Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Leukemia ; 34(1): 100-114, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31197259

RESUMO

Interleukin-1 receptor-associated kinase 4 (IRAK4) plays a critical role in Toll-like receptor (TLR) signal transduction and innate immune responses. Recruitment and subsequent activation of IRAK4 upon TLR stimulation is mediated by the myeloid differentiation primary response 88 (MYD88) adaptor protein. Around 3% of chronic lymphocytic leukemia (CLL) patients have activating mutations of MYD88, a driver mutation in this disease. Here, we studied the effects of TLR activation and the pharmacological inhibition of IRAK4 with ND2158, an IRAK4 competitive inhibitor, as a therapeutic approach in CLL. Our in vitro studies demonstrated that ND2158 preferentially killed CLL cells in a dose-dependent manner. We further observed a decrease in NF-κB and STAT3 signaling, cytokine secretion, proliferation and migration of primary CLL cells from MYD88-mutated and -unmutated cases. In the Eµ-TCL1 adoptive transfer mouse model of CLL, ND2158 delayed tumor progression and modulated the activity of myeloid and T cells. Our findings show the importance of TLR signaling in CLL development and suggest IRAK4 as a therapeutic target for this disease.

2.
Oncogene ; 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31616059

RESUMO

Targeting Notch signaling has emerged as a promising therapeutic strategy for chronic lymphocytic leukemia (CLL), particularly in NOTCH1-mutated patients. We provide first evidence that the Notch ligand DLL4 is a potent stimulator of Notch signaling in NOTCH1-mutated CLL cells while increases cell proliferation. Importantly, DLL4 is expressed in histiocytes from the lymph node, both in NOTCH1-mutated and -unmutated cases. We also show that the DLL4-induced activation of the Notch signaling pathway can be efficiently blocked with the specific anti-Notch1 antibody OMP-52M51. Accordingly, OMP-52M51 also reverses Notch-induced MYC, CCND1, and NPM1 gene expression as well as cell proliferation in NOTCH1-mutated CLL cells. In addition, DLL4 stimulation triggers the expression of protumor target genes, such as CXCR4, NRARP, and VEGFA, together with an increase in cell migration and angiogenesis. All these events can be antagonized by OMP-52M51. Collectively, our results emphasize the role of DLL4 stimulation in NOTCH1-mutated CLL and confirm the specific therapeutic targeting of Notch1 as a promising approach for this group of poor prognosis CLL patients.

3.
Int J Cancer ; 144(11): 2762-2773, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30468254

RESUMO

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has been shown to be highly effective in patients with chronic lymphocytic leukemia (CLL) and is approved for CLL treatment. Unfortunately, resistance and intolerance to ibrutinib has been observed in several studies, opening the door for more specific BTK inhibitors. CC-292 (spebrutinib) is a BTK inhibitor with increased specificity for BTK and less inhibition of other kinases. Our in vitro studies showed that CC-292 potently inhibited B-cell receptor signaling, activation, proliferation and chemotaxis of CLL cells. In in vivo studies using the adoptive transfer TCL1 mouse model of CLL, CC-292 reduced tumor load and normalized tumor-associated expansion of T cells and monocytes, while not affecting T cell function. Importantly, the combination of CC-292 and bendamustine impaired CLL cell proliferation in vivo and enhanced the control of CLL progression. Our results demonstrate that CC-292 is a specific BTK inhibitor with promising performance in combination with bendamustine in CLL. Further clinical trials are warranted to investigate the therapeutic efficacy of this combination regimen.


Assuntos
Acrilamidas/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Cloridrato de Bendamustina/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Acrilamidas/uso terapêutico , Adulto , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Idoso , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cloridrato de Bendamustina/uso terapêutico , Medula Óssea/patologia , Modelos Animais de Doenças , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Cultura Primária de Células , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/genética , Pirimidinas/uso terapêutico , Células Tumorais Cultivadas
4.
Haematologica ; 104(3): 576-586, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30262568

