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1.
Ann Oncol ; 33(9): 909-915, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35654248

RESUMO

BACKGROUND: Acetaminophen (APAP) use has been associated with blunted vaccine immune responses. This study aimed to assess APAP impact on immunotherapy efficacy in patients with cancer. PATIENTS AND METHODS: Exposure to APAP was assessed by plasma analysis and was correlated with clinical outcome in three independent cohorts of patients with advanced cancer who were treated with immune checkpoint blockers (ICBs). The immunomodulatory effects of APAP were evaluated on a preclinical tumor model and on human peripheral blood mononuclear cells (PBMCs) from healthy donors. RESULTS: Detectable plasma APAP levels at treatment onset were associated with a significantly worse clinical outcome in ICB-treated cancer patients, independently of other prognostic factors. APAP significantly reduced ICB efficacy in the preclinical MC38 model, as well as the production of PD-1 blockade-related interferon-γ secretion by human PBMCs. Moreover, reduction of ICB efficacy in vivo was associated with significantly increased tumor infiltration by regulatory T cells (Tregs). Administration of APAP over 24 h induced a significant expansion of peripheral Tregs in healthy individuals. In addition, interleukin-10, a crucial mediator of Treg-induced immune suppression, was significantly up-regulated upon treatment with ICB in cancer patients taking APAP. CONCLUSIONS: This study provides strong preclinical and clinical evidence of the role of APAP as a potential suppressor of antitumor immunity. Hence, APAP should be used with caution in patients treated with ICB.


Assuntos
Acetaminofen , Neoplasias , Acetaminofen/farmacologia , Humanos , Fatores Imunológicos/uso terapêutico , Imunoterapia , Leucócitos Mononucleares , Neoplasias/tratamento farmacológico , Linfócitos T Reguladores/patologia
4.
Br J Dermatol ; 167(5): 1138-44, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23039171

RESUMO

BACKGROUND: Imatinib mesylate is a potent inhibitor of platelet-derived growth factor and transforming growth factor-ß signalling pathways which may play a role in systemic sclerosis (SSc)-associated skin changes. OBJECTIVES: We aimed primarily at assessing the efficacy of imatinib mesylate in scleroderma skin fibrosis. METHODS: We performed a phase II double-blinded trial on patients with scleroderma with either morphoea involving > 20% of body surface area or SSc with extensive skin involvement: modified Rodnan Skin Score (mRSS) ≥ 20/51. Each patient was randomized to receive either imatinib mesylate 400 mg or placebo daily for a total of 6 months, and then was followed up 6 months after therapy discontinuation. Skin fibrosis was assessed by mRSS and measurement of the dermal thickness using skin biopsies performed at inclusion and at 6 months of treatment. In addition, quality of life (Dermatology Life Quality Index and modified Health Assessment Questionnaire for Scleroderma) was recorded at each visit, and pulmonary function before and after intervention. RESULTS: Twenty-eight patients were included in the study with a mean age of 48·9 years (range 30-71): 25 had a diagnosis of a SSc and three of diffuse cutaneous scleroderma. Demographic data, frequency of organ involvement of SSc and mRSS were comparable between groups. At 6 months, the proportion of variation of mRSS from inclusion was not statistically significantly different between the two groups (median +0·10 in imatinib group vs. -0·16 in placebo group, P = 0·098). Similarly, changes in dermal thickness, quality of life and diffusion capacity for carbon monoxide were not significantly different between groups. CONCLUSIONS: This study failed to demonstrate the efficacy of imatinib 400 mg daily to improve skin fibrosis of diffuse scleroderma after 6 months of treatment based on validated outcome measurements.


Assuntos
Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Esclerodermia Difusa/tratamento farmacológico , Pele/patologia , Adulto , Idoso , Benzamidas , Método Duplo-Cego , Feminino , Fibrose/tratamento farmacológico , Humanos , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Fator de Crescimento Derivado de Plaquetas/metabolismo , Qualidade de Vida , Esclerodermia Difusa/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Resultado do Tratamento
5.
ESMO Open ; 6(3): 100134, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33984676

RESUMO

BACKGROUND: The impact of the first coronavirus disease 2019 (COVID-19) wave on cancer patient management was measured within the nationwide network of the Unicancer comprehensive cancer centers in France. PATIENTS AND METHODS: The number of patients diagnosed and treated within 17 of the 18 Unicancer centers was collected in 2020 and compared with that during the same periods between 2016 and 2019. Unicancer centers treat close to 20% of cancer patients in France yearly. The reduction in the number of patients attending the Unicancer centers was analyzed per regions and cancer types. The impact of delayed care on cancer-related deaths was calculated based on different hypotheses. RESULTS: A 6.8% decrease in patients managed within Unicancer in the first 7 months of 2020 versus 2019 was observed. This reduction reached 21% during April and May, and was not compensated in June and July, nor later until November 2020. This reduction was observed only for newly diagnosed patients, while the clinical activity for previously diagnosed patients increased by 4% similar to previous years. The reduction was more pronounced in women, in breast and prostate cancers, and for patients without metastasis. Using an estimated hazard ratio of 1.06 per month of delay in diagnosis and treatment of new patients, we calculated that the delays observed in the 5-month period from March to July 2020 may result in an excess mortality due to cancer of 1000-6000 patients in coming years. CONCLUSIONS: In this study, the delays in cancer patient management were observed only for newly diagnosed patients, more frequently in women, for breast cancer, prostate cancer, and nonmetastatic cancers. These delays may result is an excess risk of cancer-related deaths in the coming years.


Assuntos
COVID-19 , Neoplasias/complicações , COVID-19/complicações , Feminino , França , Humanos , Masculino , SARS-CoV-2
6.
Leukemia ; 34(4): 966-984, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32127639

RESUMO

The therapeutic landscape of chronic myeloid leukemia (CML) has profoundly changed over the past 7 years. Most patients with chronic phase (CP) now have a normal life expectancy. Another goal is achieving a stable deep molecular response (DMR) and discontinuing medication for treatment-free remission (TFR). The European LeukemiaNet convened an expert panel to critically evaluate and update the evidence to achieve these goals since its previous recommendations. First-line treatment is a tyrosine kinase inhibitor (TKI; imatinib brand or generic, dasatinib, nilotinib, and bosutinib are available first-line). Generic imatinib is the cost-effective initial treatment in CP. Various contraindications and side-effects of all TKIs should be considered. Patient risk status at diagnosis should be assessed with the new EUTOS long-term survival (ELTS)-score. Monitoring of response should be done by quantitative polymerase chain reaction whenever possible. A change of treatment is recommended when intolerance cannot be ameliorated or when molecular milestones are not reached. Greater than 10% BCR-ABL1 at 3 months indicates treatment failure when confirmed. Allogeneic transplantation continues to be a therapeutic option particularly for advanced phase CML. TKI treatment should be withheld during pregnancy. Treatment discontinuation may be considered in patients with durable DMR with the goal of achieving TFR.


Assuntos
Antineoplásicos/uso terapêutico , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Compostos de Anilina/uso terapêutico , Tomada de Decisão Clínica , Conferências de Consenso como Assunto , Dasatinibe/uso terapêutico , Gerenciamento Clínico , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Expressão Gênica , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Expectativa de Vida/tendências , Monitorização Fisiológica , Nitrilas/uso terapêutico , Pirimidinas/uso terapêutico , Qualidade de Vida , Quinolinas/uso terapêutico , Análise de Sobrevida
7.
Leukemia ; 21(1): 93-101, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17109025

RESUMO

Imatinib is an effective therapy for chronic myeloid leukemia (CML), a myeloproliferative disorder characterized by the expression of the recombinant oncoprotein Bcr-Abl. In this investigation, we studied an imatinib-resistant cell line (K562-r) generated from the K562 cell line in which none of the previously described mechanisms of resistance had been detected. A threefold increase in the expression of the heat-shock protein 70 (Hsp70) was detected in these cells. This increase was not associated to heat-shock transcription factor-1 (HSF-1) overexpression or activation. RNA silencing of Hsp70 decreased dramatically its expression (90%), and was accompanied by a 34% reduction in cell viability. Overexpression of Hsp70 in the imatinib-sensitive K562 line induced resistance to imatinib as detected by a large reduction in cell death in the presence of 1 muM of imatinib. Hsp70 level was also increased in blast cells of CML patients resistant to imatinib, whereas the level remained low in responding patients. Taken together, the results demonstrate that overexpression of Hsp70 can lead to both in vitro and in vivo resistance to imatinib in CML cells. Moreover, the overexpression of Hsp70 detected in imatinib-resistant CML patients supports this mechanism and identifies potentially a marker and a therapeutic target of CML evolution.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Choque Térmico HSP70/biossíntese , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Regulação para Cima , Biomarcadores Tumorais , Linhagem Celular Tumoral , Proteínas de Fusão bcr-abl/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico HSP70/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo
8.
Leukemia ; 21(7): 1481-7, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17476280

RESUMO

Monitoring of BCR-ABL transcripts has become established practice in the management of chronic myeloid leukemia. However, nucleic acid amplification techniques are prone to variations which limit the reliability of real-time quantitative PCR (RQ-PCR) for clinical decision making, highlighting the need for standardization of assays and reporting of minimal residual disease (MRD) data. We evaluated a lyophilized preparation of a leukemic cell line (K562) as a potential quality control reagent. This was found to be relatively stable, yielding comparable respective levels of ABL, GUS and BCR-ABL transcripts as determined by RQ-PCR before and after accelerated degradation experiments as well as following 5 years storage at -20 degrees C. Vials of freeze-dried cells were sent at ambient temperature to 22 laboratories on four continents, with RQ-PCR analyses detecting BCR-ABL transcripts at levels comparable to those observed in primary patient samples. Our results suggest that freeze-dried cells can be used as quality control reagents with a range of analytical instrumentations and could enable the development of urgently needed international standards simulating clinically relevant levels of MRD.


Assuntos
Perfilação da Expressão Gênica/métodos , Perfilação da Expressão Gênica/normas , Reação em Cadeia da Polimerase/métodos , Proteínas Tirosina Quinases/genética , RNA Mensageiro/análise , Liofilização , Proteínas de Fusão bcr-abl , Humanos , Indicadores e Reagentes , Células K562 , Reação em Cadeia da Polimerase/normas , Proteínas Tirosina Quinases/análise , Controle de Qualidade , Padrões de Referência
9.
Dermatology ; 216(2): 109-17, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18216472

RESUMO

BACKGROUND: Scleroderma skin overexpresses the platelet-derived growth factor receptor beta-subunit (PDGFR-beta) in dermal vessels and PDGFR-beta messenger RNA in cultured fibroblasts. Moreover, increased levels of PDGF and stimulatory autoantibodies to PDGFR have been identified in the serum of scleroderma patients. OBJECTIVE: Imatinib being an inhibitor of tyrosine kinase receptors such as PDGFR, its effect on scleroderma fibroblasts was evaluated in vitro as a preclinical therapeutic step. METHODS: The effect of imatinib on fibroblasts grown from normal or involved/uninvolved scleroderma skin was studied by Western blot and the methyltetrazolium test. The pattern of distribution of PDGFR-beta in scleroderma versus normal skin was studied by immunohistochemistry. RESULTS: In vitro, imatinib inhibited the proliferation of normal dermal and scleroderma fibroblasts at least partly via the inhibition of the phosphorylation of PDGFR. PDGFR-beta was expressed in the epidermis and adnexae in 5 lesional scleroderma biopsies and not in controls. CONCLUSION: This study suggests that imatinib can serve as therapy to limit dermal fibroblast proliferation in scleroderma.


Assuntos
Fibroblastos/efeitos dos fármacos , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Escleroderma Sistêmico/tratamento farmacológico , Pele/citologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Western Blotting , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Mesilato de Imatinib , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteínas Tirosina Quinases/antagonistas & inibidores , Receptor beta de Fator de Crescimento Derivado de Plaquetas/biossíntese , Receptor beta de Fator de Crescimento Derivado de Plaquetas/efeitos dos fármacos , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/patologia , Pele/efeitos dos fármacos , Pele/metabolismo , Resultado do Tratamento
11.
Leukemia ; 20(6): 1061-6, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16642048

RESUMO

The emergence of ABL point mutations is the most frequent cause for imatinib resistance in chronic myelogenous leukemia (CML) patients and can occur during any phase of the disease; however, their clinical impact remains controversial. In this study, we retrospectively analyzed the predictive impact of 94 BCR-ABL kinase domain mutations (18 T315I, 26 P-loop, 50 in other sites) found in 89 imatinib-resistant CML patients. At imatinib onset, 64% of patients (57/89) were in chronic phase (CP), 24% (21/89) in accelerated phase (AP) and 12% (11/89) in blastic phase (BP). T315I and P-loop mutations were preferentially discovered in accelerated phase of BP CML, and other types of mutations in CP (P=0.003). With a median follow-up of 39.2 months (6.3-67.2), since imatinib initiation, overall survival (OS) was significantly worse for P-loop (28.3 months) and for T315I (12.6 months), and not reached for other mutations (P=0.0004). For CP only, multivariate analysis demonstrated a worse OS for P-loop mutations (P=0.014), and a worse progression-free survival (PFS) for T315I mutations (P=0.014). Therefore, P-loop and T315I mutations selectively impair the outcome of imatinib-resistant CML patients, in contrast to other mutations, which may benefit from dose escalation of imatinib, able to improve or stabilize disease response.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Piperazinas/uso terapêutico , Mutação Puntual , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Benzamidas , Análise Mutacional de DNA , Relação Dose-Resposta a Droga , Feminino , França , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
12.
Rev Med Interne ; 28(2): 116-9, 2007 Feb.
Artigo em Francês | MEDLINE | ID: mdl-17157965

RESUMO

INTRODUCTION: Hypercalcemia frequently occurs in the course of Adult T-cell leukemia/lymphoma (ATLL). We report the first case of acute pancreatitis revealing ATLL. EXEGESIS: A 41-year-old woman, without medical history, presented with acute pancreatitis. Physical examination found recent loss of weight, hepatosplenomegaly and generalised lymphoadenopathy. Biochemical tests showed severe hypercalcemia and the peripheral white blood cell count revealed an atypical lymphocytosis. ATLL was diagnosed by immunophenotypic and morphological analysis of circulating lymphocytes, bone marrow and lymphatic node biopsy. Level of serum parathyroid hormone-related protein was not increased. We discuss the mechanism of hypercalcemia in this context. CONCLUSION: In spite of the high prevalence of hypercalcemia in ATLL, acute pancreatitis revealing this pathology is an exceptional condition.


Assuntos
Hipercalcemia/complicações , Hipercalcemia/etiologia , Leucemia-Linfoma de Células T do Adulto/complicações , Leucemia-Linfoma de Células T do Adulto/diagnóstico , Pancreatite/etiologia , Doença Aguda , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Humanos , Hipercalcemia/diagnóstico , Hipercalcemia/terapia , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Pancreatite/diagnóstico , Pancreatite/terapia , Indução de Remissão
13.
Leukemia ; 31(1): 65-74, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27220663

RESUMO

Although tyrosine kinase inhibitors (TKIs) efficiently cure chronic myeloid leukemia (CML), they can fail to eradicate CML stem cells (CML-SCs). The mechanisms responsible for CML-SC survival need to be understood for designing therapies. Several previous studies suggest that TKIs could modulate CML-SC quiescence. Unfortunately, CML-SCs are insufficiently available. Induced pluripotent stem cells (iPSCs) offer a promising alternative. In this work, we used iPSCs derived from CML patients (Ph+). Ph+ iPSC clones expressed lower levels of stemness markers than normal iPSCs. BCR-ABL1 was found to be involved in stemness regulation and ERK1/2 to have a key role in the signaling pathway. TKIs unexpectedly promoted stemness marker expression in Ph+ iPSC clones. Imatinib also retained quiescence and induced stemness gene expression in CML-SCs. Our results suggest that TKIs might have a role in residual disease and confirm the need for a targeted therapy different from TKIs that could overcome the stemness-promoting effect caused by TKIs. Interestingly, a similar pro-stemness effect was observed in normal iPSCs and hematopoietic SCs. These findings could help to explain CML resistance mechanisms and the teratogenic side-effects of TKIs in embryonic cells.


Assuntos
Células-Tronco Pluripotentes Induzidas/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas de Fusão bcr-abl/fisiologia , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Sistema de Sinalização das MAP Quinases/fisiologia , Células-Tronco Neoplásicas/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Células Tumorais Cultivadas
14.
Leukemia ; 31(4): 788-797, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28090091

RESUMO

Basophils form a distinct cell lineage within the hematopoietic cell family. In various myeloid neoplasms, including chronic myeloid leukemia, basophilia is frequently seen. Acute and chronic basophilic leukemias, albeit rare, have also been described. However, no generally accepted criteria and classification of basophilic leukemias have been presented to date. To address this unmet need, a series of Working Conferences and other meetings were organized between March 2015 and March 2016. The current article provides a summary of consensus statements from these meetings, together with proposed criteria to delineate acute basophilic leukemia (ABL) from chronic basophilic leukemia (CBL) and primary forms of the disease where no preceding myeloid malignancy is detected, from the more common 'secondary' variants. Moreover, the term hyperbasophilia (HB) is proposed for cases with a persistent peripheral basophil count ⩾1000 per µl of blood. This condition, HB, is highly indicative of the presence of an underlying myeloid neoplasm. Therefore, HB is an important checkpoint in the diagnostic algorithm and requires a detailed hematologic investigation. In these patients, an underlying myeloid malignancy is often found and is then labeled with the appendix -baso, whereas primary cases of ABL or CBL are very rare. The criteria and classification proposed in this article should facilitate the diagnosis and management of patients with unexplained basophilia and basophil neoplasms in routine practice, and in clinical studies.


Assuntos
Basófilos/patologia , Leucemia Basofílica Aguda/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Transtornos Leucocíticos/diagnóstico , Algoritmos , Basófilos/imunologia , Basófilos/metabolismo , Biomarcadores , Diferenciação Celular , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/imunologia , Transformação Celular Neoplásica/metabolismo , Citogenética/métodos , Diagnóstico Diferencial , Humanos , Imuno-Histoquímica , Imunofenotipagem , Leucemia Basofílica Aguda/etiologia , Leucemia Basofílica Aguda/metabolismo , Leucemia Basofílica Aguda/terapia , Leucemia Mielogênica Crônica BCR-ABL Positiva/etiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Contagem de Leucócitos , Transtornos Leucocíticos/etiologia , Transtornos Leucocíticos/metabolismo , Transtornos Leucocíticos/terapia , Fenótipo
15.
Leukemia ; 31(5): 1108-1116, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27890936

RESUMO

Recent studies suggest that a proportion of chronic myeloid leukemia (CML) patients in deep molecular remission can discontinue the tyrosine kinase inhibitor (TKI) treatment without disease relapse. In this multi-center, prospective clinical trial (EURO-SKI, NCT01596114) we analyzed the function and phenotype of T and NK cells and their relation to successful TKI cessation. Lymphocyte subclasses were measured from 100 imatinib-treated patients at baseline and 1 month after the discontinuation, and functional characterization of NK and T cells was done from 45 patients. The proportion of NK cells was associated with the molecular relapse-free survival as patients with higher than median NK-cell percentage at the time of drug discontinuation had better probability to stay in remission. Similar association was not found with T or B cells or their subsets. In non-relapsing patients the NK-cell phenotype was mature, whereas patients with more naïve CD56bright NK cells had decreased relapse-free survival. In addition, the TNF-α/IFN-γ cytokine secretion by NK cells correlated with the successful drug discontinuation. Our results highlight the role of NK cells in sustaining remission and strengthen the status of CML as an immunogenic tumor warranting novel clinical trials with immunomodulating agents.


Assuntos
Mesilato de Imatinib/uso terapêutico , Células Matadoras Naturais/citologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Estudos de Casos e Controles , Citocinas/metabolismo , Dasatinibe/uso terapêutico , Intervalo Livre de Doença , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Contagem de Linfócitos , Subpopulações de Linfócitos/citologia , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Suspensão de Tratamento
16.
Cancer Res ; 61(21): 8005-13, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11691826

RESUMO

Leukemia cells bearing the Philadelphia (Ph) chromosome express a Bcr-Abl fusion protein with deregulated protein tyrosine kinase (PTK) activity, which plays a central role in the malignant transformation. Many different signal transduction pathways are activated by Bcr-Abl, but little is known about their downstream targets in specific cell lineages. We show here that Ph-positive cell lines as well as primary cells derived from chronic myeloid leukemia (CML) in lymphoid blast crisis or from acute lymphoblastic leukemia (ALL) consistently express high levels of cyclin D2, whereas expression of this protein is low or absent in comparable Ph-negative lines and Ph-positive myeloid lines. Inhibition of Bcr-Abl with STI571 resulted in down-regulation of cyclin D2 and reduction of the number of cells in S phase, although complete G1 arrest was not induced. The expression of cyclin D2 in Ph-positive lymphoblasts was mediated via the phosphatidyl-inositol-3 kinase pathway. Analogous results were seen in murine BaF/3 cells transfected with a BCR-ABL expression vector. In contrast to the human cell lines, murine Baf/BCR-ABL cells exposed to STI571 inhibitor were all arrested in G1. This arrest could be abrogated by exogenous expression of cyclin D2 from a transfected cDNA construct. We conclude that a direct connection exists between Bcr-Abl PTK activity and cell cycle progression in which cyclin D2 plays a critical role. However, cell cycle progression in human Ph-positive lymphoid cells is not entirely dependent on Bcr-Abl PTK, and additional genetic lesions must be present.


Assuntos
Ciclinas/biossíntese , Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Linfócitos/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Proteínas Tirosina Quinases/metabolismo , Benzamidas , Crise Blástica , Ciclina D2 , Ciclinas/genética , Regulação para Baixo , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Proteínas de Fusão bcr-abl/genética , Fase G1/efeitos dos fármacos , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Linfócitos/enzimologia , Fosfatidilinositol 3-Quinases/fisiologia , Piperazinas , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/genética , Pirimidinas/farmacologia , Fase S/efeitos dos fármacos , Transdução de Sinais , Transfecção
17.
Leukemia ; 30(8): 1638-47, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27133824

RESUMO

The advent of tyrosine kinase inhibitors (TKI) into the management of patients with chronic myeloid leukemia (CML) has profoundly improved prognosis. Survival of responders is approaching that of the general population but lifelong treatment is still recommended. In several trials, TKI treatment has been stopped successfully in approximately half of the patients with deep molecular response. This has prompted the development of a new concept in the evaluation of CML patients known as 'treatment-free remission'. The future in CML treatment will be to define criteria for the safe and most promising discontinuation of TKI on one hand, and, on the other, to increase the number of patients available for such an attempt. Until safe criteria have been defined, discontinuation of therapy is still experimental and should be restricted to clinical trials or registries. This review will provide an overview of current knowledge as well as an outlook on future challenges.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Padrões de Prática Médica/tendências , Suspensão de Tratamento/tendências , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Prognóstico , Inibidores de Proteínas Quinases/uso terapêutico , Indução de Remissão/métodos
18.
Leukemia ; 30(1): 57-64, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26437782

RESUMO

The Evaluating Nilotinib Efficacy and Safety in Clinical Trials as First-Line Treatment (ENEST1st) study included 1089 patients with newly diagnosed chronic myeloid leukemia in chronic phase. The rate of deep molecular response (MR(4) (BCR-ABL1⩽0.01% on the International Scale or undetectable BCR-ABL1 with ⩾10,000 ABL1 transcripts)) at 18 months was evaluated as the primary end point, with molecular responses monitored by the European Treatment and Outcome Study network of standardized laboratories. This analysis was conducted after all patients had completed 24 months of study treatment (80.9% of patients) or discontinued early. In patients with typical BCR-ABL1 transcripts and ⩽3 months of prior imatinib therapy, 38.4% (404/1052) achieved MR(4) at 18 months. Six patients (0.6%) developed accelerated or blastic phase, and 13 (1.2%) died. The safety profile of nilotinib was consistent with that of previous studies, although the frequencies of some nilotinib-associated adverse events were lower (for example, rash, 21.4%). Ischemic cardiovascular events occurred in 6.0% of patients. Routine monitoring of lipid and glucose levels was not mandated in the protocol. These results support the use of frontline nilotinib, particularly when achievement of a deep molecular response (a prerequisite for attempting treatment-free remission in clinical trials) is a treatment goal.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Masculino , Pessoa de Meia-Idade , Pirimidinas/efeitos adversos
19.
Leukemia ; 30(9): 1844-52, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27109508

RESUMO

Molecular monitoring of chronic myeloid leukemia patients using robust BCR-ABL1 tests standardized to the International Scale (IS) is key to proper disease management, especially when treatment cessation is considered. Most laboratories currently use a time-consuming sample exchange process with reference laboratories for IS calibration. A World Health Organization (WHO) BCR-ABL1 reference panel was developed (MR(1)-MR(4)), but access to the material is limited. In this study, we describe the development of the first cell-based secondary reference panel that is traceable to and faithfully replicates the WHO panel, with an additional MR(4.5) level. The secondary panel was calibrated to IS using digital PCR with ABL1, BCR and GUSB as reference genes and evaluated by 44 laboratories worldwide. Interestingly, we found that >40% of BCR-ABL1 assays showed signs of inadequate optimization such as poor linearity and suboptimal PCR efficiency. Nonetheless, when optimized sample inputs were used, >60% demonstrated satisfactory IS accuracy, precision and/or MR(4.5) sensitivity, and 58% obtained IS conversion factors from the secondary reference concordant with their current values. Correlation analysis indicated no significant alterations in %BCR-ABL1 results caused by different assay configurations. More assays achieved good precision and/or sensitivity than IS accuracy, indicating the need for better IS calibration mechanisms.


Assuntos
Proteínas de Fusão bcr-abl/análise , Calibragem , Proteínas de Fusão bcr-abl/normas , Genes abl , Humanos , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-bcr/genética , Padrões de Referência , Organização Mundial da Saúde
20.
J Clin Oncol ; 20(1): 214-20, 2002 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11773172

RESUMO

PURPOSE: A small proportion of patients with chronic myeloid leukemia (CML) achieve a complete cytogenetic response (CCR), defined as the disappearance of Philadelphia (Ph) chromosome-positive metaphases, after treatment with interferon alfa (IFN). In this population of patients, the question of whether treatment should then be withdrawn is not yet resolved. PATIENTS AND METHODS: In the present study, we followed 15 patients who stopped IFN after achieving CCR. In nine patients IFN was stopped in view of adverse reactions (n = 8) or patient's choice (n = 1). For the remaining six patients, the treatment was stopped because no BCR/ABL rearrangement could be detected by reverse transcriptase polymerase chain reaction (RT-PCR) in four successive analyses using peripheral-blood samples. RESULTS: Loss of CCR and survival were not statistically different (P =.48; P =.7) for the 15 patients who stopped IFN compared with 41 other CCR patients who continued IFN therapy in our institution. The median follow-up after discontinuation of IFN treatment was 36 months (range, 6 to 108 months). Seven patients (47%) (females, or CCR > 24 months and RT-PCR negative before IFN cessation; P <.0001) did not relapse. Eight other patients (53%) relapsed (lost CCR) within 3 to 33 months of treatment discontinuation. One of them relapsed in major cytogenetic remission (MCR) and was still in MCR 87 months after stopping therapy without any treatment. CONCLUSION: It is possible to stop IFN treatment at least in some patients with CML who achieve a prolonged period of CCR. This study also illustrates the hypothesis that persistence of low numbers of Ph-positive cells does not necessarily imply hematologic relapse.


Assuntos
Antineoplásicos/administração & dosagem , Interferon-alfa/administração & dosagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/efeitos adversos , Intervalo Livre de Doença , Feminino , Seguimentos , Proteínas de Fusão bcr-abl/sangue , Proteínas de Fusão bcr-abl/genética , Humanos , Interferon-alfa/efeitos adversos , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Masculino , Pessoa de Meia-Idade , Recidiva , Indução de Remissão , Fatores de Risco , Estatísticas não Paramétricas , Taxa de Sobrevida , Fatores de Tempo
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