51 research outputs found
Ruolo dell'istologia osteo-midollare nella diagnosi e nel follow up delle malattie mieloproliferative croniche Philadelphia-negative (Ph-CMPDs)
No full textCorrigendum: The Italian Mastocytosis Registry: 6-year experience from a hospital-based registry (Future Oncology (2018) 14:26 (2713-2723) DOI: 10.2217/fon-2018-0291)
No full textFollowing publication of the Research Article by SerenaMerante, Virginia V Ferretti, Chiara Elena, Valeria Brazzelli, Roberta Zanotti, Iria Neri, DiomiraMaglicane, Anna Belloni Fortina, Forer Ingeborg, Elide A Pastorello, Lisa Pieri, Cristina Papayannidis, Marina Mauro, Federica Grifoni, Roberto Minelli, Elena Guggiari, Elisa Difonzo, Monica Bocchia, Francesca Caroppo, Sergio DiNuzzo, ElenaMaria Elli,Michaela Rondoni, Rachele Ciccocioppo,Michele Di Stefano, Grazia Bossi, Emanuela Boveri, Patrizia Bonadonna, Fiorina Giona, Peter Valent &Massimo Triggiani, titled 'The Italian Mastocytosis Registry: 6-year experience from a hospital-based registry', which appeared in the November 2018 issue of Future Oncology (Future Oncology [Lond.] 14[26], 2713-2723 [2018]; DOI: 10.2217/fon-2018-0291), it has been brought to our attention that the name of Iria Neri has been corrected as follows: The author name was originally published as Iria Ner, and has been corrected to Iria Neri. The authors and editors of Future Oncology would like to sincerely apologise for any confusion or inconvenience this may have caused our readers
Particulate cytoplasmic structures with high concentration of ubiquitin-proteasome accumulate in myeloid neoplasms
No full textBACKGROUND:
Increased plasma levels of proteasome have been associated with various neoplasms, especially myeloid malignancies. Little is known of the cellular origin and release mechanisms of such proteasome. We recently identified and characterized a novel particulate cytoplasmic structure (PaCS) showing selective accumulation of ubiquitin-proteasome system (UPS) components. PaCSs have been reported in some epithelial neoplasms and in two genetic disorders characterized by hematopoietic cell dysplasia and increased risk of leukemia. However, no information is available about PaCSs in hematopoietic neoplasms.
METHODS:
PaCSs were investigated by ultrastructural, immunogold, and immunofluorescence analysis of bone marrow (BM) biopsies and peripheral blood (PB) cell preparations of 33 consecutive, untreated, or relapsed patients affected by different hematopoietic neoplasms. BM and PB samples from individuals with non-neoplastic BM or healthy donors were studied as controls. Granulocytes and platelet proteasome content was measured by immunoblotting and plasma proteasome levels by ELISA.
RESULTS:
PaCSs with typical, selective immunoreactivity for polyubiquitinated proteins and proteasome were widespread in granulocytic cells, megakaryocytes, and platelets of patients with myeloproliferative neoplasms (MPN). In acute myeloid leukemia and myelodysplastic syndromes (MDS), PaCSs were only occasionally detected in blast cells and were found consistently in cells showing granulocytic and megakaryocytic maturation. Conversely, PaCSs were poorly represented or absent in non-neoplastic hematopoietic tissue or lymphoid neoplasms. In MPN granulocytes and platelets, the presence of PaCSs was associated with increased amounts of proteasome in cell lysates. PaCSs were often localized in cytoplasmic blebs generating PaCSs-filled plasma membrane vesicles observable in the BM intercellular space. In MPN and MDS, accumulation of PaCSs was associated with significant increase in plasma proteasome. Immunogold analysis showed that PaCSs of myeloid neoplasia selectively concentrated the chaperone proteins Hsp40, Hsp70, and Hsp90.
CONCLUSIONS:
PaCSs accumulate in cells of myeloid neoplasms in a lineage- and maturation-restricted manner; in particular, they are widespread in granulocytic and megakaryocytic lineages of MPN patients. PaCSs development was associated with excess accumulation of polyubiquitinated proteins, proteasome, and chaperone molecules, indicating impairment of the UPS-dependent protein homeostasis and a possible link with Hsp90-related leukemogenesis. A mechanism of PaCSs discharge by leukemic cells could contribute to increased plasma proteasome of MPN and MDS
Pattern of somatic mutations in patients with Waldenström macroglobulinemia or IgM monoclonal gammopathy of undetermined significance.
No full textWe analyzed MYD88 and CXCR4 mutation status of 260 patients with Waldenström macroglobulinemia or IgM monoclonal gammopathy of undetermined significance using allele-specific real time quantitative polymerase chain reaction and Sanger sequencing, respectively. A subgroup of 119 patients was further studied with next-generation sequencing of 11 target genes (MYD88, CXCR4, ARID1A, KMT2D, NOTCH2, TP53, PRDM1, CD79B, TRAF3, MYBBP1A, and TNFAIP3). MYD88 (L265P) was found at diagnosis in 91% of patients with Waldenström macroglobulinemia and in 60% of patients with IgM monoclonal gammopathy of undetermined significance using allele-specific polymerase chain reaction analysis. MYD88 mutations other than the classical L265P (V217F, S219C and M232T) were found in four cases by next-generation sequencing. Waldenström macroglobulinemia patients with wild-type MYD88 had a distinct clinical phenotype characterized by less bone marrow infiltration (P=0.01) and more frequent extramedullary involvement (P=0.001) compared to patients with mutated MYD88 Patients with wild-type MYD88 did not show additional mutations in the other target genes. CXCR4 mutations were found by Sanger sequencing in 22% of patients with Waldenström macroglobulinemia. With next-generation sequencing, a CXCR4 mutation was detected in 23% of patients with Waldenström macroglobulinemia and 9% of those with IgM monoclonal gammopathy of undetermined significance. Asymptomatic Waldenström macroglobulinemia patients harboring a CXCR4 mutation had a shorter treatment-free survival (51 months) than that of patients with wild-type CXCR4 (median not reached) (P=0.007). Analysis of variant allele frequencies indicated that CXCR4 mutations were present in the dominant clone in the majority of cases. Recurrent somatic mutations of KMT2D were found in 24% of patients with Waldenström macroglobulinemia and 5% of patients with IgM monoclonal gammopathy of undetermined significance and were primarily subclonal
Vascular endothelial growth factor overexpression in myelodysplastic syndrome bone marrow cells: biological and clinical implications
No full textIn myelodysplastic syndrome (MDS), vascular endothelial growth factor (VEGF) may have regulatory effects on the hematopoietic system and contribute to disease progression. We analyzed by immunocytochemistry VEGF expression in bone marrow (BM) cells from 188 patients with MDS and 96 non-hemopathic subjects. We also measured VEGF BM plasma levels and in vitro VEGF release. Our aims were to evaluate whether VEGF expression abnormalities were associated with relevant laboratory or clinical findings and their possible prognostic value. In MDS, VEGF expression was higher than in controls (p <. 0001) and VEGF release was significantly higher in the lowrisk cases. A trend to a positive correlation between VEGF myeloid expression and apoptotic rate was observed. High myeloid VEGF levels were independently associated with longer overall survival (p <. 0001) and progression-free survival (p = .0002). Our findings suggest that, in MDS, VEGF production and release may contribute to ineffective hematopoiesis, with a potential prognostic rol
Mutation Type As a Major Determinant of Clinical Phenotype in Myeloproliferative Neoplasms Associated with Mutant Calreticulin
No full textAbout 25% of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF) carry a somatic mutation of CALR, the calreticulin gene [N Engl J Med. 2013;369:2379-90]. So far, more than 50 different indels in CALR exon 9 have been found, but a 52-bp deletion (type 1 mutation) and a 5-bp insertion (type 2) are the most common lesions. All indels generate a novel C-terminus of the mutant protein, in which the endoplasmic reticulum retention signal KDEL is lost and the negatively charged amino acids are replaced by neutral and positively charged amino acids, disrupting the Ca-binding site. This suggests that both cellular dislocation and impaired Ca-binding activity may be involved in the abnormal proliferation of cells expressing a mutant calreticulin. It is still unclear, however, why the same mutant gene is associated with 2 different disease phenotypes (ET and PMF). In particular, little in known about the effect of the mutant protein on megakaryocyte biology and bone marrow collagen deposition.
We studied the relationships between CALR mutation type, megakaryocyte biology, and clinical phenotype in patients with myeloproliferative neoplasms. According to the 2008 WHO criteria, 716 out of 892 patients had ET and 176 had PMF. Overall, 578 (65%) patients carried JAK2 (V617F), 230 (26%) had a CALR indel, and 84 (9%) had nonmutated JAK2 and CALR. Patients with MPL mutations were excluded.
Twenty-six different types of CALR lesions were identified: 120 (52%) patients had type 1 mutation, 75 (33%) had type 2, and 35 (15%) carried other indels. The frequency of type 1 mutation was significantly higher in PMF than in ET (71% vs 46%, P=.004). All these variants involved 3 different stretches of negatively charged amino acids, with an increase in the isoelectric points (pI) of the mutant protein. As type 1 and type 2 mutations affected stretch I and III, respectively, the 26 indels were categorized into 3 groups on the basis of the stretch they affected: i) type 1-like (61%), affecting stretch I; ii) type 2-like (36%), stretch III; iii) and other types (3%), stretch II. The pI values were significantly different in the 3 groups (P<.001). The frequency of type-1 like mutations was significantly higher in PMF than in ET (82% vs 55%, P=.001).
In vitro differentiated megakaryocytes from CALR-mutant patients displayed a significant increase in the extent of both intracellular Ca2+ release from the endoplasmic reticulum and extracellular Ca2+ entry inside the cytoplasm, as compared with healthy controls. Megakaryocytes carrying type 1-like CALR mutations exhibited the highest amplitude of Ca2+ flows regardless of the type of disease. In ET, impaired Ca2+ homeostasis was accompanied by atypical proplatelet architecture (ie, more branches and bifurcations).
With respect to clinical phenotype at diagnosis, ET patients with type 2-like CALR mutation showed a trend towards higher PLT count (P=.063) and lower age (P=.053), and significantly lower LDH values (P=.021) than those with type 1-like mutation. In a hierarchical cluster analysis including demographic, clinical and molecular data, CALR mutation type (1 vs 2) identified the 2 clusters with the highest dissimilarity.
Considering all patients, those with type 2-like CALR lesions had a better survival than those with JAK2 (V617F) (96.1% vs 84.4% at 10 years, P=.039), while no difference was found between the 2 CALR mutation types. ET patients with type 2-like CALR mutations showed a lower risk of thrombosis than those with JAK2 (V617F) (P=.010). By contrast, ET patients with type 1-like CALR mutations had a higher risk of myelofibrotic transformation that those with type 2-like CALR mutations (P=.029) and especially those with JAK2 (V617F) (P=.011). Finally, PMF patients with type 1-like CALR variants had a better survival than those with JAK2 (V617F) (80.1% vs 48% at 10 years, P=.008).
In summary, abnormalities in megakaryocyte calcium metabolism and proplatelet architecture are found in patients with CALR-mutant myeloproliferative neoplasms, and their extent is related to mutation type. Type 2-like CALR mutations are more likely to be associated with isolated thrombocytosis without bone marrow fibrosis, ie, with an ET phenotype. By contrast, type 1-like CALR mutations are generally associated with bone marrow fibrosis, ie, with a PMF phenotype. Thus, in CALR-mutant myeloproliferative neoplasms, the mutation type is a major determinant of the clinical phenotype
Parental Origin of the Deletion Del(20q) in Shwachman-Diamond Patients and Loss of the Paternally Derived Allele of the Imprinted L3MBTL1 Gene
No full textShwachman–Diamond syndrome (SDS) (OMIM 260400) is a rare autosomal recessive disease characterized by exocrine pancreatic insufficiency, skeletal, and hematological abnormalities and bone marrow (BM) dysfunction. Mutations in the SBDS gene cause SDS. Clonal chromosome anomalies are often present in BM, i(7)(q10) and del(20q) being the most frequent ones. We collected 6 SDS cases with del(20q): a cluster of imprinted genes, including L3MBTL1 and SGK2 is present in the deleted region. Only the paternal allele is expressed for these genes. Based on these data, we made the hypothesis that the loss of this region, in relation to parental origin of deletion, may be of relevance for the hematological phenotype.
By comparing hematological data of our 6 cases with a group of 20 SDS patients without evidence of del(20q) in BM, we observed a significant difference for Hb levels (P<0.012), and a difference slightly above the significance level for RBC counts (P<0.053): in both cases the values were higher in patients with del(20q). We also report preliminary evidence for
an increased number of BFU-E colonies in cases with paternal deletion, data on the presence of the deletion in colonies and in mature circulating lymphocytes. VC 2016 Wiley Periodicals, Inc
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