RESUMO
The prognostic impact of monocytosis has not yet been determined in patients with myelodysplastic syndromes (MDS). We examined absolute monocyte counts in the peripheral blood at the time of diagnosis in 1949 patients with a bone marrow blast count < 5%, a condition we call MDS < EB1 (MDS with a blast percentage lower than that of MDS with excess blasts 1, according to the WHO classification). Monocytosis (> 600/µl) was associated with higher median hemoglobin, WBC, and ANC, and more favorable karyotype (p = .001). Nevertheless, monocytosis was associated with shorter overall survival (OS) (108 vs. 126 months, p = .002) and earlier transformation into AML (p < .001). In patients with sideroblastic phenotype, the percentage of ring sideroblasts significantly correlated with the monocyte count (p = .005), and OS was significantly shorter when monocytosis was documented (88 vs. 132 months, p = .004). The survival disadvantage of patients with MDS < EB1 and peripheral blood monocytosis suggests that these patients suffer from a CMML-like disease. Even though they are generally classified as MDS with persistent monocytosis, such patients should be considered candidates for therapeutic options employed in CMML.
Assuntos
Medula Óssea , Síndromes Mielodisplásicas , Humanos , Prognóstico , Síndromes Mielodisplásicas/terapia , Síndromes Mielodisplásicas/tratamento farmacológico , Leucocitose , Contagem de LeucócitosRESUMO
We describe genetic and clinical characteristics of acute myeloid leukemia (AML) patients according to age from an academic population-based registry. Adult patients with newly diagnosed AML at 63 centers in Germany and Austria were followed within the AMLSG BiO registry (NCT01252485). Between January 1, 2012, and December 31, 2014, data of 3525 patients with AML (45% women) were collected. The median age was 65 years (range 18-94). The comparison of age-specific AML incidence rates with epidemiological cancer registries revealed excellent coverage in patients < 70 years old and good coverage up to the age of 80. The distribution according to the European LeukemiaNet (ELN) risk categorization from 2010 was 20% favorable, 31% intermediate-1, 28% intermediate-2, and 21% adverse. With increasing age, the relative but not the absolute prevalence of patients with ELN favorable and intermediate-1 risk (p < 0.001), with activating FLT3 mutations (p < 0.001), with ECOG performance status < 2 (p < 0.001), and with HCT-CI comorbidity index < 3 (p < 0.001) decreased. Regarding treatment, obesity and favorable risk were associated with an intensive treatment, whereas adverse risk, higher age, and comorbidity index > 0 were associated with non-intensive treatment or best supportive care. The AMLSG BiO registry provides reliable population-based distributions of genetic, clinical, and treatment characteristics according to age.
Assuntos
Leucemia Mieloide Aguda , Mutação , Sistema de Registros , Tirosina Quinase 3 Semelhante a fms , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Áustria , Feminino , Alemanha , Humanos , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/terapia , Masculino , Pessoa de Meia-Idade , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
Magnetically frustrated systems provide fertile ground for complex behaviour, including unconventional ground states with emergent symmetries, topological properties, and exotic excitations. A canonical example is the emergence of magnetic-charge-carrying quasiparticles in spin-ice compounds. Despite extensive work, a reliable experimental indicator of the density of these magnetic monopoles is yet to be found. Using measurements on single crystals of Ho2Ir2O7 combined with dipolar Monte Carlo simulations, we show that the isothermal magnetoresistance is highly sensitive to the monopole density. Moreover, we uncover an unexpected and strong coupling between the monopoles on the holmium sublattice and the antiferromagnetically ordered iridium ions. These results pave the way towards a quantitative experimental measure of monopole density and demonstrate the ability to control antiferromagnetic domain walls using a uniform external magnetic field, a key goal in the design of next-generation spintronic devices.
RESUMO
NbRh2B2 crystallises in a chiral noncentrosymmetric structure and exhibits bulk type-II superconductivity below [Formula: see text] K. Here we show that the temperature dependence of the upper critical field deviates from the behaviour expected for both Werthamer-Helfand-Hohenberg and the Ginzburg-Landau models and that [Formula: see text] T exceeds the Pauli paramagnetic limit, [Formula: see text] T. We explore the reasons for this enhancement. Transverse-field muon spectroscopy measurements suggest that the superconducting gap is either s-wave or [Formula: see text]-wave, and the pressure dependence of [Formula: see text] reveals the superconducting gap is primarily s-wave in character. The magnetic penetration depth [Formula: see text] nm. Heat capacity measurements reveal the presence of a multigap [Formula: see text]-wave superconducting order parameter and moderate electron-phonon coupling.
RESUMO
The IPSS-R proved to be a powerful tool for the assessment of prognosis in MDS patients. We aimed at a validation of the IPSS-R for patients with MDS harboring deletion (5q) isolated or accompanied by additional aberrations. The study was based on 444 MDS patients from MDS centers in Europe. 67% of the patients were female, median age was 69 years. 43.5% had MDS del(5q), 5.9% were diagnosed with RCUD, 2.0% RARS, 18.4% RCMD, 14.6% RAEB-I and 15.5% RAEB-II. According to the IPSS-R, there were 9.9% very low, 39.6% low, 16.6% intermediate, 12.8% high, 20.9% very high risk patients. For very low risk patients survival was 7.5 years, low 9.0 years, intermediate 6.5 years, high 1.5 years and very high 0.7 years (p < 0.001). For low and intermediate risk, the probability of AML evolution was significantly different (p = 0.03) as well as for high versus very high risk groups (p = 0.002). The IPSS-R proved to be an appropriate prognostic tool for MDS with del(5q).
Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 5/genética , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/terapia , Fatores de Risco , Taxa de SobrevidaRESUMO
We investigated the prognostic impact of minimal residual disease (MRD) monitoring in acute myeloid leukemia patients harboring DNA methyltransferase 3A-R882H/-R882C mutations (DNMT3Amut). MRD was determined by real-time quantitative PCR (RQ-PCR) in 1494 samples of 181 DNMT3Amut patients. At the time of diagnosis, DNMT3Amut transcript levels did not correlate with presenting clinical characteristics and concurrent gene mutations as well as the survival end points. In Cox regression analyses, bone marrow (BM) DNMT3Amut transcript levels (log10-transformed continuous variable) were not associated with the rate of relapse or death. DNMT3Amut transcript levels were significantly higher in BM than in blood after induction I (P=0.01), induction II (P=0.05), consolidation I (P=0.004) and consolidation II (P=0.008). With regard to the clinically relevant MRD time points, after two cycles of induction and at the end of therapy, DNMT3Amut transcript levels had no impact on the end point remission duration and overall survival. Of note, only a minority of the patients achieved RQ-PCR negativity, whereas most had constantly high DNMT3Amut transcript levels, a finding which is consistent with the persistence of clonal hematopoiesis in hematological remission.
Assuntos
DNA (Citosina-5-)-Metiltransferases/genética , Leucemia Mieloide Aguda/genética , Adulto , Idoso , DNA Metiltransferase 3A , Feminino , Hematopoese/genética , Humanos , Leucemia Mieloide Aguda/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Neoplasia Residual/genética , Neoplasia Residual/patologia , Prognóstico , Adulto JovemRESUMO
BACKGROUND: Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD)-positive acute myeloid leukaemia (AML) relapsing after allogeneic stem cell transplantation (allo-SCT) has a dismal prognosis with limited therapeutic options. FLT3-ITD kinase inhibition is a reasonable but palliative experimental treatment alternative in this situation. Information on long-term outcome is not available. METHODS: We performed a long-term follow-up analysis of a previously reported cohort of 29 FLT3-ITD-positive AML patients, which were treated in relapse after allo-SCT with sorafenib monotherapy. FINDINGS: With a median follow-up of 7.5 years, 6 of 29 patients (21%) are still alive. Excluding one patient who received a second allo-SCT, five patients (17%) achieved sustained complete remissions with sorafenib. Four of these patients are in treatment-free remission for a median of 4.4 years. INTERPRETATION: Sorafenib may enable cure of a proportion of very poor risk FLT3-ITD-positive AML relapsing after allo-SCT.
Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/genética , Leucemia Mieloide Aguda/terapia , Niacinamida/análogos & derivados , Compostos de Fenilureia/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Transplante de Células-Tronco/efeitos adversos , Sequências de Repetição em Tandem , Tirosina Quinase 3 Semelhante a fms/genética , Adolescente , Adulto , Idoso , Antineoplásicos/efeitos adversos , Progressão da Doença , Intervalo Livre de Doença , Feminino , Alemanha , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Niacinamida/efeitos adversos , Niacinamida/uso terapêutico , Compostos de Fenilureia/efeitos adversos , Inibidores de Proteínas Quinases/efeitos adversos , Recidiva , Indução de Remissão , Estudos Retrospectivos , Fatores de Risco , Sorafenibe , Fatores de Tempo , Transplante Homólogo , Resultado do Tratamento , Adulto JovemRESUMO
The aim of this cohort study was to compare a condensed schedule of consolidation therapy with high-dose cytarabine on days 1, 2 and 3 (HDAC-123) with the HDAC schedule given on days 1, 3 and 5 (HDAC-135) as well as to evaluate the prophylactic use of pegfilgrastim after chemotherapy in younger patients with acute myeloid leukemia in first complete remission. One hundred and seventy-six patients were treated with HDAC-135 and 392 patients with HDAC-123 with prophylactic pegfilgrastim at days 10 and 8, respectively, in the AMLSG 07-04 and the German AML Intergroup protocol. Time from start to chemotherapy until hematologic recovery with white blood cells >1.0 G/l and neutrophils >0.5 G/l was in median 4 days shorter in patients receiving HDAC-123 compared with HDAC-135 (P<0.0001, each), and further reduced by 2 days (P<0.0001) by pegfilgrastim. Rates of infections were reduced by HDAC-123 (P<0.0001) and pegfilgrastim (P=0.002). Days in hospital and platelet transfusions were significantly reduced by HDAC-123 compared with HDAC-135. Survival was neither affected by HDAC-123 versus HDAC-135 nor by pegfilgrastim. In conclusion, consolidation therapy with HDAC-123 leads to faster hematologic recovery and less infections, platelet transfusions as well as days in hospital without affecting survival.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Quimioterapia de Consolidação/métodos , Citarabina/administração & dosagem , Filgrastim/administração & dosagem , Leucemia Mieloide Aguda , Transfusão de Plaquetas , Polietilenoglicóis/administração & dosagem , Adolescente , Adulto , Daunorrubicina/administração & dosagem , Intervalo Livre de Doença , Feminino , Humanos , Tempo de Internação , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/terapia , Masculino , Pessoa de Meia-Idade , Taxa de SobrevidaRESUMO
We evaluated the impact of salvage regimens and allogeneic hematopoietic cell transplantation (allo-HCT) in acute myeloid leukemia (AML) with induction failure. Between 1993 and 2009, 3324 patients with newly diagnosed AML were enrolled in 5 prospective treatment trials of the German-Austrian AML Study Group. After first induction therapy with idarubicin, cytarabine and etoposide (ICE), 845 patients had refractory disease. In addition, 180 patients, although responding to first induction, relapsed after second induction therapy. Of the 1025 patients with induction failure, 875 (median age 55 years) received intensive salvage therapy: 7+3-based (n=59), high-dose cytarabine combined with mitoxantrone (HAM; n=150), with all-trans retinoic acid (A; A-HAM) (n=247), with gemtuzumab ozogamicin and A (GO; GO-A-HAM) (n=140), other intensive regimens (n=165), experimental treatment (n=27) and direct allo-HCT (n=87). In patients receiving intensive salvage chemotherapy (n=761), response (complete remission/complete remission with incomplete hematological recovery (CR/CRi)) was associated with GO-A-HAM treatment (odds ratio (OR), 1.93; P=0.002), high-risk cytogenetics (OR, 0.62; P=0.006) and age (OR for a 10-year difference, 0.75; P<0.0001). Better survival probabilities were seen in an extended Cox regression model with time-dependent covariables in patients responding to salvage therapy (P<0.0001) and having the possibility to perform an allo-HCT (P<0.0001). FLT3 internal tandem duplication, mutated IDH1 and adverse cytogenetics were unfavorable factors for survival.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Células-Tronco Hematopoéticas/mortalidade , Leucemia Mieloide Aguda/mortalidade , Recidiva Local de Neoplasia/mortalidade , Terapia de Salvação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Seguimentos , Humanos , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/terapia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Indução de Remissão , Taxa de Sobrevida , Transplante Homólogo , Adulto JovemRESUMO
The objective of our study was to evaluate high-dose cytarabine in consolidation therapy in patients with newly diagnosed acute promyelocytic leukemia (APL). Patients (age 16-60 years) received induction therapy according to the AIDA protocol (all-trans retinoic acid, idarubicin) followed by one cycle of ICE (idarubicin, cytarabine, etoposide) and two cycles of HAM (cytarabine 3 g/m(2) q12h, days 1-3; mitoxantrone 10 mg/m(2), days 2 and 3). From 1995 to 2003, 82 patients were enrolled. In total, 72 patients (88%) achieved a complete remission, and 10 patients (12%) died from early/hypoplastic death (ED/HD). A total of 71 patients received at least one cycle of HAM. Relapse-free survival (RFS) and overall survival (OS) after 46 months were 83 and 82%, respectively. White blood cell count above 10.0 x 10(9)/l at diagnosis and additional chromosomal aberrations were unfavorable prognostic markers for OS, whereas no prognostic markers for RFS were identified including FLT3 mutations. In conclusion, high-dose cytarabine in consolidation therapy for patients with newly diagnosed APL is an effective treatment approach.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Citarabina/administração & dosagem , Idarubicina/administração & dosagem , Leucemia Promielocítica Aguda/tratamento farmacológico , Mitoxantrona/administração & dosagem , Tretinoína/administração & dosagem , Adolescente , Adulto , Feminino , Humanos , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Indução de Remissão , Tirosina Quinase 3 Semelhante a fmsRESUMO
Deregulated apoptosis is an identifying feature of myelodysplastic syndromes (MDS). Whereas apoptosis is increased in the bone marrow (BM) of low-risk MDS patients, progression to high-risk MDS correlates with an acquired resistance to apoptosis and an aberrant expression of BCL-2 proteins. To overcome the acquired apoptotic resistance in high-risk MDS, we investigated the induction of apoptosis by inhibition of pro-survival BCL-2 proteins using the BCL-2/-XL/-W inhibitor ABT-737 or the BCL-2-selective inhibitor ABT-199. We characterized a cohort of 124 primary human BM samples from MDS/secondary acute myeloid leukemia (sAML) patients and 57 healthy, age-matched controls. Inhibition of anti-apoptotic BCL-2 proteins was specifically toxic for BM cells from high-risk MDS and sAML patients, whereas low-risk MDS or healthy controls remained unaffected. Notably, ABT-737 or ABT-199 treatment was capable of targeting the MDS stem/progenitor compartment in high-risk MDS/sAML samples as shown by the reduction in CD34(+) cells and the decreased colony-forming capacity. Elevated expression of MCL-1 conveyed resistance against both compounds. Protection by stromal cells only partially inhibited induction of apoptosis. Collectively, our data show that the apoptotic resistance observed in high-risk MDS/sAML cells can be overcome by the ABT-737 or ABT-199 treatment and implies that BH3 mimetics might delay disease progression in higher-risk MDS or sAML patients.
Assuntos
Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Síndromes Mielodisplásicas/tratamento farmacológico , Nitrofenóis/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Células-Tronco/efeitos dos fármacos , Sulfonamidas/farmacologia , Células Cultivadas , Humanos , Síndromes Mielodisplásicas/patologia , Proteína de Sequência 1 de Leucemia de Células Mieloides/análise , Piperazinas/farmacologiaRESUMO
We evaluated the frequency, genetic architecture, clinico-pathologic features and prognostic impact of RUNX1 mutations in 2439 adult patients with newly-diagnosed acute myeloid leukemia (AML). RUNX1 mutations were found in 245 of 2439 (10%) patients; were almost mutually exclusive of AML with recurrent genetic abnormalities; and they co-occurred with a complex pattern of gene mutations, frequently involving mutations in epigenetic modifiers (ASXL1, IDH2, KMT2A, EZH2), components of the spliceosome complex (SRSF2, SF3B1) and STAG2, PHF6, BCOR. RUNX1 mutations were associated with older age (16-59 years: 8.5%; ⩾60 years: 15.1%), male gender, more immature morphology and secondary AML evolving from myelodysplastic syndrome. In univariable analyses, RUNX1 mutations were associated with inferior event-free (EFS, P<0.0001), relapse-free (RFS, P=0.0007) and overall survival (OS, P<0.0001) in all patients, remaining significant when age was considered. In multivariable analysis, RUNX1 mutations predicted for inferior EFS (P=0.01). The effect of co-mutation varied by partner gene, where patients with the secondary genotypes RUNX1mut/ASXL1mut (OS, P=0.004), RUNX1mut/SRSF2mut (OS, P=0.007) and RUNX1mut/PHF6mut (OS, P=0.03) did significantly worse, whereas patients with the genotype RUNX1mut/IDH2mut (OS, P=0.04) had a better outcome. In conclusion, RUNX1-mutated AML is associated with a complex mutation cluster and is correlated with distinct clinico-pathologic features and inferior prognosis.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Leucemia Mieloide Aguda/genética , Mutação , Adolescente , Fatores Etários , Intervalo Livre de Doença , Epigenômica , Feminino , Humanos , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores Sexuais , Spliceossomos/genética , Taxa de Sobrevida , Adulto JovemRESUMO
DNA methylation changes are a constant feature of acute myeloid leukemia. Hypomethylating drugs such as azacitidine are active in acute myeloid leukemia (AML) as monotherapy. Azacitidine monotherapy is not curative. The AML-AZA trial tested the hypothesis that DNA methyltransferase inhibitors such as azacitidine can improve chemotherapy outcome in AML. This randomized, controlled trial compared the efficacy of azacitidine applied before each cycle of intensive chemotherapy with chemotherapy alone in older patients with untreated AML. Event-free survival (EFS) was the primary end point. In total, 214 patients with a median age of 70 years were randomized to azacitidine/chemotherapy (arm-A) or chemotherapy (arm-B). More arm-A patients (39/105; 37%) than arm-B (25/109; 23%) showed adverse cytogenetics (P=0.057). Adverse events were more frequent in arm-A (15.44) versus 13.52 in arm-B, (P=0.26), but early death rates did not differ significantly (30-day mortality: 6% versus 5%, P=0.76). Median EFS was 6 months in both arms (P=0.96). Median overall survival was 15 months for patients in arm-A compared with 21 months in arm-B (P=0.35). Azacitidine added to standard chemotherapy increases toxicity in older patients with AML, but provides no additional benefit for unselected patients.
Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Azacitidina/uso terapêutico , Quimioterapia de Indução/métodos , Leucemia Mieloide Aguda/tratamento farmacológico , Idoso , Citarabina/uso terapêutico , Análise Citogenética , Daunorrubicina/uso terapêutico , Feminino , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Análise de SobrevidaRESUMO
A model repertoire of variants of immunoglobulin kappa variable domain REIv with different folding stabilities was generated by oligonucleotide-directed randomization of position 29, a key conserved residue of hypervariable loop 1. Fused to ToxR', the membrane-anchored cytoplasmic domain of the Vibrio cholerae ToxR transcription activator, different members of the library induce different levels of transcription from the ctx promoter in Escherichia coli. Differences in transcription activation correlate positively with folding stabilities of the corresponding REIv domains. Since conformationally stabilized REIv derivatives elicit a dark red colony phenotype on EMB-lactose indicator plates, this procedure constitutes a genetic screen for immunoglobulin folding stability.
Assuntos
Proteínas de Bactérias , Proteínas de Ligação a DNA/genética , Biblioteca Gênica , Cadeias kappa de Imunoglobulina/genética , Dobramento de Proteína , Transdução de Sinais , Fatores de Transcrição/genética , Vibrio cholerae/química , Sequência de Aminoácidos , Sequência de Bases , Toxina da Cólera/genética , Escherichia coli/genética , Genes Bacterianos/genética , Genes de Imunoglobulinas/genética , Região Variável de Imunoglobulina/química , Região Variável de Imunoglobulina/genética , Cadeias kappa de Imunoglobulina/química , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas Recombinantes de Fusão/química , Ativação Transcricional , beta-Galactosidase/genética , beta-LactamasesRESUMO
Chronic myeloid leukemia (CML) and a subset of acute lymphoblastic leukemias arise from the genetic reciprocal translocation t(9;22), forming the BCR-ABL fusion gene. These lead to the expression of the constitutively active tyrosine kinase BCR-ABL, which is the causative oncogene for these leukemias. Allogeneic bone marrow transplantation (BMT) or stem cell transplantation (SCT) is currently considered the only curative treatment for chronic myeloid leukemia (CML). Recently, the selective tyrosine kinase inhibitor imatinib mesylate (Glivec, formerly STI-571) has been shown to induce durable hematologic and major cytogenetic responses in a high percentage of patients with chronic phase CML. In patients with advanced disease remissions are transient and most patients relapse despite continued imatinib treatment. Some of these patients go on to receive allogeneic BMT or SCT, during which administration of imatinib is usually discontinued as it is believed to interfere with bone marrow engraftment. In this study, we examined the effect of imatinib on hematopoietic engraftment in a syngeneic mouse model. We found that imatinib has no significant influence on hematopoietic recovery in lethally irradiated mice in vivo. Thus, our results suggest that continued administration of imatinib in the course of BMT or SCT may be a feasible therapeutic regimen.
Assuntos
Antineoplásicos/farmacologia , Células da Medula Óssea/efeitos dos fármacos , Transplante de Medula Óssea , Hematopoese/efeitos dos fármacos , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-kit/metabolismo , Pirimidinas/farmacologia , Animais , Benzamidas , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Feminino , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas , Mesilato de Imatinib , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Transplante Isogênico , Irradiação Corporal TotalRESUMO
Expansion of primitive hematopoietic progenitor cells (HPC) is a major challenge in stem cell biology. Stimulation by growth factors (GF) is essential for proliferation of HPC, while the role of stromal cell coculture for maintenance of progenitor/stem cell potential is unclear. We evaluated the potential of a murine stromal cell layer providing hematopoietic GF to support expansion of human CD34(+) cells. Murine MS-5 cells were transfected with the cDNA encoding huFlt3 ligand and the interleukin6/sinterleukin-6R fusion protein hyper-IL-6. Expansion of CFC and week6 CAFC was at least as efficient in transfected clones compared to control cocultures supported with exogenous GF. Cell numbers reached 17.5- to 62.3- (day 14) and 17.4- to 92.4-fold (day 21) of input cells. Expansion of CFU-GM/Mix was 4.0- to 12.8-fold (day 14) and 4.9- to 11.7-fold (day 21). Primitive week6 CAFC were expanded up to 6.5-fold (day 14) and 6.2-fold (day 21) without exogenous GF. When direct contact of HPC and stromal cells was inhibited, a loss of CFC and much more of CAFC potential was observed with unaffected overall cell proliferation. Here, we show the generation of GF producing murine stromal cells which efficiently support early hematopoiesis without exogenous GF. Direct stromal cell-HPC contact is advantageous for maintenance of differentiation potential.
Assuntos
Substâncias de Crescimento/farmacologia , Células-Tronco Hematopoéticas/citologia , Interleucina-6/biossíntese , Proteínas de Membrana/biossíntese , Células Estromais/citologia , Animais , Sequência de Bases , Adesão Celular , Primers do DNA , Humanos , Imunofenotipagem , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/metabolismoRESUMO
The purpose of our study was (i) to evaluate the impact of all-trans retinoic acid (ATRA) given as adjunct to chemotherapy and (ii) to compare second consolidation vs maintenance therapy in elderly patients with acute myeloid leukemia (AML). A total of 242 patients aged >or=61 years (median, 66.6 years) with AML were randomly assigned to ATRA beginning on day +3 after the initiation of chemotherapy (ATRA-arm, n=122) or no ATRA (standard-arm, n=120) in combination with induction and first consolidation therapy. A total of 61 patients in complete remission (CR) were randomly assigned to second intense consolidation (n=31) or 1-year oral maintenance therapy (n=30). After induction therapy the intention-to-treat analysis revealed a significant difference in CR rates between the ATRA- and the standard-arm (52 vs 39%; P=0.05). Event-free (EFS) and overall survival (OS) were significantly better in the ATRA-compared to the standard-arm (P=0.03 and 0.01, respectively). OS after second randomization was significantly better for patients assigned to intensive consolidation therapy (P<0.001). The multivariate model for survival revealed lactate dehydrogenase, cytogenetic risk group, age, and first and second randomization as prognostic variables. In conclusion, the addition of ATRA to induction and consolidation therapy may improve CR rate, EFS and OS in elderly patients with AML.
Assuntos
Anemia Refratária com Excesso de Blastos/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Mieloide/terapia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Citarabina/administração & dosagem , Etoposídeo/administração & dosagem , Humanos , Idarubicina/administração & dosagem , Pessoa de Meia-Idade , Prognóstico , Indução de Remissão , Taxa de Sobrevida , Transplante Homólogo , Tretinoína/administração & dosagemRESUMO
OBJECTIVE: Experimental strategies for ex vivo expansion of human hematopoietic stem/progenitor cells involve the use of exogenous cytokines as well as direct interaction with stromal elements. We examined the use of the interleukin-6/soluble interleukin-6 receptor (IL-6/sIL-6R) fusion protein Hyper-IL-6 (H-IL-6), which interacts directly with gp130, in conjunction with stromal support for expansion of human progenitors. MATERIALS AND METHODS: Peripheral blood CD34+ cells were cultured on the murine stromal cell line FBMD1 or in suspension for up to 28 days with different cytokines. Cells were evaluated at various time points for phenotype, proliferative and clonogenic capacity, and long-term hematopoietic activity. RESULTS: The combination of Flt3 ligand and H-IL-6 was markedly more effective than Flt3 ligand and IL-6/sIL-6R for expansion of CD34+ cells in suspension culture and on FBMD1. Addition of kit ligand but not thrombopoietin to Flt3 ligand and H-IL-6 significantly augmented proliferation and enhanced colony formation three-fold. However, long-term cobblestone area-forming cell assays indicated that although multipotent progenitors were maintained up to 21 days on FBMD1 in the presence of Flt3 ligand alone and were amplified three-fold by addition of H-IL-6, CD34+ cells cultured in the absence of stromal support rapidly lost their cobblestone area-forming cell potential. Immunophenotyping revealed that stromal support prevented up-regulation of IL-6R on CD34+ cells, which was induced within 3 days in stroma-free cultures and was enhanced in the presence of kit ligand. Delayed addition of H-IL-6 to the cultures resulted in reduced proliferation and colony-forming unit potential. CONCLUSION: H-IL-6 synergizes with stromal elements to effectively enhance proliferation and maintenance of primitive hematopoietic progenitors under prolonged ex vivo culture conditions.