16 results on '"Giulia Borella"'
Search Results
2. P435: NOVEL COMPOUNDS TO TARGET KMT2A-REARRANGED PEDIATRIC ACUTE MYELOID LEUKEMIA
- Author
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Claudia Tregnago, Maddalena Benetton, Ambra Da Ros, Giulia Borella, Giorgia Longo, Katia Polato, Jolanda Sabatino, Giovanni DI Salvo, Franco Locatelli, and Martina Pigazzi
- Subjects
Diseases of the blood and blood-forming organs ,RC633-647.5 - Published
- 2023
- Full Text
- View/download PDF
3. Novel Compounds Synergize With Venetoclax to Target KMT2A-Rearranged Pediatric Acute Myeloid Leukemia
- Author
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Claudia Tregnago, Maddalena Benetton, Ambra Da Ros, Giulia Borella, Giorgia Longo, Katia Polato, Samuela Francescato, Alessandra Biffi, and Martina Pigazzi
- Subjects
AML ,KMT2A ,venetoclax ,synergy ,targeted drugs ,Therapeutics. Pharmacology ,RM1-950 - Abstract
In pediatric acute myeloid leukemia (AML), fusions involving lysine methyltransferase 2A (KMT2A) are considered hallmarks of aggressive AML, for whom the development of targeted specific therapeutic agents to ameliorate classic chemotherapy and obtain a complete eradication of disease is urgent. In this study, we investigated the antiapoptotic proteins in a cohort of 66 pediatric AML patients, finding that 75% of the KMT2A-r are distributed in Q3 + Q4 quartiles of BCL-2 expression, and KMT2A-r have statistically significant high levels of BCL-2, phospho-BCL-2 S70, and MCL-1, indicating a high anti-apoptotic pathway activation. In an attempt to target it, we tested novel drug combinations of venetoclax, a B-cell lymphoma-2 (BCL-2) inhibitor, in KMT2A-MLLT3, for being the most recurrent, and KMT2A-AFDN, for mediating the worst prognosis, rearranged AML cell lines. Our screening revealed that both the bromodomain and extra-terminal domain (BET) inhibitor, I-BET151, and kinase inhibitor, sunitinib, decreased the BCL-2 family protein expression and significantly synergized with venetoclax, enhancing KMT2A-r AML cell line death. Blasts t (6; 11) KMT2A-AFDN rearranged, both from cell lines and primary samples, were shown to be significantly highly responsive to the combination of venetoclax and thioridazine, with the synergy being induced by a dramatic increase of mitochondrial depolarization that triggered blast apoptosis. Finally, the efficacy of novel combined drug treatments was confirmed in KMT2A-r AML cell lines or ex vivo primary KMT2A-r AML samples cultured in a three-dimensional system which mimics the bone marrow niche. Overall, this study identified that, by high-throughput screening, the most KMT2A-selective drugs converged in different but all mitochondrial apoptotic network activation, supporting the use of venetoclax in this AML setting. The novel drug combinations here unveiled provide a rationale for evaluating these combinations in preclinical studies to accelerate the introduction of targeted therapies for the life-threatening KMT2A-AML subgroup of pediatric AML.
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- 2022
- Full Text
- View/download PDF
4. The long non-coding RNA CDK6-AS1 overexpression impacts on acute myeloid leukemia differentiation and mitochondrial dynamics
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Elena Porcù, Maddalena Benetton, Valeria Bisio, Ambra Da Ros, Claudia Tregnago, Giulia Borella, Carlo Zanon, Matteo Bordi, Giuseppe Germano, Sabrina Manni, Silvia Campello, Dinesh S. Rao, Franco Locatelli, and Martina Pigazzi
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Molecular biology ,Cell biology ,Cancer ,Science - Abstract
Summary: Patients with acute myeloid leukemia (AML) carrying high-risk genetic lesions or high residual disease levels after therapy are particularly exposed to the risk of relapse. Here, we identified the long non-coding RNA CDK6-AS1 able to cluster an AML subgroup with peculiar gene signatures linked to hematopoietic cell differentiation and mitochondrial dynamics. CDK6-AS1 silencing triggered hematopoietic commitment in healthy CD34+ cells, whereas in AML cells the pathological undifferentiated state was rescued. This latter phenomenon derived from RUNX1 transcriptional control, responsible for the stemness of hematopoietic precursors and for the block of differentiation in AML. By CDK6-AS1 silencing in vitro, AML mitochondrial mass decreased with augmented pharmacological sensitivity to mitochondria-targeting drugs. In vivo, the combination of tigecycline and cytarabine reduced leukemia progression in the AML-PDX model with high CDK6-AS1 levels, supporting the concept of a mitochondrial vulnerability. Together, these findings uncover CDK6-AS1 as crucial in myeloid differentiation and mitochondrial mass regulation.
