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SANDRA PARENTI

COLLABORATORE COORDINATO CONTINUATIVO
Centro Interdipartimentale Cellule Staminali e Medicina Rigenerativa (CIDSTEM)

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Pubblicazioni

2023 - Chromosome 9p Duplication Promotes T-Cell Exhaustion and Enhances Stem Cell Clonogenic Potential in JAK2-Mutant Myeloproliferative Neoplasms [Abstract in Rivista]
Norfo, Ruggiero; Carretta, Chiara; Parenti, Sandra; Badii, Filippo; Bertesi, Matteo; Rontauroli, Sebastiano; Tavernari, Lara; Genovese, Elena; Sperduti, Samantha; Enzo, Elena; Mirabile, Margherita; Pedrazzi, Francesca; Pessina, Chiara; Colugnat, Ilaria; Mora, Barbara; Maccaferri, Monica; Tenedini, Elena; Martinelli, Silvia; Bianchi, Elisa; Casarini, Livio; Potenza, Leonardo; Luppi, Mario; Tagliafico, Enrico; Guglielmelli, Paola; Simoni, Manuela; Passamonti, Francesco; Vannucchi, Alessandro Maria; Manfredini, Rossella
abstract

2023 - Inhibition of ERK1/2 signaling prevents bone marrow fibrosis by reducing osteopontin plasma levels in a myelofibrosis mouse model [Articolo su rivista]
Bianchi, Elisa; Rontauroli, Sebastiano; Tavernari, Lara; Mirabile, Margherita; Pedrazzi, Francesca; Genovese, Elena; Sartini, Stefano; Dall'Ora, Massimiliano; Grisendi, Giulia; Fabbiani, Luca; Maccaferri, Monica; Carretta, Chiara; Parenti, Sandra; Fantini, Sebastian; Bartalucci, Niccolò; Calabresi, Laura; Balliu, Manjola; Guglielmelli, Paola; Potenza, Leonardo; Tagliafico, Enrico; Losi, Lorena; Dominici, Massimo; Luppi, Mario; Vannucchi, Alessandro Maria; Manfredini, Rossella
abstract

Clonal myeloproliferation and development of bone marrow (BM) fibrosis are the major pathogenetic events in myelofibrosis (MF). The identification of novel antifibrotic strategies is of utmost importance since the effectiveness of current therapies in reverting BM fibrosis is debated. We previously demonstrated that osteopontin (OPN) has a profibrotic role in MF by promoting mesenchymal stromal cells proliferation and collagen production. Moreover, increased plasma OPN correlated with higher BM fibrosis grade and inferior overall survival in MF patients. To understand whether OPN is a druggable target in MF, we assessed putative inhibitors of OPN expression in vitro and identified ERK1/2 as a major regulator of OPN production. Increased OPN plasma levels were associated with BM fibrosis development in the Romiplostim-induced MF mouse model. Moreover, ERK1/2 inhibition led to a remarkable reduction of OPN production and BM fibrosis in Romiplostim-treated mice. Strikingly, the antifibrotic effect of ERK1/2 inhibition can be mainly ascribed to the reduced OPN production since it could be recapitulated through the administration of anti-OPN neutralizing antibody. Our results demonstrate that OPN is a novel druggable target in MF and pave the way to antifibrotic therapies based on the inhibition of ERK1/2-driven OPN production or the neutralization of OPN activity.