RESUMO

Mutations in genes of the RAS-BRAF-MAPK-ERK pathway have not been fully explored in patients with chronic lymphocytic leukemia. We, therefore, analyzed the clinical and biological characteristics of chronic lymphocytic leukemia patients with mutations in this pathway and investigated the in vitro response of primary cells to BRAF and ERK inhibitors. Putative damaging mutations were found in 25 of 452 patients (5.5%). Among these, BRAF was mutated in nine patients (2.0%), genes upstream of BRAF (KITLG, KIT, PTPN11, GNB1, KRAS and NRAS) were mutated in 12 patients (2.6%), and genes downstream of BRAF (MAPK2K1, MAPK2K2, and MAPK1) were mutated in five patients (1.1%). The most frequent mutations were missense, subclonal and mutually exclusive. Patients with these mutations more frequently had increased lactate dehydrogenase levels, high expression of ZAP-70, CD49d, CD38, trisomy 12 and unmutated immunoglobulin heavy-chain variable region genes and had a worse 5-year time to first treatment (hazard ratio 1.8, P=0.025). Gene expression analysis showed upregulation of genes of the MAPK pathway in the group carrying RAS-BRAF-MAPK-ERK pathway mutations. The BRAF inhibitors vemurafenib and dabrafenib were not able to inhibit phosphorylation of ERK, the downstream effector of the pathway, in primary cells. In contrast, ulixertinib, a pan-ERK inhibitor, decreased phospho-ERK levels. In conclusion, although larger series of patients are needed to corroborate these findings, our results suggest that the RAS-BRAF-MAPK-ERK pathway is one of the core cellular processes affected by novel mutations in chronic lymphocytic leukemia, is associated with adverse clinical features and could be pharmacologically inhibited.

5.
Expert Opin Drug Discov ; 12(10): 1041-1052, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28776453

RESUMO

INTRODUCTION: Next generation sequencing has provided a comprehensive understanding of the mutational landscape in chronic lymphocytic leukemia (CLL), and new drivers have been identified. Some of these drivers could be pharmacologically targeted to choose the most effective personalized therapy in each CLL patient. Areas covered: In this article, the authors uncover the potential role of new targeted therapies against the most recurrent mutations in CLL as well as the recently approved therapies. The authors also provide their expert opinion and give their perspectives for the future. Expert opinion: The development of more personalized therapies is of interest to clinicians as a system to enhance the duration of treatment response and to extend the survival and quality of life of CLL patients. The main challenge, however, will be to translate the preclinical results into the clinics. Therefore, the designing and execution of clinical trials focused on molecular drivers are the need of the hour.


Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas/métodos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Animais , Desenho de Drogas , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Terapia de Alvo Molecular , Mutação , Medicina de Precisão , Qualidade de Vida , Taxa de Sobrevida
6.
Oncotarget ; 7(5): 5507-20, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26701728

RESUMO

Clinical responses to bendamustine in chronic lymphocytic leukemia (CLL) are highly heterogeneous and no specific markers to predict sensitivity to this drug have been reported. In order to identify biomarkers of response, we analyzed the in vitro activity of bendamustine and the gene expression profile in primary CLL cells. We observed that mRNA expression of CD69 (CD69) and ITGAM (CD11b) constitute the most powerful predictor of response to bendamustine. When we interrogated the predictive value of the corresponding cell surface proteins, the expression of the activation marker CD69 was the most reliable predictor of sensitivity to bendamustine. Importantly, a multivariate analysis revealed that the predictive value of CD69 expression was independent from other clinico-biological CLL features. We also showed that when CLL cells were co-cultured with distinct subtypes of stromal cells, an upregulation of CD69 was accompanied by a reduced sensitivity to bendamustine. In agreement with this, tumor cells derived from lymphoid tumor niches harbored higher CD69 expression and were less sensitive to bendamustine than their peripheral blood counterparts. Furthermore, pretreatment of CD69 high CLL cases with the B-cell receptor (BCR) pathway inhibitors ibrutinib and idelalisib decreased CD69 levels and enhanced bendamustine cytotoxic effect. Collectively, our findings indicate that CD69 could be a predictor of bendamustine response in CLL patients and the combination of clinically-tested BCR signaling inhibitors with bendamustine may represent a promising strategy for bendamustine low responsive CLL cases.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Apoptose/efeitos dos fármacos , Cloridrato de Bendamustina/farmacologia , Lectinas Tipo C/metabolismo , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/metabolismo , Purinas/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Quinazolinonas/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Antineoplásicos/farmacologia , Antineoplásicos Alquilantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Feminino , Seguimentos , Humanos , Lectinas Tipo C/genética , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Transcriptoma , Células Tumorais Cultivadas
7.
Oncotarget ; 6(26): 22734-49, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26068951