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- 2021
- Full Text
- View/download PDF
5. NPM1 Mutational Status Underlines Different Biological Features in Pediatric AML
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Claudia Tregnago, Maddalena Benetton, Davide Padrin, Katia Polato, Giulia Borella, Ambra Da Ros, Anna Marchetti, Elena Porcù, Francesca Del Bufalo, Cristina Mecucci, Franco Locatelli, and Martina Pigazzi
- Subjects
Nucleophosmin, NPM1 ,acute myeloid leukemia ,gene expression ,TP53 ,mutation ,genetic ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Nucleophosmin (NPM1) is a nucleocytoplasmic shuttling protein, predominantly located in the nucleolus, that regulates a multiplicity of different biological processes. NPM1 localization in the cell is finely tuned by specific signal motifs, with two tryptophan residues (Trp) being essential for the nucleolar localization. In acute myeloid leukemia (AML), several NPM1 mutations have been reported, all resulting in cytoplasmic delocalization, but the putative biological and clinical significance of different variants are still debated. We explored HOXA and HOXB gene expression profile in AML patients and found a differential expression between NPM1 mutations inducing the loss of two (A-like) Trp residues and those determining the loss of one Trp residue (non-A-like). We thus expressed NPM1 A-like- or non-A-like-mutated vectors in AML cell lines finding that NPM1 partially remained in the nucleolus in the non-A-like NPM1-mutated cells. As a result, only in A-like-mutated cells we detected HOXA5, HOXA10, and HOXB5 hyper-expression and p14ARF/p21/p53 pathway deregulation, leading to reduced sensitivity to the treatment with either chemotherapy or Venetoclax, as compared to non-A-like cells. Overall, we identified that the NPM1 mutational status mediates crucial biological characteristics of AML cells, providing the basis for further sub-classification and, potentially, management of this subgroup of patients.
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- 2021
- Full Text
- View/download PDF
6. Mesenchymal Stromal Cell Secretome in Acute Myeloid Leukemia Bone Marrow Niche
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Giulia Borella, Giorgia Longo, Ambra Da Ros, Elisabetta Campodoni, Margherita Montanari, Maddalena Benetton, Salvatore Nicola Bertuccio, Monica Sandri, Claudia Tregnago, Riccardo Masetti, Franco Locatelli, and Martina Pigazzi
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Immunology ,Cell Biology ,Hematology ,Biochemistry - Published
- 2022
7. Thioridazine requires calcium influx to induce MLL-AF6–rearranged AML cell death
- Author
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Silvia Campello, Paola Cogo, Elena Porcù, Manuela Simonato, Franco Locatelli, Katia Polato, Alessandro Massi, Sonia Minuzzo, Ambra Da Ros, Barbara Buldini, Claudia Tregnago, Martina Pigazzi, Giulia Borella, Romeo Romagnoli, Luca Simula, Giulia Borile, and Maddalena Benetton
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Programmed cell death ,Oncogene Proteins, Fusion ,medicine.medical_treatment ,Cell ,Hematopoietic stem cell transplantation ,acute myeloid leukemia ,Settore MED/04 ,Translocation, Genetic ,NO ,children ,AML ,In vivo ,safer drugs ,hemic and lymphatic diseases ,Precursor cell ,medicine ,Humans ,Child ,Clonogenic assay ,Myeloid Neoplasia ,Cell Death ,Thioridazine ,business.industry ,Histone-Lysine N-Methyltransferase ,Hematology ,medicine.disease ,Leukemia, Myeloid, Acute ,Leukemia ,medicine.anatomical_structure ,Settore MED/38 - PEDIATRIA GENERALE E SPECIALISTICA ,Mechanism of action ,Cancer research ,Calcium ,medicine.symptom ,business ,Myeloid-Lymphoid Leukemia Protein - Abstract
