Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Immunol ; 211(6): 981-993, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37493438

RESUMO

Current vaccine efforts to combat SARS-CoV-2 are focused on the whole spike protein administered as mRNA, viral vector, or protein subunit. However, the SARS-CoV-2 receptor-binding domain (RBD) is the immunodominant portion of the spike protein, accounting for 90% of serum neutralizing activity. In this study, we constructed several versions of RBD and together with aluminum hydroxide or DDA (dimethyldioctadecylammonium bromide)/TDB (d-(+)-trehalose 6,6'-dibehenate) adjuvant evaluated immunogenicity in mice. We generated human angiotensin-converting enzyme 2 knock-in mice to evaluate vaccine efficacy in vivo following viral challenge. We found that 1) subdomain (SD)1 was essential for the RBD to elicit maximal immunogenicity; 2) RBDSD1 produced in mammalian HEK cells elicited better immunogenicity than did protein produced in insect or yeast cells; 3) RBDSD1 combined with the CD4 Th1 adjuvant DDA/TDB produced higher neutralizing Ab responses and stronger CD4 T cell responses than did aluminum hydroxide; 4) addition of monomeric human Fc receptor to RBDSD1 (RBDSD1Fc) significantly enhanced immunogenicity and neutralizing Ab titers; 5) the Beta version of RBDSD1Fc provided a broad range of cross-neutralization to multiple antigenic variants of concern, including Omicron; and 6) the Beta version of RBDSD1Fc with DDA/TDB provided complete protection against virus challenge in the knock-in mouse model. Thus, we have identified an optimized RBD-based subunit vaccine suitable for clinical trials.


Assuntos
COVID-19 , Vacinas Virais , Humanos , Animais , Camundongos , SARS-CoV-2 , Vacinas contra COVID-19 , Hidróxido de Alumínio , Glicoproteína da Espícula de Coronavírus , Vacinas de Subunidades Antigênicas , Anticorpos Antivirais , Anticorpos Neutralizantes , Mamíferos
2.
Mol Cancer Ther ; 22(2): 192-204, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36722142

RESUMO

Aberrant cell-cycle progression is characteristic of melanoma, and CDK4/6 inhibitors, such as palbociclib, are currently being tested for efficacy in this disease. Despite the promising nature of CDK4/6 inhibitors, their use as single agents in melanoma has shown limited clinical benefit. Herein, we discovered that treatment of tumor cells with palbociclib induces the phosphorylation of the mRNA translation initiation factor eIF4E. When phosphorylated, eIF4E specifically engenders the translation of mRNAs that code for proteins involved in cell survival. We hypothesized that cancer cells treated with palbociclib use upregulated phosphorylated eIF4E (phospho-eIF4E) to escape the antitumor benefits of this drug. Indeed, we found that pharmacologic or genetic disruption of MNK1/2 activity, the only known kinases for eIF4E, enhanced the ability of palbociclib to decrease clonogenic outgrowth. Moreover, a quantitative proteomics analysis of melanoma cells treated with combined MNK1/2 and CDK4/6 inhibitors showed downregulation of proteins with critical roles in cell-cycle progression and mitosis, including AURKB, TPX2, and survivin. We also observed that palbociclib-resistant breast cancer cells have higher basal levels of phospho-eIF4E, and that treatment with MNK1/2 inhibitors sensitized these palbociclib-resistant cells to CDK4/6 inhibition. In vivo we demonstrate that the combination of MNK1/2 and CDK4/6 inhibition significantly increases the overall survival of mice compared with either monotherapy. Overall, our data support MNK1/2 inhibitors as promising drugs to potentiate the antineoplastic effects of palbociclib and overcome therapy-resistant disease.


Assuntos
Neoplasias da Mama , Melanoma , Inibidores de Proteínas Quinases , Animais , Camundongos , Fator de Iniciação 4E em Eucariotos , Melanoma/tratamento farmacológico , Piperazinas/farmacologia , Piridinas/farmacologia , Neoplasias da Mama/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Antineoplásicos/farmacologia
3.
Nat Commun ; 13(1): 6323, 2022 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-36280687

RESUMO

Statins, a family of FDA-approved cholesterol-lowering drugs that inhibit the rate-limiting enzyme of the mevalonate metabolic pathway, have demonstrated anticancer activity. Evidence shows that dipyridamole potentiates statin-induced cancer cell death by blocking a restorative feedback loop triggered by statin treatment. Leveraging this knowledge, we develop an integrative pharmacogenomics pipeline to identify compounds similar to dipyridamole at the level of drug structure, cell sensitivity and molecular perturbation. To overcome the complex polypharmacology of dipyridamole, we focus our pharmacogenomics pipeline on mevalonate pathway genes, which we name mevalonate drug-network fusion (MVA-DNF). We validate top-ranked compounds, nelfinavir and honokiol, and identify that low expression of the canonical epithelial cell marker, E-cadherin, is associated with statin-compound synergy. Analysis of remaining prioritized hits led to the validation of additional compounds, clotrimazole and vemurafenib. Thus, our computational pharmacogenomic approach identifies actionable compounds with pathway-specific activities.


Assuntos
Neoplasias da Mama , Inibidores de Hidroximetilglutaril-CoA Redutases , Humanos , Feminino , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Ácido Mevalônico/metabolismo , Farmacogenética , Vemurafenib/uso terapêutico , Nelfinavir/uso terapêutico , Clotrimazol/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Caderinas , Colesterol , Dipiridamol
4.
Sci Adv ; 8(36): eabq4293, 2022 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-36070391

RESUMO

Inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6i) are standard first-line treatments for metastatic ER+ breast cancer. However, acquired resistance to CDK4/6i invariably develops, and the molecular phenotypes and exploitable vulnerabilities associated with resistance are not yet fully characterized. We developed a panel of CDK4/6i-resistant breast cancer cell lines and patient-derived organoids and demonstrate that a subset of resistant models accumulates mitotic segregation errors and micronuclei, displaying increased sensitivity to inhibitors of mitotic checkpoint regulators TTK and Aurora kinase A/B. RB1 loss, a well-recognized mechanism of CDK4/6i resistance, causes such mitotic defects and confers enhanced sensitivity to TTK inhibition. In these models, inhibition of TTK with CFI-402257 induces premature chromosome segregation, leading to excessive mitotic segregation errors, DNA damage, and cell death. These findings nominate the TTK inhibitor CFI-402257 as a therapeutic strategy for a defined subset of ER+ breast cancer patients who develop resistance to CDK4/6i.


Assuntos
Pontos de Checagem da Fase M do Ciclo Celular , Neoplasias , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética
5.
Mol Cancer Ther ; 18(10): 1775-1786, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31358662

RESUMO

The spindle assembly checkpoint maintains genomic integrity. A key component is tyrosine threonine kinase (TTK, also known as Mps1). TTK antagonism is hypothesized to cause genomic instability and cell death. Interrogating The Cancer Genome Atlas revealed high TTK expression in lung adenocarcinomas and squamous cell cancers versus the normal lung (P < 0.001). This correlated with an unfavorable prognosis in examined lung adenocarcinoma cases (P = 0.007). TTK expression profiles in lung tumors were independently assessed by RNA in situ hybridization. CFI-402257 is a highly selective TTK inhibitor. Its potent antineoplastic effects are reported here against a panel of well-characterized murine and human lung cancer cell lines. Significant antitumorigenic activity followed independent treatments of athymic mice bearing human lung cancer xenografts (6.5 mg/kg, P < 0.05; 8.5 mg/kg, P < 0.01) and immunocompetent mice with syngeneic lung cancers (P < 0.001). CFI-402257 antineoplastic mechanisms were explored. CFI-402257 triggered aneuploidy and apoptotic death of lung cancer cells without changing centrosome number. Reverse phase protein arrays (RPPA) of vehicle versus CFI-402257-treated lung cancers were examined using more than 300 critical growth-regulatory proteins. RPPA bioinformatic analyses discovered CFI-402257 enhanced MAPK signaling, implicating MAPK antagonism in augmenting TTK inhibitory effects. This was independently confirmed using genetic and pharmacologic repression of MAPK that promoted CFI-402257 anticancer actions. TTK antagonism exerted marked antineoplastic effects against lung cancers and MAPK inhibition cooperated. Future work should determine whether CFI-402257 treatment alone or with a MAPK inhibitor is active in the lung cancer clinic.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Poliploidia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Anáfase/efeitos dos fármacos , Animais , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Centrossomo/efeitos dos fármacos , Centrossomo/metabolismo , Humanos , Camundongos , Proteínas Tirosina Quinases/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia
6.
Proc Natl Acad Sci U S A ; 116(10): 4326-4335, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30770442

RESUMO

The combination of immune checkpoint blockade with chemotherapy is currently under investigation as a promising strategy for the treatment of triple negative breast cancer (TNBC). Tumor-associated macrophages (TAMs) are the most prominent component of the breast cancer microenvironment because they influence tumor progression and the response to therapies. Here we show that macrophages acquire an immunosuppressive phenotype and increase the expression of programmed death ligand-1 (PD-L1) when treated with reactive oxygen species (ROS) inducers such as the glutathione synthesis inhibitor, buthionine sulphoximine (BSO), and paclitaxel. Mechanistically, these agents cause accumulation of ROS that in turn activate NF-κB signaling to promote PD-L1 transcription and the release of immunosuppressive chemokines. Systemic in vivo administration of paclitaxel promotes PD-L1 accumulation on the surface of TAMS in a mouse model of TNBC, consistent with in vitro results. Combinatorial treatment with paclitaxel and an anti-mouse PD-L1 blocking antibody significantly improved the therapeutic efficacy of paclitaxel by reducing tumor burden and increasing the number of tumor-associated cytotoxic T cells. Our results provide a strong rationale for the use of anti-PD-L1 blockade in the treatment of TNBC patients. Furthermore, interrogation of chemotherapy-induced PD-L1 expression in TAMs is warranted to define appropriate patient selection in the use of PD-L1 blockade.


Assuntos
Antígeno B7-H1/metabolismo , Imunossupressores/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/farmacologia , Animais , Antígeno B7-H1/genética , Neoplasias da Mama/metabolismo , Butionina Sulfoximina/farmacologia , Linhagem Celular Tumoral , Quimiocinas , Tratamento Farmacológico , Feminino , Glutationa/metabolismo , Humanos , Camundongos , Paclitaxel/farmacologia , Fenótipo , RNA Mensageiro/metabolismo , Neoplasias de Mama Triplo Negativas , Microambiente Tumoral , Regulação para Cima
7.
Proc Natl Acad Sci U S A ; 116(9): 3604-3613, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30733286

RESUMO

Cancer cells have higher reactive oxygen species (ROS) than normal cells, due to genetic and metabolic alterations. An emerging scenario is that cancer cells increase ROS to activate protumorigenic signaling while activating antioxidant pathways to maintain redox homeostasis. Here we show that, in basal-like and BRCA1-related breast cancer (BC), ROS levels correlate with the expression and activity of the transcription factor aryl hydrocarbon receptor (AhR). Mechanistically, ROS triggers AhR nuclear accumulation and activation to promote the transcription of both antioxidant enzymes and the epidermal growth factor receptor (EGFR) ligand, amphiregulin (AREG). In a mouse model of BRCA1-related BC, cancer-associated AhR and AREG control tumor growth and production of chemokines to attract monocytes and activate proangiogenic function of macrophages in the tumor microenvironment. Interestingly, the expression of these chemokines as well as infiltration of monocyte-lineage cells (monocyte and macrophages) positively correlated with ROS levels in basal-like BC. These data support the existence of a coordinated link between cancer-intrinsic ROS regulation and the features of tumor microenvironment. Therapeutically, chemical inhibition of AhR activity sensitizes human BC models to Erlotinib, a selective EGFR tyrosine kinase inhibitor, suggesting a promising combinatorial anticancer effect of AhR and EGFR pathway inhibition. Thus, AhR represents an attractive target to inhibit redox homeostasis and modulate the tumor promoting microenvironment of basal-like and BRCA1-associated BC.


Assuntos
Anfirregulina/genética , Proteína BRCA1/genética , Neoplasias da Mama/genética , Receptores de Hidrocarboneto Arílico/genética , Adulto , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Receptores ErbB/genética , Cloridrato de Erlotinib/administração & dosagem , Feminino , Regulação Neoplásica da Expressão Gênica , Homeostase/genética , Humanos , Camundongos , Pessoa de Meia-Idade , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Microambiente Tumoral/genética
9.
Sci Rep ; 8(1): 16562, 2018 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-30410118

RESUMO

Previous research has suggested that thyroid hormone receptor alpha 1 (THRα1), a hormone responsive splice variant, may play a role in breast cancer progression. Whether THRα1 can be exploited for anti-cancer therapy is unknown. The antiproliferative and antitumor effects of dronedarone, an FDA-approved anti-arrhythmic drug which has been shown to antagonize THRα1, was evaluated in breast cancer cell lines in vitro and in vivo. The THRα1 splice variant and the entire receptor, THRα, were also independently targeted using siRNA to determine the effect of target knockdown in vitro. In our study, dronedarone demonstrates cytotoxic effects in vitro and in vivo in breast cancer cell lines at doses and concentrations that may be clinically relevant. However, knockdown of either THRα1 or THRα did not cause substantial anti-proliferative or cytotoxic effects in vitro, nor did it alter the sensitivity to dronedarone. Thus, we conclude that dronedarone's cytotoxic effect in breast cancer cell lines are independent of THRα or THRα1 antagonism. Further, the depletion of THRα or THRα1 does not affect cell viability or proliferation. Characterizing the mechanism of dronedarone's anti-tumor action may facilitate drug repurposing or the development of new anti-cancer agents.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Dronedarona/administração & dosagem , Receptores alfa dos Hormônios Tireóideos/genética , Animais , Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dronedarona/farmacologia , Reposicionamento de Medicamentos , Feminino , Humanos , Camundongos , RNA Interferente Pequeno/farmacologia , Receptores alfa dos Hormônios Tireóideos/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Proc Natl Acad Sci U S A ; 115(8): 1913-1918, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29434041

RESUMO

Polo-like kinase 4 (PLK4) is a serine/threonine kinase regulating centriole duplication. CFI-400945 is a highly selective PLK4 inhibitor that deregulates centriole duplication, causing mitotic defects and death of aneuploid cancers. Prior work was substantially extended by showing CFI-400945 causes polyploidy, growth inhibition, and apoptotic death of murine and human lung cancer cells, despite expression of mutated KRAS or p53. Analysis of DNA content by propidium iodide (PI) staining revealed cells with >4N DNA content (polyploidy) markedly increased after CFI-400945 treatment. Centrosome numbers and mitotic spindles were scored. CFI-400945 treatment produced supernumerary centrosomes and mitotic defects in lung cancer cells. In vivo antineoplastic activity of CFI-400945 was established in mice with syngeneic lung cancer xenografts. Lung tumor growth was significantly inhibited at well-tolerated dosages. Phosphohistone H3 staining of resected lung cancers following CFI-400945 treatment confirmed the presence of aberrant mitosis. PLK4 expression profiles in human lung cancers were explored using The Cancer Genome Atlas (TCGA) and RNA in situ hybridization (RNA ISH) of microarrays containing normal and malignant lung tissues. PLK4 expression was significantly higher in the malignant versus normal lung and conferred an unfavorable survival (P < 0.05). Intriguingly, cyclin dependent kinase 2 (CDK2) antagonism cooperated with PLK4 inhibition. Taken together, PLK4 inhibition alone or as part of a combination regimen is a promising way to combat lung cancer.


Assuntos
Apoptose/efeitos dos fármacos , Indazóis/farmacologia , Indóis/farmacologia , Poliploidia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Centrossomo , Regulação Neoplásica da Expressão Gênica , Humanos , Indazóis/uso terapêutico , Indóis/uso terapêutico , Camundongos , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo
11.
Nat Commun ; 9(1): 166, 2018 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-29317617

RESUMO

In the original version of this Article, financial support was not fully acknowledged. This error has now been corrected in both the PDF and HTML versions of the Article.

12.
Nat Commun ; 8(1): 1126, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29066719

RESUMO

Next-generation sequencing technologies have recently been used in pharmacogenomic studies to characterize large panels of cancer cell lines at the genomic and transcriptomic levels. Among these technologies, RNA-sequencing enable profiling of alternatively spliced transcripts. Given the high frequency of mRNA splicing in cancers, linking this feature to drug response will open new avenues of research in biomarker discovery. To identify robust transcriptomic biomarkers for drug response across studies, we develop a meta-analytical framework combining the pharmacological data from two large-scale drug screening datasets. We use an independent pan-cancer pharmacogenomic dataset to test the robustness of our candidate biomarkers across multiple cancer types. We further analyze two independent breast cancer datasets and find that specific isoforms of IGF2BP2, NECTIN4, ITGB6, and KLHDC9 are significantly associated with AZD6244, lapatinib, erlotinib, and paclitaxel, respectively. Our results support isoform expressions as a rich resource for biomarkers predictive of drug response.


Assuntos
Biomarcadores/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Neoplasias/tratamento farmacológico , Neoplasias/genética , Farmacogenética , Isoformas de Proteínas/genética , Processamento Alternativo , Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , Neoplasias da Mama/genética , Proteínas de Transporte/genética , Moléculas de Adesão Celular/genética , Química Farmacêutica , Cloridrato de Erlotinib/farmacologia , Genoma Humano , Humanos , Cadeias beta de Integrinas/genética , Lapatinib , Paclitaxel/farmacologia , Quinazolinas/farmacologia , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Análise de Sequência de RNA , Transcriptoma
13.
Nat Commun ; 8: 14432, 2017 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-28211448

RESUMO

G-quadruplex DNAs form four-stranded helical structures and are proposed to play key roles in different cellular processes. Targeting G-quadruplex DNAs for cancer treatment is a very promising prospect. Here, we show that CX-5461 is a G-quadruplex stabilizer, with specific toxicity against BRCA deficiencies in cancer cells and polyclonal patient-derived xenograft models, including tumours resistant to PARP inhibition. Exposure to CX-5461, and its related drug CX-3543, blocks replication forks and induces ssDNA gaps or breaks. The BRCA and NHEJ pathways are required for the repair of CX-5461 and CX-3543-induced DNA damage and failure to do so leads to lethality. These data strengthen the concept of G4 targeting as a therapeutic approach, specifically for targeting HR and NHEJ deficient cancers and other tumours deficient for DNA damage repair. CX-5461 is now in advanced phase I clinical trial for patients with BRCA1/2 deficient tumours (Canadian trial, NCT02719977, opened May 2016).


Assuntos
Proteína BRCA1/deficiência , Proteína BRCA2/deficiência , Benzotiazóis/farmacologia , Benzotiazóis/uso terapêutico , Quadruplex G , Naftiridinas/farmacologia , Naftiridinas/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Sequência de Bases , Benzoxazinas/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Linhagem Celular Tumoral , Instabilidade Cromossômica/genética , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA Ribossômico/genética , Feminino , Quadruplex G/efeitos dos fármacos , Genoma Humano , Genótipo , Recombinação Homóloga/efeitos dos fármacos , Humanos , Camundongos , Quinolonas/farmacologia , Saccharomyces cerevisiae/metabolismo , Transcrição Gênica/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Nat Genet ; 48(10): 1260-6, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27571262

RESUMO

Sustained expression of the estrogen receptor-α (ESR1) drives two-thirds of breast cancer and defines the ESR1-positive subtype. ESR1 engages enhancers upon estrogen stimulation to establish an oncogenic expression program. Somatic copy number alterations involving the ESR1 gene occur in approximately 1% of ESR1-positive breast cancers, suggesting that other mechanisms underlie the persistent expression of ESR1. We report significant enrichment of somatic mutations within the set of regulatory elements (SRE) regulating ESR1 in 7% of ESR1-positive breast cancers. These mutations regulate ESR1 expression by modulating transcription factor binding to the DNA. The SRE includes a recurrently mutated enhancer whose activity is also affected by rs9383590, a functional inherited single-nucleotide variant (SNV) that accounts for several breast cancer risk-associated loci. Our work highlights the importance of considering the combinatorial activity of regulatory elements as a single unit to delineate the impact of noncoding genetic alterations on single genes in cancer.


Assuntos
Neoplasias da Mama/genética , Receptor alfa de Estrogênio/genética , Mutação , Polimorfismo de Nucleotídeo Único , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Sequências Reguladoras de Ácido Nucleico , Fatores de Transcrição/metabolismo
15.
Cell Stem Cell ; 19(2): 205-216, 2016 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-27184401

RESUMO

The E3 ubiquitin ligase Mule is often overexpressed in human colorectal cancers, but its role in gut tumorigenesis is unknown. Here, we show in vivo that Mule controls murine intestinal stem and progenitor cell proliferation by modulating Wnt signaling via c-Myc. Mule also regulates protein levels of the receptor tyrosine kinase EphB3 by targeting it for proteasomal and lysosomal degradation. In the intestine, EphB/ephrinB interactions position cells along the crypt-villus axis and compartmentalize incipient colorectal tumors. Our study thus unveils an important new avenue by which Mule acts as an intestinal tumor suppressor by regulation of the intestinal stem cell niche.


Assuntos
Efrina-B3/metabolismo , Intestinos/citologia , Lisossomos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Nicho de Células-Tronco , Ubiquitina-Proteína Ligases/metabolismo , Via de Sinalização Wnt , Polipose Adenomatosa do Colo/patologia , Alelos , Animais , Carcinogênese/metabolismo , Carcinogênese/patologia , Proliferação de Células , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Endocitose , Células HEK293 , Humanos , Camundongos Knockout , Modelos Biológicos , Mutação/genética , Celulas de Paneth/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Supressoras de Tumor , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/deficiência
16.
Mol Cell ; 53(6): 904-15, 2014 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-24656129

RESUMO

Little is known about how mammalian cells maintain cell size homeostasis. We conducted a novel genetic screen to identify cell-size-controlling genes and isolated Largen, the product of a gene (PRR16) that increased cell size upon overexpression in human cells. In vitro evidence indicated that Largen preferentially stimulates the translation of specific subsets of mRNAs, including those encoding proteins affecting mitochondrial functions. The involvement of Largen in mitochondrial respiration was consistent with the increased mitochondrial mass and greater ATP production in Largen-overexpressing cells. Furthermore, Largen overexpression led to increased cell size in vivo, as revealed by analyses of conditional Largen transgenic mice. Our results establish Largen as an important link between mRNA translation, mitochondrial functions, and the control of mammalian cell size.


Assuntos
Tamanho Celular/efeitos dos fármacos , Regulação da Expressão Gênica , Biossíntese de Proteínas , Proteínas/genética , RNA Mensageiro/genética , Animais , Linhagem Celular Tumoral , Escherichia coli/genética , Escherichia coli/metabolismo , Vetores Genéticos , Ensaios de Triagem em Larga Escala , Humanos , Células Jurkat , Camundongos , Camundongos Transgênicos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas/metabolismo , RNA Mensageiro/metabolismo , Retroviridae/genética , Retroviridae/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia
17.
Proc Natl Acad Sci U S A ; 111(5): 1843-8, 2014 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-24449892

RESUMO

The generation of viable sperm proceeds through a series of coordinated steps, including germ cell self-renewal, meiotic recombination, and terminal differentiation into functional spermatozoa. The p53 family of transcription factors, including p53, p63, and p73, are critical for many physiological processes, including female fertility, but little is known about their functions in spermatogenesis. Here, we report that deficiency of the TAp73 isoform, but not p53 or ΔNp73, results in male infertility because of severe impairment of spermatogenesis. Mice lacking TAp73 exhibited increased DNA damage and cell death in spermatogonia, disorganized apical ectoplasmic specialization, malformed spermatids, and marked hyperspermia. We demonstrated that TAp73 regulates the mRNA levels of crucial genes involved in germ stem/progenitor cells (CDKN2B), spermatid maturation/spermiogenesis (metalloproteinase and serine proteinase inhibitors), and steroidogenesis (CYP21A2 and progesterone receptor). These alterations of testicular histology and gene expression patterns were specific to TAp73 null mice and not features of mice lacking p53. Our work provides previously unidentified in vivo evidence that TAp73 has a unique role in spermatogenesis that ensures the maintenance of mitotic cells and normal spermiogenesis. These results may have implications for the diagnosis and management of human male infertility.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Fertilidade , Proteínas Nucleares/metabolismo , Espermatogênese , Proteínas Supressoras de Tumor/metabolismo , Proteínas ADAM/genética , Proteínas ADAM/metabolismo , Proteína ADAM17 , Envelhecimento/patologia , Animais , Apoptose/genética , Contagem de Células , Proliferação de Células , Dano ao DNA/genética , Proteínas de Ligação a DNA/deficiência , Feminino , Fertilidade/genética , Regulação da Expressão Gênica , Humanos , Infertilidade Masculina/sangue , Infertilidade Masculina/genética , Infertilidade Masculina/patologia , Masculino , Metaloproteinase 13 da Matriz/genética , Metaloproteinase 13 da Matriz/metabolismo , Camundongos , Camundongos Knockout , Proteínas Nucleares/deficiência , Estresse Oxidativo/genética , Progesterona/sangue , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espermatogênese/genética , Espermatozoides/metabolismo , Espermatozoides/patologia , Testículo/metabolismo , Testículo/patologia , Proteína Tumoral p73 , Proteínas Supressoras de Tumor/deficiência
18.
J Exp Med ; 210(8): 1529-44, 2013 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-23857982

RESUMO

Oxidative stress plays an important role in cancer development and treatment. Recent data implicate the tumor suppressor BRCA1 in regulating oxidative stress, but the molecular mechanism and the impact in BRCA1-associated tumorigenesis remain unclear. Here, we show that BRCA1 regulates Nrf2-dependent antioxidant signaling by physically interacting with Nrf2 and promoting its stability and activation. BRCA1-deficient mouse primary mammary epithelial cells show low expression of Nrf2-regulated antioxidant enzymes and accumulate reactive oxygen species (ROS) that impair survival in vivo. Increased Nrf2 activation rescues survival and ROS levels in BRCA1-null cells. Interestingly, 53BP1 inactivation, which has been shown to alleviate several defects associated with BRCA1 loss, rescues survival of BRCA1-null cells without restoring ROS levels. We demonstrate that estrogen treatment partially restores Nrf2 levels in the absence of BRCA1. Our data suggest that Nrf2-regulated antioxidant response plays a crucial role in controlling survival downstream of BRCA1 loss. The ability of estrogen to induce Nrf2 posits an involvement of an estrogen-Nrf2 connection in BRCA1 tumor suppression. Lastly, BRCA1-mutated tumors retain a defective antioxidant response that increases the sensitivity to oxidative stress. In conclusion, the role of BRCA1 in regulating Nrf2 activity suggests important implications for both the etiology and treatment of BRCA1-related cancers.