2022 - Novel Molecular Insights into Leukemic Evolution of Myeloproliferative Neoplasms: A Single Cell Perspective [Articolo su rivista]
Rontauroli, Sebastiano; Carretta, Chiara; Parenti, Sandra; Bertesi, Matteo; Manfredini, Rossella
abstract

Myeloproliferative neoplasms (MPNs) are clonal disorders originated by the serial acquisition of somatic mutations in hematopoietic stem/progenitor cells. The major clinical entities are represented by polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), that are caused by driver mutations affecting JAK2, MPL or CALR. Disease progression is related to molecular and clonal evolution. PV and ET can progress to secondary myelofibrosis (sMF) but can also evolve to secondary acute myeloid leukemia (sAML). PMF is associated with the highest frequency of leukemic transformation, which represents the main cause of death. sAML is associated with a dismal prognosis and clinical features that differ from those of de novo AML. The molecular landscape distinguishes sAML from de novo AML, since the most frequent hits involve TP53, epigenetic regulators, spliceosome modulators or signal transduction genes. Single cell genomic studies provide novel and accurate information about clonal architecture and mutation acquisition order, allowing the reconstruction of clonal dynamics and molecular events that accompany leukemic transformation. In this review, we examine our current understanding of the genomic heterogeneity in MPNs and how it affects disease progression and leukemic transformation. We focus on molecular events elicited by somatic mutations acquisition and discuss the emerging findings coming from single cell studies.

2022 - The Response to Oxidative Damage Correlates with Driver Mutations and Clinical Outcome in Patients with Myelofibrosis [Articolo su rivista]
Genovese, E.; Mirabile, M.; Rontauroli, S.; Sartini, S.; Fantini, S.; Tavernari, L.; Maccaferri, M.; Guglielmelli, P.; Bianchi, E.; Parenti, S.; Carretta, C.; Mallia, S.; Castellano, S.; Colasante, C.; Balliu, M.; Bartalucci, N.; Palmieri, R.; Ottone, T.; Mora, B.; Potenza, L.; Passamonti, F.; Voso, M. T.; Luppi, M.; Vannucchi, A. M.; Tagliafico, E.; Manfredini, R.
abstract

Myelofibrosis (MF) is the Philadelphia-negative myeloproliferative neoplasm characterized by the worst prognosis and no response to conventional therapy. Driver mutations in JAK2 and CALR impact on JAK-STAT pathway activation but also on the production of reactive oxygen species (ROS). ROS play a pivotal role in inflammation-induced oxidative damage to cellular components including DNA, therefore leading to greater genomic instability and promoting cell transformation. In order to unveil the role of driver mutations in oxidative stress, we assessed ROS levels in CD34+ hematopoietic stem/progenitor cells of MF patients. Our results demonstrated that ROS production in CD34+ cells from CALR-mutated MF patients is far greater compared with patients harboring JAK2 mutation, and this leads to increased oxidative DNA damage. Moreover, CALR-mutant cells show less superoxide dismutase (SOD) antioxidant activity than JAK2-mutated ones. Here, we show that high plasma levels of total antioxidant capacity (TAC) correlate with detrimental clinical features, such as high levels of lactate dehydrogenase (LDH) and circulating CD34+ cells. Moreover, in JAK2-mutated patients, high plasma level of TAC is also associated with a poor overall survival (OS), and multivariate analysis demonstrated that high TAC classification is an independent prognostic factor allowing the identification of patients with inferior OS in both DIPSS lowest and highest categories. Altogether, our data suggest that a different capability to respond to oxidative stress can be one of the mechanisms underlying disease progression of myelofibrosis.

2021 - Characterization of new ATM deletion associated with hereditary breast cancer [Articolo su rivista]
Parenti, S.; Rabacchi, C.; Marino, M.; Tenedini, E.; Artuso, L.; Castellano, S.; Carretta, C.; Mallia, S.; Cortesi, L.; Toss, A.; Barbieri, E.; Manfredini, R.; Luppi, M.; Trenti, T.; Tagliafico, E.
abstract

Next-generation sequencing (NGS)-based cancer risk screening with multigene panels has become the most successful method for programming cancer prevention strategies. ATM germ-line heterozygosity has been described to increase tumor susceptibility. In particular, families carrying heterozygous germ-line variants of ATM gene have a 5-to 9-fold risk of developing breast cancer. Recent studies identified ATM as the second most mutated gene after CHEK2 in BRCA-negative patients. Nowadays, more than 170 missense variants and several truncating mutations have been identified in ATM gene. Here, we present the molecular characterization of a new ATM deletion, identified thanks to the CNV algorithm implemented in the NGS analysis pipeline. An automated workflow implementing the SOPHiA Genetics’ Hereditary Cancer Solution (HCS) protocol was used to generate NGS libraries that were sequenced on Illumina MiSeq Platform. NGS data analysis allowed us to identify a new inactivating deletion of exons 19–27 of ATM gene. The deletion was characterized both at the DNA and RNA level.

2021 - Gene expression profile correlates with molecular and clinical features in patients with myelofibrosis [Articolo su rivista]
Rontauroli, S.; Castellano, S.; Guglielmelli, P.; Zini, R.; Bianchi, E.; Genovese, E.; Carretta, C.; Parenti, S.; Fantini, S.; Mallia, S.; Tavernari, L.; Sartini, S.; Mirabile, M.; Mannarelli, C.; Gesullo, F.; Pacilli, A.; Pietra, D.; Rumi, E.; Salmoiraghi, S.; Mora, B.; Villani, L.; Grilli, A.; Rosti, V.; Barosi, G.; Passamonti, F.; Rambaldi, A.; Malcovati, L.; Cazzola, M.; Bicciato, S.; Tagliafico, E.; Vannucchi, A. M.; Manfredini, R.
abstract

Myelofibrosis (MF) belongs to the family of classic Philadelphia-negative myeloproliferative neoplasms (MPNs). It can be primary myelofibrosis (PMF) or secondary myelofibrosis (SMF) evolving from polycythemia vera (PV) or essential thrombocythemia (ET). Despite the differences, PMF and SMF patients are currently managed in the same way, and prediction of survival is based on the same clinical and genetic features. In the last few years, interest has grown concerning the ability of gene expression profiles (GEPs) to provide valuable prognostic information. Here, we studied the GEPs of granulocytes from 114 patients with MF, using a microarray platform to identify correlations with patient characteristics and outcomes. Cox regression analysis led to the identification of 201 survival-related transcripts characterizing patients who are at high risk for death. High-risk patients identified by this gene signature displayed an inferior overall survival and leukemia-free survival, together with clinical and molecular detrimental features included in contemporary prognostic models, such as the presence of high molecular risk mutations. The high-risk group was enriched in post-PV and post-ET MF and JAK2V617F homozygous patients, whereas pre-PMF was more frequent in the low-risk group. These results demonstrate that GEPs in MF patients correlate with their molecular and clinical features, particularly their survival, and represent the proof of concept that GEPs might provide complementary prognostic information to be applied in clinical decision making.

2021 - Magnesium favors the capacity of vitamin d3 to induce the monocyte differentiation of u937 cells [Articolo su rivista]
Parenti, S.; Sandoni, L.; Montanari, M.; Zanocco-Marani, T.; Anesi, A.; Iotti, S.; Manfredini, R.; Frassineti, C.; Davalli, P.; Grande, A.
abstract

The hematopoietic U937 cells are able to differentiate into monocytes, macrophages, or osteoclasts when stimulated, respectively, with vitamin D3 (VD3), phorbol 12-myristate 13-acetate (PMA) or PMA plus VD3. We have previously demonstrated that magnesium (Mg) strongly potentiates the osteoclastic differentiation of U937 cells. In this study, we investigated whether such an effect may be ascribed to a capacity of Mg to modulate the monocyte differentiation of U937 cells and/or to an ability of Mg and VD3 to act directly and independently on the early phases of the osteoclastic differentiation. To address this issue, we subjected U937 cells to an individual and combined treatment with Mg and VD3 and then we analyzed, by flow cytometry and quantitative real-time polymerase chain reaction, the expression of a number of genes related to the early phases of the differentiation pathways under consideration. The results obtained indicated that Mg favors the monocyte differentiation of U937 cells induced by VD3 and at the same time, Mg contrasts the inhibitory effect that VD3 exerts on the osteoclastic differentiation in the absence of PMA. The crucial and articulated role played by Mg in diverse pathways of the osteoclastic differentiation of U973 cells is emphasized.

2021 - Mutated clones driving leukemic transformation are already detectable at the single-cell level in CD34-positive cells in the chronic phase of primary myelofibrosis [Articolo su rivista]
Parenti, Sandra; Rontauroli, Sebastiano; Carretta, Chiara; Mallia, Selene; Genovese, Elena; Chiereghin, Chiara; Peano, Clelia; Tavernari, Lara; Bianchi, Elisa; Fantini, Sebastian; Sartini, Stefano; Romano, Oriana; Bicciato, Silvio; Tagliafico, Enrico; Della Porta, Matteo; Manfredini, Rossella
abstract

Disease progression of myeloproliferative neoplasms is the result of increased genomic complexity. Since the ability to predict disease evolution is crucial for clinical decisions, we studied single-cell genomics and transcriptomics of CD34-positive cells from a primary myelofibrosis (PMF) patient who progressed to acute myeloid leukemia (AML) while receiving Ruxolitinib. Single-cell genomics allowed the reconstruction of clonal hierarchy and demonstrated that TET2 was the first mutated gene while FLT3 was the last one. Disease evolution was accompanied by increased clonal heterogeneity and mutational rate, but clones carrying TP53 and FLT3 mutations were already present in the chronic phase. Single-cell transcriptomics unraveled repression of interferon signaling suggesting an immunosuppressive effect exerted by Ruxolitinib. Moreover, AML transformation was associated with a differentiative block and immune escape. These results suggest that single-cell analysis can unmask tumor heterogeneity and provide meaningful insights about PMF progression that might guide personalized therapy.

2021 - Promoter Methylation Leads to Decreased ZFP36 Expression and Deregulated NLRP3 Inflammasome Activation in Psoriatic Fibroblasts [Articolo su rivista]
Bertesi, M.; Fantini, S.; Alecci, C.; Lotti, R.; Martello, A.; Parenti, S.; Carretta, C.; Marconi, A.; Grande, A.; Pincelli, C.; Zanocco Marani, T.
abstract

The mRNA-destabilizing protein tristetraprolin (TTP), encoded by the ZFP36 gene, is known to be able to end inflammatory responses by directly targeting and destabilizing mRNAs encoding pro-inflammatory cytokines. We analyzed its role in psoriasis, a disease characterized by chronic inflammation. We observed that TTP is downregulated in fibroblasts deriving from psoriasis patients compared to those deriving from healthy individuals and that psoriatic fibroblasts exhibit abnormal inflammasome activity compared to their physiological counterpart. This phenomenon depends on TTP downregulation. In fact, following restoration, TTP is capable of directly targeting for degradation NLRP3 mRNA, thereby drastically decreasing inflammasome activation. Moreover, we provide evidence that ZFP36 undergoes methylation in psoriasis, by virtue of the presence of long stretches of CpG dinucleotides both in the promoter and the coding region. Besides confirming that a perturbation of TTP expression might underlie the pathogenesis of psoriasis, we suggest that deregulated inflammasome activity might play a role in the disease alongside deregulated cytokine expression.

2020 - Genomic analysis of hematopoietic stem cell at the single-cell level: Optimization of cell fixation and whole genome amplification (WGA) protocol [Articolo su rivista]
Carretta, C.; Mallia, S.; Genovese, E.; Parenti, S.; Rontauroli, S.; Bianchi, E.; Fantini, S.; Sartini, S.; Tavernari, L.; Tagliafico, E.; Manfredini, R.
abstract

Single-cell genomics has become the method of choice for the study of heterogeneous cell populations and represents an elective application in defining the architecture and clonal evolution in hematological neoplasms. Reconstructing the clonal evolution of a neoplastic population therefore represents the main way to understand more deeply the pathogenesis of the neoplasm, but it is also a potential tool to understand the evolution of the tumor population with respect to its response to therapy. Pre-analytical phase for single-cell genomics analysis is crucial to obtain a cell population suitable for single-cell sorting, and whole genome amplification is required to obtain the necessary amount of DNA from a single cell in order to proceed with sequencing. Here, we evaluated the impact of different methods of cellular immunostaining, fixation and whole genome amplification on the efficiency and yield of single-cell sequencing.

2019 - Gene expression profiles of human granulosa cells treated with bioequivalent doses of corifollitropin alfa (CFA) or recombinant human follicle-stimulating hormone (recFSH) [Articolo su rivista]
Sacchi, Sandro; Tenedini, Elena; Tondelli, Debora; Parenti, Sandra; Tagliasacchi, Daniela; Xella, Susanna; Marsella, Tiziana; Tagliafico, Enrico; La Marca, Antonio
abstract

Using recombinant DNA technologies, a chimeric gene containing the coding sequences of follicle stimulating hormone (FSH) β-subunit and C-terminal peptide of the human chorionic gonadotrophin (hCG) β-subunit have been designed to generate a new gonadotrophin named corifollitropin alfa (CFA). CFA has longer elimination half-life and slower rate of absorption compared with FSH, which makes CFA a long-acting hormone employed as a substitute of the recombinant FSH (recFSH) in the controlled ovarian stimulation (COS). The purpose of this study is to compare the gene expression profiles elicited by bioequivalent doses of CFA or recFSH in primary cultures of human granulosa cells (hGCs). Gonadotrophins exert their functions by binding FSH receptors (FSHRs), activating signaling pathways that increase the cyclic adenosine monophosphate (cAMP) intracellular content. Bioequivalence has been defined as the dose/duration of gonadotrophin treatment able to promote the same amount of intracellular cAMP. hGCs were treated with different doses of either gonadotrophin and the cAMP was measured after different incubation times to establish the bioequivalence. Results obtained by comparing the bioequivalent treatments, showed that CFA is more effective than recFSH in inducing aromatase gene expression after 6 and 24 h from the initial stimulation in agreement with its long-acting characteristic.

2019 - Loss of expression of μ-protocadherin and protocadherin-24 in sporadic and hereditary nonpolyposis colorectal cancers [Articolo su rivista]
Losi, Lorena; Lancellotti, Cesare; Parenti, Sandra; Scurani, Letizia; Zanocco-Marani, Tommaso; Buffoli, Federico; Grassia, Roberto; Ferrari, Sergio; Grande, Alexis
abstract

Colorectal cancer (CRC) is a neoplastic disease in which normal mucosa undergoes a process of malignant transformation due to the progressive accumulation of molecular alterations affecting proto-oncogenes and oncosuppressor genes. Some of these modifications exert their carcinogenic potential by promoting a constitutive activation of the β-catenin signaling proliferation pathway, and when present, loss of cadherin expression also significantly contributes to the same effect. Using a combined approach of molecular and immunohistochemical analysis, we have previously demonstrated that most sporadic CRCs exhibit a down-regulated expression of a cadherin, named μ-protocadherin, that is generally observed in association with a higher proliferation rate and a worse prognosis. The aim of this report was to perform a comparative immunohistochemical assessment of μ-protocadherin and a similar cadherin, named protocadherin-24, in sporadic CRC and hereditary nonpolyposis colorectal cancer. The data obtained put in evidence that double-negative CRCs, lacking both the analyzed protocadherins, are more represented among sporadic tumors, whereas double-positive CRCs, maintaining their expression, exhibit an opposite trend. As expected, loss of protocadherin expression was accompanied by nuclear localization of β-catenin and increased positivity of the Ki-67 proliferation marker. This finding is consistent with the different clinical evolution of the 2 considered CRC sets according to which patients with hereditary nonpolyposis colorectal cancer experience a better prognosis as compared with those affected by a sporadic CRC.