In pediatric acute myeloid leukemia (AML), intensive chemotherapy and allogeneic hematopoietic stem cell transplantation are the cornerstones of treatment in high-risk cases, with severe late effects and a still high risk of disease recurrence as the main drawbacks. The identification of targeted, more effective, safer drugs is thus desirable. We performed a high-throughput drug-screening assay of 1280 compounds and identified thioridazine (TDZ), a drug that was highly selective for the t(6;11)(q27;q23) MLL-AF6 (6;11)AML rearrangement, which mediates a dramatically poor (below 20%) survival rate. TDZ induced cell death and irreversible progress toward the loss of leukemia cell clonogenic capacity in vitro. Thus, we explored its mechanism of action and found a profound cytoskeletal remodeling of blast cells that led to Ca2+ influx, triggering apoptosis through mitochondrial depolarization, confirming that this latter phenomenon occurs selectively in t(6;11)AML, for which AF6 does not work as a cytoskeletal regulator, because it is sequestered into the nucleus by the fusion gene. We confirmed TDZ-mediated t(6;11)AML toxicity in vivo and enhanced the drug’s safety by developing novel TDZ analogues that exerted the same effect on leukemia reduction, but with lowered neuroleptic effects in vivo. Overall, these results refine the MLL-AF6 AML leukemogenic mechanism and suggest that the benefits of targeting it be corroborated in further clinical trials.
- Published
- 2020
8. The long non-coding RNA CDK6-AS1 overexpression impacts on acute myeloid leukemia differentiation and mitochondrial dynamics
- Author
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Martina Pigazzi, Ambra Da Ros, Elena Porcù, Sabrina Manni, Maddalena Benetton, Dinesh S. Rao, Franco Locatelli, Claudia Tregnago, Giulia Borella, Matteo Bordi, Silvia Campello, Carlo Zanon, Giuseppe Germano, and Valeria Bisio
- Subjects
Cell biology ,Myeloid ,Settore BIO/06 ,Childhood Leukemia ,Pediatric Cancer ,Cancer ,Molecular biology ,Science ,CD34 ,Biology ,Article ,chemistry.chemical_compound ,Rare Diseases ,Stem Cell Research - Nonembryonic - Human ,hemic and lymphatic diseases ,Genetics ,medicine ,2.1 Biological and endogenous factors ,Gene silencing ,Aetiology ,Pediatric ,Multidisciplinary ,Myeloid leukemia ,Hematology ,Stem Cell Research ,medicine.disease ,Haematopoiesis ,Leukemia ,medicine.anatomical_structure ,Settore MED/38 - PEDIATRIA GENERALE E SPECIALISTICA ,RUNX1 ,chemistry ,Cancer research ,Cytarabine ,medicine.drug - Abstract
Summary Patients with acute myeloid leukemia (AML) carrying high-risk genetic lesions or high residual disease levels after therapy are particularly exposed to the risk of relapse. Here, we identified the long non-coding RNA CDK6-AS1 able to cluster an AML subgroup with peculiar gene signatures linked to hematopoietic cell differentiation and mitochondrial dynamics. CDK6-AS1 silencing triggered hematopoietic commitment in healthy CD34+ cells, whereas in AML cells the pathological undifferentiated state was rescued. This latter phenomenon derived from RUNX1 transcriptional control, responsible for the stemness of hematopoietic precursors and for the block of differentiation in AML. By CDK6-AS1 silencing in vitro, AML mitochondrial mass decreased with augmented pharmacological sensitivity to mitochondria-targeting drugs. In vivo, the combination of tigecycline and cytarabine reduced leukemia progression in the AML-PDX model with high CDK6-AS1 levels, supporting the concept of a mitochondrial vulnerability. Together, these findings uncover CDK6-AS1 as crucial in myeloid differentiation and mitochondrial mass regulation., Graphical abstract, Highlights • CDK6-AS1 acts in concert with CDK6 • High CDK6-AS1 levels trigger RUNX1 early differentiation arrest in myeloid cells • CDK6-AS1 controls mitochondrial mass of AML blasts • CDK6-AS1 levels impact on mitochondrial-targeted agents sensitivity, Molecular biology; Cell biology; Cancer
- Published
- 2021
9. Targeting mesenchymal stromal cells plasticity to reroute acute myeloid leukemia course
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Barbara Montini, Barbara Buldini, Giulia Borile, Stefano Cairo, Franco Locatelli, Valeria Bisio, Silvia Bresolin, Anna Leszl, Barbara Michielotto, Monica Montesi, Giulia Borella, Ambra Da Ros, Elisabetta Campodoni, Alice Cani, Maddalena Benetton, Monica Sandri, Claudia Tregnago, Elena Porcù, Anna Marchetti, and Martina Pigazzi
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business.industry ,Cell growth ,Immunology ,Mesenchymal stem cell ,Myeloid leukemia ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,Chemotherapy regimen ,Transcriptome ,Leukemia ,medicine.anatomical_structure ,In vivo ,hemic and lymphatic diseases ,medicine ,Cancer research ,Bone marrow ,business - Abstract
Bone marrow (BM) microenvironment contributes to the regulation of normal hematopoiesis through a finely tuned balance of self-renewal and differentiation processes, cell-cell interaction and secretion of cytokines that during leukemogenesis are altered and favor tumor cell growth. In pediatric acute myeloid leukemia (AML), chemotherapy is the standard of care, but still >30% of patients relapse. The need to accelerate the evaluation of innovative medicines prompted us to investigate the mesenchymal stromal cells (MSCs) role in the leukemic niche to define its contribution to the mechanisms of leukemia escape. We generated humanized three-dimensional (3D) niche with AML cells and MSCs derived from either patients (AML-MSCs) or healthy donors. We observed that AML cells establish physical connections with MSCs, mediating a reprogrammed transcriptome inducing aberrant cell proliferation and differentiation, and severely compromising their immunomodulatory capability. We confirmed that AML cells modulate h-MSCs transcriptional profile promoting functions similar to the AML-MSCs when co-cultured in vitro, thus facilitating leukemia progression. Conversely, MSCs derived from BM of patients at time of disease remission showed recovered healthy features, at transcriptional and functional levels, including the secretome. We proved that AML blasts alter MSCs activities in the BM niche, favoring disease development and progression. We discovered that a novel AML-MSCs selective CaV1.2 channel blocker drug, Lercanidipine, is able to impair leukemia progression in 3D niche both in vitro and when implanted in vivo, if used in combination with chemotherapy, supporting the hypothesis that synergistic effects can be obtained by dual targeting approaches.
- Published
- 2021
10. NPM1 mutational status underlines different biological features in pediatric AML
- Author
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Giulia Borella, Ambra Da Ros, Davide Padrin, Anna Marchetti, Elena Porcù, Claudia Tregnago, Martina Pigazzi, Katia Polato, Francesca Del Bufalo, Cristina Mecucci, Maddalena Benetton, and Franco Locatelli
- Subjects
0301 basic medicine ,Cancer Research ,NPM1 ,Nucleolus ,Cell ,Biology ,medicine.disease_cause ,Article ,HOX genes ,Nucleophosmin, NPM1 ,TP53 ,acute myeloid leukemia ,drug treatment ,gene expression ,genetic ,mutation ,03 medical and health sciences ,chemistry.chemical_compound ,Drug treatment ,0302 clinical medicine ,p14arf ,Genetic ,medicine ,RC254-282 ,Acute myeloid leukemia ,Gene expression ,Mutation ,Nucleophosmin ,Venetoclax ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Myeloid leukemia ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,chemistry ,Settore MED/38 - PEDIATRIA GENERALE E SPECIALISTICA ,030220 oncology & carcinogenesis ,Cancer research - Abstract
Simple Summary Nucleophosmin (NPM1) protein regulates several cellular processes and is predominantly located in the nucleolus, owing to the localization signal provided by two tryptophan residues. In acute myeloid leukemia (AML), NPM1 gene is frequently mutated, leading to the aberrant translocation of the protein into cytoplasm. In the present work, we classified NPM1 mutations according to the loss of either one or both tryptophan residues as non-A-like and A-like mutations, respectively, and evaluated their biological features. We found that non-A-like mutations partially delocalize NPM1 protein into the cytoplasm, with a proportion of remaining nucleolar protein preserving p53 protein expression and downstream activity. Different HOXA and HOXB gene expression and cell death pathway activation between A-like and non-A-like NPM1-mutated cells were shown, with an enhanced sensitivity to chemotherapy for AML cells with non-A-like mutations. This study suggests the need for a sub-classification of NPM1-mutated AML, with subsequent implications in the therapeutic management. Abstract Nucleophosmin (NPM1) is a nucleocytoplasmic shuttling protein, predominantly located in the nucleolus, that regulates a multiplicity of different biological processes. NPM1 localization in the cell is finely tuned by specific signal motifs, with two tryptophan residues (Trp) being essential for the nucleolar localization. In acute myeloid leukemia (AML), several NPM1 mutations have been reported, all resulting in cytoplasmic delocalization, but the putative biological and clinical significance of different variants are still debated. We explored HOXA and HOXB gene expression profile in AML patients and found a differential expression between NPM1 mutations inducing the loss of two (A-like) Trp residues and those determining the loss of one Trp residue (non-A-like). We thus expressed NPM1 A-like- or non-A-like-mutated vectors in AML cell lines finding that NPM1 partially remained in the nucleolus in the non-A-like NPM1-mutated cells. As a result, only in A-like-mutated cells we detected HOXA5, HOXA10, and HOXB5 hyper-expression and p14ARF/p21/p53 pathway deregulation, leading to reduced sensitivity to the treatment with either chemotherapy or Venetoclax, as compared to non-A-like cells. Overall, we identified that the NPM1 mutational status mediates crucial biological characteristics of AML cells, providing the basis for further sub-classification and, potentially, management of this subgroup of patients.
- Published
- 2021
11. Targeting the plasticity of mesenchymal stromal cells to reroute the course of acute myeloid leukemia
- Author
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Giulia, Borella, Ambra, Da Ros, Giulia, Borile, Elena, Porcù, Claudia, Tregnago, Maddalena, Benetton, Anna, Marchetti, Valeria, Bisio, Barbara, Montini, Barbara, Michielotto, Alice, Cani, Anna, Leszl, Elisabetta, Campodoni, Monica, Sandri, Monica, Montesi, Silvia, Bresolin, Stefano, Cairo, Barbara, Buldini, Franco, Locatelli, and Martina, Pigazzi
- Subjects
Dihydropyridines ,Leukemia, Myeloid, Acute ,Calcium Channels, L-Type ,Human Umbilical Vein Endothelial Cells ,Tumor Cells, Cultured ,Tumor Microenvironment ,Humans ,Mesenchymal Stem Cells ,Transcriptome ,Cell Proliferation ,Neoplasm Proteins - Abstract
Bone marrow (BM) microenvironment contributes to the regulation of normal hematopoiesis through a finely tuned balance of self-renewal and differentiation processes, cell-cell interaction, and secretion of cytokines that during leukemogenesis are altered and favor tumor cell growth. In pediatric acute myeloid leukemia (AML), chemotherapy is the standard of care, but30% of patients still relapse. The need to accelerate the evaluation of innovative medicines prompted us to investigate the role of mesenchymal stromal cells (MSCs) in the leukemic niche to define its contribution to the mechanism of leukemia drug escape. We generated a humanized 3-dimensional (3D) niche with AML cells and MSCs derived from either patients (AML-MSCs) or healthy donors. We observed that AML cells establish physical connections with MSCs, mediating a reprogrammed transcriptome inducing aberrant cell proliferation and differentiation and severely compromising their immunomodulatory capability. We confirmed that AML cells modulate h-MSCs transcriptional profile promoting functions similar to the AML-MSCs when cocultured in vitro, thus facilitating leukemia progression. Conversely, MSCs derived from BM of patients at time of disease remission showed recovered healthy features at transcriptional and functional levels, including the secretome. We proved that AML blasts alter MSCs activities in the BM niche, favoring disease development and progression. We discovered that a novel AML-MSC selective CaV1.2 channel blocker drug, lercanidipine, is able to impair leukemia progression in 3D both in vitro and when implanted in vivo if used in combination with chemotherapy, supporting the hypothesis that synergistic effects can be obtained by dual targeting approaches.
- Published
- 2020
12. Pumpless Microfluidic System for Bone Marrow Niche-on-a-Chip in vitro Modelling and Multiphoton Imaging in Leukemia
- Author
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Giulia Borella, Filippo Romanato, Giulia Borile, Kurt S. Anderson, Andrea Filippi, Camille Charoy, and Martina Pigazzi
- Subjects
Leukemia ,medicine.anatomical_structure ,Chemistry ,Microfluidics ,Biophysics ,medicine ,Bone marrow ,medicine.disease ,Chip ,Multiphoton imaging ,In vitro ,Biomedical engineering - Published
- 2020
13. Acute Myeloid Leukemia (AML) in a 3D Bone Marrow Niche Showed High Performance for in Vitro and In Vivo Drug Screenings
- Author
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Monica Sandri, Stefano Cairo, Monica Montesi, Martina Pigazzi, Silvia Panseri, Maddalena Benetton, Elisabetta Campodoni, Franco Locatelli, Valeria Bisio, Elena Porcù, Claudia Tregnago, Giulia Borella, and Ambra Da Ros
- Subjects
Oncology ,medicine.medical_specialty ,business.industry ,Immunology ,Mesenchymal stem cell ,Myeloid leukemia ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,Minimal residual disease ,Dasatinib ,Leukemia ,Immunophenotyping ,medicine.anatomical_structure ,hemic and lymphatic diseases ,Internal medicine ,medicine ,Bone marrow ,business ,Clonogenic assay ,medicine.drug - Abstract
Chemotherapy still remains the pillar of treatment of children with AML, a disease in which refinements in diagnostic approaches, minimal residual disease monitoring, and patient stratification have resulted into remarkable progresses during the past decade. However, most of the recently tested, novel anti-leukemia agents failed during pre-clinical and clinical validation phases, and one main limit in AML field is the inappropriateness of current preclinical models used to study drug efficacy, this jeopardizing the advance of phase II and III clinical trials, especially for children. In light of this consideration, we aimed at creating novel robust in vitro and in vivo approaches to discover or to re-assess alternative treatments to improve the portfolio of agents active in childhood AML. For this purpose, we developed new protocols for long-term 3D-AML cultures to perform more predictable high throughput drug screening in vitro, and, once identified the best compounds, to create new pre-clinical in vivo models. We set up the bone marrow (BM) endosteal niche by using a biomimetic 3D structure, made up of engineered hydroxyapatite and collagen I, where we seeded mesenchymal stromal cells derived either from AML patients (AML-MSCs) or from healthy BM donors (h-MSCs), together with osteoblasts, endothelial cells and finally AML blasts. We studied AML cell proliferation and clonogenicity cultured in 3D. We obtained results from twenty 3D long-term cultures of different primary AML, confirming blast proliferation up to 21 days. Clonogenic potential and immunophenotype preservation of the original AML blasts was also documented. At the same time, we compared AML-MSCs with h-MSCs, finding that AML-MSCs exhibited a higher proliferation rate (40% increase proliferation at 72 and 96 hours, p Disclosures Locatelli: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Miltenyi: Honoraria; bluebird bio: Consultancy.