RESUMO

Mutations or deregulated expression of the components of the spliceosome can influence the splicing pattern of several genes and contribute to the development of tumors. In this context, we report that the spliceosome modulator sudemycin induces selective cytotoxicity in primary chronic lymphocytic leukemia (CLL) cells when compared with healthy lymphocytes and tumor cells from other B-lymphoid malignancies, with a slight bias for CLL cases with mutations in spliceosome-RNA processing machinery. Consistently, sudemycin exhibits considerable antitumor activity in NOD/SCID/IL2Rγ-/- (NSG) mice engrafted with primary cells from CLL patients. The antileukemic effect of sudemycin involves the splicing modulation of several target genes important for tumor survival, both in SF3B1-mutated and -unmutated cases. Thus, the apoptosis induced by this compound is related to the alternative splicing switch of MCL1 toward its proapoptotic isoform. Sudemycin also functionally disturbs NF-κB pathway in parallel with the induction of a spliced RELA variant that loses its DNA binding domain. Importantly, we show an enhanced antitumor effect of sudemycin in combination with ibrutinib that might be related to the modulation of the alternative splicing of the inhibitor of Btk (IBTK). In conclusion, we provide first evidence that the spliceosome is a relevant therapeutic target in CLL, supporting the use of splicing modulators alone or in combination with ibrutinib as a promising approach for the treatment of CLL patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Cicloexilaminas/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Pirazóis/farmacologia , Pirimidinas/farmacologia , Compostos de Espiro/farmacologia , Adulto , Idoso , Animais , Cicloexilaminas/administração & dosagem , Sinergismo Farmacológico , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Pessoa de Meia-Idade , Mutação , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem , Processamento de RNA , Compostos de Espiro/administração & dosagem , Spliceossomos/efeitos dos fármacos , Spliceossomos/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Oncotarget ; 6(25): 21159-72, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26110568

RESUMO

Acadesine is a nucleoside analogue with known activity against B-cell malignancies. Herein, we showed that in mantle cell lymphoma (MCL) cells acadesine induced caspase-dependent apoptosis through turning on the mitochondrial apoptotic machinery. At the molecular level, the compound triggered the activation of the AMPK pathway, consequently modulating known downstream targets, such as mTOR and the cell motility-related vasodilator-stimulated phosphoprotein (VASP). VASP phosphorylation by acadesine was concomitant with a blockade of CXCL12-induced migration. The inhibition of the mTOR cascade by acadesine, committed MCL cells to enter in apoptosis by a translational downregulation of the antiapoptotic Mcl-1 protein. In contrast, Bcl-2 protein levels were unaffected by acadesine and MCL samples expressing high levels of Bcl-2 tended to have a reduced response to the drug. Targeting Bcl-2 with the selective BH3-mimetic agent ABT-199 sensitized Bcl-2high MCL cells to acadesine. This effect was validated in vivo, where the combination of both agents displayed a more marked inhibition of tumor outgrowth than each drug alone. These findings support the notions that antiapoptotic proteins of the Bcl-2 family regulate MCL cell sensitivity to acadesine and that the combination of this agent with Bcl-2 inhibitors might be an interesting therapeutic option to treat MCL patients.


Assuntos
Aminoimidazol Carboxamida/análogos & derivados , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Moléculas de Adesão Celular/metabolismo , Linfoma de Célula do Manto/metabolismo , Proteínas dos Microfilamentos/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ribonucleosídeos/administração & dosagem , Sulfonamidas/administração & dosagem , Actinas/química , Aminoimidazol Carboxamida/administração & dosagem , Animais , Apoptose , Linhagem Celular Tumoral/efeitos dos fármacos , Movimento Celular , Quimiocina CXCL12/metabolismo , Quimiotaxia , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos SCID , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Transplante de Neoplasias
9.
Oncotarget ; 5(16): 6788-800, 2014 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-25216518

RESUMO

Phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway activation contributes to mantle cell lymphoma (MCL) pathogenesis and drug resistance. Antitumor activity has been observed with mTOR inhibitors. However, they have shown limited clinical efficacy in relation to drug activation of feedback loops. Selective PI3K inhibition or dual PI3K/mTOR catalytic inhibition are different therapeutic approaches developed to achieve effective pathway blockage. Here, we have performed a comparative analysis of the mTOR inhibitor everolimus, the pan-PI3K inhibitor NVP-BKM120 and the dual PI3K/mTOR inhibitor NVP-BEZ235 in primary MCL cells. We found NVP-BEZ235 to be more powerful than everolimus or NVP-BKM120 in PI3K/Akt/mTOR signaling inhibition, indicating that targeting the PI3K/Akt/mTOR pathway at multiple levels is likely to be a more effective strategy for the treatment of MCL than single inhibition of these kinases. Among the three drugs, NVP-BEZ235 induced the highest change in gene expression profile. Functional validation demonstrated that NVP-BEZ235 inhibited angiogenesis, migration and tumor invasiveness in MCL cells. NVP-BEZ235 was the only drug able to block IL4 and IL6/STAT3 signaling which compromise the therapeutic effect of chemotherapy in MCL. Our findings support the use of the dual PI3K/mTOR inhibitor NVP-BEZ235 as a promising approach to interfere with the microenvironment-related processes in MCL.


Assuntos
Linfoma de Célula do Manto/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Aminopiridinas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Quimiocina CXCL12/metabolismo , Everolimo , Células Endoteliais da Veia Umbilical Humana , Humanos , Imidazóis/farmacologia , Interleucina-4/antagonistas & inibidores , Interleucina-4/metabolismo , Interleucina-6/antagonistas & inibidores , Interleucina-6/metabolismo , Linfoma de Célula do Manto/metabolismo , Morfolinas/farmacologia , Quinolinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Transcriptoma , Microambiente Tumoral/efeitos dos fármacos
10.
Clin Cancer Res ; 20(13): 3458-71, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24799524

RESUMO

PURPOSE: To uncover the signaling pathways underlying follicular lymphoma-follicular dendritic cells (FL-FDC) cross-talk and its validation as new targets for therapy. EXPERIMENTAL DESIGN: FL primary cells and cell lines were cocultured in the presence or absence of FDC. After 24 and 48 hours, RNA was isolated from FL cells and subjected to gene expression profiling (GEP) and data meta-analysis using DAVID and GSEA softwares. Blockade of PI3K pathway by the pan-PI3K inhibitor BKM120 (buparlisib; Novartis Pharmaceutical Corporation) and the effect of PI3K inhibition on FL-FDC cross-talk were analyzed by means of ELISA, RT-PCR, human umbilical vein endothelial cell tube formation, adhesion and migration assays, Western blot, and in vivo studies in mouse FL xenografts. RESULTS: GEP of FL-FDC cocultures yields a marked modulation of FL transcriptome by FDC. Pathway assignment by DAVID and GSEA software uncovered an overrepresentation of genes related to angiogenesis, cell adhesion, migration, and serum-response factors. We demonstrate that the addition of the pan-PI3K inhibitor BKM120 to the cocultures was able to downregulate the expression and secretion of proangiogenic factors derived from FL-FDC cocultures, reducing in vitro and in vivo angiogenesis. Moreover, BKM120 efficiently counteracts FDC-mediated cell adhesion and impedes signaling and migration induced by the chemokine CXCL12. BKM120 inhibits both constitutive PI3K/AKT pathway and FDC- or CXCL12-induced PI3K/AKT pathway, hampers FDC survival signaling, and reduces cell proliferation of FL cells in vitro and in mouse xenografts. CONCLUSIONS: These data support the use of BKM120 in FL therapy to counteract microenvironment-related survival signaling in FL cells.


Assuntos
Aminopiridinas/farmacologia , Células Dendríticas Foliculares/imunologia , Células Dendríticas Foliculares/metabolismo , Linfoma Folicular/imunologia , Linfoma Folicular/metabolismo , Morfolinas/farmacologia , Animais , Adesão Celular/imunologia , Comunicação Celular/efeitos dos fármacos , Comunicação Celular/imunologia , Linhagem Celular Tumoral , Movimento Celular/imunologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Quimiocina CXCL12/metabolismo , Análise por Conglomerados , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Perfilação da Expressão Gênica , Humanos , Linfoma Folicular/genética , Linfoma Folicular/patologia , Camundongos , Neovascularização Patológica/genética , Neovascularização Patológica/imunologia , Receptores CXCR4/metabolismo , Transdução de Sinais/efeitos dos fármacos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Oncotarget ; 5(3): 726-39, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24519895

RESUMO

Mantle cell lymphoma (MCL) is considered one of the most challenging lymphoma, with limited responses to current therapies. Acadesine, a nucleoside analogue has shown antitumoral effects in different preclinical cancer models as well as in a recent phase I/II clinical trial conducted in patients with chronic lymphocytic leukemia. Here we observed that acadesine exerted a selective antitumoral activity in the majority of MCL cell lines and primary MCL samples, independently of adverse cytogenetic factors. Moreover, acadesine was highly synergistic, both in vitro and in vivo, with the anti-CD20 monoclonal antibody rituximab, commonly used in combination therapy for MCL. Gene expression profiling analysis in harvested tumors suggested that acadesine modulates immune response, actin cytoskeleton organization and metal binding, pointing out a substantial impact on metabolic processes by the nucleoside analog. Rituximab also induced changes on metal binding and immune responses.The combination of both drugs enhanced the gene signature corresponding to each single agent, showing an enrichment of genes involved in inflammation, metabolic stress, apoptosis and proliferation. These effects could be important as aberrant apoptotic and proinflammatory pathways play a significant role in the pathogenesis of MCL. In summary, our results suggest that acadesine exerts a cytotoxic effect in MCL in combination with rituximab, by decreasing the proliferative and survival signatures of the disease, thus supporting the clinical examination of this strategy in MCL patients.


Assuntos
Aminoimidazol Carboxamida/análogos & derivados , Anticorpos Monoclonais Murinos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Linfoma de Célula do Manto/tratamento farmacológico , Ribonucleosídeos/farmacologia , Aminoimidazol Carboxamida/administração & dosagem , Aminoimidazol Carboxamida/farmacologia , Animais , Anticorpos Monoclonais Murinos/administração & dosagem , Anticorpos Monoclonais Murinos/imunologia , Antígenos CD20/imunologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Estudos de Coortes , Modelos Animais de Doenças , Sinergismo Farmacológico , Feminino , Humanos , Camundongos , Camundongos SCID , Distribuição Aleatória , Ribonucleosídeos/administração & dosagem , Rituximab , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Haematologica ; 98(11): 1739-47, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23850807

RESUMO

Phosphatidylinositol-3-kinase pathway is constitutively activated in chronic lymphocytic leukemia mainly due to microenvironment signals, including stromal cell interaction and CXCR4 and B-cell receptor activation. Because of the importance of phosphatidylinositol-3-kinase signaling in chronic lymphocytic leukemia, we investigated the activity of the NVP-BKM120, an orally available pan class I phosphatidylinositol-3-kinase inhibitor. Sensitivity to NVP-BKM120 was analyzed in chronic lymphocytic leukemia primary samples in the context of B-cell receptor and microenvironment stimulation. NVP-BKM120 promoted mitochondrial apoptosis in most primary cells independently of common prognostic markers. NVP-BKM120 activity induced the blockage of phosphatidylinositol-3-kinase signaling, decreased Akt and FoxO3a phosphorylation leading to concomitant Mcl-1 downregulation and Bim induction. Accordingly, selective knockdown of BIM rescued cells from NVP-BKM120-induced apoptosis, while the kinase inhibitor synergistically enhanced the apoptosis induced by the BH3-mimetic ABT-263. We also found NVP-BKM120 to inhibit B-cell receptor- and stroma-dependent Akt pathway activation, thus sensitizing chronic lymphocytic leukemia cells to bendamustine and fludarabine. Furthermore, NVP-BKM120 down-regulated secretion of chemokines after B-cell receptor stimulation and inhibited cell chemotaxis and actin polymerization upon CXCR4 triggering by CXCL12. Our findings establish that NVP-BKM120 effectively inhibits the phosphatidylinositol-3-kinase signaling pathway and disturbs the protective effect of the tumor microenvironment with the subsequent apoptosis induction through the Akt/FoxO3a/Bim axis. We provide here a strong rationale for undertaking clinical trials of NVP-BKM120 in chronic lymphocytic leukemia patients alone or in combination therapies.


Assuntos
Aminopiridinas/farmacologia , Proteínas Reguladoras de Apoptose/fisiologia , Fatores de Transcrição Forkhead/fisiologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Proteínas de Membrana/fisiologia , Morfolinas/farmacologia , Proteína Oncogênica v-akt/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Microambiente Tumoral/fisiologia , Idoso , Idoso de 80 Anos ou mais , Aminopiridinas/uso terapêutico , Proteína 11 Semelhante a Bcl-2 , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Técnicas de Cocultura , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Proteína Forkhead Box O3 , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Pessoa de Meia-Idade , Morfolinas/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Microambiente Tumoral/efeitos dos fármacos
13.
Autophagy ; 9(1): 115-7, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23079699

RESUMO

Mantle cell lymphoma (MCL) is an aggressive neoplasm, which lacks effective therapy. The mechanistic target of rapamycin (MTOR) kinase inhibitor everolimus (RAD001) has shown activity in preclinical and clinical models of MCL, despite the fact that its mechanism of action has not been fully elucidated. We found that everolimus activity in MCL cells is closely linked to AKT phosphorylation status, and that the prevention of AKT rephosphorylation upon everolimus treatment by means of a selective AKT inhibitor, greatly enhances everolimus activity. Furthermore, our data show that an accumulation of autophagic vacuoles correlates with a lack of efficacy of dual AKT-MTOR targeting and that the complete therapeutic potential of this strategy can be restored by ATG gene selective knockdown or secondary inhibition of autolysosome formation by hydroxychloroquine. We thus demonstrated for the first time that the use of an autophagy inhibitor can overcome resistance to the combination of MTOR and AKT inhibitors in MCL cell lines and primary samples, demonstrating the prosurvival role of autophagy in AKT-MTOR compromised cells, and pointing out some potential opportunities using this triple combinational strategy in hematological malignancies.


Assuntos
Autofagia/fisiologia , Linfoma de Célula do Manto/tratamento farmacológico , Linfoma de Célula do Manto/patologia , Sirolimo/análogos & derivados , Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Everolimo , Humanos , Linfoma de Célula do Manto/fisiopatologia , Modelos Biológicos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Células Tumorais Cultivadas
14.
Clin Cancer Res ; 19(3): 586-97, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23231952

RESUMO

PURPOSE: We evaluated the antitumoral properties of the multikinase inhibitor sorafenib in mantle cell lymphoma (MCL), an aggressive B lymphoma for which current therapies have shown limited efficacy. EXPERIMENTAL DESIGN: Sensitivity to sorafenib was analyzed in MCL cell lines and primary samples in the context of BCR and microenvironment simulation. Sorafenib signaling was characterized by quantitative PCR, Western blotting, immunofluorescence, and protein immunoprecipitation. Migration analysis included flow cytometric counting, actin polymerization assays, and siRNA-mediated knockdown of focal adhesion kinase (FAK). In vivo antitumor effect of sorafenib and bortezomib was analyzed in an MCL xenograft mouse model. RESULTS: Sorafenib rapidly dephosphorylates the BCR-associated kinases, Syk and Lyn, as well as FAK, an Src target involved in focal adhesion. In this line, sorafenib displays strong synergy with the Syk inhibitor, R406. Sorafenib also blocks Mcl-1 and cyclin D1 translation, which promotes an imbalance between pro- and antiapoptotic proteins and facilitates Bax release from cyclin D1, leading to the induction of mitochondrial apoptosis and caspase-dependent and -independent mechanisms. Moreover, sorafenib inhibits MCL cell migration and CXCL12-induced actin polymerization. FAK knockdown partially prevents this inhibitory effect, indicating that FAK is a relevant target of sorafenib. Furthermore, sorafenib enhances the antitumoral activity of bortezomib in an MCL xenograft mouse model as well as overcomes stroma-mediated bortezomib resistance in MCL cells. CONCLUSION: We show for the first time that sorafenib interferes with BCR signaling, protein translation and modulates the microenvironment prosurvival signals in MCL, suggesting that sorafenib, alone or in combination with bortezomib, may represent a promising approach to treat patients with MCL.


Assuntos
Movimento Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Linfoma de Célula do Manto/metabolismo , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Actinas/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Quimiocina CXCL12/metabolismo , Ciclina D1/genética , Modelos Animais de Doenças , Feminino , Humanos , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Camundongos , Proteína de Sequência 1 de Leucemia de Células Mieloides , Niacinamida/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Multimerização Proteica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Sorafenibe , Células Estromais , Transplante Heterólogo
15.
Clin Cancer Res ; 18(19): 5278-89, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22879389

RESUMO

PURPOSE: Mantle cell lymphoma (MCL) is an aggressive B-lymphoid neoplasm with poor response to conventional chemotherapy and short survival. The phosphatidylinositol 3-kinase/Akt/mTOR survival pathway is constitutively activated in MCL cells, thereby making the mTOR inhibition an attractive therapeutic strategy. The first clinical studies of everolimus (RAD001), an mTOR inhibitor, in relapsed MCL patients have reported a significant response. Our aim was to analyze the mechanism related to everolimus resistance/sensitivity in MCL cells. EXPERIMENTAL DESIGN: Sensitivity to everolimus was analyzed in MCL cell lines and primary MCL cells. Everolimus mechanism of action was determined by flow cytometry and Western blot. Particularly, autophagy was studied by LC3BI/II expression, autophagolysosomes detection by flow cytometry and fluorescence microscopy, and siRNA-mediated gene silencing. RESULTS: Everolimus exerted antitumoral effect on MCL cells while sparing normal cells. In MCL cell lines, this phenomenon was associated to G(1) cell-cycle arrest, dephosphorylation of the mTOR downstream targets, 4E-BP1 and S6RP, and rephosphorylation of Akt. A synergistic cytotoxic effect was observed between everolimus and an Akt inhibitor, which overcame the compensatory reactivation within the mTOR signaling pathway. Interestingly, MCL cells with low response to this combination showed high levels of autophagy. Accordingly, selective triple knockdown of the autophagy genes ATG7, ATG5 and ATG3, and pretreatment with the autophagy inhibitor hydroxychloroquine, efficiently overcame the resistance to Akt/mTOR inhibitors, leading to the activation of the mitochondrial apoptotic pathway. CONCLUSIONS: These results suggest that autophagy induction protects MCL cells from Akt/mTOR targeting and counteracting autophagy may represent an attractive strategy for sensitizing MCL cells to everolimus-based therapy.


Assuntos
Autofagia/genética , Linfoma de Célula do Manto/tratamento farmacológico , Transdução de Sinais , Sirolimo/análogos & derivados , Serina-Treonina Quinases TOR , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Everolimo , Humanos , Linfoma de Célula do Manto/patologia , Terapia de Alvo Molecular , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
16.
Clin Cancer Res ; 17(12): 3956-68, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21652541

RESUMO

PURPOSE: Mantle cell lymphoma (MCL) is an aggressive B-cell neoplasm with generally poor prognosis, for which current therapies have shown limited efficacy. Vorinostat is a histone deacetylase inhibitor (HDACi) that has been approved for the treatment of cutaneous T-cell lymphoma. Our purpose was to describe the molecular mechanism whereby vorinostat induces apoptosis in MCL with particular emphasis on the role of proapoptotic BH3-only proteins. EXPERIMENTAL DESIGN: The sensitivity to vorinostat was analyzed in eight MCL cell lines and primary cells from 10 MCL patients. Determination of vorinostat mechanism of action was done by flow cytometry, immunoblotting, HDAC activity assay kit, quantitative reverse transcription PCR, chromatin immunoprecipitation, and siRNA-mediated transfection. RESULTS: Vorinostat inhibited total histone deacetylase activity leading to selective toxicity toward tumor cells. Vorinostat-mediated cell death implied the activation of mitochondrial apoptosis, as attested by BAX and BAK conformational changes, mitochondrial depolarization, reactive oxygen species generation, and subsequent caspase-dependent cell death. This phenomenon was linked to H4 hyperacetylation on promoter regions and consequent transcriptional activation of the proapoptotic BH3-only genes BIM, BMF, and NOXA. Selective knockdown of the three corresponding proteins rescued cells from vorinostat-induced apoptosis. Moreover, vorinostat enhanced the activity of the BH3-mimetic ABT-263 in MCL cells, leading to synergistic apoptosis induction. CONCLUSION: These results indicated that transcriptional upregulation of BH3-only proteins plays an important role in the antitumoral activity of vorinostat in MCL, and that HDACi alone or in combination with BH3-mimetizing agents may represent a promising therapeutic approach for MCL patients.


Assuntos
Apoptose/efeitos dos fármacos , Apoptose/genética , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Regiões Promotoras Genéticas/genética , Acetilação/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Compostos de Anilina/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sinergismo Farmacológico , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Vorinostat
17.
Blood ; 117(4): 1270-9, 2011 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-21106982

RESUMO

Despite the promising introduction of the proteasome inhibitor bortezomib in the treatment of mantle cell lymphoma (MCL), not all patients respond, and resistance often appears after initial treatment. By analyzing a set of 18 MCL samples, including cell lines with constitutive or induced resistance to bortezomib, we found a high correlation between loss of sensitivity to the proteasome inhibitor and up-regulation of the prosurvival chaperone BiP/Grp78. BiP/Grp78 stabilization was ensured at a posttranscriptional level by an increase in the chaperoning activity of heat shock protein of 90 kDa (Hsp90). In bortezomib-resistant cells, both BiP/Grp78 knockdown and cell pretreatment with the Hsp90 inhibitor of the ansamycin class, IPI-504, led to synergistic induction of apoptotic cell death when combined with bortezomib. Cell exposure to the IPI-504-bortezomib combination provoked the dissociation of Hsp90/BiP complexes, leading to BiP/Grp78 depletion, inhibition of unfolded protein response, and promotion of NOXA-mediated mitochondrial depolarization. The IPI-504-bortezomib combination also prevented BiP/Grp78 accumulation, thereby promoting apoptosis and inhibiting the growth of bortezomib-resistant tumors in a mouse model of MCL xenotransplantation. These results suggest that targeting unfolded protein response activation by the inhibition of Hsp90 may be an attractive model for the design of a new bortezomib-based combination therapy for MCL.


Assuntos
Benzoquinonas/farmacologia , Ácidos Borônicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas de Choque Térmico/genética , Lactamas Macrocíclicas/farmacologia , Linfoma de Célula do Manto/tratamento farmacológico , Pirazinas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Benzoquinonas/uso terapêutico , Bortezomib , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Regulação para Baixo/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico/metabolismo , Humanos , Lactamas Macrocíclicas/uso terapêutico , Linfoma de Célula do Manto/genética , Masculino , Camundongos , Camundongos SCID , Camundongos Transgênicos , Pessoa de Meia-Idade , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Receptores Estrogênicos/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Pharmacology ; 82(3): 171-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18679046

RESUMO

On the centenary of Paul Ehrlich's Nobel Prize, this German researcher deserves to be remembered as a pioneer in a large number of scientific disciplines. As a result of his enthusiasm and scientific abilities, dedication, and contacts with other scientists of his time, he was able to make countless contributions in fields as diverse as histology, haematology, immunology, oncology, microbiology and pharmacology, among others. Although the Swedish award was meant to recognize the standardization of the manufacture of antidiphtheria serum, it was the discovery of arsphenamine (Salvarsan) for the treatment of syphilis which won him wider international acclaim. From a pharmacological perspective, Ehrlich's outstanding contributions include dissemination of the 'magic bullet' concept for the synthesis of antibacterials, introduction of concepts such as chemoreceptor and chemotherapy, and linking the chemical structure of compounds to their pharmacological activity. These achievements took place within the framework he established for the transition from experimental pharmacology to therapeutic pharmacology. He introduced a modern research system based on the synthesis of multiple chemical structures for pharmacological screening in animal models of disease states. These contributions were undoubtedly decisive in propitiating the wider development of antibiotics decades later. For these reasons, it is fitting to mark the 100th anniversary of the Nobel Prize awarded to this great scientist by commemorating the importance of his contributions to the advance of pharmacology.


Assuntos
Desenho de Drogas , Prêmio Nobel , Farmacologia/história , Animais , Modelos Animais de Doenças , História do Século XIX , História do Século XX , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA