Publications by authors named "Silvia Bungaro"

9 Publications

  • Page 1 of 1

Integrated Genomic, Functional, and Prognostic Characterization of Atypical Chronic Myeloid Leukemia.

Hemasphere 2020 Dec 6;4(6):e497. Epub 2020 Nov 6.

Department of Medicine and Surgery, University of Milano - Bicocca, Monza, Italy.

Atypical chronic myeloid leukemia (aCML) is a -negative clonal disorder, which belongs to the myelodysplastic/myeloproliferative group. This disease is characterized by recurrent somatic mutations in , and genes, as well as high genetic heterogeneity, thus posing a great therapeutic challenge. To provide a comprehensive genomic characterization of aCML we applied a high-throughput sequencing strategy to 43 aCML samples, including both whole-exome and RNA-sequencing data. Our dataset identifies , , and as the most frequently mutated genes with a total of 43.2%, 29.7 and 16.2%, respectively. We characterized the clonal architecture of 7 aCML patients by means of colony assays and targeted resequencing. The results indicate that variants occur early in the clonal evolution history of aCML, while mutations often represent a late event. The presence of actionable mutations conferred both ex vivo and in vivo sensitivity to specific inhibitors with evidence of strong in vitro synergism in case of multiple targeting. In one patient, a clinical response was obtained. Stratification based on RNA-sequencing identified two different populations in terms of overall survival, and differential gene expression analysis identified 38 significantly overexpressed genes in the worse outcome group. Three genes correctly classified patients for overall survival.
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http://dx.doi.org/10.1097/HS9.0000000000000497DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655091PMC
December 2020

The Polo-Like Kinase 1 (PLK1) inhibitor NMS-P937 is effective in a new model of disseminated primary CD56+ acute monoblastic leukaemia.

PLoS One 2013 8;8(3):e58424. Epub 2013 Mar 8.

Oncology, Nerviano Medical Sciences, Nerviano, Milano, Italy.

CD56 is expressed in 15-20% of acute myeloid leukaemias (AML) and is associated with extramedullary diffusion, multidrug resistance and poor prognosis. We describe the establishment and characterisation of a novel disseminated model of AML (AML-NS8), generated by injection into mice of leukaemic blasts freshly isolated from a patient with an aggressive CD56(+) monoblastic AML (M5a). The model reproduced typical manifestations of this leukaemia, including presence of extramedullary masses and central nervous system involvement, and the original phenotype, karyotype and genotype of leukaemic cells were retained in vivo. Recently Polo-Like Kinase 1 (PLK1) has emerged as a new candidate drug target in AML. We therefore tested our PLK1 inhibitor NMS-P937 in this model either in the engraftment or in the established disease settings. Both schedules showed good efficacy compared to standard therapies, with a significant increase in median survival time (MST) expecially in the established disease setting (MST = 28, 36, 62 days for vehicle, cytarabine and NMS-P937, respectively). Importantly, we could also demonstrate that NMS-P937 induced specific biomarker modulation in extramedullary tissues. This new in vivo model of CD56(+) AML that recapitulates the human tumour lends support for the therapeutic use of PLK1 inhibitors in AML.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0058424PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3592825PMC
September 2013

A de novo supernumerary genomic discontinuous ring chromosome 21 in a child with mild intellectual disability.

Am J Med Genet A 2011 Jun 13;155A(6):1425-31. Epub 2011 May 13.

Medical Genetics Laboratory, S. Gerardo Hospital, Monza, Italy.

Small supernumerary marker chromosomes (sSMCs) are structurally abnormal extra chromosomes that cannot be unambiguously identified or characterized by conventional banding techniques alone, and they are generally equal in size or smaller than chromosome 20 of the same metaphase spread. Small supernumerary ring chromosomes (sSRCs), a smaller class of marker chromosomes, comprise about 10% of the cases. For various reasons these marker chromosomes have been the most difficult to characterize; although specific syndromes have not yet been defined, 60% of cases are associated with an abnormal phenotype. The chromosomal material involved, the degree and tissutal distribution of mosaicism, and the possible presence of uniparental disomy, are the important factors determining whether or not the ring chromosome will give rise to symptoms. Using conventional and molecular cytogenetics approaches we identified a de novo chromosome 21 sSRC in a child with speech delay and mild intellectual disability. By using aCGH analysis and SNP arrays, we report the presence of two discontinuous regions of chromosome 21 and the paternal origin of the sSRC. A thorough neuropsychiatric evaluation is also provided. Only few other cases of complex discontinuous ring chromosomes have been described in detail.
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http://dx.doi.org/10.1002/ajmg.a.34010DOI Listing
June 2011

ETV6-RUNX1 fusion gene and additional genetic changes in infant leukemia: a genome-wide analysis.

Cancer Genet Cytogenet 2009 Sep;193(2):86-92

Pediatric Hematology-Oncology Program, National Cancer Institute, INCA, Rua André Cavalcanti, 37, 20231-050 Rio de Janeiro, RJ, Brazil.

Acute lymphoblastic leukemia (ALL) in infants is characterized by a high frequency of MLL gene rearrangements. By contrast, the t(12;21) ETV6-RUNX1 fusion gene is typically detected in children older than 2 years. In a series of Brazilian infant leukemia cases, however, four younger cases harbored ETV6-RUNX1, at ages 2, 3, 5, and 7 months. This finding could represent a unique model for delineating the additional genomic hits required to accelerate the emergence of a frank leukemia in these t(12;21)-positive cases. We applied a whole-genome copy number analysis with single-nucleotide polymorphism (SNP) arrays, comparing t(12;21) infants with older pediatric age groups. Recurrent deletions, including 9p21.3 (CDKN2A, CKDN2B, and MTAP), 11p13 (CD44), 12p13.2 (ETV6), and patient-specific abnormalities were identified. Although infant cases with t(12;21) did not display specific genetic abnormalities explaining the short latency to overt leukemia, the frequency of copy number abnormalities increased proportionally with age. This novel SNP array analysis in an extremely rare series of cases opens new ideas about the etiology of ETV6-RUNX1-positive ALL.
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http://dx.doi.org/10.1016/j.cancergencyto.2009.04.021DOI Listing
September 2009

Integration of genomic and gene expression data of childhood ALL without known aberrations identifies subgroups with specific genetic hallmarks.

Genes Chromosomes Cancer 2009 Jan;48(1):22-38

Centro Ricerca Tettamanti, Clinica Pediatrica Università Milano-Bicocca, Ospedale San Gerardo, Monza, Italy.

Pediatric acute lymphoblastic leukemia (ALL) comprises genetically distinct subtypes. However, 25% of cases still lack defined genetic hallmarks. To identify genomic aberrancies in childhood ALL patients nonclassifiable by conventional methods, we performed a single nucleotide polymorphisms (SNP) array-based genomic analysis of leukemic cells from 29 cases. The vast majority of cases analyzed (19/24, 79%) showed genomic abnormalities; at least one of them affected either genes involved in cell cycle regulation or in B-cell development. The most relevant abnormalities were CDKN2A/9p21 deletions (7/24, 29%), ETV6 (TEL)/12p13 deletions (3/24, 12%), and intrachromosomal amplifications of chromosome 21 (iAMP21) (3/24, 12%). To identify variation in expression of genes directly or indirectly affected by recurrent genomic alterations, we integrated genomic and gene expression data generated by microarray analyses of the same samples. SMAD1 emerged as a down-regulated gene in CDKN2A homozygous deleted cases compared with nondeleted. The JAG1 gene, encoding the Jagged 1 ligand of the Notch receptor, was among a list of differentially expressed (up-regulated) genes in ETV6-deleted cases. Our findings demonstrate that integration of genomic analysis and gene expression profiling can identify genetic lesions undetected by routine methods and potential novel pathways involved in B-progenitor ALL pathogenesis.
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http://dx.doi.org/10.1002/gcc.20616DOI Listing
January 2009

Assessment of submicroscopic genetic lesions by single nucleotide polymorphism arrays in a child with acute myeloid leukemia and FLT3-internal tandem duplication.

Haematologica 2006 Jul 1;91(7):998-1000. Epub 2006 Jun 1.

The same FLT3-internal tandem duplication (ITD) positive clone was detected at diagnosis and relapse, but not at birth, in a child with M1 acute myeloid leukemia. Single nucleotide polymorphism arrays demonstrated that chromosome 13 acquired uniparental disomy, in association with del(9q), represented a progressive event in the course of the disease, and it was responsible for the homozygous FLT3-ITD at relapse.
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July 2006

Alpha1 acid glycoprotein binds to imatinib (STI571) and substantially alters its pharmacokinetics in chronic myeloid leukemia patients.

Clin Cancer Res 2003 Feb;9(2):625-32

Department of Experimental Oncology, Istituto Nazionale Tumori, Milano, Italy. carlo.gambacorti@

Purpose: Imatinib (Glivec) is a potent inhibitor of bcr/abl, an oncogenic fusion protein that causes chronic myelogenous leukemia (CML). alpha1 acid glycoprotein (AGP) binds to imatinib with high affinity and inhibits imatinib activity in vitro and in vivo in an animal model. A pharmacokinetics analysis of imatinib was undertaken in CML patients.

Experimental Design: Imatinib plasma concentrations were measured in 19 CML patients treated with imatinib (400 or 600 mg/day). Five patients received a concomitant short-term course of clindamycin (CLI).

Results: A positive correlation between AGP and imatinib plasma levels was observed. CLI administration decreased imatinib plasma concentrations, evaluated as area under the curve (AUC) and peak concentrations (C(max)). The effects of a bolus of CLI was studied in three patients on imatinib 23 h after the last imatinib dose. Within 5-10 min in three of three cases, CLI caused a decrease in imatinib plasma concentrations of 2.6-, 2.7-, and 4.7-fold, respectively. In vitro experiments using fresh blasts from CML patients showed that AGP, at concentrations observed in the patients, decreased imatinib intracellular concentrations up to 10 times and blocked imatinib activity. The incubation with CLI restored imatinib intracellular concentrations and biological activity.

Conclusion: AGP exerts significant effects of the pharmacokinetics, plasma concentrations, and intracellular distribution of imatinib in CML patients; these data indicate that plasma imatinib levels represent unreliable indicators of the cellular concentrations of this molecule.
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February 2003

Differences between in vivo and in vitro sensitivity to imatinib of Bcr/Abl+ cells obtained from leukemic patients.

Blood Cells Mol Dis 2002 May-Jun;28(3):361-72

Department of Experimental Oncology, Istituto Nazionale Tumori, Via Venezian 1, 20133 Milan, Italy.

Imatinib mesylate (imatinib) inhibits Bcr/Abl, an oncogenic fusion protein. The in vitro effects of imatinib on BCR/ABL+ leukemic cells include inhibition of Bcr/Abl tyrosine phosphorylation, block of proliferation, and induction of apoptosis. The in vivo effects of imatinib were evaluated in 12 CML (chronic myeloid leukemia) patients in blast crisis or accelerated phase who were treated with imatinib. Treatment caused a decrease in spontaneous proliferation of leukemic cells in 10 of 12 evaluable patients and the development of apoptosis in 9 of 11 cases. Imatinib also caused an inhibition of Bcr/Abl autophosphorylation; however, the degree of inhibition obtained in vivo was substantially lower than that achieved in vitro with similar concentrations of imatinib. In seven patients cells could be evaluated at relapse: spontaneous proliferation was no longer inhibited and Bcr/Abl phosphorylation was comparable or superior to that present at the beginning of treatment, before imatinib administration. Plasma imatinib concentrations were not reduced. Leukemic cells obtained at relapse maintained in vitro sensitivity (Bcr/Abl autophosphorylation and proliferation inhibition) to imatinib concentration measured in vivo (3 microM or higher), although a partial resistance to the antiproliferative effects of imatinib was present at low (0.01-0.3 microM) concentrations. In four patients, addition of erythromycin to blood samples obtained at relapse restored imatinib sensitivity in terms of phosphorylation inhibition, indicating that the majority of plasma imatinib was not available to cells and probably bound to alpha1 acid glycoprotein. These data suggest that measurements of Bcr/Abl kinase activity in peripheral blood samples may represent a more reliable indicator of active concentrations than the measurement of imatinib plasma levels.
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http://dx.doi.org/10.1006/bcmd.2002.0526DOI Listing
July 2003