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1.
Blood ; 143(14): 1399-1413, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38194688

RESUMO

ABSTRACT: SETBP1 mutations are found in various clonal myeloid disorders. However, it is unclear whether they can initiate leukemia, because SETBP1 mutations typically appear as later events during oncogenesis. To answer this question, we generated a mouse model expressing mutated SETBP1 in hematopoietic tissue: this model showed profound alterations in the differentiation program of hematopoietic progenitors and developed a myeloid neoplasm with megakaryocytic dysplasia, splenomegaly, and bone marrow fibrosis, prompting us to investigate SETBP1 mutations in a cohort of 36 triple-negative primary myelofibrosis (TN-PMF) cases. We identified 2 distinct subgroups, one carrying SETBP1 mutations and the other completely devoid of somatic variants. Clinically, a striking difference in disease aggressiveness was noted, with patients with SETBP1 mutation showing a much worse clinical course. In contrast to myelodysplastic/myeloproliferative neoplasms, in which SETBP1 mutations are mostly found as a late clonal event, single-cell clonal hierarchy reconstruction in 3 patients with TN-PMF from our cohort revealed SETBP1 to be a very early event, suggesting that the phenotype of the different SETBP1+ disorders may be shaped by the opposite hierarchy of the same clonal SETBP1 variants.


Assuntos
Sistema Hematopoético , Doenças Mieloproliferativas-Mielodisplásicas , Transtornos Mieloproliferativos , Mielofibrose Primária , Animais , Camundongos , Humanos , Mielofibrose Primária/genética , Transtornos Mieloproliferativos/genética , Mutação , Proteínas de Transporte/genética , Proteínas Nucleares/genética
2.
Ann Hematol ; 100(1): 105-116, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33089365

RESUMO

Mesenchymal stromal cells (MSCs) represent an essential component of the bone marrow (BM) niche and display disease-specific alterations in several myeloid malignancies. The aim of this work was to study possible MSC abnormalities in Philadelphia-negative myeloproliferative neoplasms (MPNs) in relationship to the degree of BM fibrosis. MSCs were isolated from BM of 6 healthy donors (HD) and of 23 MPN patients, classified in 3 groups according to the diagnosis and the grade of BM fibrosis: polycythemia vera and essential thrombocythemia (PV/ET), low fibrosis myelofibrosis (LF-MF), and high fibrosis MF (HF-MF). MSC cultures were established from 21 of 23 MPN patients. MPN-derived MSCs did not exhibit any functional impairment in their adipogenic/osteogenic/chondrogenic differentiation potential and displayed a phenotype similar to HD-derived MSCs but with a decreased expression of CD146. All MPN-MSC lines were negative for the patient-specific hematopoietic clone mutations (JAK2, MPL, CALR). MSCs derived from HF-MF patients displayed a reduced clonogenic potential and a lower growth kinetic compared to MSCs from HD, LF-MF, and PV/ET patients. mRNA levels of hematopoiesis regulatory molecules were unaffected in MSCs from HF-MF compared to HD. Finally, in vitro ActivinA secretion by MSCs was increased in HF-MF compared to LF-MF patients, in association with a lower hemoglobin value. Increased ActivinA immunolabeling on stromal cells and erythroid precursors was also observed in HF-MF BM biopsies. In conclusion, higher grade of BM fibrosis is associated with functional impairment of MSCs and the increased secretion of ActivinA may represent a suitable target for anemia treatment in MF patients.


