RESUMEN
Myelodysplastic syndromes (MDS) are hematological malignancies classically defined by the presence of cytopenia(s) and dysmorphic myeloid cells. It is now known that MDS can be preceded by a pre-malignant condition called clonal cytopenia of unknown significance (CCUS), which associates a clonality marker with cytopenia in the absence of criteria of dysplasia. However, to date, it is not clear whether chromosomal abnormalities should be considered in the definition of CCUS or if they carry a prognostic impact in CCUS patients. In this study, we analyzed the clinico-biological features and outcomes of 34 patients who presented with one or more cytopenias, an absence of significant dysplasia, and a presence of a chromosomal abnormality (CA). We named this entity chromosomal abnormality with cytopenia of undetermined significance (CACtUS). We show that these patients are slightly older than MDS patients and that they more frequently presented with normocytic anemia. Most CACtUS patients exhibited only one unbalanced CA. The number and type of mutations were comparable between CACtUS patients and MDS patients. Regardless of the cytogenetic abnormality, the clinicobiological characteristics, overall survival, and risk of progression to high-risk (HR) MDS were similar between CACtUS patients and low-risk MDS patients. Thus, we suggest that CACtUS patients can be considered as HR-CCUS and should receive the follow-up regimen recommended for MDS patients.
Asunto(s)
Anemia , Trastornos de los Cromosomas , Neoplasias Hematológicas , Síndromes Mielodisplásicos , Humanos , Aberraciones Cromosómicas , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/patología , MutaciónRESUMEN
Translocation t(4;12)(q11-13;p13) is a recurrent but very rare chromosomal aberration in acute myeloid leukaemia (AML) resulting in the non-constant expression of a CHIC2/ETV6 fusion transcript. We report clinico-biological features, molecular characteristics and outcomes of 21 cases of t(4;12) including 19 AML and two myelodysplastic syndromes (MDS). Median age at the time of t(4;12) was 78 years (range, 56-88). Multilineage dysplasia was described in 10 of 19 (53%) AML cases and CD7 and/or CD56 expression in 90%. FISH analyses identified ETV6 and CHIC2 region rearrangements in respectively 18 of 18 and 15 of 17 studied cases. The t(4;12) was the sole cytogenetic abnormality in 48% of cases. The most frequent associated mutated genes were ASXL1 (n = 8/16, 50%), IDH1/2 (n = 7/16, 44%), SRSF2 (n = 5/16, 31%) and RUNX1 (n = 4/16, 25%). Interestingly, concurrent FISH and molecular analyses showed that t(4;12) can be, but not always, a founding oncogenic event. Median OS was 7.8 months for the entire cohort. In the 16 of 21 patients (76%) who received antitumoral treatment, overall response and first complete remission rates were 37% and 31%, respectively. Median progression-free survival in responders was 13.7 months. Finally, t(4;12) cases harboured many characteristics of AML with myelodysplasia-related changes (multilineage dysplasia, MDS-related cytogenetic abnormalities, frequent ASXL1 mutations) and a poor prognosis.
Asunto(s)
Cromosomas Humanos Par 12 , Cromosomas Humanos Par 4 , Predisposición Genética a la Enfermedad , Trastornos Mieloproliferativos/diagnóstico , Trastornos Mieloproliferativos/genética , Translocación Genética , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Aberraciones Cromosómicas , Análisis Citogenético , Femenino , Estudios de Asociación Genética , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/etiología , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/terapia , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/etiología , Síndromes Mielodisplásicos/mortalidad , Síndromes Mielodisplásicos/terapia , Trastornos Mieloproliferativos/mortalidad , Trastornos Mieloproliferativos/terapia , PronósticoRESUMEN
Clonal chromosome abnormalities in Philadelphia-negative cells could concern chronic myeloid leukemia patients treated by tyrosine kinase inhibitors. The European LeukemiaNet distinguishes -7/del(7q) abnormalities as a "warning". However, the impact of clonal chromosome abnormalities, and specifically those of -7/del(7q), in Philadelphia-negative cells on clinical outcomes is unclear and based on case-reports showing morphological dysplasia and increased risk of acute myeloid leukemia, suggesting the coexistence of chronic myeloid leukemia and high-risk myelodysplastic syndrome. The aim of this study was to determine whether the impact of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells on the clinical outcome is different from that of other types of abnormalities, and we argue for an underlying associated high-risk myelodysplastic syndrome. Among 102 chronic myeloid leukemia patients with clonal chromosome abnormalities in Philadelphia-negative cells with more than a median of 6 years of follow up, patients with -7/del(7q) more frequently had signs of dysplasia, a lower cumulative incidence of deep molecular response and often needed further treatment lines, with the consequent impact on event-free and progression-free survival. Morphological features of dysplasia are associated with myelodysplastic syndrome/acute myeloid leukemia mutations and compromise the optimal response to tyrosine kinase inhibitors, irrespectively of the type of clonal chromosome abnormalities in Philadelphia-negative cells. However, mutation patterns determined by next-generation sequencing could not clearly explain the underlying high-risk disease. We hereby confirm the pejorative prognostic value of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells and suggest that myelodysplastic features constitute a warning signal that response to tyrosine kinase inhibitors may be less than optimal.
