RESUMEN
Baraitser-Winter, Fryns-Aftimos and cerebrofrontofacial syndrome types 1 and 3 have recently been associated with heterozygous gain-of-function mutations in one of the two ubiquitous cytoplasmic actin-encoding genes ACTB and ACTG1 that encode ß- and γ-actins. We present detailed phenotypic descriptions and neuroimaging on 36 patients analyzed by our group and six cases from the literature with a molecularly proven actinopathy (9 ACTG1 and 33 ACTB). The major clinical anomalies are striking dysmorphic facial features with hypertelorism, broad nose with large tip and prominent root, congenital non-myopathic ptosis, ridged metopic suture and arched eyebrows. Iris or retinal coloboma is present in many cases, as is sensorineural deafness. Cleft lip and palate, hallux duplex, congenital heart defects and renal tract anomalies are seen in some cases. Microcephaly may develop with time. Nearly all patients with ACTG1 mutations, and around 60% of those with ACTB mutations have some degree of pachygyria with anteroposterior severity gradient, rarely lissencephaly or neuronal heterotopia. Reduction of shoulder girdle muscle bulk and progressive joint stiffness is common. Early muscular involvement, occasionally with congenital arthrogryposis, may be present. Progressive, severe dystonia was seen in one family. Intellectual disability and epilepsy are variable in severity and largely correlate with CNS anomalies. One patient developed acute lymphocytic leukemia, and another a cutaneous lymphoma, indicating that actinopathies may be cancer-predisposing disorders. Considering the multifaceted role of actins in cell physiology, we hypothesize that some clinical manifestations may be partially mutation specific. Baraitser-Winter cerebrofrontofacial syndrome is our suggested designation for this clinical entity.
Asunto(s)
Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Anomalías Craneofaciales/diagnóstico , Anomalías Craneofaciales/genética , Actinas/genética , Adolescente , Adulto , Sustitución de Aminoácidos , Niño , Preescolar , Facies , Femenino , Orden Génico , Sitios Genéticos , Humanos , Masculino , Mutación , Fenotipo , Adulto JovenRESUMEN
The bone marrow (BM) microenvironment has clearly been implicated in the pathogenesis of B-cell chronic lymphocytic leukemia (B-CLL). However, the potential involvement of BM stromal progenitors, the mesenchymal stem cells (MSCs), in the pathophysiology of the disease has not been extensively investigated. We expanded in vitro BM-MSCs from B-CLL patients (n=11) and healthy individuals (n=16) and comparatively assessed their reserves, proliferative potential, differentiation capacity, and immunoregulatory effects on T- and B-cells. We also evaluated the anti-apoptotic effect of patient-derived MSCs on leukemic cells and studied their cytogenetic characteristics in comparison to BM hematopoietic cells. B-CLL-derived BM MSCs exhibit a similar phenotype, differentiation potential, and ability to suppress T-cell proliferative responses as compared with MSCs from normal controls. Furthermore, they do not carry the cytogenetic abnormalities of the leukemic clone, and they exert a similar anti-apoptotic effect on leukemic cells and healthy donor-derived B-cells, as their normal counterparts. On the other hand, MSCs from B-CLL patients significantly promote normal B-cell proliferation and IgG production, in contrast to healthy-donor-derived MSCs. Furthermore, they have impaired reserves, defective cellular growth due to increased apoptotic cell death and exhibit aberrant production of stromal cell-derived factor 1, B-cell activating factor, a proliferation inducing ligand, and transforming growth factor ß1, cytokines that are crucial for the survival/nourishing of the leukemic cells. We conclude that ex vivo expanded B-CLL-derived MSCs harbor intrinsic qualitative and quantitative abnormalities that may be implicated in disease development and/or progression.
Asunto(s)
Leucemia Linfocítica Crónica de Células B/patología , Células Madre Mesenquimatosas/inmunología , Anciano , Anciano de 80 o más Años , Apoptosis , Linfocitos B/fisiología , Estudios de Casos y Controles , Diferenciación Celular , Proliferación Celular , Forma de la Célula , Supervivencia Celular , Células Cultivadas , Técnicas de Cocultivo , Citocinas/metabolismo , Femenino , Células Madre Hematopoyéticas/metabolismo , Humanos , Inmunoglobulina G/metabolismo , Leucemia Linfocítica Crónica de Células B/inmunología , Masculino , Células Madre Mesenquimatosas/metabolismo , Persona de Mediana Edad , Linfocitos T/fisiologíaRESUMEN
Myelodysplastic syndromes comprise a heterogeneous group of clonal hematopoietic stem cell malignancies characterized by ineffective bone marrow (BM) hematopoiesis, peripheral blood cytopenias and substantial risk for progression to acute myeloid leukemia. It is generally accepted that myelodysplastic syndromes originate as a result of multistep leukemogenesis, implicating genetic, epigenetic and immune-mediated alterations of an early hematopoietic stem cell. However, alterations in the BM microenvironment in terms of abnormal hematopoietic-to-stromal cell interactions, relative deficiency of hematopoietic growth factors and aberrant release of inhibitors may also have a role in myelodysplastic syndrome (MDS) pathogenesis. The possible involvement of the BM mesenchymal stem cells (MSC) in the pathogenetic/pathophysiologic process of MDS has been recently studied but existing data on MSCs' cytogenetic and functional integrity are controversial. Notably, in our study we did not find any significant quantitative or qualitative deficits in MDS-derived MSCs. As no conclusive data on the characteristics of BM MSCs have been reported so far, future studies should aim at elucidating whether BM MSCs belong primarily to the abnormal clone or whether they are indirectly damaged and whether they might be safely used for therapeutic purposes in MDS patients. This article aims to give an overview of the current state of the art on the quantitative, functional, immunoregulatory and cytogenetic properties of BM MSCs in MDS.
Asunto(s)
Médula Ósea/patología , Células Madre Mesenquimatosas/patología , Síndromes Mielodisplásicos/patología , Animales , HumanosRESUMEN
Alterations of the ten-eleven translocation-2 (TET2) gene have been recently identified in patients with myeloid malignancies using molecular, comparative genomic hybridization and single nucleotide polymorphism array techniques. We have performed TET2 fluorescence in situ hybridization analysis in a cohort of patients with myeloid disorders including myeloid malignancies and chronic idiopathic neutropenia, aiming to determine the usefulness of the technique in the identification of TET2 gene alterations. A TET2 deletion was found in one patient with chronic myelomonocytic leukemia suggesting that fluorescence in situ hybridization may have a role in identification of TET2 deletions, at least in this group of patients.
Asunto(s)
Proteínas de Unión al ADN/genética , Eliminación de Gen , Hibridación Fluorescente in Situ , Leucemia Mielomonocítica Crónica/genética , Síndromes Mielodisplásicos/genética , Trastornos Mieloproliferativos/genética , Neutropenia/genética , Proteínas Proto-Oncogénicas/genética , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Dioxigenasas , Femenino , Humanos , Leucemia Mielomonocítica Crónica/patología , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/patología , Trastornos Mieloproliferativos/patología , Neutropenia/patologíaRESUMEN
BACKGROUND: Lenalidomide improves erythropoiesis in patients with low/intermediate-1 risk myelodysplastic syndrome and interstitial deletion of the long arm of chromosome 5 [del(5q)]. The aim of this study was to explore the effect of lenalidomide treatment on the reserves and functional characteristics of bone marrow hematopoietic progenitor/precursor cells, bone marrow stromal cells and peripheral blood lymphocytes in patients with low/intermediate-1 risk myelodysplastic syndrome with del(5q). DESIGN AND METHODS: We evaluated the number and clonogenic potential of bone marrow erythroid/myeloid/megakaryocytic progenitor cells using clonogenic assays, the apoptotic characteristics and adhesion molecule expression of CD34(+) cells by flow cytometry, the hematopoiesis-supporting capacity of bone marrow stromal cells using long-term bone marrow cultures and the number and activation status of peripheral blood lymphocytes in ten patients with low/intermediate-1 risk myelodysplastic syndrome with del(5q) receiving lenalidomide. RESULTS: Compared to baseline, lenalidomide treatment significantly decreased the proportion of bone marrow CD34+ cells, increased the proportion of CD36(+)/GlycoA(+) and CD36(-)/GlycoA(+) erythroid cells and the percentage of apoptotic cells within these cell compartments. Treatment significantly improved the clonogenic potential of bone marrow erythroid, myeloid, megakaryocytic colony-forming cells and increased the proportion of CD34(+) cells expressing the adhesion molecules CD11a, CD49d, CD54, CXCR4 and the SLAM antigen CD48. The hematopoiesis-supporting capacity of bone marrow stroma improved significantly following treatment, as demonstrated by the number of colony-forming cells and the level of stromal-derived factor-1 alpha and intercellular adhesion molecule-1 in long-term bone marrow culture supernatants. Lenalidomide treatment also increased the proportion of activated peripheral blood T lymphocytes. CONCLUSIONS: The beneficial effect of lenalidomide in patients with lower risk myelodysplastic syndrome with del(5q) is associated with significant increases in the proportion of bone marrow erythroid precursor cells and in the frequency of clonogenic progenitor cells, a substantial improvement in the hematopoiesis-supporting potential of bone marrow stroma and significant alterations in the adhesion profile of bone marrow CD34(+) cells.