Assuntos
Ativinas/metabolismo , Medula Óssea/metabolismo , Células-Tronco Mesenquimais/metabolismo , Transtornos Mieloproliferativos/metabolismo , Mielofibrose Primária/metabolismo , Adulto , Idoso , Medula Óssea/patologia , Diferenciação Celular/fisiologia , Células Cultivadas , Estudos de Coortes , Feminino , Humanos , Masculino , Células-Tronco Mesenquimais/patologia , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/patologia , Policitemia Vera/metabolismo , Policitemia Vera/patologia , Mielofibrose Primária/patologia , Trombocitemia Essencial/metabolismo , Trombocitemia Essencial/patologia
3.
Blood ; 123(11): 1691-8, 2014 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-24366361

RESUMO

Childhood BCR-ABL1-positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has an unfavorable outcome and shows high frequency of IKZF1 deletions. The prognostic value of IKZF1 deletions was evaluated in 2 cohorts of BCR-ABL1-positive BCP-ALL patients, before tyrosine kinase inhibitors (pre-TKI) and after introduction of imatinib (in the European Study for Philadelphia-Acute Lymphoblastic Leukemia [EsPhALL]). In 126/191 (66%) cases an IKZF1 deletion was detected. In the pre-TKI cohort, IKZF1-deleted patients had an unfavorable outcome compared with wild-type patients (4-year disease-free survival [DFS] of 30.0 ± 6.8% vs 57.5 ± 9.4%; P = .01). In the EsPhALL cohort, the IKZF1 deletions were associated with an unfavorable prognosis in patients stratified in the good-risk arm based on early clinical response (4-year DFS of 51.9 ± 8.8% for IKZF1-deleted vs 78.6 ± 13.9% for IKZF1 wild-type; P = .03), even when treated with imatinib (4-year DFS of 55.5 ± 9.5% for IKZF1-deleted vs 75.0 ± 21.7% for IKZF1 wild-type; P = .05). In conclusion, the highly unfavorable outcome for childhood BCR-ABL1-positive BCP-ALL with IKZF1 deletions, irrespective of imatinib exposure, underscores the need for alternative therapies. In contrast, good-risk patients with IKZF1 wild-type responded remarkably well to imatinib-containing regimens, providing a rationale to potentially avoid hematopoietic stem-cell transplantation in this subset of patients.


Assuntos
Aberrações Cromossômicas , Proteínas de Fusão bcr-abl/genética , Fator de Transcrição Ikaros/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Antineoplásicos/uso terapêutico , Benzamidas/uso terapêutico , Criança , Estudos de Coortes , Feminino , Seguimentos , Humanos , Mesilato de Imatinib , Masculino , Cromossomo Filadélfia , Piperazinas/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Prognóstico , Pirimidinas/uso terapêutico , Deleção de Sequência , Taxa de Sobrevida
4.
BMC Med Genet ; 7: 77, 2006 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-17052327

RESUMO

BACKGROUND: Rubinstein-Taybi Syndrome (RSTS, MIM 180849) is a rare congenital disorder characterized by mental and growth retardation, broad and duplicated distal phalanges of thumbs and halluces, facial dysmorphisms and increased risk of tumors. RSTS is caused by chromosomal rearrangements and point mutations in one copy of the CREB-binding protein gene (CREBBP or CBP) in 16p13.3. To date mutations in CREBBP have been reported in 56.6% of RSTS patients and an average figure of 10% has ascribed to deletions. METHODS: Our study is based on the mutation analysis of CREBBP in 31 Italian RSTS patients using segregation analysis of intragenic microsatellites, BAC FISH and direct sequencing of PCR and RT-PCR fragments. RESULTS: We identified a total of five deletions, two of the entire gene and three, all in a mosaic condition, involving either the 5' or the 3' region. By direct sequencing a total of 14 de novo mutations were identified: 10 truncating (5 frameshift and 5 nonsense), one splice site, and three novel missense mutations. Two of the latter affect the HAT domain, while one maps within the conserved nuclear receptor binding of (aa 1-170) and will probably destroy a Nuclear Localization Signal. Identification of the p.Asn1978Ser in the healthy mother of a patient also carrying a de novo frameshift mutation, questions the pathogenetic significance of the missense change reported as recurrent mutation. Thirteen additional polymorphisms, three as of yet unreported, were also detected. CONCLUSION: A high detection rate (61.3%) of mutations is confirmed by this Italian study which also attests one of the highest microdeletion rate (16%) documented so far.


Assuntos
Proteína de Ligação a CREB/genética , Mutação , Síndrome de Rubinstein-Taybi/genética , Adolescente , Adulto , Sequência de Aminoácidos , Proteína de Ligação a CREB/química , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Itália , Masculino , Dados de Sequência Molecular , Sinais de Localização Nuclear , Linhagem , Mutação Puntual , Síndrome de Rubinstein-Taybi/diagnóstico , Alinhamento de Sequência , Deleção de Sequência
5.
Mediterr J Hematol Infect Dis ; 7(1): e2015041, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26075048

RESUMO

BACKGROUND AND OBJECTIVES: Acute lymphoblastic leukaemia (ALL) carrying t(9;22) or t(4;11) genetic abnormalities represents a very high risk subtype of disease (VHR-ALL). Hematopoietic stem cell transplantation (HSCT) remains the best curative option not only for t(4;11) ALL, but also for t(9;22) ALL in the tyrosin-kinase inhibitors era. In the last years, low molecular level of minimal residual disease (MRD) before HSCT was reported as one of the best favourable indexes for survival in ALL. Here we observed that even these patients can show a favourable outcome if submitted to HSCT with very low MRD. METHODS: We considered 18 consecutive VHR-ALL patients eligible to HSCT. 16 of them were transplanted in first remission, as soon as possible, employing myelo-ablative conditioning regimens. Molecular MRD has been evaluated before and after HSCT. RESULTS: Immediately before HSCT, MRD revealed: complete molecular remission (MRD(neg)) for five patients, and a level <1×10(-3) for seven patients. 100 days after HSCT we had: MRD(neg) for seven patients and a decrease for all the others after HSCT. After the tapering of immunosuppressive drugs, 13 patients reached the MRD(neg) in a median time of 8 months (range 3-16). In the intention to treat analysis, 14/18 patients are alive and disease free at the date of analysis. Overall survival and event free survival is of 78% and 66% respectively, with an average follow-up of 45 months (range 6-84) since HSCT. CONCLUSION: Early transplantation with low MRD level seems to be correlated with a favourable outcome also in VHR-ALL.

6.
Leuk Res ; 34(10): 1287-95, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20227111

RESUMO

The t(8;21) Acute Myeloid Leukaemia (AML) Kasumi-1 cell line with N822K KIT mutation, is a model system for leukemogenesis. As AML initiating cells reside in the CD34(+)CD38(-) fraction, we addressed the refined cytogenomic characterization and miRNA expression of Kasumi-1 cell line and its FACS-sorted subpopulations focussing on this compartment. By conventional cytogenetics, Spectral-Karyotyping and array-CGH the cytogenomic profile of Kasumi-1 cells evidenced only subtle regions differentially represented in CD34(+)CD38(-) cells. Expression profiling by a miRNA platform showed a set of miRNA differentially expressed in paired subpopulations and the signature of miR-584 and miR-182 upregulation in the CD34(+)CD38(-) fraction.


Assuntos
ADP-Ribosil Ciclase 1/análise , Antígenos CD34/análise , Leucemia Mieloide Aguda/genética , MicroRNAs/análise , Linhagem Celular Tumoral , Cromossomos Humanos Par 4 , Hibridização Genômica Comparativa , Perfilação da Expressão Gênica , Humanos , Imunofenotipagem , Leucemia Mieloide Aguda/imunologia , Proteínas Proto-Oncogênicas c-kit/genética
7.
Eur J Hum Genet ; 18(7): 768-75, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20125191

RESUMO

Rubinstein-Taybi syndrome (RSTS) is a rare autosomal dominant disorder characterised by facial dysmorphisms, growth and psychomotor development delay, and skeletal defects. The known genetic causes are point mutations or deletions of the CREBBP (50-60%) and EP300 (5%) genes. To detect chromosomal rearrangements indicating novel positional candidate RSTS genes, we used a-CGH to study 26 patients fulfilling the diagnostic criteria for RSTS who were negative at fluorescence in situ hybridisation analyses of the CREBBP and EP300 regions, and direct sequencing analyses of the CREBBP gene. We found seven imbalances (27%): four de novo and three inherited rearrangements not reported among the copy number variants. A de novo 7p21.1 deletion of 500 kb included the TWIST1 gene, a suggested candidate for RSTS that is responsible for the Saethre-Chotzen syndrome, an entity that enters in differential diagnosis with RSTS. A similar issue of differential diagnosis was raised by a large 4.3 Mb 2q22.3q23.1 deletion encompassing ZEB2, the gene responsible for the Mowat-Wilson syndrome, whose signs may overlap with RSTS. Positional candidate genes could not be sought in the remaining pathogenetic imbalances, because of the size of the involved region (a 9 Mb 2q24.3q31.1 deletion) and/or the relative paucity of suitable genes (a 5 Mb 3p13p12.3 duplication). One of the inherited rearrangements, the 17q11.2 379Kb duplication, represents the reciprocal event of the deletion underlying an overgrowth syndrome, both being mediated by the NF1-REP-P1 and REP-P2 sub-duplicons. The contribution of this and the other detected CNVs to the clinical RSTS phenotype is difficult to assess.


Assuntos
Proteína de Ligação a CREB/genética , Dosagem de Genes/genética , Síndrome de Rubinstein-Taybi/genética , Adolescente , Adulto , Desequilíbrio Alélico/genética , Criança , Pré-Escolar , Mapeamento Cromossômico , Hibridização Genômica Comparativa , Análise Mutacional de DNA , Fácies , Feminino , Deformidades Congênitas do Pé/complicações , Deformidades Congênitas do Pé/genética , Genoma Humano/genética , Deformidades Congênitas da Mão/complicações , Deformidades Congênitas da Mão/genética , Humanos , Lactente , Recém-Nascido , Padrões de Herança/genética , Masculino , Síndrome de Rubinstein-Taybi/complicações , Adulto Jovem
8.
Genomics ; 90(5): 567-73, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17855048

RESUMO

Rubinstein-Taybi syndrome (RSTS) is a rare malformation disorder caused by mutations in the closely related CREBBP and EP300 genes, accounting respectively for up to 60 and 3% of cases. About 10% of CREBBP mutations are whole gene deletions often extending into flanking regions. Using FISH and microsatellite analyses as a first step in the CREBBP mutation screening of 42 Italian RSTS patients, we identified six deletions, three of which were in a mosaic condition that has not been previously reported in RSTS. The use of region-specific BAC clones and small CREBBP probes allowed us to assess the extent of all of the deletions by mapping their endpoints to genomic intervals of 5-10 kb. Four of our five intragenic breakpoints cluster at the 5' end of CREBBP, where there is a peak of breakpoints underlying rearrangements in RSTS patients and tumors. The search for genomic motifs did not reveal any low-copy repeats (LCRs) or any greater density of repetitive sequences. In contrast, the percentage of interspersed repetitive elements (mainly Alu and LINEs in the CREBBP exon 2 region) is significantly higher than that in the entire gene or the average in the genome, thus suggesting that this characteristic may be involved in the region's vulnerability to breaking and nonhomologous pairing. The FISH analysis extended to the EP300 genomic region did not reveal any deletions. The clinical presentation was typical in all cases, but more severe in the three patients carrying constitutional deletions, raising a question about the possible underdiagnosis of a few cases of mild RSTS.


Assuntos
Proteína de Ligação a CREB/genética , Células Germinativas/fisiologia , Síndrome de Rubinstein-Taybi/genética , Deleção de Sequência , Adulto , Proteína de Ligação a CREB/metabolismo , Mapeamento Cromossômico , Feminino , Humanos , Recém-Nascido , Síndrome de Rubinstein-Taybi/patologia
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