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1.
Nat Commun ; 11(1): 4931, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004795

RESUMO

Testis-restricted melanoma antigen (MAGE) proteins are frequently hijacked in cancer and play a critical role in tumorigenesis. MAGEs assemble with E3 ubiquitin ligases and function as substrate adaptors that direct the ubiquitination of novel targets, including key tumor suppressors. However, how MAGEs recognize their targets is unknown and has impeded the development of MAGE-directed therapeutics. Here, we report the structural basis for substrate recognition by MAGE ubiquitin ligases. Biochemical analysis of the degron motif recognized by MAGE-A11 and the crystal structure of MAGE-A11 bound to the PCF11 substrate uncovered a conserved substrate binding cleft (SBC) in MAGEs. Mutation of the SBC disrupted substrate recognition by MAGEs and blocked MAGE-A11 oncogenic activity. A chemical screen for inhibitors of MAGE-A11:substrate interaction identified 4-Aminoquinolines as potent inhibitors of MAGE-A11 that show selective cytotoxicity. These findings provide important insights into the large family of MAGE ubiquitin ligases and identify approaches for developing cancer-specific therapeutics.


Assuntos
Antígenos de Neoplasias/ultraestrutura , Proteínas de Neoplasias/ultraestrutura , Neoplasias/tratamento farmacológico , Ubiquitina-Proteína Ligases/metabolismo , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo , Motivos de Aminoácidos , Aminoquinolinas/farmacologia , Aminoquinolinas/uso terapêutico , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinogênese/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Células HeLa , Ensaios de Triagem em Larga Escala , Humanos , Mutagênese , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias/genética , Neoplasias/patologia , Estudo de Prova de Conceito , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Domínios Proteicos/genética , Mapeamento de Interação de Proteínas , Relação Estrutura-Atividade , Especificidade por Substrato/efeitos dos fármacos , Especificidade por Substrato/genética , Ubiquitinação/efeitos dos fármacos , Ubiquitinação/genética
2.
Pharm Res ; 37(10): 194, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32918191

RESUMO

PURPOSE: We characterized three canine P-gp (cP-gp) deficient MDCKII cell lines. Their relevance for identifying efflux transporter substrates and predicting limitation of brain penetration were evaluated. In addition, we discuss how compound selection can be done in drug discovery by using these cell systems. METHOD: hMDR1, hBCRP-transfected, and non-transfected MDCKII ZFN cells (all with knock-down of endogenous cP-gp) were used for measuring permeability and efflux ratios for substrates. The compounds were also tested in MDR1_Caco-2 and BCRP_Caco-2, each with a double knock-out of BCRP/MRP2 or MDR1/MRP2 transporters respectively. Efflux results were compared between the MDCK and Caco-2 models. Furthermore, in vitro MDR1_ZFN efflux data were correlated with in vivo unbound drug brain-to-plasma partition coefficient (Kp,uu). RESULTS: MDR1 and BCRP substrates are correctly classified and robust transporter affinities with control substrates are shown. Cell passage mildly influenced mRNA levels of transfected transporters, but the transporter activity was proven stable for several years. The MDCK and Caco-2 models were in high consensus classifying same efflux substrates. Approx. 80% of enlisted substances were correctly predicted with the MDR1_ZFN model for brain penetration. CONCLUSION: cP-gp deficient MDCKII ZFN models are reliable tools to identify MDR1 and BCRP substrates and useful for predicting efflux liability for brain penetration.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/deficiência , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Proteínas de Neoplasias/metabolismo , Farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Células CACO-2 , Permeabilidade da Membrana Celular , Dibenzocicloeptenos/farmacologia , Dicetopiperazinas/farmacologia , Cães , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Células Madin Darby de Rim Canino , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Prazosina/farmacocinética , Quinidina/farmacocinética , Quinolinas/farmacologia , Especificidade por Substrato , Transfecção
4.
Commun Biol ; 3(1): 374, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641750

RESUMO

The recent outbreak of infections and the pandemic caused by SARS-CoV-2 represent one of the most severe threats to human health in more than a century. Emerging data from the United States and elsewhere suggest that the disease is more severe in men. Knowledge gained, and lessons learned, from studies of the biological interactions and molecular links that may explain the reasons for the greater severity of disease in men, and specifically in the age group at risk for prostate cancer, will lead to better management of COVID-19 in prostate cancer patients. Such information will be indispensable in the current and post-pandemic scenarios.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Neoplasias da Próstata/epidemiologia , Distribuição por Sexo , Antineoplásicos Hormonais/uso terapêutico , Antivirais/uso terapêutico , Betacoronavirus/fisiologia , Betacoronavirus/ultraestrutura , Comorbidade , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/imunologia , Suscetibilidade a Doenças , Reposicionamento de Medicamentos , Feminino , Previsões , Hormônios Esteroides Gonadais/fisiologia , Humanos , Masculino , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/fisiologia , Peptidil Dipeptidase A/fisiologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/imunologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Inibidores de Proteases/uso terapêutico , Receptores Virais/efeitos dos fármacos , Receptores Virais/fisiologia , Fatores de Risco , Serina Endopeptidases/biossíntese , Serina Endopeptidases/fisiologia , Estados Unidos/epidemiologia , Internalização do Vírus
5.
PLoS Biol ; 18(7): e3000755, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32644996

RESUMO

Kindlin-1, -2, and -3 directly bind integrin ß cytoplasmic tails to regulate integrin activation and signaling. Despite their functional significance and links to several diseases, structural information on full-length kindlin proteins remains unknown. Here, we report the crystal structure of human full-length kindlin-3, which reveals a novel homotrimer state. Unlike kindlin-3 monomer, which is the major population in insect and mammalian cell expression systems, kindlin-3 trimer does not bind integrin ß cytoplasmic tail as the integrin-binding pocket in the F3 subdomain of 1 protomer is occluded by the pleckstrin homology (PH) domain of another protomer, suggesting that kindlin-3 is auto-inhibited upon trimer formation. This is also supported by functional assays in which kindlin-3 knockout K562 erythroleukemia cells reconstituted with the mutant kindlin-3 containing trimer-disrupting mutations exhibited an increase in integrin-mediated adhesion and spreading on fibronectin compared with those reconstituted with wild-type kindlin-3. Taken together, our findings reveal a novel mechanism of kindlin auto-inhibition that involves its homotrimer formation.


Assuntos
Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/química , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/química , Multimerização Proteica , Movimento Celular , Humanos , Integrinas/metabolismo , Células K562 , Proteínas de Membrana/metabolismo , Modelos Moleculares , Proteínas de Neoplasias/metabolismo , Ligação Proteica , Domínios Proteicos , Homologia Estrutural de Proteína , Relação Estrutura-Atividade
6.
SAR QSAR Environ Res ; 31(6): 439-455, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32539470

RESUMO

The human breast cancer resistance protein (BCRP), one of the members of the large ATP binding cassette (ABC) transporter superfamily, is crucial for resistance against chemotherapeutic agents. Currently, it has been emerged as one of the best biological targets for the designing of small molecule drugs capable of eliminating multidrug resistance in breast cancer. In order to gain insights into the relationship between the molecular structure of compounds and the ABCG2 inhibition, a multi-QSAR approach using different methods was performed on a dataset of 294 ABCG2 inhibitors with diverse scaffolds. The best models obtained by different chemometric methods have the following statistical characteristics: Monte Carlo Optimization-based QSAR (sensitivity = 0.905, specificity = 0.6255, accuracy = 0.756, and MCC = 0.545), Bayesian classification model (sensitivity = 0.735, specificity = 0.775, and concordance = 0.757); structural and physicochemical interpretation analysis-random forest method (balance accuracy = 0.750, sensitivity = 0.810, and specificity = 0.700). Additionally, structural fingerprints modulating the ABCG2 inhibitory properties were identified from the best models of each method and also validated with each other. The current modelling study is an attempt to get a deep insight into the different important structural fingerprints modulating ABCG2 inhibition.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Proteínas de Neoplasias/antagonistas & inibidores , Mapeamento de Nucleotídeos , Relação Quantitativa Estrutura-Atividade , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/química , Teorema de Bayes , Estrutura Molecular , Método de Monte Carlo , Proteínas de Neoplasias/química
7.
PLoS One ; 15(5): e0233720, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32459817

RESUMO

Since patients with medullary thyroid cancer (MTC) often have metastatic disease at the time of diagnosis, the development of efficient systemic treatment options for MTC is important. Vandetanib and cabozantinib are two tyrosine kinase inhibitors (TKIs) that were recently approved by FDA and EMA for systemic treatment of metastatic MTC. Additionally, since MTC is of a neuroendocrine tumour type, treatment with radiolabelled somatostatin analogues (e.g. 177Lu-octreotate) is a valid option for patients with MTC. The aim of this study was to investigate the potentially increased therapeutic effect of combining radiation therapy with these TKIs for treatment of MTC in a mouse model. Nude mice carrying patient-derived MTC tumours (GOT2) were treated with external beam radiotherapy (EBRT) and/or one of the two TKIs vandetanib or cabozantinib. The tumour volume was determined and compared with that of mock-treated controls. The treatment doses were chosen to give a moderate effect as monotherapy to be able to detect any increased therapeutic effect from the combination therapy. At the end of follow-up, tumours were processed for immunohistochemical (IHC) analyses. The animals in the combination therapy groups showed the largest reduction in tumour volume and the longest time to tumour progression. Two weeks after start of treatment, the tumour volume for these mice was reduced by about 70-75% compared with controls. Furthermore, also EBRT and TKI monotherapy resulted in a clear anti-tumour effect with a reduced tumour growth compared with controls. The results show that an increased therapeutic effect could be achieved when irradiation is combined with TKIs for treatment of MTC. Future studies should evaluate the potential of using 177Lu-octreotate therapy in combination with TKIs in patients.


Assuntos
Anilidas/farmacologia , Carcinoma Neuroendócrino/terapia , Quimiorradioterapia , Proteínas de Neoplasias/antagonistas & inibidores , Piperidinas/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Piridinas/farmacologia , Quinazolinas/farmacologia , Neoplasias da Glândula Tireoide/terapia , Animais , Carcinoma Neuroendócrino/enzimologia , Carcinoma Neuroendócrino/patologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Proteínas Tirosina Quinases/metabolismo , Neoplasias da Glândula Tireoide/enzimologia , Neoplasias da Glândula Tireoide/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Cancer Discov ; 10(7): 916-921, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32444466

RESUMO

The mapping of SARS-CoV-2 human protein-protein interactions by Gordon and colleagues revealed druggable targets that are hijacked by the virus. Here, we highlight several oncogenic pathways identified at the host-virus interface of SARS-CoV-2 to enable cancer biologists to apply their knowledge for rapid drug repurposing to treat COVID-19, and help inform the response to potential long-term complications of the disease.


Assuntos
Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Reposicionamento de Medicamentos , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Ciclo Celular , Infecções por Coronavirus/genética , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/fisiopatologia , Dano ao DNA , Epigenômica , Humanos , Proteínas de Neoplasias/efeitos dos fármacos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/fisiopatologia , Pandemias , Pneumonia Viral/genética , Pneumonia Viral/metabolismo , Pneumonia Viral/fisiopatologia , Biossíntese de Proteínas
9.
PLoS One ; 15(5): e0227844, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32470043

RESUMO

Morroniside is a biologically active polyphenol found in Cornus officinalis Sieb. et Zucc (CO) that exhibits a broad spectrum of pharmacological activities, such as protecting nerves, and preventing diabetic liver damage and renal damage. However, little data are available regarding the mechanism of its intestinal absorption. Here, an in vitro human intestinal epithelial cell model of cultured Caco-2 cells was applied to study the absorption and transport of morroniside. The effects of donor concentration, pH and inhibitors were investigated. The bidirectional permeability of morroniside from the apical (AP) to the basolateral (BL) side and in the reverse direction was studied. When administered at three tested concentrations (5, 25 and 100 µM), the apparent permeability coefficient (Papp) values in the AP-to-BL direction ranged from 1.59 × 10-6 to 2.66 × 10-6 cm/s. In the reverse direction, BL-to-AP, the value was ranged from 2.67 × 10-6 to 4.10 × 10-6 cm/s. The data indicated that morroniside transport was pH-dependent. The permeability of morroniside was affected by treatment with various inhibitors, such as multidrug resistance protein inhibitors MK571 and indomethacin, as well as the breast cancer resistance protein inhibitor apigenin. The mechanisms of the intestinal absorption of morroniside may involve multiple transport pathways, such as the passive diffusion and efflux protein-mediated active transport especially involving multidrug resistance protein 2 and breast cancer resistance protein. After the addition of CO, the Papp values in the AP-to-BL direction increased significantly, therefore, it can be assumed that some ingredients in the CO promote morroniside absorption in the small intestine.


Assuntos
Cornus/química , Glicosídeos/farmacologia , Absorção Intestinal/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Células CACO-2 , Proliferação de Células/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Indometacina/farmacologia , Absorção Intestinal/genética , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Neoplasias/patologia , Permeabilidade/efeitos dos fármacos , Propionatos/farmacologia , Quinolinas/farmacologia
12.
Clin Exp Immunol ; 200(2): 155-162, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32297328

RESUMO

Immune checkpoint blockers improve the overall survival of a limited number of patients among different cancers. Identifying pathways that influence the immunological and clinical response to treatment is critical to improve the therapeutic efficacy and predict clinical responses. Recently, a key role has been assigned to innate immune mechanisms in checkpoint blockade-driven anti-tumor responses. However, inflammatory pathways can both improve and impair anti-tumor immunity. In this review, we discuss how different inflammatory pathways, particularly inflammasome activation, can influence the clinical outcome of immune checkpoint blockers. Inflammasome activation may reinforce anti-tumor immunity by boosting CD8+ T cell priming as well as by enhancing T helper type 17 (Th17) responses. In particular, we focus on the modulation of the cation channel transmembrane protein 176B (TMEM176B) and the ectonucleotidase CD39 as potential targets to unleash inflammasome activation leading to reinforced anti-tumor immunity and improved efficacy of immune checkpoint blockers. Future studies should be aimed at investigating the mechanisms and cell subsets involved in inflammasome-driven anti-tumor responses.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Apirase , Inflamassomos/imunologia , Proteínas de Membrana , Proteínas de Neoplasias , Neoplasias , Animais , Apirase/antagonistas & inibidores , Apirase/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/imunologia , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/imunologia , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/patologia , Células Th17/imunologia , Células Th17/patologia
14.
Cancer Res ; 80(8): 1735-1747, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32161100

RESUMO

Checkpoint kinase 1 (CHK1) is a key mediator of the DNA damage response that regulates cell-cycle progression, DNA damage repair, and DNA replication. Small-molecule CHK1 inhibitors sensitize cancer cells to genotoxic agents and have shown single-agent preclinical activity in cancers with high levels of replication stress. However, the underlying genetic determinants of CHK1 inhibitor sensitivity remain unclear. We used the developmental clinical drug SRA737 in an unbiased large-scale siRNA screen to identify novel mediators of CHK1 inhibitor sensitivity and uncover potential combination therapies and biomarkers for patient selection. We identified subunits of the B-family of DNA polymerases (POLA1, POLE, and POLE2) whose silencing sensitized the human A549 non-small cell lung cancer (NSCLC) and SW620 colorectal cancer cell lines to SRA737. B-family polymerases were validated using multiple siRNAs in a panel of NSCLC and colorectal cancer cell lines. Replication stress, DNA damage, and apoptosis were increased in human cancer cells following depletion of the B-family DNA polymerases combined with SRA737 treatment. Moreover, pharmacologic blockade of B-family DNA polymerases using aphidicolin or CD437 combined with CHK1 inhibitors led to synergistic inhibition of cancer cell proliferation. Furthermore, low levels of POLA1, POLE, and POLE2 protein expression in NSCLC and colorectal cancer cells correlated with single-agent CHK1 inhibitor sensitivity and may constitute biomarkers of this phenotype. These findings provide a potential basis for combining CHK1 and B-family polymerase inhibitors in cancer therapy. SIGNIFICANCE: These findings demonstrate how the therapeutic benefit of CHK1 inhibitors may potentially be enhanced and could have implications for patient selection and future development of new combination therapies.


Assuntos
Afidicolina/farmacologia , Quinase 1 do Ponto de Checagem/antagonistas & inibidores , Neoplasias Colorretais/tratamento farmacológico , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Retinoides/farmacologia , Apoptose , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Dano ao DNA , DNA Polimerase I/antagonistas & inibidores , DNA Polimerase I/genética , DNA Polimerase I/metabolismo , DNA Polimerase II/antagonistas & inibidores , DNA Polimerase II/genética , DNA Polimerase II/metabolismo , DNA Polimerase beta , Drogas em Investigação/farmacologia , Inibidores Enzimáticos/farmacologia , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Ligação a Poli-ADP-Ribose/antagonistas & inibidores , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Interferente Pequeno/análise , RNA Interferente Pequeno/genética
15.
Clin Immunol ; 214: 108382, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32169439

RESUMO

With the successful treatment of B-cell lymphomas using rituximab, a monoclonal antibody targeting CD20, novel immunotherapies have developed rapidly in recent years. Immune checkpoint blockade and chimeric antigen receptor-T (CAR-T) cell therapy, which are antibody-based therapy and cell-based therapy, respectively, show promising efficacy and have been approved by the Food and Drug Administration for treating hematological malignancies. However, considering severe side effects and short-term clinical remission, the combination of CAR-T cell therapy and programmed cell-death protein-1 (PD-1) blockade has been applied to enhance therapeutic efficacy in preclinical models and clinical trials. Herein, we review the mechanism of the two therapies, show their toxicities and clinical use respectively, address their combined application, and discuss the scope of further investigations of this mechanism-based combination therapy.


Assuntos
Neoplasias Hematológicas/terapia , Imunoterapia Adotiva , Linfoma de Células B/terapia , Terapia de Alvo Molecular , Proteínas de Neoplasias/antagonistas & inibidores , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos Imunológicos/efeitos adversos , Antineoplásicos Imunológicos/uso terapêutico , Ensaios Clínicos como Assunto , Terapia Combinada , Neoplasias Hematológicas/tratamento farmacológico , Humanos , Imunoterapia Adotiva/efeitos adversos , Imunoterapia Adotiva/métodos , Linfoma de Células B/tratamento farmacológico , Terapia de Alvo Molecular/efeitos adversos , Estudos Multicêntricos como Assunto , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Nivolumabe/efeitos adversos , Nivolumabe/uso terapêutico , Receptor de Morte Celular Programada 1/biossíntese , Receptor de Morte Celular Programada 1/genética , Transdução de Sinais , Regulação para Cima
16.
PLoS One ; 15(3): e0229272, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32119704

RESUMO

BACKGROUND AND AIMS: Radiotherapy is one of the major remedies for the treatment of cancer, including nasopharyngeal carcinoma (NPC). Radioresistance occurs very often in target cells that is a large drawback in cancer treated with radiotherapy. Livin involves the over-growth of cancer cells. This study aims to investigate the role of livin in the radioresistance formation in NPC cells. METHODS: NPC cell lines were exposed to small doses of irradiation to establish a cell model of radioresistance, in which the role of livin in the development of radioresistance was evaluated. RESULTS: The expression of livin was observed in NPC cells, which was significantly increased after exposing to small doses of irradiation. A negative correlation was detected between livin and Fas expression in NPC cells. Livin formed a complex with heat shock factor-1 (HSF1, the transcription factor of Fas) in NPC cells after irradiation, which sped up ubiquitination of HSF1. Livin was involved in suppressing Fas expression in NPC cells with radioresistance. Exposure to livin inhibitors prevented radioresistance development and overcame the established radioresistance in NPC cells. CONCLUSIONS: Livin expression in NPC cells plays a critical role in the development of radioresistance. Depletion of livin increases the sensitiveness of NPC cells to irradiation. Target therapy against livin may have the translational potential for the treatment of NPC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/metabolismo , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Tolerância a Radiação , Regulação para Cima , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Fatores de Transcrição de Choque Térmico/metabolismo , Humanos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/radioterapia , Proteínas de Neoplasias/antagonistas & inibidores , Peptídeos/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Transdução de Sinais , Ubiquitinação , Regulação para Cima/efeitos dos fármacos , Receptor fas/metabolismo
17.
PLoS One ; 15(3): e0224344, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32176701

RESUMO

A key event in the development of both major forms of diabetes is the loss of functional pancreatic islet ß-cell mass. Strategies aimed at enhancing ß-cell regeneration have long been pursued, but methods for reliably inducing human ß-cell proliferation with full retention of key functions such as glucose-stimulated insulin secretion (GSIS) are still very limited. We have previously reported that overexpression of the homeobox transcription factor NKX6.1 stimulates ß-cell proliferation, while also enhancing GSIS and providing protection against ß-cell cytotoxicity through induction of the VGF prohormone. We developed an NKX6.1 pathway screen by stably transfecting 832/13 rat insulinoma cells with a VGF promoter-luciferase reporter construct, using the resultant cell line to screen a 630,000 compound chemical library. We isolated three compounds with consistent effects to stimulate human islet cell proliferation, but not expression of NKX6.1 or VGF, suggesting an alternative mechanism of action. Further studies of the most potent of these compounds, GNF-9228, revealed that it selectively activates human ß-cell relative to α-cell proliferation and has no effect on δ-cell replication. In addition, pre-treatment, but not short term exposure of human islets to GNF-9228 enhances GSIS. GNF-9228 also protects 832/13 insulinoma cells against ER stress- and inflammatory cytokine-induced cytotoxicity. GNF-9228 stimulates proliferation via a mechanism distinct from recently emergent DYRK1A inhibitors, as it is unaffected by DYRK1A overexpression and does not activate NFAT translocation. In conclusion, we have identified a small molecule with pleiotropic positive effects on islet biology, including stimulation of human ß-cell proliferation and insulin secretion, and protection against multiple agents of cytotoxic stress.


Assuntos
Proliferação de Células/efeitos dos fármacos , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Insulinoma/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Animais , Linhagem Celular Tumoral , Células Secretoras de Glucagon/metabolismo , Células Secretoras de Glucagon/patologia , Glucose/farmacologia , Proteínas de Homeodomínio/metabolismo , Humanos , Células Secretoras de Insulina/patologia , Insulinoma/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Ratos
18.
Bull Cancer ; 107(4): 410-416, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32145962

RESUMO

Tumor profiling has been shown to benefit patients with rare or refractory metastatic cancer, but several limitations hamper its use in daily clinical practice. We aim to assess the added benefit of a comprehensive tumor profiling, including factors predictive of response to targeted and cytotoxic therapy, in the treatment of refractory or rare solid tumors outside of a formal clinical trial. Patients were included between 2013 and 2017. Multiplatform comprehensive tumor profiling (CTP) was performed on FFPE specimens. Tumor response was evaluated by imaging using the RECIST criteria version 1.1. The PFS ratio was defined as PFS under CTP-guided therapy (PFS2)/PFS under previous standard therapy (PFS1). A clinical benefit was identified if the PFS ratio exceeded the 1.3 threshold value. In total, 184 patients were enrolled among whom 104 were evaluable for the PFS ratio. Objective response rates (ORR) were equal to 25% (CI95: 16.6-33.4%) and 36.5% (CI95: 27.2-45.8%) on the last therapy before CTP and on the CTP-guided therapy respectively (P-value=0.058 on paired proportion comparison test). The proportion of patients achieving a PFS2/PFS1 ratio≥1.3 was equal to 50%. The median PFS1 was statistically lower than PFS2 (120 days compared to 184 days respectively, P-value log rank 0.01). These results confirm the feasibility and the added benefit of a CTP in patients with refractory tumors in daily clinical practice especially in patients not able to enter a clinical trial.


Assuntos
Antineoplásicos/uso terapêutico , Terapia de Alvo Molecular/métodos , Proteínas de Neoplasias/genética , Neoplasias/tratamento farmacológico , Neoplasias/genética , Doenças Raras/tratamento farmacológico , Doenças Raras/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/antagonistas & inibidores , Tomada de Decisão Clínica , Estudos de Viabilidade , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imuno-Histoquímica , Hibridização In Situ/métodos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/mortalidade , Probabilidade , Intervalo Livre de Progressão , Análise Serial de Proteínas/métodos , Doenças Raras/mortalidade , Critérios de Avaliação de Resposta em Tumores Sólidos , Taxa de Sobrevida , Adulto Jovem
19.
Cancer Res ; 80(8): 1669-1680, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32060145

RESUMO

The role of the ataxia-telangiectasia-mutated (ATM) gene in human malignancies, especially in solid tumors, remains poorly understood. In the present study, we explored the involvement of ATM in transforming primary human cells into cancer stem cells. We show that ATM plays an unexpected role in facilitating oncogene-induced malignant transformation through transcriptional reprogramming. Exogenous expression of an oncogene cocktail induced a significant amount of DNA double-strand breaks in human fibroblasts that caused persistent activation of ATM, which in turn enabled global transcriptional reprogramming through chromatin relaxation, allowing oncogenic transcription factors to access chromatin. Consistently, deficiencies in ATM significantly attenuated oncogene-induced transformation of human cells. In addition, ATM inhibition significantly reduced tumorigenesis in a mouse model of mammary cancer. ATM and cellular DNA damage response therefore play a previously unknown role in facilitating rather than suppressing oncogene-induced malignant transformation of mammalian cells. SIGNIFICANCE: These findings uncover a novel pro-oncogenic role for ATM and show that contrary to established theory, ATM does not always function as a tumor suppressor; its function is however dependent on cell type.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Transformação Celular Neoplásica/genética , Reprogramação Celular/genética , Quebras de DNA de Cadeia Dupla , Reparo do DNA/fisiologia , Células-Tronco Neoplásicas/patologia , Animais , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/deficiência , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Linhagem Celular , Transformação Celular Neoplásica/patologia , Cromatina/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Feminino , Fibroblastos/patologia , Técnicas de Inativação de Genes , Marcação de Genes/métodos , Genes p53 , Humanos , Neoplasias Mamárias Animais/genética , Neoplasias Mamárias Animais/patologia , Camundongos , Camundongos Nus , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/deficiência , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , RNA Mensageiro/metabolismo , Ativação Transcricional , Transcriptoma/fisiologia , Proteína 28 com Motivo Tripartido/genética , Proteína 28 com Motivo Tripartido/metabolismo , Ensaio Tumoral de Célula-Tronco/métodos
20.
Cancer Res ; 80(8): 1681-1692, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32086240

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to radiotherapy, chemotherapy, or a combination of these modalities, and surgery remains the only curative intervention for localized disease. Although cancer-associated fibroblasts (CAF) are abundant in PDAC tumors, the effects of radiotherapy on CAFs and the response of PDAC cells to radiotherapy are unknown. Using patient samples and orthotopic PDAC biological models, we showed that radiotherapy increased inducible nitric oxide synthase (iNOS) in the tumor tissues. Mechanistic in vitro studies showed that, although undetectable in radiotherapy-activated tumor cells, iNOS expression and nitric oxide (NO) secretion were significantly increased in CAFs secretome following radiotherapy. Culture of PDAC cells with conditioned media from radiotherapy-activated CAFs increased iNOS/NO signaling in tumor cells through NF-κB, which, in turn, elevated the release of inflammatory cytokines by the tumor cells. Increased NO after radiotherapy in PDAC contributed to an acidic microenvironment that was detectable using the radiolabeled pH (low) insertion peptide (pHLIP). In murine orthotopic PDAC models, pancreatic tumor growth was delayed when iNOS inhibition was combined with radiotherapy. These data show the important role that iNOS/NO signaling plays in the effectiveness of radiotherapy to treat PDAC tumors. SIGNIFICANCE: A radiolabeled pH-targeted peptide can be used as a PET imaging tool to assess therapy response within PDAC and blocking iNOS/NO signaling may improve radiotherapy outcomes.


Assuntos
Fibroblastos Associados a Câncer/efeitos da radiação , Carcinoma Ductal Pancreático/radioterapia , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico/metabolismo , Neoplasias Pancreáticas/radioterapia , Animais , Fibroblastos Associados a Câncer/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Meios de Cultivo Condicionados , Citocinas/metabolismo , Humanos , Camundongos , NF-kappa B/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Resultado do Tratamento , Microambiente Tumoral
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