Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 117(4): 2084-2091, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31932421

RESUMO

BRCA1 promotes error-free, homologous recombination-mediated repair (HRR) of DNA double-stranded breaks (DSBs). When excessive and uncontrolled, BRCA1 HRR activity promotes illegitimate recombination and genome disorder. We and others have observed that the BRCA1-associated protein RAP80 recruits BRCA1 to postdamage nuclear foci, and these chromatin structures then restrict the amplitude of BRCA1-driven HRR. What remains unclear is how this process is regulated. Here we report that both BRCA1 poly-ADP ribosylation (PARsylation) and the presence of BRCA1-bound RAP80 are critical for the normal interaction of BRCA1 with some of its partners (e.g., CtIP and BACH1) that are also known components of the aforementioned focal structures. Surprisingly, the simultaneous loss of RAP80 and failure therein of BRCA1 PARsylation results in the dysregulated accumulation in these foci of BRCA1 complexes. This in turn is associated with the intracellular development of a state of hyper-recombination and gross chromosomal disorder. Thus, physiological RAP80-BRCA1 complex formation and BRCA1 PARsylation contribute to the kinetics by which BRCA1 HRR-sustaining complexes normally concentrate in nuclear foci. These events likely contribute to aneuploidy suppression.

2.
Pigment Cell Melanoma Res ; 32(2): 292-302, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30281931

RESUMO

This study evaluates the use of HMG-CoA reductase inhibitors, or statins, as an adjunctive to BRAF and MEK inhibition as a treatment in melanomas and other tumors with driver mutations in the MAPK pathway. Experiments used simvastatin in conjunction with vemurafenib and selumetinib in vitro and simvastatin with vemurafenib in vivo to demonstrate additional growth abrogation beyond MAPK blockade alone. Additional studies demonstrated that statin anti-tumor effects appeared to depend on inhibition of isoprenoid synthesis given rescue with add-back of downstream metabolites. Ultimately, we concluded that statins represent a possible useful adjunctive therapy in MAPK-driven tumors when given with current approved targeted therapy.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/tratamento farmacológico , Melanoma/tratamento farmacológico , Prenilação , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Masculino , Melanoma/enzimologia , Melanoma/patologia , Ácido Mevalônico/metabolismo , Camundongos Nus , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
3.
Pigment Cell Melanoma Res ; 32(3): 435-440, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30343532

RESUMO

The aim of this study is to determine the significance of programmed death ligand 1 (PD-L1 or CD274) methylation in relation to PD-L1 expression and survival in melanoma. Despite the clinical importance of therapies targeting the PD-1/PD-L1 immune checkpoint in melanoma, factors regulating PD-L1 expression, including epigenetic mechanisms, are not completely understood. In this study, we examined PD-L1 promoter methylation in relation to PD-L1 expression and overall survival in melanoma patients. Our results suggest that DNA methylation regulates PD-L1 expression in melanoma, and we identify the key methylated CpG loci in the PD-L1 promoter, establish PD-L1 methylation as an independent survival prognostic factor, provide proof of concept for altering PD-L1 expression by hypomethylating agents, and uncover that PD-L1 methylation is associated with an interferon signaling transcriptional phenotype. Based on our findings, measuring and altering PD-L1 promoter DNA methylation may have potential prognostic and therapeutic applications in melanoma.


Assuntos
Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/análise , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Melanoma/mortalidade , Estudos de Coortes , Humanos , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Prognóstico , Regiões Promotoras Genéticas , Taxa de Sobrevida
4.
5.
J Invest Dermatol ; 137(10): 2187-2196, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28599981

RESUMO

Despite improvements in survival in metastatic melanoma with combined BRAF and mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor treatment, the overwhelming majority of patients eventually acquire resistance to both agents. Consequently, new targets for therapy in resistant tumors are currently being evaluated. Previous studies have identified p90 subfamily of ribosomal S6 kinase (p90RSK) family kinases as key factors for growth and proliferation, as well as protein synthesis via assembly of the 7-methyl-guanosine triphosphate cap-dependent translation complex. We sought to evaluate inhibitors of p90RSK family members: BI-D1870 and BRD7389, for their ability to inhibit both proliferation and protein synthesis in patient-derived melanoma cell lines with acquired resistance to combined treatment with the BRAF inhibitor vemurafenib and the mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor selumetinib. We found that the RSK inhibitors blocked cell proliferation and protein synthesis in multiple dual-resistant melanoma lines. In addition, single agent RSK inhibitor treatment was effective in drug-naïve lines, two of which are innately vemurafenib resistant. We also used Reverse Phase Protein Array screening to identify differential protein expression that correlates with BI-D1870 sensitivity, and identified prognostic biomarkers for survival in human melanoma patients. These findings establish p90RSK inhibition as a therapeutic strategy in treatment-resistant melanoma and provide insight into the mechanism of action.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , MAP Quinase Quinase 1/biossíntese , Melanoma/metabolismo , Proteínas Proto-Oncogênicas B-raf/biossíntese , Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , MAP Quinase Quinase 1/efeitos dos fármacos , Melanoma/tratamento farmacológico , Melanoma/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/efeitos dos fármacos , Pteridinas , Proteínas Quinases S6 Ribossômicas 90-kDa/antagonistas & inibidores , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Transdução de Sinais
6.
Clin Epigenetics ; 9: 34, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28396701

RESUMO

Aberrant DNA methylation is an epigenetic hallmark of melanoma, known to play important roles in melanoma formation and progression. Recent advances in genome-wide methylation methods have provided the means to identify differentially methylated genes, methylation signatures, and potential biomarkers. However, despite considerable effort and advances in cataloging methylation changes in melanoma, many questions remain unanswered. The aim of this review is to summarize recent developments, emerging trends, and important unresolved questions in the field of aberrant DNA methylation in melanoma. In addition to reviewing recent developments, we carefully synthesize the findings in an effort to provide a framework for understanding the current state and direction of the field. To facilitate clarity, we divided the review into DNA methylation changes in melanoma, biomarker opportunities, and therapeutic developments. We hope this review contributes to accelerating the utilization of the diagnostic, prognostic, and therapeutic potential of DNA methylation for the benefit of melanoma patients.


Assuntos
Metilação de DNA , Melanoma/tratamento farmacológico , Melanoma/genética , MicroRNAs/genética , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Azacitidina/uso terapêutico , Biomarcadores Tumorais/genética , Metilação de DNA/efeitos dos fármacos , Decitabina , Epigênese Genética/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Prognóstico
7.
Pigment Cell Melanoma Res ; 30(4): 428-435, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28379630

RESUMO

Human melanomas exhibit relatively high somatic mutation burden compared to other malignancies. These somatic mutations may produce neoantigens that are recognized by the immune system, leading to an antitumor response. By irradiating a parental mouse melanoma cell line carrying three driver mutations with UVB and expanding a single-cell clone, we generated a mutagenized model that exhibits high somatic mutation burden. When inoculated at low cell numbers in immunocompetent C57BL/6J mice, YUMMER1.7 (Yale University Mouse Melanoma Exposed to Radiation) regresses after a brief period of growth. This regression phenotype is dependent on T cells as YUMMER1.7 tumors grow significantly faster in immunodeficient Rag1-/- mice and C57BL/6J mice depleted of CD4 and CD8 T cells. Interestingly, regression can be overcome by injecting higher cell numbers of YUMMER1.7, which results in tumors that grow without effective rejection. Mice that have previously rejected YUMMER1.7 tumors develop immunity against higher doses of YUMMER1.7 tumor challenge. In addition, escaping YUMMER1.7 tumors are sensitive to anti-CTLA-4 and anti-PD-1 therapy, establishing a new model for the evaluation of immune checkpoint inhibition and antitumor immune responses.


Assuntos
Melanoma/genética , Melanoma/patologia , Mutação/genética , Linfócitos T/metabolismo , Linfócitos T/efeitos da radiação , Raios Ultravioleta , Animais , Apoptose/genética , Modelos Animais de Doenças , Proteínas de Fluorescência Verde/metabolismo , Camundongos Endogâmicos C57BL , Mitose/genética , Sequenciamento Completo do Exoma
8.
Melanoma Res ; 27(2): 85-96, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27997431

RESUMO

Epigenetic modification of DNA, namely covalent changes of cytosine residues, plays a key role in the maintenance of inactive chromatin regions, both in health and in disease. In the vast majority of malignant melanomas, the most notable known epigenetic abnormality is the attenuation of 5-hydroxymethylcytosine (5-hmC) residues. However, it remains unknown whether a decrease in 5-hmC represents a primary defect of melanoma cancer epigenome or whether it is secondary to the loss of 5-methylcytosine (5-mC), a chemical substrate for 5-hmC. Here, we evaluated 5-mC levels in a spectrum of melanocytic proliferations. To study the epigenetic features of melanocytic nuclei, we began by measuring 5-mC levels in histologic specimens semiquantitatively by immunohistochemistry. We next treated established melanoma cell lines with S-adenosyl methionine (SAM), a universal methyl group donor, in an effort to cause changes in 5-mC levels. We detected a marked reduction in 5-mC levels in both primary and metastatic melanomas compared with 5-mC levels in benign melanocytic nevi. We also empirically induced changes in 5-mC in melanoma cell lines by incubation with SAM. To our surprise, we observed a significant cytoreductive effect of SAM on all melanoma cell lines examined. At subcytotoxic levels, SAM treatment is accompanied by a genome-wide increase in 5-mC. Moreover, we recorded a dose-dependent increase in genome-wide 5-mC levels in melanoma cell lines following SAM treatment. Taken together, we report that genome-wide attenuation of 5-mC is a hallmark of malignant melanomas. We propose that genome-wide attenuation of 5-mC is not merely an epiphenomenon as it is required for melanoma cell growth, albeit by an as of yet undetermined mechanism. Given its potential benefit in slowing down the growth of melanoma cells, SAM should be studied further to determine its role in epigenome modulation.


Assuntos
5-Metilcitosina/metabolismo , DNA de Neoplasias/metabolismo , Melanoma/genética , Nevo Pigmentado/genética , S-Adenosilmetionina/farmacologia , Neoplasias Cutâneas/genética , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Metilação de DNA/efeitos dos fármacos , Epigênese Genética , Genoma , Humanos , Melanoma/secundário
9.
Cancer J ; 22(4): 257-66, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27441745

RESUMO

Immunotherapy, particularly immune-checkpoint inhibition, is producing encouraging clinical responses and affecting the way numerous cancers are treated. Yet immune-checkpoint therapy is not effective for many patients, and even those who initially respond can experience relapse, fueling interest in finding new processes or tools to improve the effectiveness of these novel therapeutics. One such tool is radiation. Both preclinical and clinical studies have demonstrated that the systemic effects of immunotherapy can be amplified when it is used in combination with radiation and, conversely, that the immunogenic effects of local irradiation can be amplified and extended to distant sites when used with immunotherapy. We review how stereotactic ablative radiation therapy, a technique specifically indicated for tumors treated with immune-checkpoint inhibitors, can potentiate the effects of immune-checkpoint therapy. We further explore how these novel therapeutics may transform radiation, previously considered a local treatment option, into powerful systemic therapy.


Assuntos
Imunoterapia/métodos , Neoplasias/terapia , Radiocirurgia/métodos , Terapia Combinada , Humanos , Neoplasias/imunologia , Neoplasias/radioterapia
10.
BMC Genomics ; 17: 463, 2016 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-27301971

RESUMO

BACKGROUND: Long INterspersed Element-1 (LINE-1 or L1) is the only autonomously active, transposable element in the human genome. L1 sequences comprise approximately 17 % of the human genome, but only the evolutionarily recent, human-specific subfamily is retrotransposition competent. The L1 promoter has a bidirectional orientation containing a sense promoter that drives the transcription of two proteins required for retrotransposition and an antisense promoter. The L1 antisense promoter can drive transcription of chimeric transcripts: 5' L1 antisense sequences spliced to the exons of neighboring genes. RESULTS: The impact of L1 antisense promoter activity on cellular transcriptomes is poorly understood. To investigate this, we analyzed GenBank ESTs for messenger RNAs that initiate in the L1 antisense promoter. We identified 988 putative L1 antisense chimeric transcripts, 911 of which have not been previously reported. These appear to be alternative genic transcripts, sense-oriented with respect to gene and initiating near, but typically downstream of, the gene transcriptional start site. In multiple cell lines, L1 antisense promoters display enrichment for YY1 transcription factor and histone modifications associated with active promoters. Global run-on sequencing data support the activity of the L1 antisense promoter. We independently detected 124 L1 antisense chimeric transcripts using long read Pacific Biosciences RNA-seq data. Furthermore, we validated four chimeric transcripts by quantitative RT-PCR and Sanger sequencing and demonstrated that they are readily detectable in many normal human tissues. CONCLUSIONS: We present a comprehensive characterization of human L1 antisense promoter-driven transcripts and provide substantial evidence that they are transcribed in a variety of human cell-types. Our findings reveal a new wide-reaching aspect of L1 biology by identifying antisense transcripts affecting as many as 4 % of all human genes.


Assuntos
Genoma Humano , Estudo de Associação Genômica Ampla , Elementos Nucleotídeos Longos e Dispersos , Regiões Promotoras Genéticas , RNA Antissenso , Transcrição Genética , Animais , Etiquetas de Sequências Expressas , Humanos , Camundongos , Retroelementos
11.
Pigment Cell Melanoma Res ; 29(5): 590-7, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27287723

RESUMO

The remarkable success of immune therapies emphasizes the need for immune-competent cancer models. Elegant genetically engineered mouse models of a variety of cancers have been established, but their effective use is limited by cost and difficulties in rapidly generating experimental data. Some mouse cancer cell lines are transplantable to immunocompetent host mice and have been utilized extensively to study cancer immunology. Here, we describe the Yale University Mouse Melanoma (YUMM) lines, a comprehensive system of mouse melanoma cell lines that are syngeneic to C57BL/6, have well-defined human-relevant driver mutations, and are genomically stable. This will be a useful tool for the study of tumor immunology and genotype-specific cancer biology.


Assuntos
Biomarcadores Tumorais/genética , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Imunidade Celular/genética , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Mutação , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C57BL
12.
J Histochem Cytochem ; 64(7): 403-11, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27270967

RESUMO

We developed a method, termed Cell and Tissue Display (CTD), for embedding 16 or more different tissue samples in multi-compartment agarose blocks. The CTD-generated blocks allow uniform multiplexing of cell lines and small tissue fragments within a single histologic block. The distribution of individual cells within the CTD blocks is improved, likely because the individual agarose compartments are small and uniform. The composition of each CTD block can be customized based on intended use. Some potential uses of CTD histologic blocks include improved sectioning of small tissue fragments, such as needle biopsy specimens or punch biopsies; multiplexing of tissue fragments within a single block; and the generation of control slides for laboratory proficiency testing. .


Assuntos
Sefarose , Inclusão do Tecido/métodos , Animais , Encéfalo/citologia , Linhagem Celular Tumoral , Colo/citologia , Humanos , Melanoma/patologia , Camundongos Endogâmicos C57BL , Microscopia , Pele/citologia , Neoplasias Cutâneas/patologia
13.
Cell Rep ; 14(10): 2476-89, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26947078

RESUMO

On the basis of multidimensional and comprehensive molecular characterization (including DNA methalylation and copy number, RNA, and protein expression), we classified 894 renal cell carcinomas (RCCs) of various histologic types into nine major genomic subtypes. Site of origin within the nephron was one major determinant in the classification, reflecting differences among clear cell, chromophobe, and papillary RCC. Widespread molecular changes associated with TFE3 gene fusion or chromatin modifier genes were present within a specific subtype and spanned multiple subtypes. Differences in patient survival and in alteration of specific pathways (including hypoxia, metabolism, MAP kinase, NRF2-ARE, Hippo, immune checkpoint, and PI3K/AKT/mTOR) could further distinguish the subtypes. Immune checkpoint markers and molecular signatures of T cell infiltrates were both highest in the subtype associated with aggressive clear cell RCC. Differences between the genomic subtypes suggest that therapeutic strategies could be tailored to each RCC disease subset.


Assuntos
Carcinoma de Células Renais/patologia , Genômica , Neoplasias Renais/patologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/mortalidade , Cromatina/metabolismo , Perfilação da Expressão Gênica , Humanos , Neoplasias Renais/genética , Neoplasias Renais/mortalidade , MicroRNAs/metabolismo , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais/genética , Taxa de Sobrevida , Serina-Treonina Quinases TOR/metabolismo
14.
Cell Rep ; 14(9): 2180-2192, 2016 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-26923591

RESUMO

DNA methyltransferase DNMT3B is frequently overexpressed in tumor cells and plays important roles during the formation and progression of several cancer types. However, the specific signaling pathways controlled by DNMT3B in cancers, including melanoma, are poorly understood. Here, we report that DNMT3B plays a pro-tumorigenic role in human melanoma and that DNMT3B loss dramatically suppresses melanoma formation in the Braf/Pten mouse melanoma model. Loss of DNMT3B results in hypomethylation of the miR-196b promoter and increased miR-196b expression, which directly targets the mTORC2 component Rictor. Loss of RICTOR in turn prevents mTORC2 activation, which is critical for melanoma formation and growth. These findings establish Dnmt3b as a regulator of melanoma formation through its effect on mTORC2 signaling. Based on these results, DNMT3B is a potential therapeutic target in melanoma.


Assuntos
Proteínas de Transporte/metabolismo , DNA (Citosina-5-)-Metiltransferases/fisiologia , Melanoma Experimental/enzimologia , Neoplasias Cutâneas/enzimologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Humanos , Alvo Mecanístico do Complexo 2 de Rapamicina , Melanoma Experimental/mortalidade , Melanoma Experimental/patologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Nus , MicroRNAs/genética , Complexos Multiproteicos/metabolismo , Transplante de Neoplasias , Modelos de Riscos Proporcionais , Interferência de RNA , Proteína Companheira de mTOR Insensível à Rapamicina , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Serina-Treonina Quinases TOR/metabolismo , Carga Tumoral
16.
Cell ; 162(6): 1217-28, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26321681

RESUMO

Activated T cells engage aerobic glycolysis and anabolic metabolism for growth, proliferation, and effector functions. We propose that a glucose-poor tumor microenvironment limits aerobic glycolysis in tumor-infiltrating T cells, which suppresses tumoricidal effector functions. We discovered a new role for the glycolytic metabolite phosphoenolpyruvate (PEP) in sustaining T cell receptor-mediated Ca(2+)-NFAT signaling and effector functions by repressing sarco/ER Ca(2+)-ATPase (SERCA) activity. Tumor-specific CD4 and CD8 T cells could be metabolically reprogrammed by increasing PEP production through overexpression of phosphoenolpyruvate carboxykinase 1 (PCK1), which bolstered effector functions. Moreover, PCK1-overexpressing T cells restricted tumor growth and prolonged the survival of melanoma-bearing mice. This study uncovers new metabolic checkpoints for T cell activity and demonstrates that metabolic reprogramming of tumor-reactive T cells can enhance anti-tumor T cell responses, illuminating new forms of immunotherapy.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos do Interstício Tumoral/imunologia , Melanoma/imunologia , Melanoma/terapia , Monitorização Imunológica , Fosfoenolpiruvato/metabolismo , Microambiente Tumoral , Animais , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Glicólise , Hexoquinase/metabolismo , Imunoterapia , Camundongos , Fatores de Transcrição NFATC/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/imunologia
17.
Mol Cancer Ther ; 14(7): 1680-92, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25948295

RESUMO

BRAF kinase inhibitors have dramatically affected treatment of BRAF(V600E) (/) (K)-driven metastatic melanoma. Early responses assessed using [(18)F]fluorodeoxyglucose uptake-positron emission tomography (FDG-PET) have shown dramatic reduction of radiotracer signal within 2 weeks of treatment. Despite high response rates, relapse occurs in nearly all cases, frequently at sites of treated metastatic disease. It remains unclear whether initial loss of (18)FDG uptake is due to tumor cell death or other reasons. Here, we provide evidence of melanoma cell volume reduction in a patient cohort treated with BRAF inhibitors. We present data demonstrating that BRAF inhibition reduces melanoma glucose uptake per cell, but that this change is no longer significant following normalization for cell volume changes. We also demonstrate that volume normalization greatly reduces differences in transmembrane glucose transport and hexokinase-mediated phosphorylation. Mechanistic studies suggest that this loss of cell volume is due in large part to decreases in new protein translation as a consequence of vemurafenib treatment. Ultimately, our findings suggest that cell volume regulation constitutes an important physiologic parameter that may significantly contribute to radiographic changes observed in clinic.


Assuntos
Tamanho Celular , Glucose/metabolismo , Melanoma/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Transporte Biológico/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Citometria de Fluxo , Fluordesoxiglucose F18/metabolismo , Fluordesoxiglucose F18/farmacocinética , Glucose/farmacocinética , Hexoquinase/genética , Hexoquinase/metabolismo , Humanos , Immunoblotting , Indóis/farmacologia , Melanoma/genética , Melanoma/patologia , Tomografia por Emissão de Pósitrons , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Interferência de RNA , Sulfonamidas/farmacologia , Vemurafenib
18.
Cancer Cell ; 27(1): 41-56, 2015 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-25584893

RESUMO

Braf(V600E) induces benign, growth-arrested melanocytic nevus development, but also drives melanoma formation. Cdkn2a loss in Braf(V600E) melanocytes in mice results in rare progression to melanoma, but only after stable growth arrest as nevi. Immediate progression to melanoma is prevented by upregulation of miR-99/100, which downregulates mTOR and IGF1R signaling. mTORC1 activation through Stk11 (Lkb1) loss abrogates growth arrest of Braf(V600E) melanocytic nevi, but is insufficient for complete progression to melanoma. Cdkn2a loss is associated with mTORC2 and Akt activation in human and murine melanocytic neoplasms. Simultaneous Cdkn2a and Lkb1 inactivation in Braf(V600E) melanocytes results in activation of both mTORC1 and mTORC2/Akt, inducing rapid melanoma formation in mice. In this model, activation of both mTORC1/2 is required for Braf-induced melanomagenesis.


Assuntos
Melanoma Experimental/patologia , Complexos Multiproteicos/metabolismo , Nevo/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Neoplasias Cutâneas/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Melanócitos/metabolismo , Melanoma Experimental/metabolismo , Camundongos , MicroRNAs/metabolismo , Dados de Sequência Molecular , Mutação , Nevo/patologia , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Neoplasias Cutâneas/patologia
19.
Arch Biochem Biophys ; 563: 56-9, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24997363

RESUMO

Melanoma is the most lethal form of skin cancer and its incidence is rapidly rising. Breakthroughs in the understanding of the basic biology of melanoma in the past decade have yielded several new treatments, and advances continue to be made on a variety of fronts. One such area involves the delineation of changes in mitochondria that occur during melanoma formation, and how these changes affect responses to therapy. In this review, we summarize recent developments on the multiple functions that mitochondria play in melanoma, and how these roles are currently being evaluated as new targets for clinical intervention.


Assuntos
Melanoma/metabolismo , Mitocôndrias/metabolismo , Neoplasias Cutâneas/metabolismo , Animais , Apoptose , Metabolismo Energético , Humanos , Melanoma/etiologia , Redes e Vias Metabólicas , Fator de Transcrição Associado à Microftalmia/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Cutâneas/etiologia , Fatores de Transcrição/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA