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1.
Transplantation ; 100(8): 1732-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26528768

RESUMO

BACKGROUND: The impact of antithymocyte globulin (ATG) in the setting of a myeloablative conditioning transplantation remains controversial, especially when using bone marrow (BM) as the stem cell source. METHODS: We therefore conducted a retrospective analysis to investigate the impact of ATG in patients with acute myeloid leukemia or myelodysplastic syndrome receiving myeloablative conditioning followed by a matched 10 of 10 unrelated donor transplant from BM or peripheral blood stem cells (PBSCs). Our study included 356 patients conditioned with cyclophosphamide associated with fractionated total body irradiation or busulfan. RESULTS: Median follow-up was 17.6 months (range, 0-156). The ATG and PBSCs were the only variables that independently decreased the cumulative incidence (CI) of chronic graft-versus-host disease (GvHD) (hazards ratio [HR], 0.4; 95% CI, 0.21-0.73; P < 0.01; and HR, 0.53; 95% CI, 0.30-0.90; P = 0.02, respectively). The ATG had no impact on overall survival, disease-free survival, relapse, and nonrelapse mortality. In the PBSC group (n = 139), ATG was associated with a lower CI of both grades III to IV acute GvHD (HR, 0.17; 95% CI, 0.03-0.91; P = 0.04), chronic GvHD (HR, 0.31; 95% CI, 0.11-0.87; P = 0.03), and GvHD-free/relapse-free survival (HR, 0.48; 95% CI, 0.29-0.80; P < 0.01), whereas these correlations were not significant in the group of patients (n = 217) receiving BM (HR, 0.36; 95% CI, 0.11-1.93; P = 0.06 for grade III-IV acute GvHD; HR, 0.49; 95% CI, 0.22-1.06; P = 0.08 for chronic GvHD; and HR, 0.69; 95% CI, 0.46-1.01; P = 0.06 for GvHD-free/relapse-free survival). CONCLUSIONS: Although our results confirm the recommendation for ATG to be added after PBSC transplantation, no obvious benefit was identified using this approach in the setting of BM transplantation. Only prospective studies may yield definitive answers to this question.


Assuntos
Soro Antilinfocitário/uso terapêutico , Transplante de Medula Óssea , Antígenos HLA/imunologia , Imunossupressores/uso terapêutico , Leucemia Mieloide Aguda/cirurgia , Síndromes Mielodisplásicas/cirurgia , Transplante de Células-Tronco de Sangue Periférico , Condicionamento Pré-Transplante/métodos , Doadores não Relacionados , Adolescente , Adulto , Soro Antilinfocitário/efeitos adversos , Transplante de Medula Óssea/métodos , Transplante de Medula Óssea/mortalidade , Bussulfano/uso terapêutico , Distribuição de Qui-Quadrado , Doença Crônica , Ciclofosfamida/uso terapêutico , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Feminino , França , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/prevenção & controle , Histocompatibilidade , Teste de Histocompatibilidade , Humanos , Imunossupressores/efeitos adversos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Agonistas Mieloablativos/uso terapêutico , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/imunologia , Síndromes Mielodisplásicas/mortalidade , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Transplante de Células-Tronco de Sangue Periférico/métodos , Transplante de Células-Tronco de Sangue Periférico/mortalidade , Modelos de Riscos Proporcionais , Recidiva , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/mortalidade , Resultado do Tratamento , Irradiação Corporal Total , Adulto Jovem
2.
J Acquir Immune Defic Syndr ; 68(2): 204-8, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25590273

RESUMO

BACKGROUND: Viremia copy-years (VCY) has been reported as a short-term predictor of mortality. We evaluated the association of this parameter with 10-year outcome within the APROCO-COPILOTE cohort. METHODS: Prospective data from 1281 HIV-1-infected patients who started a first protease inhibitor-containing regimen in 1997-1999 were analyzed. Patients with baseline plasma viral load (pVL) > 500 copies per milliliter and at least 2 pVL measures from the eighth month of follow-up were selected. VCY was calculated individually over the follow-up as the area under the pVL curve. Multivariate Cox models analyzed the relation between all-cause mortality and the following variables: age, sex, geographical origin, transmission group, HIV infection duration, ART-naive, pVL at baseline, time-dependent CD4 count, and VCY. RESULTS: Nine hundred seventy-nine patients were followed up for a median of 10 years (interquartile range: 5-11.5). At baseline, median (interquartile range) values for duration of HIV infection, pVL, and CD4 cell count were 43 (4-95) months, 4.6 (3.9-5.2) log10 copies per milliliter, and 278 (125-416) cells per cubic millimeter, respectively. At censoring date, 77 patients (8%) had died. VCY >1.4 log10 copies × yrs/mL was an independent predictor of death (hazard ratio: 2.0; 95% confidence interval: 1.2 to 3.5), which was no longer the case after adjustment for the latest pVL value [risk ratio (RR): 1.2 for 1 additional log10 copies per milliliter; 95% confidence interval: 1.1 to 1.4]. CONCLUSIONS: VCY was associated with mortality in HIV-infected patients under combined antiretroviral therapy but did not overweigh the predictive value of the latest pVL. VCY might be more useful as a marker of persistent viral replication than for routine clinical care.


Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Inibidores da Protease de HIV/uso terapêutico , HIV-1/isolamento & purificação , Viremia , Adulto , Contagem de Linfócito CD4 , Estudos de Coortes , Demografia , Feminino , Infecções por HIV/mortalidade , Humanos , Masculino , Plasma/virologia , Prognóstico , Estudos Prospectivos , Análise de Sobrevida , Carga Viral
3.
Am J Hematol ; 88(9): 780-3, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23757315

RESUMO

IPSS-R classifies cytogenetic abnormalities into five prognostic groups for survival. Monosomal karyotype (MK) is not a subgroup of IPSS-R. Additional prognostic information from MK in poor and very poor karyotype has been recently shown. The aim of our study was to determine the prognostic value of IPSS-R and MK for response and survival in AZA-treated high-risk MDS and AML with 20-30% of blasts patients. The study population included 154 patients who were classified according to IPSS-R. IPSS-R was not predictive of response (intermediate, 64%; poor, 44%; very poor, 56%; P = 0.28) or survival (intermediate, 25 months; poor, 12 months; very poor, 11 months; P = 0.14). Twenty-one patients (15%) presented with MK and had a median OS of 9 months. Patients with a very high IPSS-R score without MK had a median OS of 15 months, while patients with a high IPSS-R score without MK had a median OS of 13 months (P = 0.18). We reclassified patients into the following three groups to include MK status: very high (MK only; OS median: 9 months), high (very high IPSS-R without MK and high IPSS-R without MK; OS median: 14 months) and intermediate (OS median: 25 months). As in recent publication including MK prognostic, we confirmed that this classification was predictive for survival in AZA treated patients (P = 0.008). IPSS-R failed to discriminate between the prognostic subgroups. Stratification with MK has value in the prognosis of our cohort of AZA-treated patients.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/uso terapêutico , Cariotipagem/classificação , Leucemia Mieloide Aguda/tratamento farmacológico , Monossomia , Síndromes Mielodisplásicas/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Cariótipo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/mortalidade , Análise de Sobrevida , Resultado do Tratamento
4.
Oncotarget ; 3(12): 1557-65, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23238683

RESUMO

The advent of tyrosine kinase inhibitor (TKI) therapy has considerably improved the survival of patients suffering chronic myelogenous leukemia (CML). Indeed, inhibition of BCR-ABL by imatinib, dasatinib or nilotinib triggers durable responses in most patients suffering from this disease. Moreover, resistance to imatinib due to kinase domain mutations can be generally circumvented using dasatinib or nilotinib, but the multi-resistant T315I mutation that is insensitive to these TKIs, remains to date a major clinical problem. In this line, ponatinib (AP24534) has emerged as a promising therapeutic option in patients with all kinds of BCR-ABL mutations, especially the T315I one. However and surprisingly, the effect of ponatinib has not been extensively studied on imatinib-resistant CML cell lines. Therefore, in the present study, we used several CML cell lines with different mechanisms of resistance to TKI to evaluate the effect of ponatinib on cell viability, apoptosis and signaling. Our results show that ponatinib is highly effective on both sensitive and resistant CML cell lines, whatever the mode of resistance and also on BaF3 murine B cells carrying native BCR-ABL or T315I mutation. We conclude that ponatinib could be effectively used for all types of TKI-resistant patients.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Imidazóis/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Piridazinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Benzamidas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Dasatinibe , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Mesilato de Imatinib , Concentração Inibidora 50 , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Mutação , Piperazinas/farmacologia , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Tiazóis/farmacologia , Células Tumorais Cultivadas
5.
Oncotarget ; 3(4): 490-501, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22577154

RESUMO

Azacitidine is the leading compound to treat patients suffering myelodysplastic syndrome (MDS) or AML with less than 30% of blasts, but a majority of patients is primary refractory or rapidly relapses under treatment. These patients have a drastically reduced life expectancy as compared to sensitive patients. Therefore identifying predictive factors for AZA resistance is of great interest to propose alternative therapeutic strategies for non-responsive patients. We generated AZA-resistant myeloid cell line (SKM1-R) that exhibited increased expression of BCL2L10 an anti-apoptotic Bcl-2 member. Importantly, BCL2L10 knockdown sensitized SKM1-R cells to AZA effect suggesting that increased BCL2L10 expression is linked to AZA resistance in SKM1-R. We next established in 77 MDS patients that resistance to AZA is significantly correlated with the percentage of MDS or AML cells expressing BCL2L10. In addition, we showed that the proportion of BCL2L10 positive bone marrow cells can predict overall survival in MDS or AML patients. We propose a convenient assay in which the percentage of BCL2L10 expressing cells as assessed by flow cytometry is predictive of whether or not a patient will become resistant to AZA. Therefore, systematic determination of BCL2L10 expression could be of great interest in newly diagnosed and AZA-treated MDS patients.


Assuntos
Azacitidina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Leucemia Mieloide Aguda/tratamento farmacológico , Síndromes Mielodisplásicas/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Biomarcadores Farmacológicos/metabolismo , Linhagem Celular Tumoral , Humanos , Leucemia Mieloide Aguda/patologia , Síndromes Mielodisplásicas/patologia , Valor Preditivo dos Testes , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Interferente Pequeno/genética , Análise de Sobrevida , Transgenes/genética
6.
J Mol Cell Biol ; 4(4): 207-20, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22467682

RESUMO

Chronic myelogenous leukemia (CML) is a cytogenetic disorder resulting from the expression of p210BCR-ABL. Imatinib, an inhibitor of BCR-ABL, has emerged as the leading compound to treat CML patients. Despite encouraging clinical results, resistance to imatinib represents a major drawback for therapy, as a substantial proportion of patients are refractory to this treatment. Recent publications have described the existence of a small cancer cell population with the potential to exhibit the phenotypic switch responsible for chemoresistance. To investigate the existence of such a chemoresistant cellular subpopulation in CML, we used a two-step approach of pulse and continuous selection by imatinib in different CML cell lines that allowed the emergence of a subpopulation of adherent cells (IM-R Adh) displaying an epithelial-mesenchymal transition (EMT)-like phenotype. Overexpression of several EMT markers was observed in this CML subpopulation, as well as in CD34(+) CML primary cells from patients who responded poorly to imatinib treatment. In response to imatinib, this CD44(high)/CD24(low) IM-R Adh subpopulation exhibited increased adhesion, transmigration and invasion in vitro and in vivo through specific overexpression of the αVß3 receptor. FAK/Akt pathway activation following integrin ß3 (ITGß3) engagement mediated the migration and invasion of IM-R Adh cells, whereas persistent activation of ERK counteracted BCR-ABL inhibition by imatinib, promoting cell adhesion-mediated resistance.


Assuntos
Benzamidas/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Mesoderma/efeitos dos fármacos , Mesoderma/patologia , Piperazinas/farmacologia , Pirimidinas/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Mesilato de Imatinib , Integrina alfaVbeta3/metabolismo , Camundongos , Fenótipo
7.
J Immunother ; 35(2): 154-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22306903

RESUMO

There is now substantial evidence that imatinib may affect immune responses, especially those mediated by T lymphocytes. Fas (CD95/Apo-1), a cell death receptor, is a key regulator of the immune system. We have explored the consequences of treatment on the Fas system in chronic myeloid leukemia patients treated with imatinib. In comparison with healthy controls, we found not only a mild blood lymphopenia but also impairment of phytohemagglutinin activation in CD4Fas and CD8Fas lymphocytes of imatinib-treated patients. Moreover, these lymphocyte populations were more sensitive to FasL-induced cell death in relation to an increase in Fas expression at the cell surface. Taken together, these results reveal the role of Fas receptor in the lymphopenia observed in patients treated with imatinib, with potential deleterious consequences on antileukemic responses against this immunogenic hematological malignancy.


Assuntos
Antineoplásicos/efeitos adversos , Apoptose/efeitos dos fármacos , Proteína Ligante Fas/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Piperazinas/efeitos adversos , Pirimidinas/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose/imunologia , Benzamidas , Separação Celular , Feminino , Citometria de Fluxo , Humanos , Mesilato de Imatinib , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Linfopenia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Receptor fas/imunologia
8.
Oncotarget ; 2(11): 874-85, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22141136

RESUMO

AXL is a receptor tyrosine kinase of the TAM family, the function of which is poorly understood. We previously identified AXL overexpression in Imatinib (IM)-resistant CML cell lines and patients. The present study was conducted to investigate the role of AXL and the mechanisms underlying AXL overexpression in Tyrosine Kinase Inhibitor (TKI)-resistant CML cells. We present evidence that high AXL expression level is a feature of TKI-resistant CML cells and knockdown of AXL sensitized TKI-resistant cells to IM. In addition, expression of wild-type AXL but not a dominant negative form of AXL confers IM-sensitive CML cells the capacity to resist IM effect. AXL overexpression required PKCα and ß and constitutive activation of ERK1/2. Accordingly, GF109203X a PKC inhibitor, U0126 a MEK1 inhibitor and PKCα/ß knockdown restore sensitivity to IM while PKCα or PKCß overexpression in CML cells promotes protection against IM-induced cell death. Finally, using luciferase promoter activity assays we established that AXL is regulated transcriptionally through the AP1 transcription factor. Our findings reveal an unexpected role of AXL in resistance to TKI in CML cells, identify the molecular mechanisms involved in its overexpression and support the notion that AXL is a new marker of resistance to TKI in CML.


Assuntos
Resistencia a Medicamentos Antineoplásicos/fisiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Antineoplásicos/farmacologia , Apoptose/fisiologia , Benzamidas , Western Blotting , Linhagem Celular Tumoral , Separação Celular , Citometria de Fluxo , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Piperazinas/farmacologia , Pirimidinas/farmacologia , Interferência de RNA , Transdução de Sinais/fisiologia , Transfecção , Regulação para Cima , Receptor Tirosina Quinase Axl
9.
Cell Cycle ; 10(23): 4138-48, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22101270

RESUMO

Mitotic catastrophe (MC) is induced when stressed cells enter prematurely or inappropriately into mitosis and can be caused by ionizing radiation and anticancer drugs. Foretinib is a multikinase inhibitor whose mechanism of action is incompletely understood. We investigated here the effect of Foretinib on chronic myelogenous leukemia (CML) cell lines either sensitive (IM-S) or resistant (IM-R) to the tyrosine kinase inhibitor Imatinib. Foretinib decreased viability and clonogenic potential of IM-S and IM-R CML cells as well. Foretinib-treated cells exhibited increased size, spindle assembly checkpoint anomalies and enhanced ploidy that collectively evoked mitotic catastrophe (MC). Accordingly, Foretinib-stimulated CML cells displayed decreased expression of Cdk1, Cyclin B1 and Plk1. In addition, Foretinib triggered caspase-2 activation that precedes mitochondrial membrane permeabilization. Accordingly, z-VAD-fmk and a caspase-2 siRNA abolished Foretinib-mediated cell death but failed to affect MC, indicating that Foretinib-mediated apoptosis and MC are two independent events. Anisomycin, a JNK activator, impaired Foretinib-induced MC and inhibition or knockdown of JNK phenotyped its effect on MC. Moreover, we found that Foretinib acted as a potent inhibitor of JNK. Importantly, Foretinib exhibited no or very little effect on normal peripheral blood mononuclear cells, monocytes or melanocytes cells but efficiently inhibited the clonogenic potential of CD34+ cell from CML patients. Collectively, our data show that the multikinase inhibitor Foretinib induces MC in CML cells and other cell lines via JNK-dependent inhibition of Plk1 expression and triggered apoptosis by a caspase 2-mediated mechanism. This unusual mechanism of action may have important implications for the treatment of cancer.


Assuntos
Anilidas/farmacologia , Morte Celular , Sistema de Sinalização das MAP Quinases , Inibidores de Proteínas Quinases/farmacologia , Quinolinas/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Anisomicina/farmacologia , Antígenos CD34/metabolismo , Antineoplásicos/farmacologia , Benzamidas , Proteína Quinase CDC2/genética , Proteína Quinase CDC2/metabolismo , Caspase 2/genética , Caspase 2/metabolismo , Inibidores de Caspase , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Tamanho Celular , Sobrevivência Celular , Ciclina B1/genética , Ciclina B1/metabolismo , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Ativação Enzimática , Ensaios Enzimáticos , Humanos , Mesilato de Imatinib , Células K562/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Mitose/efeitos dos fármacos , Fenótipo , Piperazinas/farmacologia , Ploidias , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Pirimidinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transfecção , Quinase 1 Polo-Like
10.
Cell Cycle ; 10(14): 2339-43, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21654192

RESUMO

Azacitidine (AZA) is the current treatment for patients with high-risk myelodysplastic syndrome, but resistance is a common feature of AZA-treated patients. To investigate the mechanisms associated with AZA resistance in vitro, we generated AZA-resistant SKM1 myeloid cells, called hereafter AZA-R. AZA-R cells exhibit impaired mitochondrial membrane permeabilization and caspase activation in response to AZA compared to their AZA-sensitive (AZA-S) counterpart. AZA induced LC3-II accumulation and cathepsin B activity in AZA-S cells, two hallmarks of autophagy. AZA-R cells displayed increased basal autophagy but are resistant to AZA-mediated autophagy. Inhibition of autophagy using LC3 siRNA revealed that autophagy is protective in AZA-S cells and AZA-R cells in basal conditions. By contrast, AZA-R cells exhibited impaired autophagy in response to AZA. Collectively, our findings indicate that AZA promotes apoptosis and autophagy in SKM1 cells, and that AZA-R cells are resistant to both apoptosis and autophagy induced by AZA.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Apoptose , Autofagia , Azacitidina/farmacologia , Mitocôndrias/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Síndromes Mielodisplásicas/patologia , Interferência de RNA , RNA Interferente Pequeno
12.
Mol Cancer Ther ; 10(1): 37-46, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21220490

RESUMO

FOXO proteins are Akt-regulated transcription factors involved in the control of cell cycle, DNA repair, stress defense, apoptosis, and tumor suppression. We reported that plasmid-based overexpression of constitutively active FOXO3 in cells from chronic lymphocytic leukemia (CLL) reduced their survival, suggesting that increasing FOXO3 activity in hematologic malignancies may represent a promising therapeutic strategy. The transactivating transcription factor (TAT) protein transduction domain (PTD) derived from the HIV TAT protein was shown to efficiently deliver macromolecular cargo in various cell types. In this study, wild-type FOXO3 and FOXO3 mutated on Akt sites [FOXO3 T32A/S253A/S315A or TM (triple mutant)] were fused to the TAT-PTD. Using biochemical techniques, flow cytometry, and microscopy analysis, we found a rapid and dose-dependent cell penetration into leukemic cells of unlabeled and fluorescein isothiocyanate-labeled TAT-FOXO3 fusion proteins followed by their accumulation within nuclear and cytoplasmic compartments. Treatment with TAT-FOXO3 TM-but not wild-type TAT-FOXO3-proteins induced Jurkat and K562 leukemic cell death and affected cell viability of other hematologic malignancies including primary cells from CLL. Cell transduction with TAT-FOXO3 TM induced apoptotic cell death as shown by morphologic changes, Annexin V/7-AAD (7-amino-actinomycin D) staining, activation of effector caspases, and PARP cleavage, caspase blockade through the use of the inhibitor Z-VAD, and expression of Bim and p27(KIP1). By contrast, TAT-FOXO3 TM blocked cell proliferation of primary T cells, without affecting their viability. Together, our data show that cell penetrating TAT-FOXO3 TM fusion proteins constitute novel potential therapeutic agents in the treatment of lymphoproliferative disorders and hematologic malignancies.


Assuntos
Fatores de Transcrição Forkhead/farmacologia , Produtos do Gene tat/farmacologia , Leucemia/tratamento farmacológico , Proteínas de Fusão Oncogênica/farmacologia , Apoptose/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p27/biossíntese , Inibidor de Quinase Dependente de Ciclina p27/imunologia , Relação Dose-Resposta a Droga , Fluoresceína-5-Isotiocianato/farmacocinética , Proteína Forkhead Box O3 , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/farmacocinética , Produtos do Gene tat/genética , Produtos do Gene tat/farmacocinética , Humanos , Proteínas I-kappa B/biossíntese , Proteínas I-kappa B/imunologia , Células Jurkat , Células K562 , Leucemia/genética , Leucemia/metabolismo , Leucemia/patologia , Ativação Linfocitária/efeitos dos fármacos , Proteína Oncogênica v-akt/metabolismo , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/farmacocinética , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Transdução Genética , Células U937
13.
Cancer Res ; 70(23): 9659-70, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21098700

RESUMO

SPARC is an extracellular matrix protein that exerts pleiotropic effects on extracellular matrix organization, growth factor availability, cell adhesion, differentiation, and immunity in cancer. Chronic myelogenous leukemia (CML) cells resistant to the BCR-ABL inhibitor imatinib (IM-R cells) were found to overexpress SPARC mRNA. In this study, we show that imatinib triggers SPARC accumulation in a variety of tyrosine kinase inhibitor (TKI)-resistant CML cell lines. SPARC silencing in IM-R cells restored imatinib sensitivity, whereas enforced SPARC expression in imatinib-sensitive cells promoted viability as well as protection against imatinib-mediated apoptosis. Notably, we found that the protective effect of SPARC required intracellular retention inside cells. Accordingly, SPARC was not secreted into the culture medium of IM-R cells. Increased SPARC expression was intimately linked to persistent activation of the Fyn/ERK kinase signaling axis. Pharmacologic inhibition of this pathway or siRNA-mediated knockdown of Fyn kinase resensitized IM-R cells to imatinib. In support of our findings, increased levels of SPARC mRNA were documented in blood cells from CML patients after 1 year of imatinib therapy compared with initial diagnosis. Taken together, our results highlight an important role for the Fyn/ERK signaling pathway in imatinib-resistant cells that is driven by accumulation of intracellular SPARC.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Osteonectina/metabolismo , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzamidas , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , MAP Quinases Reguladas por Sinal Extracelular/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Mesilato de Imatinib , Immunoblotting , Espaço Intracelular/metabolismo , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Osteonectina/genética , Proteínas Proto-Oncogênicas c-fyn/genética , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , Regulação para Cima
14.
Cancer Res ; 70(3): 1042-52, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-20103647

RESUMO

Autophagy that is induced by starvation or cellular stress can enable cancer cell survival by sustaining energy homeostasis and eliminating damaged organelles and proteins. In response to stress, cancer cells have been reported to accumulate the protein p62/SQSTM1 (p62), but its role in the regulation of autophagy is controversial. Here, we report that the plant phytoalexin resveratrol (RSV) triggers autophagy in imatinib-sensitive and imatinib-resistant chronic myelogenous leukemia (CML) cells via JNK-dependent accumulation of p62. JNK inhibition or p62 knockdown prevented RSV-mediated autophagy and antileukemic effects. RSV also stimulated AMPK, thereby inhibiting the mTOR pathway. AMPK knockdown or mTOR overexpression impaired RSV-induced autophagy but not JNK activation. Lastly, p62 expression and autophagy in CD34+ progenitors from patients with CML was induced by RSV, and disrupting autophagy protected CD34+ CML cells from RSV-mediated cell death. We concluded that RSV triggered autophagic cell death in CML cells via both JNK-mediated p62 overexpression and AMPK activation. Our findings show that the JNK and AMPK pathways can cooperate to eliminate CML cells via autophagy.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Autofagia/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Estilbenos/farmacologia , Proteínas Quinases Ativadas por AMP/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Clorometilcetonas de Aminoácidos/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Benzamidas , Western Blotting , Inibidores de Caspase , Caspases/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Humanos , Mesilato de Imatinib , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Macrolídeos/farmacologia , Microscopia Confocal , Microscopia Eletrônica , Piperazinas/farmacologia , Pirimidinas/farmacologia , Interferência de RNA , Resveratrol , Proteína Sequestossoma-1 , Células Tumorais Cultivadas , ATPases Vacuolares Próton-Translocadoras/antagonistas & inibidores , ATPases Vacuolares Próton-Translocadoras/metabolismo
15.
PLoS One ; 4(11): e7889, 2009 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-19924252

RESUMO

CML is an hematopoietic stem cell disease characterized by the t(9;22) (q34;q11) translocation encoding the oncoprotein p210BCR-ABL. The effect of acadesine (AICAR, 5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside) a compound with known antileukemic effect on B cell chronic lymphoblastic leukemia (B-CLL) was investigated in different CML cell lines. Acadesine triggered loss of cell metabolism in K562, LAMA-84 and JURL-MK1 and was also effective in killing imatinib-resistant K562 cells and Ba/F3 cells carrying the T315I-BCR-ABL mutation. The anti-leukemic effect of acadesine did not involve apoptosis but required rather induction of autophagic cell death. AMPK knock-down by Sh-RNA failed to prevent the effect of acadesine, indicating an AMPK-independent mechanism. The effect of acadesine was abrogated by GF109203X and Ro-32-0432, both inhibitor of classical and new PKCs and accordingly, acadesine triggered relocation and activation of several PKC isoforms in K562 cells. In addition, this compound exhibited a potent anti-leukemic effect in clonogenic assays of CML cells in methyl cellulose and in a xenograft model of K562 cells in nude mice. In conclusion, our work identifies an original and unexpected mechanism by which acadesine triggers autophagic cell death through PKC activation. Therefore, in addition to its promising effects in B-CLL, acadesine might also be beneficial for Imatinib-resistant CML patients.


Assuntos
Aminoimidazol Carboxamida/análogos & derivados , Autofagia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Ribonucleosídeos/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Aminoimidazol Carboxamida/farmacologia , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Células K562 , Camundongos , Camundongos Nus , Proteína Quinase C/metabolismo , RNA Interferente Pequeno/metabolismo , Translocação Genética
16.
Autophagy ; 5(8): 1092-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19786835

RESUMO

Autophagy is a highly conserved catabolic process for the elimination and recycling of organelles and macromolecules, characterized by the formation of double-membrane vesicles called autophagosomes. To date, the function of autophagy in cell differentiation is poorly documented. Here, we investigated the possibility that megakaryocytic differentiation of the Chronic Myelogenous Leukemia (CML) cell line K562, a process known to be accompanied by accumulation of vacuoles inside the cells, might involve autophagy. Using various complementary approaches, we show that the combination of the phorbol ester PMA and the p38(MAPK) inhibitor SB202190 (SB), which engaged a majority of K562 cells towards the megakaryocytic lineage, also triggered vacuolization and autophagy. The combination of PMA + SB appears to induce both increase in autophagic fluxes and an autophagic degradation blockage. Induction of autophagy was accompanied also by increased expression of Beclin 1 and p62/SQSTM1 and was found to precede the onset of megakaryocytic differentiation. Moreover, knockdown of LC3 and Beclin 1 by specific siRNAs impaired PMA + SB-mediated vacuolization, LC3-II accumulation and megakaryocytic differentiation, as well. To the best of our knowledge, this is the first description that induction of autophagy is involved in megakaryocytic differentiation of K562 CML cells.


Assuntos
Autofagia , Diferenciação Celular , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Megacariócitos/citologia , Diferenciação Celular/efeitos dos fármacos , Humanos , Imidazóis/farmacologia , Células K562 , Megacariócitos/efeitos dos fármacos , Megacariócitos/ultraestrutura , Piridinas/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Vacúolos/efeitos dos fármacos , Vacúolos/metabolismo
17.
Mol Cancer Ther ; 8(7): 1924-33, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19567819

RESUMO

Imatinib is used to treat chronic myelogenous leukemia (CML), but resistance develops in all phases of this disease. The purpose of the present study was to identify the mode of resistance of newly derived imatinib-resistant (IM-R) and PD166326-resistant (PD-R) CML cells. IM-R and PD-R clones exhibited an increase in viability and a decrease in caspase activation in response to various doses of imatinib and PD166326, respectively, as compared with parental K562 cells. Resistance involved neither mutations in BCR-ABL nor increased BCR-ABL, MDR1 or Lyn expression, all known modes of resistance. To gain insight into the resistance mechanisms, we used pangenomic microarrays and identified 281 genes modulated in parental versus IM-R and PD-R cells. The gene signature was similar for IM-R and PD-R cells, accordingly with the cross-sensitivity observed for both inhibitors. These genes were functionally associated with pathways linked to development, cell adhesion, cell growth, and the JAK-STAT cascade. Especially relevant were the increased expression of the tyrosine kinases AXL and Fyn as well as CD44 and HMGA2. Small interfering RNA experiments and pharmacologic approaches identified FYN as a candidate for resistance to imatinib. Our findings provide a comprehensive picture of the transcriptional events associated with imatinib and PD166326 resistance and identify Fyn as a new potential target for therapeutic intervention in CML.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-fyn/genética , Piridinas/farmacologia , Pirimidinas/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzamidas , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Análise em Microsséries , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-fyn/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-fyn/metabolismo , RNA Interferente Pequeno/farmacologia , Células Tumorais Cultivadas
18.
FASEB J ; 22(6): 1894-904, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18245170

RESUMO

Imatinib is successfully used in the treatment of chronic myelogenous leukemia (CML), and the main mechanisms of resistance in refractory patients are now partially understood. In the present study, we investigated the mechanism of action of resveratrol in imatinib-sensitive (IM-S) and -resistant (IM-R) CML cell lines. Resveratrol induced loss of viability and apoptosis in IM-S and IM-R in a time- and dose-dependent fashion. Inhibition of cell viability was detected for concentrations of resveratrol as low as 5 microM, and the IC(50) values for viability, clonogenic assays, apoptosis, and erythroid differentiation were in the 10-25 microM range. The effect of imatinib and resveratrol was additive in IM-S but not in IM-R clones in which the resveratrol effect was already maximal. The effect of resveratrol on apoptosis was partially rescued by zVAD-fmk, suggesting a caspase-independent contribution. Resveratrol action was independent of BCR-ABL expression and phosphorylation, and in agreement was additive to BCR-ABL silencing. Finally, phytoalexin inhibited the growth of BaF3 cells expressing mutant BCR-ABL proteins found in resistant patients, including the multiresistant T315I mutation. Our findings show that resveratrol induces apoptosis, caspase-independent death, and differentiation that collectively contribute to the specific elimination of CML cells. Resveratrol should provide therapeutic benefits in IM-R patients and in other hematopoietic malignancies.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Piperazinas/farmacologia , Pirimidinas/farmacologia , Estilbenos/farmacologia , Antineoplásicos Fitogênicos , Apoptose/efeitos dos fármacos , Benzamidas , Caspases , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Resveratrol
19.
Haematologica ; 92(5): 627-34, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17488686

RESUMO

BACKGROUND AND OBJECTIVES: High-dose chemotherapy with allogeneic stem cell transplantation (SCT) has proven to be a successful treatment for low-grade lymphoma (LGL), but is associated with considerable transplant-related mortality (TRM). In an effort to reduce toxic mortality while maintaining the graft-versus-leukemia effect, allogeneic SCT has been combined with a reduced-intensity conditioning (RIC) regimen. The aim of this study was to determine the outcome of patients with LGL treated with RIC allogeneic SCT. DESIGN AND METHODS: This retrospective multicenter study included 73 patients with relapsed or refractory LGL allografted after a RIC regimen between 1998 and 2005 whose data were recorded in a French registry. RESULTS: Patients received a median of three lines of therapy prior to RIC allogeneic SCT. The most widely used conditioning regimens were fludarabine + busulfan + antithymocyte globulin (n=43) and fludarabine + total body irradiation (n=21). Prior to allografting, patients were in complete response (CR; n=21), partial response (PR; n=33) or had chemoresistant disease (n=19). The median follow-up was 37 months (range, 16 to 77 months). In patients in CR, PR and chemoresistant disease, the 3-year overall survival rates were 66%, 64% and 32%, respectively, while the 3-year event-free survival rates were 66%, 52% and 32%, respectively. The 3-year cumulative incidences of TRM were 32%, 28% and 63%, respectively. The incidence of relapse was 9.6%. INTERPRETATION AND CONCLUSIONS: Although associated with significant TRM, RIC allogeneic SCT in advanced chemosensitive disease leads to long-term survival.


Assuntos
Transplante de Células-Tronco Hematopoéticas/estatística & dados numéricos , Linfoma não Hodgkin/cirurgia , Condicionamento Pré-Transplante/métodos , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Soro Antilinfocitário/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bussulfano/administração & dosagem , Carmustina/administração & dosagem , Terapia Combinada , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Coleta de Dados , Intervalo Livre de Doença , Etoposídeo/administração & dosagem , Feminino , França , Doença Enxerto-Hospedeiro/epidemiologia , Doença Enxerto-Hospedeiro/etiologia , Efeito Enxerto vs Leucemia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Estimativa de Kaplan-Meier , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/mortalidade , Masculino , Melfalan/administração & dosagem , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Indução de Remissão , Estudos Retrospectivos , Terapia de Salvação , Análise de Sobrevida , Taxa de Sobrevida , Linfócitos T , Condicionamento Pré-Transplante/efeitos adversos , Transplante Homólogo , Resultado do Tratamento , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados , Irradiação Corporal Total
20.
J Acquir Immune Defic Syndr ; 41(4): 477-85, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-16652057

RESUMO

This study aimed to identify factors associated with nonadherence during the maintenance phase of highly active antiretroviral therapy (months 12-60) in the Anti PROtease Cohort (APROCO) cohort after correcting for the bias due to missing outcome data. A Heckman 2-stage approach (generalized estimating equations probit model) was used to compare visits with moderate or poor adherence and visits with high adherence. Between months 12 and 60, at least 1 self-reported adherence measure was available for 970 of the 1110 patients with at least 12 months of follow-up (3889 visits with adherence assessments). Adherence was rated as high at 2466 visits, moderate at 1125, and poor at 298. After adjustment for "missingness," moderate and poor adherence were independently associated with age (younger), perceived treatment side effects, dosing frequency different from twice daily, and a protease inhibitor-based regimen. They were also associated with depression and lack of support from the main partner. High adherence was most likely among patients born outside the European Union. A comparison restricted to poor-adherence and high-adherence visits yielded a similar pattern of predictors. Adjusting for missing outcome data changed the predictor set. Reasons for nonadherence are multifactorial. Psychosocial interventions and the selection of the best-tolerated regimens are needed to improve long-term adherence of HIV-infected patients to their lifelong treatment.


Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/uso terapêutico , Recusa do Paciente ao Tratamento , Adulto , Fatores Etários , Depressão , Esquema de Medicação , Etnicidade , Feminino , Seguimentos , Inibidores da Protease de HIV/administração & dosagem , Inibidores da Protease de HIV/efeitos adversos , Humanos , Masculino , Fatores de Risco , Apoio Social , Estatística como Assunto
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