2019 - Physiological expression of miR-130a during differentiation of CD34+ human hematopoietic stem cells results in the inhibition of monocyte differentiation [Articolo su rivista]
Mammoli, F.; Parenti, S.; Lomiento, M.; Gemelli, C.; Atene, C. G.; Grande, A.; Corradini, R.; Manicardi, Agnese; Fantini, S.; Zanocco-Marani, T.; Ferrari, S.
abstract

MicroRNAs (miRNA) are small noncoding RNAs that regulate gene expression by targeting mRNAs in a sequence specific manner, thereby determining their degradation or inhibiting translation. They are involved in processes such as proliferation, differentiation and apoptosis by fine-tuning the expression of genes underlying such events. The expression of specific miRNAs is involved in hematopoietic differentiation and their deregulation contributes to the development of hematopoietic malignancies such as acute myeloid leukemia (AML). miR-130a is over-expressed in AML. Here we show that miR-130a is physiologically expressed in myeloblasts and down-regulated during monocyte differentiation. Gain- and loss-of-function experiments performed on CD34+ human hematopoietic stem cells confirmed that expression of miR-130a inhibits monocyte differentiation by interfering with the expression of key transcription factors HOXA10, IRF8, KLF4, MAFB and PU-1. The data obtained in this study highlight that the correct modulation of miR-130a is necessary for normal differentiation to occur and confirming that deregulation of this miRNA might underlie the differentiation block occurring in AML.

2018 - ERBB2 mutations in hormone receptor positive primary breast cancers samples and in their matched endocrine-resistant recurrences. [Poster]
Venturelli, M.; Toss, A.; Piacentini, F.; Artuso, L.; Bernardis, I.; Parenti, S.; Tenedini, E.; Omarini, C.; Moscetti., 1; Cascinu, S.; Tagliafico, E.; Cortesi, L.
abstract

Previous preclinical studies showed that mutations in ERBB2 might represent an alternative mechanism for HER2 activation and the rate of mutations in BC is around 2%. They occur more frequently in HER2-negative (HER2-) BC and are associated with poor survival. On these bases, HER2- pts with mutation are potentially candidates for HER2-targeted therapy, as already showed by Neratinib. We evaluated the incidence of ERBB2 mutations in 14 hormone receptor (HR) positive BC and in their matched endocrine-resistant recurrences. Using an NGS technology, we evaluated a panel of genes including ERBB2, in FFPE tissues. We analysed 14 HR positive BCs and their matched recurrences. All the relapses have been developed during an endocrine treatment. 29% of pts were diagnosed with HER2+ BC, while 71% of pts developed HER2- BC. 3 pts were diagnosed at stage I, 6 pts at stage II, 5 pts at stage III. We found 8 different mutations in 9 samples: A356D, Q1206X, Q396X, Q393X, P523L, I654V, G1220C, 135+3G>T. Only I654V was previously described in literature. All but one (135+3G>T) of these mutations are exonic variants. 5 mutations were in the extracellular domain, 1 in the tyrosine kinase domain and 2 in the carboxy tail. 28.6% of pts had ERBB2 mutations in the primary BCs and 35.7% in the relapsed site. 66.6% of HER2+ primary BCs showed an ERBB2 mutation, while only 21% of HER2- samples brought a mutation. 2 patients acquired a new mutation in the relapsed site, while 1 patient lost the mutation in the relapsed tissue. The mDFS was 35.3 months. mDFS in HER2+ and/or mutated pts was 46.4 months, while mDFS in HER2- wild type pts was 28.5. The mOS was 104 months (6 pts still alive). mOS in HER2+ and/or mutated pts was 115.6 months while mOS in HER2- wild type pts was 97.5. We found an overall detection rate of mutations higher than that described in literature (ERBB2 mutations were present in 32.1% of our samples), meaning that our pts have been highly selected. In fact, only tumors relapsing 26 Tumori Journal 104(4S) under an endocrine treatment, and thus with proved endocrine resistance, have been included in our analyses. The identification of an ERBB2 mutation in primary BCs might justify a more targeted neo/adjuvant approach and, might guide the subsequent treatment choices when the mutation is identified in the relapsed tissue. Contrary to previous literature, in our study the majority of mutations occurred in HER2+ samples and HER2+ and/or mutated samples did not show worse outcomes.

