Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Clin Oncol ; 36(10): 1020-1044, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29380678

RESUMO

A MESSAGE FROM ASCO'S PRESIDENT I remember when ASCO first conceived of publishing an annual report on the most transformative research occurring in cancer care. Thirteen reports later, the progress we have chronicled is remarkable, and this year is no different. The research featured in ASCO's Clinical Cancer Advances 2018 report underscores the impressive gains in our understanding of cancer and in our ability to tailor treatments to tumors' genetic makeup. The ASCO 2018 Advance of the Year, adoptive cell immunotherapy, allows clinicians to genetically reprogram patients' own immune cells to find and attack cancer cells throughout the body. Chimeric antigen receptor (CAR) T-cell therapy-a type of adoptive cell immunotherapy-has led to remarkable results in young patients with acute lymphoblastic leukemia (ALL) and in adults with lymphoma and multiple myeloma. Researchers are also exploring this approach in other types of cancer. This advance would not be possible without robust federal investment in cancer research. The first clinical trial of CAR T-cell therapy in children with ALL was funded, in part, by grants from the National Cancer Institute (NCI), and researchers at the NCI Center for Cancer Research were the first to report on possible CAR T-cell therapy for multiple myeloma. These discoveries follow decades of prior research on immunology and cancer biology, much of which was supported by federal dollars. In fact, many advances that are highlighted in the 2018 Clinical Cancer Advances report were made possible thanks to our nation's support for biomedical research. Funding from the US National Institutes of Health and the NCI helps researchers pursue critical patient care questions and addresses vital, unmet needs that private industry has little incentive to take on. Federally supported cancer research generates the biomedical innovations that fuel the development and availability of new and improved treatments for patients. We need sustained federal research investment to accelerate the discovery of the next generation of cancer treatments. Another major trend in this year's report is progress in precision medicine approaches to treat cancer. Although precision medicine offers promise to people with cancer and their families, that promise is only as good as our ability to make these treatments available to all patients. My presidential theme, "Delivering Discoveries: Expanding the Reach of Precision Medicine," focuses on tackling this formidable challenge so that new targeted therapies are accessible to anyone who faces a cancer diagnosis. By improving access to high-quality care, harnessing big data on patient outcomes from across the globe, and pursuing innovative clinical trials, I am optimistic that we will speed the delivery of these most promising treatments to more patients. Sincerely, Bruce E. Johnson, FASCO ASCO President, 2017 to 2018.


Assuntos
Oncologia/métodos , Neoplasias/terapia , Pediatria/métodos , Criança , Humanos
4.
J Clin Oncol ; 33(7): 786-809, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25605863
5.
J Clin Oncol ; 32(2): 129-60, 2014 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-24327669

RESUMO

A MESSAGE FROM ASCO'S PRESIDENT: Since its founding in 1964, the American Society of Clinical Oncology (ASCO) has been committed to improving cancer outcomes through research and the delivery of quality care. Research is the bedrock of discovering better treatments--providing hope to the millions of individuals who face a cancer diagnosis each year. The studies featured in "Clinical Cancer Advances 2013: Annual Report on Progress Against Cancer From the American Society of Clinical Oncology" represent the invaluable contributions of thousands of patients who participate in clinical trials and the scientists who conduct basic and clinical research. The insights described in this report, such as how cancers hide from the immune system and why cancers may become resistant to targeted drugs, enable us to envision a future in which cancer will be even more controllable and preventable. The scientific process is thoughtful, deliberate, and sometimes slow, but each advance, while helping patients, now also points toward new research questions and unexplored opportunities. Both dramatic and subtle breakthroughs occur so that progress against cancer typically builds over many years. Success requires vision, persistence, and a long-term commitment to supporting cancer research and training. Our nation's longstanding investment in federally funded cancer research has contributed significantly to a growing array of effective new treatments and a much deeper understanding of the drivers of cancer. But despite this progress, our position as a world leader in advancing medical knowledge and our ability to attract the most promising and talented investigators are now threatened by an acute problem: Federal funding for cancer research has steadily eroded over the past decade, and only 15% of the ever-shrinking budget is actually spent on clinical trials. This dismal reality threatens the pace of progress against cancer and undermines our ability to address the continuing needs of our patients. Despite this extremely challenging economic environment, we continue to make progress. Maintaining and accelerating that progress require that we keep our eyes on the future and pursue a path that builds on the stunning successes of the past. We must continue to show our policymakers the successes in cancer survival and quality of life (QOL) they have enabled, emphasizing the need to sustain our national investment in the remarkably productive US cancer research enterprise. We must also look to innovative methods for transforming how we care for-and learn from-patients with cancer. Consider, for example, that fewer than 5% of adult patients with cancer currently participate in clinical trials. What if we were able to draw lessons from the other 95%? This possibility led ASCO this year to launch CancerLinQ, a groundbreaking health information technology initiative that will provide physicians with access to vast quantities of clinical data about real-world patients and help achieve higher quality, higher value cancer care. As you read the following pages, I hope our collective progress against cancer over the past year inspires you. More importantly, I hope the pride you feel motivates you to help us accelerate the pace of scientific advancement. Clifford A. Hudis, MD, FACP President American Society of Clinical Oncology.


Assuntos
Relatórios Anuais como Assunto , Pesquisa Biomédica/métodos , Oncologia/métodos , Neoplasias/terapia , Pesquisa Biomédica/economia , Pesquisa Biomédica/tendências , Detecção Precoce de Câncer , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Testes Genéticos , Humanos , Oncologia/organização & administração , Oncologia/tendências , National Institutes of Health (U.S.)/economia , Neoplasias/diagnóstico , Neoplasias/genética , Guias de Prática Clínica como Assunto , Apoio à Pesquisa como Assunto/estatística & dados numéricos , Apoio à Pesquisa como Assunto/tendências , Sociedades Médicas , Estados Unidos
7.
Exp Cell Res ; 317(20): 2981-94, 2011 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-22001118

RESUMO

Glucagon levels are elevated in diabetes and some liver diseases. Increased glucagon secretion leads to abnormal stimulation of glucagon receptors (GRs) and consequent elevated glucose production in the liver. Blocking glucagon receptor signaling has been proposed as a potential treatment option for diabetes and other conditions associated with hyperglycemia. Elucidating mechanisms of GR desensitization and downregulation may help identify new drug targets besides GR itself. The present study explores the mechanisms of GR internalization and the role of PKCα, GPCR kinases (GRKs) and ß-arrestins therein. We have reported previously that PKCα mediates GR phosphorylation and desensitization. While the PKC agonist, PMA, did not affect GR internalization when tested alone, it increased glucagon-mediated GR internalization by 25-40% in GR-expressing HEK-293 cells (HEK-GR cells). In both primary hepatocytes and HEK-GR cells, glucagon treatment recruited PKCα to the plasma membrane where it colocalized with GR. We also observed that overexpression of GRK2, GRK3, or GRK5 enhanced GR internalization. In addition, we found that GR utilizes both clathrin- and caveolin-mediated endocytosis in HEK-GR cells. Glucagon triggered translocation of both ß-arrestin1 and ß-arrestin2 from the cytosol to the perimembrane region, and overexpression of ß-arrestin1 and ß-arrestin2 increased GR internalization. Furthermore, both ß-arrestin1 and ß-arrestin2 colocalized with GR and with Cav-1, suggesting the possible involvement of these arrestins in GR internalization.


Assuntos
Arrestinas/metabolismo , Quinases de Receptores Acoplados a Proteína G/metabolismo , Proteína Quinase C-alfa/metabolismo , Receptores de Glucagon/metabolismo , Animais , Caveolinas/metabolismo , Membrana Celular/metabolismo , Células Cultivadas , Clatrina/metabolismo , Cricetinae , Endocitose/fisiologia , Glucagon/metabolismo , Células HEK293 , Hepatócitos/metabolismo , Humanos , Masculino , Transporte Proteico , beta-Arrestinas
8.
Am J Physiol Cell Physiol ; 295(5): C1230-7, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18787074

RESUMO

Glucagon receptor (GR) activity and expression are altered in several diseases, including Type 2 diabetes. Previously, we investigated the mechanism of GR desensitization and internalization. The present study focused on the fate of internalized GR. Using both hamster hepatocytes and human embryonic kidney (HEK)-293 cells, we showed that internalized GR recycled to the plasma membrane within 30-60 min following stimulation of the cells with 100 nM glucagon. In HEK-293 cells and during recycling, GR colocalized with Rab4, Rab11, beta-arrestin1, beta-arrestin2, and actin filaments, in the cytosolic and/or perinuclear domains. Glucagon treatment triggered redistribution of actin filaments from the plasma membrane to the cytosol. GR coimmunoprecipitated with beta-actin in both hepatocytes and HEK-293 cells. Downregulation of beta-arrestin1 and beta-arrestin2 or disruption of the cytoskeleton inhibited recycling, but not internalization of GR. Deletion of the GR carboxyl-terminal 70 amino acids abolished internalization of GR in response to glucagon while deletion of the last 40 amino acids only did not affect GR internalization and recycling. After exposure of the cells to either high concentrations or prolonged duration of glucagon, GR colocalized with lysosomes. GR degradation was inhibited by lysosomal, but not proteosomal, inhibitors. In conclusion, GR recycles through Rab4- and Rab11- positive vesicles. The actin cytoskeleton, beta-arrestin1, beta-arrestin2, and the receptor's carboxyl terminus are involved in recycling. Prolonged stimulation with glucagon targets GR for degradation in lysosomes. Therefore, the present study provides a better understanding of the GR recycling mechanism, which could become useful in the treatment of certain diseases, including diabetes.


Assuntos
Arrestinas/metabolismo , Citoesqueleto/metabolismo , Glucagon/metabolismo , Receptores de Glucagon/metabolismo , Animais , Arrestinas/genética , Membrana Celular/metabolismo , Células Cultivadas , Cricetinae , Citosol/metabolismo , Hepatócitos/metabolismo , Humanos , Lisossomos/metabolismo , Mesocricetus , Mutação , Estrutura Terciária de Proteína , Transporte Proteico , Receptores de Glucagon/química , Receptores de Glucagon/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Tempo , Transfecção , Vesículas Transportadoras/metabolismo , beta-Arrestinas , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab4 de Ligação ao GTP/metabolismo
9.
Endocrinology ; 147(11): 5294-302, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16916948

RESUMO

Dihydroxy bile acids like chenodeoxycholic acid (CDCA) induce heterologous glucagon receptor desensitization. We previously demonstrated that protein kinase C (PKC) was activated by certain bile acids and mediated the CDCA-induced decrease in glucagon responsiveness. The aim of the present study was to explore the role of PKC in the phosphorylation and desensitization of the glucagon receptor by CDCA. Desensitization was evaluated by measuring adenylyl cyclase activity. Receptor phosphorylation was assayed by metabolic labeling with [gamma-(32)P] ATP. Protein kinase C (PKC) translocation and activation was visualized by fluorescence microscopy. CDCA decreased cAMP production induced by glucagon in a dose-dependent manner without affecting cAMP synthesis through stimulation of either stimulatory GTP-binding protein (Gs) by NaF or adenylyl cyclase by forskolin. The CDCA-induced inhibition of adenylyl cyclase activity was potentiated by the phosphatase inhibitor, okadaic acid. The desensitizing effect of CDCA was bile acid-specific and was significantly reduced in the presence of PKC inhibitors and after PKC down-regulation by phorbol 12-myristate 13-acetate. CDCA increased glucagon receptor phosphorylation more than 3-fold at concentrations as low as 25 mum. Furthermore, CDCA significantly stimulated human recombinant PKCalpha autophosphorylation in vitro, as well as PKCalpha translocation to the plasma membrane and phosphorylation in vivo at concentrations as low as 25 mum. CDCA also stimulated PKCdelta translocation to the perinuclear region. Activated PKCalpha, PKCzeta, and to a lesser extent, PKCdelta, phosphorylated the glucagon receptor in vitro. This study demonstrates that certain bile acids, such as CDCA, stimulate phosphorylation and heterologous desensitization of the glucagon receptor, involving at least PKCalpha activation.


Assuntos
Ácido Quenodesoxicólico/farmacologia , Glucagon/farmacologia , Proteína Quinase C-alfa/fisiologia , Receptores de Glucagon/metabolismo , Adenilil Ciclases/metabolismo , Animais , Células Cultivadas , AMP Cíclico/biossíntese , Humanos , Fosforilação , Proteína Quinase C-delta/fisiologia , Ratos , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Glucagon/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia
10.
Am J Physiol Gastrointest Liver Physiol ; 291(2): G275-87, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16710050

RESUMO

The aim was to identify the specific PKC isoform(s) and their mechanism of activation responsible for the modulation of cAMP production by bile acids in human dermal fibroblasts. Stimulation of fibroblasts with 25-100 microM of chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA) led to YFP-PKCalpha and YFP-PKCdelta translocation in 30-60 min followed by a transient 24- to 48-h downregulation of the total PKCalpha, PKCdelta, and PKCepsilon protein expression by 30-50%, without affecting that of PKCzeta. Increased plasma membrane translocation of PKCalpha was associated with an increased PKCalpha phosphorylation, whereas increased PKCdelta translocation to the perinuclear domain was associated with an increased accumulation of phospho-PKCdelta Thr505 and Tyr311 in the nucleus. The PKCalpha specificity on the attenuation of cAMP production by CDCA was demonstrated with PKC downregulation or inhibition, as well as PKC isoform dominant-negative mutants. Under these same conditions, neither phosphatidylinositol 3-kinase, p38 MAP kinase, p42/44 MAP kinase, nor PKA inhibitors had any significant effect on the CDCA-induced cAMP production attenuation. CDCA concentrations as low as 10 microM stimulated PKCalpha autophosphorylation in vitro. This bile acid effect required phosphatidylserine and was completely abolished by the presence of Gö6976. CDCA at concentrations less than 50 microM enhanced the PKCalpha activation induced by PMA, whereas greater CDCA concentrations reduced the PMA-induced PKCalpha activation. CDCA alone did not affect PKCalpha activity in vitro. In conclusion, although CDCA and UDCA activate different PKC isoforms, PKCalpha plays a major role in the bile acid-induced inhibition of cAMP synthesis in fibroblasts. This study emphasizes potential consequences of increased systemic bile acid concentrations and cellular bile acid accumulation in extrahepatic tissues during cholestatic liver diseases.


Assuntos
Alprostadil/administração & dosagem , Ácidos e Sais Biliares/administração & dosagem , AMP Cíclico/metabolismo , Fibroblastos/metabolismo , Proteína Quinase C-alfa/metabolismo , Pele/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Humanos , Fosforilação/efeitos dos fármacos , Pele/citologia , Pele/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...