drug exposures. Here, we categorize these multi-faceted defense mechanisms into unique Hallmarks of Cancer Drug Tolerance. At the highest level, these are comprised of heterogeneity, signaling plasticity, differentiation, proliferation/metabolism, stress management, genomic integrity, crosstalk with the tumor microenvironment, immune escape, and epigenetic regulatory mechanisms. Of these, epigenetics was both one of the first proposed means of non-genetic resistance and one of the first discovered. As we describe in this review, epigenetic regulatory factors are involved in most facets of DTP biology, positioning this hallmark as an overarching mediator of drug tolerance and a potential avenue to novel therapies.


Asunto(s)
Antineoplásicos , Neoplasias , Humanos , Epigenoma , Resistencia a Antineoplásicos/genética , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/patología , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Tolerancia a Medicamentos , Microambiente Tumoral
12.
Mob DNA ; 14(1): 18, 2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-37990347

RESUMEN

In November 2022 the first Dark Genome Symposium was held in Boston, USA. The meeting was hosted by Rome Therapeutics and Enara Bio, two biotechnology companies working on translating our growing understanding of this vast genetic landscape into therapies for human disease. The spirit and ambition of the meeting was one of shared knowledge, looking to strengthen the network of researchers engaged in the field. The meeting opened with a welcome from Rosana Kapeller and Kevin Pojasek followed by a first session of field defining talks from key academics in the space. A series of panels, bringing together academia and industry views, were then convened covering a wide range of pertinent topics. Finally, Richard Young and David Ting gave their views on the future direction and promise for patient impact inherent in the growing understanding of the Dark Genome.

13.
Front Cell Dev Biol ; 10: 826461, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35602594

RESUMEN

Despite advancements in understanding cancer pathogenesis and the development of many effective therapeutic agents, resistance to drug treatment remains a widespread challenge that substantially limits curative outcomes. The historical focus on genetic evolution under drug "pressure" as a key driver of resistance has uncovered numerous mechanisms of therapeutic value, especially with respect to acquired resistance. However, recent discoveries have also revealed a potential role for an ancient evolutionary balance between endogenous "viral" elements in the human genome and diverse factors involved in their restriction in tumor evolution and drug resistance. It has long been appreciated that the stability of genomic repeats such as telomeres and centromeres affect tumor fitness, but recent findings suggest that de-regulation of other repetitive genome elements, including retrotransposons, might also be exploited as cancer therapy. This review aims to present an overview of these recent findings.

14.
J Exp Med ; 202(1): 157-68, 2005 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-15998794

RESUMEN

Cyclin-dependent kinase inhibitors (CKIs) and Notch receptor activation have been shown to influence adult stem cells and progenitors by altering stem cell self-renewal and proliferation. Yet, no interaction between these molecular pathways has been defined. Here we show that ligand-independent and ligand-dependent activation of Notch1 induces transcription of the S phase kinase-associated protein 2 (SKP2), the F-box subunit of the ubiquitin-ligase complex SCF(SKP2) that targets proteins for degradation. Up-regulation of SKP2 by Notch signaling enhances proteasome-mediated degradation of the CKIs, p27 Kip1 and p21 Cip1, and causes premature entry into S phase. Silencing of SKP2 by RNA interference in G1 stabilizes p27 Kip1 and p21 Cip1 and abolishes Notch effect on G1-S progression. Thus, SKP2 serves to link Notch1 activation with the cell cycle machinery. This novel pathway involving Notch/SKP2/CKIs connects a cell surface receptor with proximate mediators of cell cycle activity, and suggests a mechanism by which a known physiologic mediator of cell fate determination interfaces with cell cycle control.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Fase G1/fisiología , Receptores de Superficie Celular/metabolismo , Fase S/fisiología , Proteínas Quinasas Asociadas a Fase-S/genética , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Células 3T3 , Animales , Secuencia de Bases , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , ADN/genética , Humanos , Ratones , Ratones Noqueados , Ratones Transgénicos , Modelos Biológicos , Interferencia de ARN , Receptor Notch1 , Transcripción Genética , Ubiquitina/metabolismo
15.
Dev Cell ; 2(5): 553-65, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12015964

RESUMEN

Rho GTPases regulate several aspects of tissue morphogenesis during animal development. We found that mice lacking the Rho-inhibitory protein, p190-B RhoGAP, are 30% reduced in size and exhibit developmental defects strikingly similar to those seen in mice lacking the CREB transcription factor. In p190-B RhoGAP-deficient mice, CREB phosphorylation is substantially reduced in embryonic tissues. Embryo-derived cells contain abnormally high levels of active Rho protein, are reduced in size, and exhibit defects in CREB activation upon exposure to insulin or IGF-1. The cell size defect is rescued by expression of constitutively activated CREB, and in wild-type cells, expression of activated Rho or dominant-negative CREB results in reduced cell size. Together, these results suggest that activity of the Rho GTPase modulates a signal from insulin/IGFs to CREB that determines cell size and animal size during embryogenesis.


Asunto(s)
Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Animales , Constitución Corporal , Tamaño de la Célula , Proteínas de Unión al ADN , Desarrollo Embrionario y Fetal , Proteínas Activadoras de GTPasa , Factores de Intercambio de Guanina Nucleótido/deficiencia , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Insulina/metabolismo , Proteínas Sustrato del Receptor de Insulina , Ratones , Ratones Noqueados , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Modelos Biológicos , Proteínas Nucleares/deficiencia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenotipo , Fosfoproteínas/metabolismo , Fosforilación , Proteínas Represoras , Transducción de Señal
16.
Mol Cell Biol ; 26(4): 1170-82, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16449633

RESUMEN

Most human cancers involve either mutational activation of the Ras oncogenic pathway and/or inactivation of the retinoblastoma tumor suppressor (RB) pathway. Paradoxically, tumors that harbor Ras mutations almost invariably retain expression of a wild-type pRB protein. We explain this phenomenon by demonstrating that Ras-induced oncogenic transformation surprisingly depends on functional pRB protein. Cells lacking pRB are less susceptible to the oncogenic actions of H-RasV12 than wild-type cells and activated Ras has an inhibitory effect on the proliferation of pRB-deficient human tumor cells. In addition, depletion of pRB from Ras-transformed murine cells or human tumor cells that harbor Ras pathway mutations inhibits their proliferation and anchorage-independent growth. In sharp contrast to pRB-/- 3T3 cells, fibroblasts deficient in other pRB family members (p107 and p130) are more susceptible to Ras-mediated transformation than wild-type 3T3 cells. Moreover, loss of pRB in tumor cells harboring a Ras mutation results in increased expression of p107, and overexpression of p107 but not pRB strongly inhibits proliferation of these tumor cells. Together, these findings suggest that pRB and p107 have distinct roles in Ras-mediated transformation and suggest a novel tumor-suppressive role for p107 in the context of activated Ras.


Asunto(s)
Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Genes ras , Proteína de Retinoblastoma/metabolismo , Células 3T3 , Animales , Secuencia de Bases , Línea Celular Tumoral , Proliferación Celular , Transformación Celular Neoplásica/patología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Genes de Retinoblastoma , Humanos , Ratones , Ratones Noqueados , Modelos Biológicos , Neoplasias/etiología , Neoplasias/genética , Neoplasias/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/genética , Proteína de Retinoblastoma/deficiencia , Proteína p107 Similar a la del Retinoblastoma/deficiencia , Proteína p107 Similar a la del Retinoblastoma/genética , Proteína p130 Similar a la del Retinoblastoma/deficiencia , Proteína p130 Similar a la del Retinoblastoma/genética
17.
Mol Cancer Ther ; 7(11): 3575-85, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19001440

RESUMEN

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively kills tumor cells. However, its short half-life, poor delivery, and TRAIL-resistant tumor cells have diminished its clinical efficacy. In this study, we explored whether novel delivery methods will represent new and effective ways to treat gliomas and if adjuvant therapy with the chemotherapeutic agent temozolomide would enhance the cytotoxic properties of TRAIL in glioma lines resistant to TRAIL monotherapy. We have engineered adeno-associated virus (AAV) vectors encoding recombinant secreted TRAIL (S-TRAIL) and bioluminescent-fluorescent marker fusion proteins and show that AAV-delivered S-TRAIL leads to varying degrees of killing in multiple glioma lines, which correspond with caspase-3/7 activation. In vivo, dual bioluminescent imaging revealed efficient delivery of therapeutic AAV vectors directly into the tumor mass, which induced marked attenuation of tumor progression. Treatment of glioma cells with the chemotherapeutic agent temozolomide alone lead to a significant accumulation of cells in G(2)-M phase, activated the cell cycle checkpoint protein Chk1, and increased death receptor expression in a time-dependent manner. Furthermore, combined treatment with AAV-S-TRAIL or neural stem cell-S-TRAIL and temozolomide induced cell killing and markedly up-regulated proapoptotic proteins in glioma cells least sensitive to TRAIL. This study elucidates novel means of delivering S-TRAIL to gliomas and suggests combination of clinically relevant temozolomide and S-TRAIL may represent a new therapeutic option with increased potency for glioblastoma patients.


Asunto(s)
Antineoplásicos Alquilantes/uso terapéutico , Dacarbazina/análogos & derivados , Glioma/terapia , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Antineoplásicos Alquilantes/administración & dosificación , Línea Celular Tumoral , Dacarbazina/uso terapéutico , Dependovirus/genética , Terapia Genética/métodos , Vectores Genéticos/administración & dosificación , Glioma/tratamiento farmacológico , Glioma/metabolismo , Humanos , Microscopía Fluorescente , Transducción de Señal , Trasplante de Células Madre , Células Madre/citología , Células Madre/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Temozolomida , Ensayos Antitumor por Modelo de Xenoinjerto
18.
Trends Cancer ; 4(8): 583-597, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30064665

RESUMEN

Nearly half of the human genome is comprised of repetitive elements that are tightly regulated to protect the host genome from deleterious consequences associated with their inappropriate activation. Cancer cells often misexpress these elements, in part, due to decreases in DNA methylation. Recent discoveries suggest that tumor suppressor proteins contribute to repression of repetitive elements, and their functional inactivation promotes repeat element misexpression during carcinogenesis. Recent findings also suggest that increased expression of repetitive elements beyond a threshold of tolerance can augment cancer therapy responses. Such advances, reviewed here, paint a picture in which deregulated expression of repetitive genome elements not only contributes to the development of cancer but may also provide a tumor-specific Achilles heel for cancer treatment.


Asunto(s)
Antígenos de Neoplasias/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias/genética , Retroelementos , Regulación del Desarrollo de la Expresión Génica , Silenciador del Gen , Heterocromatina/genética , Heterocromatina/metabolismo , Humanos
19.
Cancer Res ; 78(5): 1127-1139, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29282222

RESUMEN

The H3K4 demethylase KDM5B is amplified and overexpressed in luminal breast cancer, suggesting it might constitute a potential cancer therapy target. Here, we characterize, in breast cancer cells, the molecular effects of a recently developed small-molecule inhibitor of the KDM5 family of proteins (KDM5i), either alone or in combination with the DNA-demethylating agent 5-aza-2'-deoxycytidine (DAC). KDM5i treatment alone increased expression of a small number of genes, whereas combined treatment with DAC enhanced the effects of the latter for increasing expression of hundreds of DAC-responsive genes. ChIP-seq studies revealed that KDM5i resulted in the broadening of existing H3K4me3 peaks. Furthermore, cells treated with the drug combination exhibited increased promoter and gene body H3K4me3 occupancy at DAC-responsive genes compared with DAC alone. Importantly, treatment with either DAC or DAC+KDM5i induced a dramatic increase in H3K27ac at enhancers with an associated significant increase in target gene expression, suggesting a previously unappreciated effect of DAC on transcriptional regulation. KDM5i synergized with DAC to reduce the viability of luminal breast cancer cells in in vitro assays. Our study provides the first look into the molecular effects of a novel KDM5i compound and suggests that combinatorial inhibition along with DAC represents a new area to explore in translational epigenetics.Significance: This study offers a first look into the molecular effects of a novel KDM5 inhibitory compound, suggesting how its use in combination with DNA methylation inhibitors presents new opportunities to explore in translational cancer epigenetics. Cancer Res; 78(5); 1127-39. ©2017 AACR.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Metilación de ADN , Decitabina/farmacología , Inhibidores Enzimáticos/farmacología , Genoma Humano , Histonas/química , Histona Demetilasas con Dominio de Jumonji/antagonistas & inhibidores , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Represoras/antagonistas & inhibidores , Apoptosis , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/patología , Proliferación Celular , Epigénesis Genética , Femenino , Ensayos Analíticos de Alto Rendimiento , Humanos , Histona Demetilasas con Dominio de Jumonji/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Represoras/metabolismo , Células Tumorales Cultivadas
20.
J Cell Biol ; 217(2): 763-777, 2018 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-29229751

RESUMEN

Epithelial-to-mesenchymal transition is implicated in metastasis, where carcinoma cells lose sessile epithelial traits and acquire mesenchymal migratory potential. The mesenchymal state is also associated with cancer stem cells and resistance to chemotherapy. It might therefore be therapeutically beneficial to promote epithelial identity in cancer. Because large-scale cell identity shifts are often orchestrated on an epigenetic level, we screened for candidate epigenetic factors and identified the histone methyltransferase SUV420H2 (KMT5C) as favoring the mesenchymal identity in pancreatic cancer cell lines. Through its repressive mark H4K20me3, SUV420H2 silences several key drivers of the epithelial state. Its knockdown elicited mesenchymal-to-epithelial transition on a molecular and functional level, and cells displayed decreased stemness and increased drug sensitivity. An analysis of human pancreatic cancer biopsies was concordant with these findings, because high levels of SUV420H2 correlated with a loss of epithelial characteristics in progressively invasive cancer. Together, these data indicate that SUV420H2 is an upstream epigenetic regulator of epithelial/mesenchymal state control.


Asunto(s)
Transición Epitelial-Mesenquimal , N-Metiltransferasa de Histona-Lisina/metabolismo , Neoplasias Pancreáticas/metabolismo , Línea Celular Tumoral , Epigénesis Genética/genética , Regulación Neoplásica de la Expresión Génica/genética , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología
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