- Published
- 2019
14. The Long Noncoding RNA BALR2 Controls Novel Transcriptional Circuits Involved in Chemotherapy Sensitivity of Pediatric Acute Myeloid Leukemia (AML) Blasts
- Author
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Franco Locatelli, Matteo Bordi, Ambra Da Ros, Dinesh S. Rao, Giuseppe Germano, Sabrina Manni, Maddalena Benetton, Martina Pigazzi, Silvia Campello, Giulia Borella, Elena Porcù, Valeria Bisio, Claudia Tregnago, and Carlo Zanon
- Subjects
Myeloid ,Immunology ,CD34 ,Myeloid leukemia ,Cell Biology ,Hematology ,Biology ,medicine.disease ,Biochemistry ,Minimal residual disease ,Haematopoiesis ,chemistry.chemical_compound ,Leukemia ,medicine.anatomical_structure ,Myeloid stem cell ,RUNX1 ,chemistry ,hemic and lymphatic diseases ,medicine ,Cancer research - Abstract
In acute myeloid leukemia (AML), the assessment of post-induction minimal residual disease (MRD) is largely utilized for choosing post-remission therapies aimed at maintaining complete remission (CR) and preventing relapse. This latter is still the major cause of treatment failure in pediatric AML, and even if several efforts have been spent to validate MRD as a prognostic marker, numerous studies demonstrated that MRD negativity cannot be considered a completely reliable surrogate biomarker predicting outcome, since it does not exclude a relapse. The current interpretation is that disease relapse is due to mechanisms leading to therapy resistance mainly depending on driver chimeric or oncogenic protein-coding genes, which are monitored during treatment, and does not consider that chemotherapy resistance may arise from other genetic markers, phenomenon linked to methylation and non-coding RNAs genomic pressure. We, thus, hypothesized that other markers need to be explored to re-interpret leukemia progression. We showed an overall hyper-expression of the lncRNA BALR2 in 132 de novo AML bone marrow samples collected at diagnosis and analyzed the gene expression profile (GEP) of 58 cases. By unsupervised clustering analysis, we produced important advances in identifying BALR2 as a robust novel molecular marker of a new subgroup of AML characterized by a high rate of resistance to induction therapy, independently from the genetic lesions detected at diagnosis and any other prognostic clinical and genetic features. We demonstrated in vitro that BALR2 has a direct role in controlling bi-directionally its own and of its neighbor gene CDK6 promoter activity. This latter finding of high CDK6 expression was shown to sustain its complex with RUNX1 in order to inhibit RUNX1 binding to its target promoters, thus preventing the process of hematopoietic differentiation progression. To support BALR2 as a new proto-oncogene involved in the control of the myeloid differentiation program, we ranked the genes across the expression profile obtaining a signature of 337 transcripts able to cluster CD34+ human stem cell precursors (HSCPs) separately from more mature CD14+ cells. These in silico findings were validated in vitro by showing that, after BALR2 depletion, CD34+ cells had a skewed myeloid differentiation. Furthermore, we found that AML differentiation toward mature myeloid cells with increased phagocytic capacity was obtained through BALR2 level reduction, and enhanced by combinatorial differentiation stimuli. Our findings attribute a distinct role to BALR2 in the block of myeloid stem cell differentiation occurring during leukemogenesis. At the same time, we interrogated GEP ontology, finding that enrichments of genes involved in mitochondrial synthesis pathways were significantly correlated to patients with highest BALR2 levels, and confirmed the same mitochondriogenesis profile in the immature CD34+ HSCPs. We moved to deconvolute this feature and demonstrated that BALR2, by controlling mitochondria gene balance, was directly controlling the mitochondrial mass, which dramatically decreased after BALR2 silencing, this supporting the hypothesis that BALR2 would maintain mitochondrial functions to confer AML resistance to cytotoxicity. Consistently with this line of reasoning, we inhibited mitochondria by tigecycline, demonstrating that its activity was dramatically strengthened in BALR2 depleted cells, when used either alone or in combination with cytosine-arabinoside (Ara-C). Concomitantly, tigecycline treatment in BALR2 silenced AML cells reduced mitochondria depolarization, and increased the number of differentiated M-CFU colonies formation, confirming that BALR2, together with CDK6, forms novel transcriptional networks to create a circuit able to impair myeloid differentiation and to lower chemo-sensitivity in AML. We speculate that a novel therapeutic window of mitochondrial targeting in defined AML subgroups, identified through assessment of BALR2 levels at diagnosis or persistent MRD levels, could be envisaged to optimize the outcome of childhood AML. Disclosures Locatelli: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; bluebird bio: Consultancy; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Miltenyi: Honoraria.
- Published
- 2019
15. Epigenetic heterogeneity affects the risk of relapse in children with t(8;21)RUNX1-RUNX1T1-rearranged AML
- Author
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Valentina Serafin, Luca Simula, Elena Manara, Martina Pigazzi, Claudia Tregnago, Barbara Buldini, Matteo Zampini, Giuseppe Basso, Silvia Campello, Valeria Bisio, Giulia Borella, Carlo Zanon, Benedetta Accordi, Franco Locatelli, Andrea Pession, and Francesca Zonta
- Subjects
Epigenomics ,Risk ,0301 basic medicine ,Cancer Research ,Myeloid ,Adolescent ,Chromosomes, Human, Pair 21 ,RHOB ,acute myeloid leukemia ,children ,genetic heterogeneity ,Translocation, Genetic ,03 medical and health sciences ,RUNX1 Translocation Partner 1 Protein ,AML ,Cell Movement ,Recurrence ,hemic and lymphatic diseases ,Cell Adhesion ,medicine ,Humans ,Child ,rhoB GTP-Binding Protein ,Cytoskeleton ,business.industry ,Myeloid leukemia ,Hematology ,Actin cytoskeleton ,medicine.disease ,Leukemia, Myeloid, Acute ,Leukemia ,030104 developmental biology ,medicine.anatomical_structure ,Differentially methylated regions ,Settore MED/38 - PEDIATRIA GENERALE E SPECIALISTICA ,Oncology ,Child, Preschool ,Core Binding Factor Alpha 2 Subunit ,DNA methylation ,Cancer research ,Blast Crisis ,business ,Chromosomes, Human, Pair 8 - Abstract
The somatic translocation t(8;21)(q22;q22)/RUNX1-RUNX1T1 is one of the most frequent rearrangements found in children with standard-risk acute myeloid leukemia (AML). Despite the favorable prognostic role of this aberration, we recently observed a higher than expected frequency of relapse. Here, we employed an integrated high-throughput approach aimed at identifying new biological features predicting relapse among 34 t(8;21)-rearranged patients. We found that the DNA methylation status of patients who suffered from relapse was peculiarly different from that of children maintaining complete remission. The epigenetic signature, made up of 337 differentially methylated regions, was then integrated with gene and protein expression profiles, leading to a network, where cell-to-cell adhesion and cell-motility pathways were found to be aberrantly activated in relapsed patients. We identified most of these factors as RUNX1-RUNX1T1 targets, with Ras Homolog Family Member (RHOB) overexpression being the core of this network. We documented how RHOB re-organized the actin cytoskeleton through its downstream ROCK-LIMK-COFILIN axis: this increases blast adhesion by stress fiber formation, and reduces mitochondrial apoptotic cell death after chemotherapy treatment. Altogether, our data show an epigenetic heterogeneity within t(8;21)-rearranged AML patients at diagnosis able to influence the program of the chimeric transcript, promoting blast re-emergence and progression to relapse.
- Published
- 2018
16. PS1226 DEVELOPMENT OF INNOVATIVE PRECLINICAL IN VITRO AND IN VIVO TOOLS FOR AN EFFECTIVE THERAPEUTIC STRATEGY IN PEDIATRIC ACUTE MYELOID LEUKEMIA
- Author
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Silvia Panseri, Claudia Tregnago, Valeria Bisio, Martina Pigazzi, A. Da Ros, Elisabetta Campodoni, Monica Montesi, Franco Locatelli, Monica Sandri, Stefano Cairo, Maddalena Benetton, and Giulia Borella
- Subjects
business.industry ,In vivo ,Pediatric acute myeloid leukemia ,Cancer research ,Medicine ,Hematology ,business ,In vitro ,Therapeutic strategy - Published
- 2019
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