Asunto(s)
Aberraciones Cromosómicas , Cromosomas Humanos Par 7 , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Leucemia Mielógena Crónica BCR-ABL Positiva/etiología , Metafase/genética , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/genética , Alelos , Deleción Cromosómica , Progresión de la Enfermedad , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Hibridación Fluorescente in Situ , Leucemia Mielógena Crónica BCR-ABL Positiva/mortalidad , Leucemia Mielógena Crónica BCR-ABL Positiva/terapia , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Mutación , Síndromes Mielodisplásicos/mortalidad , Síndromes Mielodisplásicos/terapia , Pronóstico , Análisis de SupervivenciaRESUMEN
Acute myeloid leukemia is driven by leukemic stem cells which can be identified by cross lineage expression or arrest of differentiation compared to normal hematopoietic stem cells. Self-renewal and lack of differentiation are also features of stem cells and have been associated with the expression of embryonic genes. The aim of our study was to evaluate the expression of embryonic antigens (OCT4, NANOG, SOX2, SSEA1, SSEA3) in hematopoietic stem cell subsets (CD34+CD38- and CD34+CD38+) from normal bone marrows and in samples from acute myeloid leukemia patients. We observed an upregulation of the transcription factors OCT4 and SOX2 in leukemic cells as compared to normal cells. Conversely, SSEA1 protein was downregulated in leukemic cells. The expression of OCT4, SOX2, and SSEA3 was higher in CD34+CD38- than in CD34+CD38+ subsets in leukemic cells. There was no correlation with biological characteristics of the leukemia. We evaluated the prognostic value of marker expression in 69 patients who received an intensive treatment. The rate of complete remission was not influenced by the level of expression of markers. Overall survival was significantly better for patients with high SOX2 levels, which was unexpected because of the inverse correlation with favorable genetic subtypes. These results prompt us to evaluate the potential role of these markers in leukemogenesis and to test their relevance for better leukemic stem cell identification.
Asunto(s)
Biomarcadores de Tumor/biosíntesis , Fucosiltransferasas/biosíntesis , Leucemia Mieloide Aguda/tratamiento farmacológico , Antígeno Lewis X/biosíntesis , Factor 3 de Transcripción de Unión a Octámeros/biosíntesis , Factores de Transcripción SOXB1/biosíntesis , ADP-Ribosil Ciclasa 1/genética , Adulto , Anciano , Antígenos CD34/genética , Células de la Médula Ósea/metabolismo , Diferenciación Celular/genética , Células Madre Embrionarias/metabolismo , Células Madre Embrionarias/patología , Femenino , Citometría de Flujo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/patología , Humanos , Inmunofenotipificación , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
Patients with Core-Binding Factor (CBF) and NPM1-mutated acute myeloid leukemia (AML) can be monitored by quantitative PCR after having achieved first complete remission (CR) to detect morphologic relapse and drive preemptive therapy. How to best manage these patients is unknown. We retrospectively analyzed 303 patients with CBF and NPM1-mutated AML, aged 18-60 years, without allogeneic hematopoietic cell transplantation (HCT) in first CR, with molecular monitoring after first-line intensive therapy. Among these patients, 153 (51%) never relapsed, 95 (31%) had molecular relapse (53 received preemptive therapy and 42 progressed to morphologic relapse at salvage therapy), and 55 (18%) had upfront morphologic relapse. Patients who received preemptive therapy had higher OS than those who received salvage therapy after having progressed from molecular to morphologic relapse and those with upfront morphologic relapse (three-year OS: 78% vs. 51% vs. 51%, respectively, P = 0.01). Preemptive therapy included upfront allogeneic HCT (n = 19), intensive chemotherapy (n = 21), and non-intensive therapy (n = 13; three-year OS: 92% vs. 79% vs. 58%, respectively, P = 0.09). Although not definitive due to the non-randomized allocation of patients to different treatment strategies at relapse, our study suggests that molecular monitoring should be considered during follow-up to start preemptive therapy before overt morphologic relapse.
Asunto(s)
Leucemia Mieloide Aguda , Mutación , Proteínas Nucleares , Nucleofosmina , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/patología , Adulto , Persona de Mediana Edad , Femenino , Masculino , Proteínas Nucleares/genética , Adolescente , Adulto Joven , Estudios Retrospectivos , Recurrencia , Trasplante de Células Madre Hematopoyéticas/métodos , Factores de Unión al Sitio Principal/genética , Pronóstico , Terapia Recuperativa , Inducción de Remisión , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patologíaRESUMEN
INTRODUCTION: Many patients referred for suspicion of myelodysplastic neoplasm (MDS) are subjected to unnecessary discomfort from bone marrow aspiration, due to the low disease prevalence in this population. Flow cytometric analysis of peripheral blood neutrophil myeloperoxidase expression could rule out MDS with sensitivity and negative predictive value estimates close to 100%, ultimately obviating the need for bone marrow aspiration in up to 35% of patients. However, the generalisability of these findings is uncertain due to the limited sample size, the enrolment of patients at a single study site, and the reliability issues associated with laboratory-developed tests and varying levels of operator experience. This study aims to validate the accuracy attributes of peripheral blood neutrophil myeloperoxidase expression quantified by flow cytometric analysis in an independent multicentre sample. METHODS AND ANALYSIS: The MPO-MDS-Valid project is a cross-sectional diagnostic accuracy study comparing an index test to a reference standard. Consecutive adult patients referred for suspicion of MDS are being recruited at seven university hospitals and one cancer centre in France. At each site, flow cytometric analysis of peripheral blood samples is performed by operators who are blinded to the reference diagnosis. A central adjudication committee whose members are unaware of the index test results will determine the reference diagnosis of MDS, based on cytomorphological evaluation of bone marrow performed in duplicate by experienced hematopathologists. The target sample size is 400 patients and the anticipated study recruitment completion date is 31 December 2025. ETHICS AND DISSEMINATION: An institutional review board (Comité de Protection des Personnes Nord-Ouest III, Caen, France) approved the protocol, prior to the start of the study. Participants are recruited using an opt-out approach. Efforts will be made to publish the primary results within 6 months after study completion. TRIAL REGISTRATION NUMBER: NCT05175469.
Asunto(s)
Citometría de Flujo , Síndromes Mielodisplásicos , Neutrófilos , Peroxidasa , Humanos , Peroxidasa/sangre , Peroxidasa/metabolismo , Neutrófilos/metabolismo , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/sangre , Estudios Transversales , Reproducibilidad de los Resultados , Francia , Masculino , Estudios Multicéntricos como Asunto , Femenino , Sensibilidad y Especificidad , AdultoRESUMEN
OBJECTIVES: Acute myeloid leukemia (AML) with inv(16)/t(16;16) is among the most frequent AML subtypes. It is recognized by the detection of the CBFB-MYH11 fusion which confers a favorable prognosis, irrespective of the presence of secondary cytogenetic abnormalities. However, the effect of additional genetic anomalies on the behavior of inv(16) AML is debatable. Recent case reports describe an unfavorable prognosis for those patients, characterized by early relapse and death. In this study, we present a series of patients with CBFB-MYH11 fusion and high-risk rearrangements to increase knowledge about this potentially distinct subgroup. METHODS: All cases with inv(16)/ t(16;16) and one or more high risk abnormalities were reviewed at two tertiary healthcare centers between years 2006 and 2020 in terms of demographics, biological and clinical data. RESULTS: Among the total 1447 and 1283 AML cases, the frequency was found to be 0,2% and 0.3%. Clinical data could be retrieved for 5 patients. Detected high-risk abnormalities included TP53 and 5q deletion, complex and monosomal karyotype. The median age was 67 years, with a majority of females (M:F = 1:1.5). Two out of 5 patients presented with therapy related AML, with short latency periods. All patients presented with thrombocytopenia and/or leukocytopenia. Bone marrow aspirates revealed atypical morphology and the detection of rare CBFB-MYH11 fusion transcripts. All 5 patients died, with a short mean overall survival of 5.8 months. DISCUSSION AND CONCLUSION: Our series suggests that the presence of high risk abnormalities confers distinct biological features and poor prognosis to inv(16) AML.
Asunto(s)
Inversión Cromosómica , Leucemia Mieloide Aguda , Anciano , Femenino , Fusión Génica , Reordenamiento Génico , Humanos , Leucemia Mieloide Aguda/diagnóstico , Proteínas de Fusión Oncogénica/genéticaRESUMEN
INTRODUCTION: Suspicion of myelodysplastic syndromes (MDS) is the most common reason for bone marrow aspirate in elderly patients. Peripheral blood neutrophil myeloperoxidase expression quantified by flow cytometric analysis might rule out MDS for up to 35% of patients referred for suspected disease, without requiring bone marrow aspiration. Yet laboratory-developed liquid antibody cocktails have practical limitations, because of lack of standardisation and poor stability. This research project aims to estimate the level of agreement and comparative accuracy between a single-use flow cytometry tube of lyophilised reagents (BD Lyotube Stain 468) and its laboratory-developed liquid reagent counterpart in quantifying peripheral blood neutrophil myeloperoxidase expression, among adult patients referred for suspected MDS. METHODS AND ANALYSIS: The MPO-MDS-Develop project is a cross-sectional diagnostic accuracy study of two index tests by comparison with a reference standard in consecutive unselected adult patients conducted at a single university hospital. Flow cytometry analysis of peripheral blood samples will be performed by independent operators blinded to the reference diagnosis, using either Lyotube Stain 468 or laboratory-developed liquid reagent cocktail. The reference diagnosis of MDS will be established by cytomorphological evaluation of bone marrow aspirate by two independent haematopathologists blinded to the index test results. Morphologic assessment will be complemented by bone marrow flow cytometric score, karyotype and targeted next-generation sequencing panel of 43 genes, where relevant. The target sample size is 103 patients. ETHICS AND DISSEMINATION: An institutional review board (Comité de Protection des Personnes Sud Est III, Lyon, France) approved the protocol prior to study initiation (reference number: 2020-028-B). Participants will be recruited using an opt-out approach. Efforts will be made to release the primary results within 6 months of study completion. TRIAL REGISTRATION NUMBER: NCT04399018.
Asunto(s)
Síndromes Mielodisplásicos , Neutrófilos , Adulto , Anciano , Estudios Transversales , Citometría de Flujo/métodos , Humanos , Indicadores y Reactivos , Síndromes Mielodisplásicos/diagnóstico , Neutrófilos/metabolismo , PeroxidasaRESUMEN
Mitochondria not only are essential for cell metabolism and energy supply but are also engaged in calcium homeostasis and reactive oxygen species generation and play a key role in apoptosis. As a consequence, functional mitochondrial disorders are involved in many human cancers including acute myeloid leukemia (AML). However, very few data are available on the deregulation of their number and/or shape in leukemic cells, despite the evident link between ultrastructure and function. In this context, we analyzed the ultrastructural mitochondrial parameters (number per cell, mitochondria area, number of cristae/mitochondria, cristal thickness) in five leukemia cell lines (HEL, HL60, K562, KG1, and OCI-AML3) together with the functional assay of their respiratory profile. First, we describe significant differences in basal respiration, maximal respiration, ATP production, and spare respiratory capacity between our cell lines, confirming the various respiratory profiles among leukemia subtypes. Second, we highlight that these variations are obviously associated with significant interleukemia heterogeneity of the number and/or shape of mitochondria. For instance, KG1, characterized by the smallest number of mitochondria together with reduced cristal diameter, had a particularly deficient respiratory profile. In comparison, the HEL and K562 cell lines, both with high respiratory profiles, harbored the largest number of mitochondria/cells with high cristal diameters. Moreover, we report that K562, carrying the ASXL1 mutation, presents significant mitochondria-endoplasmic reticulum deficiency reflected by decreases in the numbers of matrix granules and mitochondria-associated endoplasmic reticulum membrane (MAM) and mitochondrial-derived vesicle (MDV) precursors, which are implicated in the regulatory pathways of cell mortality via the processes of mitophagy and calcium homeostasis. Contrarily, HL60 carried high levels of matrix granules and MAMs and had a higher sensitivity to drugs targeting mitochondria (rotenone/antimycin). We confirm the implication of ASXL1 mutation in this mitochondria dysregulation through the study of transcript expression (from 415 patients with public data) involved in three mitochondrial pathways: (1) endoplasmic reticulum-mitochondria contacts (MAMs), (2) matrix granule homeostasis, and (3) MDV precursor production. Our study offers new and original data on mitochondria structural alterations linked to deregulation of respiration profiles in AMLs and some genetic characteristics, suggesting that modifications of mitochondrial shape and/or number in leukemic cells participate in chemoresistance and could be a targeted mechanism to regulate their proliferative potential.
Asunto(s)
Leucemia Mieloide Aguda , Mitocondrias , Proteínas de Neoplasias , Consumo de Oxígeno , Proteínas Represoras , Células HL-60 , Humanos , Células K562 , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Mitocondrias/genética , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , Mutación , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismoRESUMEN
BACKGROUND: The first week of human pre-embryo development is characterized by the induction of totipotency and then pluripotency. The understanding of this delicate process will have far reaching implication for in vitro fertilization and regenerative medicine. Human mature MII oocytes and embryonic stem (ES) cells are both able to achieve the feat of cell reprogramming towards pluripotency, either by somatic cell nuclear transfer or by cell fusion, respectively. Comparison of the transcriptome of these two cell types may highlight genes that are involved in pluripotency initiation. RESULTS: Based on a microarray compendium of 205 samples, we compared the gene expression profile of mature MII oocytes and human ES cells (hESC) to that of somatic tissues. We identified a common oocyte/hESC gene expression profile, which included a strong cell cycle signature, genes associated with pluripotency such as LIN28 and TDGF1, a large chromatin remodelling network (TOP2A, DNMT3B, JARID2, SMARCA5, CBX1, CBX5), 18 different zinc finger transcription factors, including ZNF84, and several still poorly annotated genes such as KLHL7, MRS2, or the Selenophosphate synthetase 1 (SEPHS1). Interestingly, a large set of genes was also found to code for proteins involved in the ubiquitination and proteasome pathway. Upon hESC differentiation into embryoid bodies, the transcription of this pathway declined. In vitro, we observed a selective sensitivity of hESC to the inhibition of the activity of the proteasome. CONCLUSION: These results shed light on the gene networks that are concurrently overexpressed by the two human cell types with somatic cell reprogramming properties.
Asunto(s)
Células Madre Embrionarias/metabolismo , Perfilación de la Expresión Génica , Oocitos/metabolismo , Ciclo Celular/genética , Células Cultivadas , Ensamble y Desensamble de Cromatina/genética , Homólogo de la Proteína Chromobox 5 , Femenino , Regulación del Desarrollo de la Expresión Génica , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Análisis de Componente Principal , Complejo de la Endopetidasa Proteasomal/genética , Ubiquitinación , Dedos de Zinc/genéticaRESUMEN
Chronic myelomonocytic leukemia (CMML) is a myelodysplastic/myeloproliferative neoplasm, characterized by persistent monocytosis and dysplasia in at least one myeloid cell lineage. This persistent monocytosis should be distinguished from the reactive monocytosis which is sometimes observed in a context of infections or solid tumors. In 2015, Selimoglu-Buet et al. observed an increased percentage of classical monocytes (CD14+/CD16- >94%) in the peripheral blood (PB) of CMML patients. In this study, using multiparametric flow cytometry (MFC), we assessed the monocytic distribution in PB samples and in bone marrow aspirates from 63 patients with monocytosis or CMML suspicion, and in seven follow-up blood samples from CMML patients treated with hypomethylating agents (HMA). A control group of 12 healthy age-matched donors was evaluated in parallel in order to validate the analysis template. The CMML diagnosis was established in 15 cases in correlation with other clinical manifestations and biological tests. The MFC test for the evaluation of the repartition of monocyte subsets, as previously described by Selimoglu-Buet et al. showed a specificity of 97% in blood and 100% in marrow samples. Additional information regarding the expression of intermediate MO2 monocytes percentage improved the specificity to 100% in blood samples allowing the screening of abnormal monocytosis. The indicative thresholds of CMML monocytosis were different in PB compared to BM samples (classical monocytes >95% for PB and >93% for BM). A decrease of monocyte levels in PB and BM, along with a normalization of monocytes distribution, was observed after treatment in 4/7 CMML patients with favorable evolution. No significant changes were observed in 3/7 patients who did not respond to HMA therapy and also presented unfavorable molecular prognostic factors at diagnosis (ASXL1, TET2, and IDH2 mutations). Considering its simplicity and robustness, the monocyte subsets evaluation by MFC provides relevant information for CMML diagnosis.
RESUMEN
Successful peripheral blood stem cell (PBSC) collection depends on the timing of apheresis based on CD34+ cell enumeration. Because this analysis is expensive and induces organization difficulties, we evaluated hematopoietic progenitor cell (HPC) quantification on the Sysmex XE-2100 as a surrogate analysis. We tested 157 blood samples for CD34+ cells and HPC counts. We found a good linear correlation between HPC and CD34+ and determined simple rules allowing to use HPC count in daily practice. We set a positive cut-off >30 HPC/mm(3) for allowing PBSC harvest and a negative cut-off at 0 HPC/mm(3) for which collection should be delayed. These two situations accounted for 62% of cases and CD34+ cell count by flow cytometry confirmed HPC result in 95% of cases. Between 0 and 30 HPC/mm3, CD34+ enumeration is required for decision-making. We conclude that HPC count may be a useful surrogate for CD34+ enumeration in PBSC harvest monitoring.
Asunto(s)
Recuento de Células Sanguíneas/instrumentación , Células Madre Hematopoyéticas/citología , Recolección de Tejidos y Órganos , Antígenos CD34/análisis , Antígenos CD34/sangre , Humanos , Sensibilidad y EspecificidadRESUMEN
Embryonic stem cells typically show properties of long-term self-renewal and lack of differentiation. When appropriately stimulated, they are able to differentiate into all cell lineages, and lose their self-renewal characteristics. These properties are controlled by a series of genes encoding several transcription factors, including OCT4, the product of POU5F1 gene. OCT4 is expressed in germ cell tumors but also aberrantly in cancers developing in differentiated tissues. In a previous study, we observed a high expression of OCT4 in acute myeloid cell lines and primary cells, regardless of the acute myeloid leukemia (AML) subtype. In this study, we investigated the putative oncogenic role of OCT4 in proliferation and differentiation arrest. OCT4 expression was assessed in a panel of myeloid cell lines, together with clonogenic and proliferation properties, before and after differentiation in the presence of retinoic acid (RA). Same experiments were performed under short hairpin RNA (shRNA)-mediated OCT4 inhibition. In the presence of RA, we observed a decrease of OCT4 expression, associated with a loss of clonogenic and proliferation capacities, cell cycle arrest, and upregulation of p21, in HL60, NB4, KASUMI, and Me-1 cell lines. This effect was absent in the KG1a cell line, which did not differentiate. Downregulation of OCT4 by shRNA resulted in the same pattern of differentiation and loss of proliferation. Although KG1a did not differentiate, a decrease in proliferation was observed. Our findings suggest that OCT4 is implicated in the differentiation arrest at least in some types of AML, and that it also plays a role in cell proliferation through different oncogenic mechanisms. OCT4 might be a potential new target for antileukemic treatments.
Asunto(s)
Leucemia Mieloide Aguda/patología , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Apoptosis/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Linaje de la Célula/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Transformación Celular Neoplásica , Regulación hacia Abajo/efectos de los fármacos , Genes Homeobox/efectos de los fármacos , Humanos , Tretinoina/farmacologíaAsunto(s)
Biomarcadores de Tumor/genética , Exones , Janus Quinasa 2/genética , Mutación , Trastornos Mieloproliferativos/patología , Policitemia Vera/patología , Adulto , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Francia , Humanos , Masculino , Persona de Mediana Edad , Trastornos Mieloproliferativos/genética , Policitemia Vera/genética , Pronóstico , Tasa de SupervivenciaRESUMEN
Over recent years, the development of molecular biology techniques has improved the hematological diseases diagnostic and follow-up. Consequently, these techniques are largely used in the biological screening of these diseases; therefore the Hemato-oncology molecular diagnostics laboratories must be actively involved in the accreditation process according the ISO 15189 standard. The French group of molecular biologists (GBMHM) provides requirements for the implementation of quality assurance for the medical molecular laboratories. This guideline states the recommendations for the pre-analytical, analytical (methods validation procedures, quality controls, reagents), and post-analytical conditions. In addition, herein we state a strategy for the internal quality control management. These recommendations will be regularly updated.
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Acreditación/normas , Neoplasias Hematológicas/patología , Laboratorios/normas , Biología Molecular/normas , Francia , Humanos , Personal de Laboratorio/educación , Personal de Laboratorio/normas , Garantía de la Calidad de Atención de Salud , Control de Calidad , Reproducibilidad de los ResultadosAsunto(s)
Daño del ADN , Vesículas Extracelulares/fisiología , Células Madre Hematopoyéticas/metabolismo , Células Madre Mesenquimatosas/fisiología , Mutagénesis , Síndromes Mielodisplásicos/patología , ARN Helicasas DEAD-box/genética , Humanos , MicroARNs , Síndromes Mielodisplásicos/etiología , Síndromes Mielodisplásicos/genética , Ribonucleasa III/genéticaAsunto(s)
Síndrome de Budd-Chiari/genética , Janus Quinasa 2/genética , Mutación , Trastornos Mieloproliferativos/genética , Vena Porta , Trombosis de la Vena/genética , Adolescente , Adulto , Anciano , Síndrome de Budd-Chiari/sangre , Síndrome de Budd-Chiari/enzimología , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Trastornos Mieloproliferativos/sangre , Trastornos Mieloproliferativos/diagnóstico , Trastornos Mieloproliferativos/enzimología , Polimorfismo de Nucleótido Simple , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Trombosis de la Vena/sangre , Trombosis de la Vena/enzimología , Adulto JovenRESUMEN
The multifunctional E4F1 protein was originally discovered as a target of the E1A viral oncoprotein. Growing evidence indicates that E4F1 is involved in key signaling pathways commonly deregulated during cell transformation. In this study, we investigate the influence of E4F1 on tumorigenesis. Wild-type mice injected with fetal liver cells from mice lacking CDKN2A, the gene encoding Ink4a/Arf, developed histiocytic sarcomas (HSs), a tumor originating from the monocytic/macrophagic lineage. Cre-mediated deletion of E4F1 resulted in the death of HS cells and tumor regression in vivo and extended the lifespan of recipient animals. In murine and human HS cell lines, E4F1 inactivation resulted in mitochondrial defects and increased production of reactive oxygen species (ROS) that triggered massive cell death. Notably, these defects of E4F1 depletion were observed in HS cells but not healthy primary macrophages. Short hairpin RNA-mediated depletion of E4F1 induced mitochondrial defects and ROS-mediated death in several human myeloid leukemia cell lines. E4F1 protein is overexpressed in a large subset of human acute myeloid leukemia samples. Together, these data reveal a role for E4F1 in the survival of myeloid leukemic cells and support the notion that targeting E4F1 activities might have therapeutic interest.