Assuntos
Antioxidantes/metabolismo , Proteína BRCA1/metabolismo , Sobrevivência Celular , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais , Animais , Proteína BRCA1/deficiência , Proteína BRCA1/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular , Sobrevivência Celular/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Estrogênios/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Inativação de Genes , Humanos , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Camundongos , Mutação , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo , Ligação Proteica , Estabilidade Proteica , Espécies Reativas de Oxigênio/metabolismo , Ubiquitinação
19.
Genes Dev ; 27(10): 1101-14, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23699408

RESUMO

Tumorigenesis results from dysregulation of oncogenes and tumor suppressors that influence cellular proliferation, differentiation, apoptosis, and/or senescence. Many gene products involved in these processes are substrates of the E3 ubiquitin ligase Mule/Huwe1/Arf-BP1 (Mule), but whether Mule acts as an oncogene or tumor suppressor in vivo remains controversial. We generated K14Cre;Mule(flox/flox(y)) (Mule kKO) mice and subjected them to DMBA/PMA-induced skin carcinogenesis, which depends on oncogenic Ras signaling. Mule deficiency resulted in increased penetrance, number, and severity of skin tumors, which could be reversed by concomitant genetic knockout of c-Myc but not by knockout of p53 or p19Arf. Notably, in the absence of Mule, c-Myc/Miz1 transcriptional complexes accumulated, and levels of p21CDKN1A (p21) and p15INK4B (p15) were down-regulated. In vitro, Mule-deficient primary keratinocytes exhibited increased proliferation that could be reversed by Miz1 knockdown. Transfer of Mule-deficient transformed cells to nude mice resulted in enhanced tumor growth that again could be abrogated by Miz1 knockdown. Our data demonstrate in vivo that Mule suppresses Ras-mediated tumorigenesis by preventing an accumulation of c-Myc/Miz1 complexes that mediates p21 and p15 down-regulation.


Assuntos
Transformação Celular Neoplásica , Inibidor de Quinase Dependente de Ciclina p15/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Regulação para Baixo , Proteínas Nucleares/antagonistas & inibidores , Proteína Oncogênica p21(ras)/metabolismo , Proteínas Inibidoras de STAT Ativados/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-myc/antagonistas & inibidores , Ubiquitina-Proteína Ligases/metabolismo , 9,10-Dimetil-1,2-benzantraceno/farmacologia , Animais , Transformação Celular Neoplásica/genética , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p15/biossíntese , Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor p16 de Quinase Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Inibidor de Quinase Dependente de Ciclina p21/genética , Feminino , Genes ras , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/patologia , Masculino , Camundongos , Camundongos Knockout , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteína Oncogênica p21(ras)/antagonistas & inibidores , Proteína Oncogênica p21(ras)/genética , Proteínas Inibidoras de STAT Ativados/deficiência , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/metabolismo , Proteínas Proto-Oncogênicas c-myc/deficiência , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Acetato de Tetradecanoilforbol/farmacologia , Proteína Supressora de Tumor p53 , Proteínas Supressoras de Tumor , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética
20.
Nat Immunol ; 14(1): 27-33, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23179078

RESUMO

The E3 ligase ARIH2 has an unusual structure and mechanism of elongating ubiquitin chains. To understand its physiological role, we generated gene-targeted mice deficient in ARIH2. ARIH2 deficiency resulted in the embryonic death of C57BL/6 mice. On a mixed genetic background, the lethality was attenuated, with some mice surviving beyond weaning and then succumbing to an aggressive multiorgan inflammatory response. We found that in dendritic cells (DCs), ARIH2 caused degradation of the inhibitor IκBß in the nucleus, which abrogated its ability to sequester, protect and transcriptionally coactivate the transcription factor subunit p65 in the nucleus. Loss of ARIH2 caused dysregulated activation of the transcription factor NF-κB in DCs, which led to lethal activation of the immune system in ARIH2-sufficent mice reconstituted with ARIH2-deficient hematopoietic stem cells. Our data have therapeutic implications for targeting ARIH2 function.


Assuntos
Células Dendríticas/imunologia , Desenvolvimento Embrionário/imunologia , Insuficiência de Múltiplos Órgãos/imunologia , Ubiquitina-Proteína Ligases/fisiologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Desenvolvimento Embrionário/genética , Hematopoese/genética , Humanos , Sistema Imunitário/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Terapia de Alvo Molecular , Insuficiência de Múltiplos Órgãos/genética , NF-kappa B/metabolismo , Ativação Transcricional/imunologia , Ubiquitina-Proteína Ligases/genética , Ubiquitinação/genética , Ubiquitinação/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...