RESUMO
Chromosomal rearrangements involving 3q26 are recurrent findings in myeloid malignancies leading to MECOM overexpression, which has been associated with a very poor prognosis. Other 3q abnormalities have been reported and cryptic MECOM rearrangements have been identified in some cases. By fluorescence in situ hybridization (FISH) analysis, we investigated 97 acute myeloid leukemia/myelodysplastic syndrome patients with various 3q abnormalities to determine the role and the frequency of the involvement of MECOM. We identified MECOM rearrangements in 51 patients, most of them showed 3q26 involvement by chromosome banding analysis (CBA): inv(3)/t(3;3) (n = 26) and other balanced 3q26 translocations (t(3q26)) (n = 15); the remaining cases (n = 10) showed various 3q abnormalities: five with balanced translocations involving 3q21 or 3q25; two with homogenously staining region (hsr) on 3q; and three with other various 3q abnormalities. Complex rearrangements with multiple breakpoints on 3q, masking 3q26 involvement, were identified in cases with 3q21/3q25 translocations. Furthermore, multiple breaks were observed in two cases with t(3q26), suggesting that complex rearrangement may also occur in apparently simple t(3q26). Intrachromosomal gene amplification was another mechanism leading to MECOM overexpression in two cases with hsr on 3q. In the last three cases, FISH analysis revealed 3q26 involvement that was missed by CBA because of metaphases' suboptimal quality. All cases with MECOM rearrangements showed overexpression by real-time quantitative PCR. Finally, MECOM rearrangements can occur in patients with 3q abnormalities even in the absence of specific 3q26 involvement, underlining that their frequency is underestimated. As MECOM rearrangement has been associated with very poor prognosis, its screening should be performed in patients with any 3q abnormalities.
Assuntos
Cromossomos Humanos Par 3 , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/genética , Proto-Oncogenes/genética , Fatores de Transcrição/genética , Translocação Genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Bandeamento Cromossômico , Feminino , Humanos , Hibridização in Situ Fluorescente , Proteína do Locus do Complexo MDS1 e EVI1 , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Myelofibrosis (MF) is a clonal neoplasia of the hemopoietic stem/progenitor cells associated with genetic mutations in the Janus kinase 2 (JAK2), myeloproliferative leukemia virus oncogene (MPL), and calreticulin (CALR) genes. MF is also characterized by a state of chronic inflammation. Calreticulin (CRT), as a multifunctional protein, is involved in a spectrum of cellular processes including inflammation, autoimmunity, and cancer initiation/progression. Based on this background, we hypothesised that in MF circulating CRT might reflect the inflammatory process. In the present study we show that circulating CRT is increased in MF patients compared to healthy controls. Also, in MF, CRT levels highly correlate with bone marrow fibrosis, splenomegaly, and Interleukin-6 (IL-6) plasma levels. In turn, higher IL-6 levels also correlated with disease severity in terms of increased spleen size, bone marrow fibrosis, number of circulating CD34+ cells, and lower hemoglobin values. These results demonstrate that the circulating CRT takes part in the inflammatory network of MF and correlates with aggressiveness of the disease.
RESUMO
Additional chromosomal abnormalities (ACAs) in Philadelphia-positive cells have been reported in â¼ 5% of patients with newly diagnosed chronic myeloid leukemia (CML) in chronic phase (CP). Few studies addressing the prognostic significance of baseline ACAs in patients treated with imatinib have been published previously. The European LeukemiaNet recommendations suggest that the presence of ACAs at diagnosis is a "warning" for patients in early CP, but there is not much information about their outcome after therapy with tyrosine kinase inhibitors. To investigate the role of ACAs in early CP CML patients treated with imatinib mesylate, we performed an analysis in a large series of 559 patients enrolled in 3 prospective trials of the Gruppo Italiano Malattie Ematologiche dell'Adulto Working Party on CML: 378 patients were evaluable and ACAs occurred in 21 patients (5.6%). The overall cytogenetic and molecular response rates were significantly lower and the time to response was significantly longer in patients with ACAs. The long-term outcome of patients with ACAs was inferior, but the differences were not significant. The prognostic significance of each specific cytogenetic abnormality was not assessable. Therefore, we confirm that ACAs constitute an adverse prognostic factor in CML patients treated with imatinib as frontline therapy.
Assuntos
Antineoplásicos/efeitos adversos , Aberrações Cromossômicas/induzido quimicamente , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/genética , Cromossomo Filadélfia , Piperazinas/efeitos adversos , Pirimidinas/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Análise Citogenética , Feminino , Humanos , Mesilato de Imatinib , Hibridização in Situ Fluorescente , Leucemia Mieloide de Fase Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Adulto JovemRESUMO
Variant Philadelphia (Ph) chromosome translocations have been reported in 5%-10% of patients with newly diagnosed chronic myeloid leukemia (CML). Variant translocations may involve one or more chromosomes in addition to 9 and 22, and can be generated by 2 different mechanisms, 1-step and 2-step rearrangements, as revealed by fluorescence in situ hybridization. The prognostic significance of the occurrence of variant translocations has been discussed in previous studies. The European LeukemiaNet recommendations do not provide a "warning" for patients with variant translocations, but there is limited information about their outcome after therapy with tyrosine kinase inhibitors. To identify the role of variant translocations in early chronic phase (CP) CML patients treated with imatinib mesylate, we performed an analysis in a large series of 559 patients enrolled in 3 prospective imatinib trials of the Gruppo Italiano Malattie EMatologiche dell'Adulto (GIMEMA) Working Party on CML. Variant translocations occurred in 30 patients (5%). Our data show that the presence of variant translocations has no impact on the cytogenetic and molecular response or on outcome, regardless of the involvement of different mechanisms, the number of involved chromosomes, or the presence of deletions. Therefore, we suggest that patients with variant translocations do not constitute a "warning" category in the imatinib era. This study is registered at www.clinicaltrials.gov as NCT00514488 and NCT00510926.
Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Cromossomo Filadélfia , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Análise Citogenética , Feminino , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Sobrevida , Adulto JovemRESUMO
The translocation t(5;12)(q31;p13)/ETV6::ACSL6 is a rare cytogenetic abnormality, although it is reported in various myeloid malignancies. To date, only 16 cases of t(5;12) and ETV6::ACSL6 rearrangement, confirmed by either molecular or Fluorescence In Situ Hyridization (FISH) analysis, have been reported. Eosinophilia is a distinctive and common feature associated with this rearrangement. Although few cases have been described, the prognosis of patients with ETV6::ACSL6 is considered poor. We report two additional cases of t(5;12)(q31;p13)/ETV6::ACLS6 rearrangement and eosinophilia. Unusually, in our cases, the ETV6::ACSL6 rearrangement occurred at the relapse of Acute Myeloid Leukemia (AML) patients who had t(6;9)(p23;q34)/DEK::NUP214 rearrangement at disease onset. The concurrence of these two rare abnormalities has never been reported and may suggest a cooperative role of t(5;12) and t(6;9), leading to disease relapse. Moreover, at relapse, both cases presented with eosinophilia, further strengthening the association of t(5;12) with eosinophilia in myeloid malignancies. Given the poor prognosis and the non-responsiveness to tyrosine kinase inhibitors of cases of ETV6::ACSL6 rearrangement, in contrast to cases of ETV6::PDGFRB rearrangement, we recommend the introduction of testing for this abnormality in myeloid malignancies with eosinophilia.
Assuntos
Eosinofilia , Leucemia Mieloide Aguda , Transtornos Mieloproliferativos , Proteínas Cromossômicas não Histona/genética , Aberrações Cromossômicas , Eosinofilia/complicações , Eosinofilia/genética , Humanos , Hibridização in Situ Fluorescente , Leucemia Mieloide Aguda/complicações , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Proteínas Oncogênicas/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Recidiva , Translocação GenéticaRESUMO
Imatinib mesylate has become the treatment of choice for chronic myeloid leukemia (CML): the standard dose for chronic- phase (CP) CML is 400 mg daily. Response rates are different according to Sokal score, being significantly lower in intermediate and high Sokal risk patients. Phase 1 and 2 trials have shown a dose-response effect and high-dose imatinib trials in early CP CML showed better results compared with standard dose. Our study is the first prospective trial planned to evaluate the efficacy and tolerability of high-dose imatinib in previously untreated intermediate Sokal risk CML patients. Seventy-eight patients were treated with 400 mg imatinib twice daily: complete cytogenetic response (CCgR) rates at 12 and 24 months were 88% and 91%; moreover, at 12 and 24 months 56% and 73% of CCgR patients achieved a major molecular response. The incidence of adverse events was slightly higher than reported by the most important standard-dose trials. With a median follow-up of 24 months, 3 patients progressed to advanced phase. In intermediate Sokal risk newly diagnosed CML patients, high-dose imatinib induced rapid and high response rates, apparently faster than those documented in the International Randomized Study of IFN and Imatinib for the same risk category. These clinical trials are registered at www.clinicaltrials.gov as no. NCT00510926.
Assuntos
Antineoplásicos/administração & dosagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/epidemiologia , Piperazinas/administração & dosagem , Pirimidinas/administração & dosagem , Adulto , Idoso , Antineoplásicos/efeitos adversos , Benzamidas , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Piperazinas/efeitos adversos , Estudos Prospectivos , Pirimidinas/efeitos adversos , Fatores de Risco , Resultado do TratamentoRESUMO
Nilotinib has a higher binding affinity and selectivity for BCR-ABL with respect to imatinib and is an effective treatment of chronic myeloid leukemia (CML) after imatinib failure. In a phase 2 study, 73 early chronic-phase, untreated, Ph(+) CML patients, received nilotinib at a dose of 400 mg twice daily. The primary endpoint was the complete cytogenetic response (CCgR) rate at 1 year. With a median follow-up of 15 months, the CCgR rate at 1 year was 96%, and the major molecular response rate 85%. Responses were rapid, with 78% CCgR and 52% major molecular response at 3 months. During the first year, the treatment was interrupted at least once in 38 patients (52%). The mean daily dose ranged between 600 and 800 mg in 74% of patients, 400 and 599 mg in 18% of patients, and was less than 400 mg in 8% of patients. Dose interruptions were mainly due to nonhematologic and biochemical side effects. Myelosuppression was irrelevant. One patient progressed to blastic crisis after 6 months; one went off-treatment for lipase increase grade 4 (no pancreatitis). Nilotinib is safe and very active in early chronic-phase CML. These data support a role for nilotinib for the frontline treatment of CML. This study was registered at ClinicalTrials.gov as NCT00481052.
Assuntos
Antineoplásicos/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Proteínas de Fusão bcr-abl/efeitos dos fármacos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
In chronic myeloid leukemia, different methods are available to monitor the response to therapy: chromosome banding analysis (CBA), interphase fluorescence in situ hybridization (I-FISH), and real-time quantitative polymerase chain reaction (RT-Q-PCR). The GIMEMA CML WP (Gruppo Italiano Malattie Ematologiche Adulto Chronic Myeloid Leukemia Working Party) has performed a prospective study to compare CBA and I-FISH for the definition of complete cytogenetic response (CCgR). Samples (n = 664) were evaluated simultaneously by CBA and I-FISH. Of 537 cases in CCgR, the number of positive nuclei by I-FISH was less than 1% in 444 cases (82.7%). Of 451 cases with less than 1% positive nuclei by I-FISH, 444 (98.4%) were classified as CCgR by CBA. The major molecular response rate was significantly greater in cases with I-FISH less than 1% than in those with I-FISH 1% to 5% (66.8% vs 51.6%, P < .001) and in cases with CCgR and I-FISH less than 1% than in cases with CCgR and I-FISH 1% to 5% (66.1% vs 49.4%, P = .004). I-FISH is more sensitive than CBA and can be used to monitor CCgR. With appropriate probes, the cutoff value of I-FISH may be established at 1%. These trials are registered at http://www.clinicaltrials.gov as NCT00514488 and NCT00510926.
Assuntos
Bandeamento Cromossômico , Hibridização in Situ Fluorescente , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Antineoplásicos/uso terapêutico , Ensaios Clínicos como Assunto , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Indução de Remissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Resultado do TratamentoAssuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 8/genética , Rearranjo Gênico , Neoplasias Hematológicas/genética , Histona Acetiltransferases/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Adulto , Idoso , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-IdadeRESUMO
An increase in the serum concentration of pancreatic enzymes (amylase and lipase) was reported in a proportion of imatinib-resistant and/or intolerant Philadelphia-positive chronic myeloid leukemia patients treated with nilotinib. Acute pancreatitis was very rare, and the relevance of these laboratory alterations remains unknown. We report on 8 chronic myeloid leukemia patients who developed serum lipase/amylase elevation during treatment with nilotinib. After a median follow-up of 26 months, none of these patients developed an acute pancreatitis or clinical signs of pancreatic disease. Pancreatic hyperenzymemia never led to permanent drug discontinuation and required nilotinib temporary interruption in one case only. The median cumulative duration of dose interruptions and response to treatment were comparable in patients with or without pancreatic enzyme elevation. The mechanisms of action of nilotinib on pancreatic enzymes deserves to be investigated: however, in our experience, the relevance of pancreatic hyperenzymemia was clinically very limited.
Assuntos
Amilases/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Lipase/sangue , Pirimidinas/uso terapêutico , Adolescente , Adulto , Idoso , Benzamidas , Criança , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Mesilato de Imatinib , Masculino , Pessoa de Meia-Idade , Piperazinas/efeitos adversos , Piperazinas/uso terapêutico , Pirimidinas/efeitos adversos , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: Imatinib mesylate is the first line treatment for chronic myeloid leukemia. The advent of imatinib increased survival significantly in patients in an advanced phase of the disease. However, few long-term data on the outcome of these patients based on large, prospective and controlled trials are available. DESIGN AND METHODS: A phase 2 multicenter trial of the use of imatinib 600 mg/daily in patients with accelerated phase chronic myeloid leukemia was sponsored and promoted by the Italian Cooperative Study Group on Chronic Myeloid Leukemia in 2001. RESULTS: One hundred and eleven patients were enrolled; the median follow-up of the 41 living patients is 82 months (range, 73-87). One hundred and seven patients (96%) returned to chronic phase and 79 patients (71%) achieved a complete hematologic response. Cumulative best rates of major cytogenetic response and complete cytogenetic response were 30% and 21%, respectively. All responses were maintained for a minimum of 4 weeks. At last follow-up, four patients were alive in complete remission after allogeneic transplant, 16 patients (14%) had switched to a second generation tyrosine kinase inhibitor and 21 patients (19%) were alive on imatinib therapy. No late toxicities were observed. Progression-free survival and event-free survival rates were 36.5% and 15%, respectively, at 7 years. The median survival time was 37 months, and was significantly associated with the achievement of a complete hematologic response or a complete cytogenetic response. CONCLUSIONS: Imatinib may induce durable responses, associated with prolonged survival, in patients with accelerated phase chronic myeloid leukemia.
Assuntos
Leucemia Mieloide de Fase Acelerada/tratamento farmacológico , Piperazinas/administração & dosagem , Pirimidinas/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Análise Citogenética , Feminino , Seguimentos , Humanos , Mesilato de Imatinib , Leucemia Mieloide de Fase Acelerada/mortalidade , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND: Imatinib mesylate is the first line treatment for chronic myeloid leukemia. In patients with advanced phase of the disease, the advent of imatinib significantly increased survival. However, few long-term data, based on large, prospective and controlled trials are available on the outcome of these patients. DESIGN AND METHODS: We conducted a phase II trial of imatinib 600 mg daily in patients with chronic myeloid leukemia in blast crisis. The return to chronic phase was defined as <15% blasts and <30% blasts plus promyelocytes in blood or bone marrow and <20% peripheral basophils. A complete hematologic response required the normalization of platelet and white cell differential counts and absence of extramedullary involvement. Cytogenetic response was assessed by the standard banding technique and rated as usual. RESULTS: Ninety-two patients were enrolled (20 with lymphoid blast crisis and 72 with myeloid blast crisis). Forty-six patients (50%) returned to chronic phase, and 24 patients (26%) achieved also a complete hematologic response. Sixteen patients (17%) had a cytogenetic response (9 complete, 1 partial, and 6 minor or minimal). The complete cytogenetic response was subsequently lost by all but two patients between 2 and 12 months after first having achieved it: the median duration of complete cytogenetic response was 7 months. All responses were sustained for a minimum of 4 weeks. The median survival of all the patients was 7 months. After a median observation time of 66 months, seven (8%) patients are alive. Three of these patients are on imatinib treatment (1 in complete hematologic remission, 1 in partial cytogenetic response and 1 in complete cytogenetic remission). Three patients are in complete remission after allogeneic stem cell transplantation. One patient is alive in blast crisis, on therapy with a second-generation tyrosine kinase inhibitor. CONCLUSIONS: Imatinib was effective and safe in the short-term treatment of chronic myeloid leukemia in blast crisis, but longer-term outcome was not significantly influenced (ClinicalTrials.gov identifier: NCT00514969).
Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Piperazinas/administração & dosagem , Pirimidinas/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Crise Blástica , Feminino , Seguimentos , Transplante de Células-Tronco Hematopoéticas , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida , Fatores de Tempo , Transplante Homólogo , Resultado do Tratamento , Adulto JovemRESUMO
The emergence of resistance to the Bcr-Abl inhibitor imatinib mesylate in patients with Philadelphia chromosome-positive (Ph+) leukemia has prompted the development of second-generation compounds active against several imatinib-insensitive mutant forms of Bcr-Abl, including dasatinib (BMS-354825; Bristol-Myers Squibb). In order to assess which pre-existent or emerging kinase domain mutations are associated with decreased clinical efficacy of desatinib, we analyzed BCR-ABL kinase sequences before and during treatment in 21 Ph+ patients who failed to respond to or relapsed during dasatinib therapy. In all patients but one, resistance to dasatinib was invariably found to be associated with mutations at residue 315 and/or at residue 317.
Assuntos
Substituição de Aminoácidos , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Mutação de Sentido Incorreto , Proteínas de Neoplasias/genética , Mutação Puntual , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Tiazóis/farmacologia , Adolescente , Adulto , Idoso , Antineoplásicos/uso terapêutico , Benzamidas , Códon/genética , Análise Mutacional de DNA , DNA de Neoplasias/genética , Dasatinibe , Feminino , Seguimentos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Proteínas de Fusão bcr-abl/química , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/antagonistas & inibidores , Piperazinas/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Recidiva , Relação Estrutura-Atividade , Tiazóis/uso terapêuticoRESUMO
Myelofibrosis (MF) is a clonal neoplasia associated with chronic inflammation due to aberrant cytokine production. Mutations in Janus Kinase-2 (JAK2), calreticulin (CALR) and myeloproliferative leukemia protein (MPL) genes have been recently associated to MF and they all activate the JAK/STAT signaling pathway. Since this pathway is essential in shaping the immune response, we investigated the role of circulating immune subsets and cytokines in 38 patients (20 carrying JAK2(V617F),13 exon-9 CALR mutation and 5 triple negative). In comparison to healthy donors, patients presented a reduced amount of circulating dendritic cells (DCs) associated with a defective ability of monocytes in differentiating into DCs. In addition, we found a reduction in circulating T-helper (Th)1 and Th17 and hypo-functional innate lymphoid cells (ILC). Results analyzed according to the mutational status showed that patients carrying JAK2(V617F) mutation had a reduction in Th17, myeloid-DCs and effector Tregs as well as increased ILC1 and cytokine producing Tregs. The CALR mutated patients revealed high ILC3 levels, reduced Th1 and their monocytes had a reduced capacity to mature in vitro into fully committed DCs. Their Tregs were also less effective in inhibiting the proliferation of autologous effector T-cells due to an increased proliferative status induced by CALR mutation. Triple negative patients presented a reduced amount of total circulating CD3, effectors Tregs and Th1 with increased ILC1. Overall, we have demonstrated that in MF different mutations lead to phenotypic and functional alterations in different immune subsets that may have a potential role in disease progression and susceptibility to infections.
RESUMO
At diagnosis, about 5% of Chronic Myeloid Leukemia (CML) patients lacks Philadelphia chromosome (Ph), despite the presence of the BCR/ABL rearrangement. Two mechanisms have been proposed about the occurrence of this rearrangement: the first one is a cryptic insertion between chromosomes 9 and 22; the second one involves two sequential translocations: a classic t(9;22) followed by a reverse translocation, which reconstitutes the normal morphology of the partner chromosomes. Out of 398 newly diagnosed CML patients, we selected 12 Ph-negative cases. Six Ph-negative patients treated with tyrosine kinase inhibitors (TKIs) were characterized, in order to study the mechanisms leading to the rearrangement and the eventual correlation with prognosis in treatment with TKIs. FISH analysis revealed cryptic insertion in 5 patients and classic translocation in the last one. In more detail, we observed 4 different patterns of rearrangement, suggesting high genetic heterogeneity of these patients. In our cases, the BCR/ABL rearrangement mapped more frequently on 9q34 region than on 22q11 region, in contrast to previous reports. Four patients, with low Sokal risk, achieved Complete Cytogenetic Response and/or Major Molecular Response after TKIs therapy. Therapy resistance was observed in one patient with duplication of BCR/ABL rearrangement and in another one with high risk. Even if the number patient is inevitably low, we can confirm that the rare Ph-negative CML patients do not constitute a "warning" category, meanwhile the presence of further cytogenetic abnormalities remains an adverse prognostic factor even in TKI era.
Assuntos
Proteínas de Fusão bcr-abl/genética , Variação Genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Humanos , Hibridização in Situ Fluorescente , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Farmacogenética , Cromossomo Filadélfia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Translocação Genética , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: Point mutations within the ABL kinase domain of the BCR-ABL gene have been associated with clinical resistance to imatinib mesylate in chronic myeloid leukemia (CML) patients. To shed further light on the frequency, distribution, and prognostic significance of ABL mutations, we retrospectively analyzed a homogeneous cohort of late chronic phase CML patients who showed primary cytogenetic resistance to imatinib. PATIENTS AND METHODS: Using denaturing high-performance liquid chromatography (D-HPLC) and sequencing, we screened for ABL mutations in a total of 178 bone marrow and/or peripheral blood samples from 40 late chronic phase CML patients homogeneously treated with imatinib 400 mg/d, who did not reach a major cytogenetic response at 12 months. RESULTS: Mutations were found in 19 of 40 patients (48%). Mutations were already detectable by D-HPLC at a median of 3 months from the onset of therapy. The presence of a missense mutation was significantly associated with a greater likelihood of subsequent progression to accelerated phase/blast crisis (P = .0002) and shorter survival (P = .001). Patients carrying mutations falling within the P-loop seemed to have a particularly poor outcome in terms of time to progression (P = .032) and survival (P = .045). CONCLUSION: Our results show that, irrespective of the hematologic response, monitoring for emerging mutations in the first months of therapy may play a role in detecting patients with worse prognosis, for whom a revision of the therapeutic strategy should be considered.
Assuntos
Antineoplásicos/uso terapêutico , Análise Citogenética/métodos , Resistencia a Medicamentos Antineoplásicos/genética , Genes abl/genética , Leucemia Mieloide de Fase Crônica/genética , Piperazinas/uso terapêutico , Mutação Puntual , Pirimidinas/uso terapêutico , Adulto , Idoso , Benzamidas , Crise Blástica , Distribuição de Qui-Quadrado , Cromatografia Líquida de Alta Pressão , Análise Mutacional de DNA , Progressão da Doença , Feminino , Humanos , Mesilato de Imatinib , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Prognóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não Paramétricas , Análise de SobrevidaRESUMO
Along with molecular abnormalities (mutations in JAK2, Calreticulin (CALR) and MPL genes), chronic inflammation is the major hallmark of Myelofibrosis (MF). Here, we investigated the in vitro effects of crucial factors of the inflammatory microenvironment (Interleukin (IL)-1ß, Tumor Necrosis Factor (TNF)-α, Tissue Inhibitor of Metalloproteinases (TIMP)-1 and ATP) on the functional behaviour of MF-derived circulating CD34+ cells.We found that, regardless mutation status, IL-1ß or TNF-α increases the survival of MF-derived CD34+ cells. In addition, along with stimulation of cell cycle progression to the S-phase, IL-1ß or TNF-α ± TIMP-1 significantly stimulate(s) the in vitro clonogenic ability of CD34+ cells from JAK2V617 mutated patients. Whereas in the JAK2V617F mutated group, the addition of IL-1ß or TNF-α + TIMP-1 decreased the erythroid compartment of the CALR mutated patients. Megakaryocyte progenitors were stimulated by IL-1ß (JAK2V617F mutated patients only) and inhibited by TNF-α. IL-1ß + TNF-α + C-X-C motif chemokine 12 (CXCL12) ± TIMP-1 highly stimulates the in vitro migration of MF-derived CD34+ cells. Interestingly, after migration toward IL-1ß + TNF-α + CXCL12 ± TIMP-1, CD34+ cells from JAK2V617F mutated patients show increased clonogenic ability.Here we demonstrate that the interplay of these inflammatory factors promotes and selects the circulating MF-derived CD34+ cells with higher proliferative activity, clonogenic potential and migration ability. Targeting these micro-environmental interactions may be a clinically relevant approach.
Assuntos
Células-Tronco Hematopoéticas/efeitos dos fármacos , Interleucina-1beta/farmacologia , Mielofibrose Primária/metabolismo , Inibidor Tecidual de Metaloproteinase-1/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34/sangue , Antígenos CD34/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Clonais/efeitos dos fármacos , Células Clonais/metabolismo , Feminino , Células-Tronco Hematopoéticas/metabolismo , Humanos , Interleucina-1beta/sangue , Masculino , Pessoa de Meia-Idade , Mielofibrose Primária/sangue , Mielofibrose Primária/patologia , Inibidor Tecidual de Metaloproteinase-1/sangue , Fator de Necrose Tumoral alfa/sangueAssuntos
Amplificação de Genes , Rearranjo Gênico , Leucemia Promielocítica Aguda/genética , Proteínas de Fusão Oncogênica/genética , Cromossomos Humanos Par 15 , Cromossomos Humanos Par 17 , Sondas de DNA , Humanos , Leucemia Promielocítica Aguda/patologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Translocação GenéticaRESUMO
Beta Catenin signaling is critical for the self-renewal of leukemic stem cells in chronic myeloid leukemia. It is driven by multiple events, enhancing beta catenin stability and promoting its transcriptional co-activating function. We investigated the impact of BCR-ABL1 on Chibby1, a beta catenin antagonist involved in cell differentiation and transformation. Relative proximity of the Chibby1 encoding gene (C22orf2) on chromosome 22q12 to the BCR breakpoint (22q11) lets assume its involvement in beta catenin activation in chronic myeloid leukemia as a consequence of deletions of distal BCR sequences encompassing one C22orf2 allele. Forty patients with chronic myeloid leukemia in chronic phase were analyzed for C22orf2 relocation and Chibby1 expression. Fluorescent in situ hybridization analyses established that the entire C22orf2 follows BCR regardless of chromosomes involved in the translocation. In differentiated hematopoietic progenitors (bone marrow mononuclear cell fractions) of 30/40 patients, the expression of Chibby1 protein was reduced below 50% of the reference value (peripheral blood mononuclear cell fractions of healthy persons). In such cell context, Chibby1 protein reduction is not dependent on C22orf2 transcriptional downmodulation; however, it is strictly dependent upon BCR-ABL1 expression because it was not observed at the moment of major molecular response under tyrosine kinase inhibitor therapy. Moreover, it was not correlated with the disease prognosis or response to therapy. Most importantly, a remarkable Chibby1 reduction was apparent in a putative BCR-ABL1+ leukemic stem cell compartment identified by a CD34+ phenotype compared to more differentiated hematopoietic progenitors. In CD34+ cells, Chibby1 reduction arises from transcriptional events and is driven by C22orf2 promoter hypermethylation. These results advance low Chibby1 expression associated with BCR-ABL1 as a component of beta catenin signaling in leukemic stem cells.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Proteínas Nucleares/metabolismo , beta Catenina/antagonistas & inibidores , Transporte Ativo do Núcleo Celular , Antígenos CD34/metabolismo , Proteínas de Transporte/genética , Núcleo Celular/metabolismo , Cromossomos Humanos Par 9/genética , Regulação para Baixo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Modelos Moleculares , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Proteínas Nucleares/genética , Conformação de Ácido Nucleico , Transdução de Sinais , Ativação Transcricional , beta Catenina/genética , beta Catenina/metabolismoRESUMO
We investigated whether low-level Bcr-Abl kinase domain mutations can be detected in patients who have stable responses to first-line nilotinib-like it is known to happen in patients receiving imatinib. We screened for mutations twelve such patients by cloning and sequencing. Only one case was found to harbor mutations at low levels (including a T315I). However, major molecular response (MMR) was maintained and it even improved to complete molecular response. Our results suggest that a) Bcr-Abl mutations, even at low level, seem to be very rare in patients in MMR on first-line nilotinib; b) low-level mutations do not always predict for subsequent relapse.