Asunto(s)
Antineoplásicos/uso terapéutico , Deleción Cromosómica , Cromosomas Humanos Par 5/genética , Hematopoyesis/efectos de los fármacos , Síndromes Mielodisplásicos/tratamiento farmacológico , Talidomida/análogos & derivados , Anciano , Anciano de 80 o más Años , Células de la Médula Ósea/efectos de los fármacos , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Citocinas/metabolismo , Femenino , Citometría de Flujo , Células Madre Hematopoyéticas/efectos de los fármacos , Humanos , Lenalidomida , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/patología , Talidomida/uso terapéuticoRESUMEN
Defective hematopoiesis supporting capacity of bone marrow (BM) stroma has been implicated in the pathophysiology of myelodysplastic syndromes (MDS). The aim of this study is to explore whether the BM stroma progenitors, namely the mesenchymal stem cells (MSCs), are primarily affected in MDS by evaluating the reserves, the functional properties, as well as the cytogenetic characteristics, in comparison to BM hematopoietic cells, in patients with de novo MDS (n = 13). The number, differentiation potential toward adipocytes/chondrocytes/osteoblasts and immunosuppressive function in terms of inhibition of mitogen-induced T-cell proliferation did not differ significantly between patient and normal (n = 20) MSCs. Patient MSCs did not show any aberrations in the production of proinflammatory or growth-promoting cytokines and did not harbor the cytogenetic abnormalities present in hematopoietic cells. Occasional patient and normal MSC cultures, however, developed irrelevant chromosomal alterations (trisomies 5 and 7) with uncertain pathophysiologic significance. Compared to controls, patient MSCs displayed impaired proliferative and clonogenic potential through passages that might represent a nonspecific abnormality associated with the chronic inflammatory process present in patients' BM. These data suggest that BM MSCs from MDS patients do not belong to the abnormal clone and do not represent the main cellular source contributing to the inflammatory marrow microenvironment.
Asunto(s)
Células de la Médula Ósea/fisiología , Aberraciones Cromosómicas , Células Madre Hematopoyéticas/fisiología , Células Madre Mesenquimatosas/fisiología , Síndromes Mielodisplásicos/fisiopatología , Anciano , Anciano de 80 o más Años , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/inmunología , Diferenciación Celular/fisiología , Proliferación Celular , Células Cultivadas , Citocinas/metabolismo , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/inmunología , Humanos , Inmunofenotipificación , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/inmunología , Persona de Mediana Edad , Síndromes Mielodisplásicos/patología , Linfocitos T/fisiologíaRESUMEN
BACKGROUND: Chronic idiopathic neutropenia (CIN) is a bone marrow (BM) failure syndrome characterized by accelerated apoptosis of myeloid progenitor cells because of a local imbalance between pro-inflammatory and anti-inflammatory cytokines. In this study, we investigated the interplay among transforming growth factor-beta1 (TGF-beta1), interleukin-10 (IL-10), and soluble flt-3 ligand (sFL) within the BM of CIN patients and probed the role of these cytokines in the pathophysiology of CIN. DESIGN: We used long-term BM cultures (LTBMC) to evaluate TGF-beta1, IL-10, and sFL levels in CIN patients (n = 70) and healthy subjects (n = 35). Cytokine levels in LTBMC supernatants were correlated with the number of circulating neutrophils and the proportion of BM CD34+/CD33+ myeloid progenitor cells. RESULTS: CIN patients had increased TGF-beta1 and sFL levels in LTBMCs compared with controls and individual cytokine values were found to be correlated inversely with the number of neutrophils and the proportion of CD34+/CD33+ cells. Patients displayed low supernatant IL-10 levels compared with controls and cytokine values were found to be correlated positively with the number of neutrophils and the proportion of CD34+/CD33+ cells. The levels of TGF-beta1 were found to be inversely correlated with IL-10 and positively with sFL values in LTBMC, supernatants suggesting a possible interplay among these cytokines in CIN BM. Neutralization of TGF-beta1 in LTBMCs increased IL-10 levels significantly in patients but not in controls, while neutralization had no effect on sFL levels. CONCLUSION: Excessive production of TGF-beta1 within the BM microenvironment of CIN patients results in downregulation of IL-10 and reduction of myeloid progenitor cells. Overexpression of sFL probably represents a compensatory mechanism to the low myeloid progenitor cells.
Asunto(s)
Células de la Médula Ósea/metabolismo , Interleucina-10/biosíntesis , Neutropenia/sangre , Factor de Crecimiento Transformador beta1/metabolismo , Adolescente , Adulto , Anciano , Antígenos CD/biosíntesis , Antígenos CD34/biosíntesis , Antígenos de Diferenciación Mielomonocítica/biosíntesis , Citocinas/metabolismo , Femenino , Humanos , Interleucina-10/metabolismo , Masculino , Proteínas de la Membrana/metabolismo , Persona de Mediana Edad , Neutropenia/metabolismo , Lectina 3 Similar a Ig de Unión al Ácido SiálicoRESUMEN
In about 55% of acute myeloid leukemia (AML) cases, chromosome aberrations are detectable by cytogenetics. Close correlations between cytomorphology and cytogenetics have been reported. To determine a pattern of cytogenetic abnormalities within the French-American-British (FAB) subtypes AML M0, M1, and M2, we analyzed 48 AML M0, 179 AML M1, and 425 AML M2 and compared cytogenetic data to a cohort of 1,062 AML M3/3v, M4, M4eo, M5a/5b, M6, and M7. Cytogenetic abnormalities were significantly more frequent in AML M0 (71%) compared to M1 (49%), M2 (53%), and the total cohort (56%; P < 0.02). While +8 was the most common numeric abnormality in all FAB subtypes, +13, +14, and +11 were associated with AML M0-M2. The only recurring balanced translocation that was associated with one of these FAB subtypes was t(8;21) in M2 (12.5%) and, rarely, M1 (1.7%) (M0, 0% and M3-7, 0.09%; P=0.001). To evaluate the frequency of cytogenetically undetectable abnormalities, we performed fluorescence in situ hybridization (FISH) analyses in 273 AML M0-M2 with normal karyotype using probes for ETO, ABL, MLL, TEL, RB, P53, AML1, and BCR. In two cases we identified numerical aberrations of RB only in interphases nuclei. In seven additional cases, TEL and MLL abnormalities were found. In conclusion, t(8;21), +11, +13, and +14 are strongly associated with AML M0, M1, and M2. The FISH screening analyses identified abnormalities in an additional 3% in normal karyotypes.
Asunto(s)
Aberraciones Cromosómicas , Leucemia Mieloide Aguda/clasificación , Leucemia Mieloide Aguda/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Proliferación Celular , Estudios de Cohortes , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Translocación GenéticaRESUMEN
In acute myelocytic leukemia (AML), predominantly in AML M5a, a recurrent chromosome aberration involves 11q23/MLL and the short arm of chromosome 10. Molecular studies have shown that the AF10 gene at 10p12 is consistently a partner gene in cases with 10;11 rearrangement. A simple reciprocal translocation cannot lead to the known MLL-AF10 fusion transcript because the 3' part of the MLL gene is orientated to the telomere and the 3' part of the AF10 gene to the centromere. In a series of 1897 AML samples, 14 cases (0.74%) showed 10;11 rearrangements leading to a MLL-AF10 fusion transcript. These cases were analyzed in detail with G banding analyses, fluorescence in situ hybridization, and molecular investigation in a single center. Five different mechanisms of (10;11) rearrangements leading to a MLL-AF10 fusion transcript can be observed (i.e., reciprocal translocations, insertions of either 10p into 11q or 11q into 10p, as well as complex and cryptic rearrangements). Compared to translocations involving MLL and other partner genes, complex rearrangements are unique for MLL-AF10 fusions. This may result from the opposite orientation of MLL and AF10.
Asunto(s)
Aberraciones Cromosómicas , Cromosomas Humanos Par 10 , Cromosomas Humanos Par 11 , Hibridación Fluorescente in Situ/métodos , Leucemia Mieloide Aguda/genética , Proteínas de Fusión Oncogénica/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Adulto , Anciano , Femenino , Humanos , Cariotipificación , Leucemia Mieloide Aguda/patología , Masculino , Metafase , Persona de Mediana Edad , Proteína de la Leucemia Mieloide-LinfoideRESUMEN
Acute myeloid leukemia (AML) cases with 11q23 abnormalities involving the MLL gene comprise one category of recurring genetic abnormalities in the WHO classification. In an unselected series of 1897 AML cases, 54 patients with an 11q23/MLL rearrangement were identified, resulting in an incidence of 2.8%. The incidence of AML with MLL rearrangement was significantly higher in therapy-related AML (t-AML) than in de novo AML (9.4% vs 2.6%, P <.0001). The frequency of MLL rearrangements was significantly higher in patients younger than 60 years (5.3% vs 0.8%, P <.0001). While the incidence of MLL rearrangements in AML M4, M5a, and M5b was 4.7%, 33.3%, and 15.9%, respectively, it was found in only 0.9% of all other French-American-British (FAB) subtypes (P <.0001). Compared with AML with intermediate karyotype, AML with 11q23/MLL rearrangement had a worse outcome, which was rather comparable with AML with unfavorable karyotype. Compared with t-AML, the median overall survival (OS) of de novo AML with MLL rearrangement was significantly better (2.5 vs 10 months, P =.0143). No significant differences in median OS were observed between cases with t(9;11) compared with all other MLL rearrangements (10.0 vs 8.9 months, P =.36). In conclusion, the category AML with 11q23/MLL abnormalities accounts for 2.8% of unselected AML, is closely associated with monocytic differentiation, and has a dismal prognosis. (