2018 - Genomic alterations at the basis of treatment resistance in metastatic breast cancer: Clinical applications [Articolo su rivista]
Toss, Angela; Piacentini, Federico; Cortesi, Laura; Artuso, Lucia; Bernardis, Isabella; Parenti, Sandra; Tenedini, Elena; Ficarra, Guido; Maiorana, Antonino; Iannone, Anna; Omarini, Claudia; Moscetti, Luca; Cristofanilli, Massimo; Federico, Massimo; Tagliafico, Enrico
abstract

The standard of care for breast cancer has gradually evolved from empirical treatments based on clinical-pathological characteristics to the use of targeted approaches based on the molecular profile of the tumor. Consequently, an increasing number of molecularly targeted drugs have been developed. These drugs target specific alterations, called driver mutations, which confer a survival advantage to cancer cells. To date, the main challenge remains the identification of predictive biomarkers for the selection of the optimal treatment. On this basis, we evaluated a panel of 25 genes involved in the mechanisms of targeted treatment resistance, in 16 primary breast cancers and their matched recurrences, developed during treatment. Overall, we found a detection rate of mutations higher than that described in the literature. In particular, the most frequently mutated genes were ERBB2 and those involved in the PI3K/AKT/mTOR and the MAPK signaling pathways. The study revealed substantial discordances between primary tumors and metastases, stressing the need for analysis of metastatic tissues at recurrence. We observed that 85.7% of patients with an early-stage or locally advanced primary tumor showed at least one mutation in the primary tumor. This finding could explain the subsequent relapse and might therefore justify more targeted adjuvant treatments. Finally, the mutations detected in 50% of relapsed tissues could have guided subsequent treatment choices in a different way. This study demonstrates that mutation events may be present at diagnosis or arise during cancer treatment. As a result, profiling primary and metastatic tumor tissues may be a major step in defining optimal treatments.

2018 - KLF4 mediates the effect of 5-ASA on the b-catenin pathway in colon cancer cells [Articolo su rivista]
Parenti, Sandra; Montorsi, Lucia; Fantini, Sebastian; Mammoli, Fabiana; Gemelli, Claudia; Atene, Claudio Giacinto; Losi, Lorena; Frassineti, Chiara; Calabretta, Bruno; Tagliafico, Enrico; Ferrari, Sergio; Zanocco-Marani, Tommaso; Grande, Alexis
abstract

Mesalazine (5-ASA) is an aminosalicylate anti-inflammatory drug capable of inducing m-protocadherin, a protein expressed by colorectal epithelial cells that is downregulated upon malignant transformation. Treatment with 5-ASA restores m-protocadherin expression and promotes the sequestration of b-catenin to the plasma membrane. Here, we show that 5-ASA–induced m-protocadherin expression is directly regulated by the KLF4 transcription factor. In addition, we suggest the existence of a dual mechanism whereby 5-ASA–mediated b-catenin inhibition is caused by m-protocadherin–dependent sequestration of b-catenin to the plasma membrane and by the direct binding of KLF4 to b-catenin. In addition, we found that 5-ASA treatment suppresses the expression of miR-130a and miR-135b, which target KLF4 mRNA, raising the possibility that this mechanism is involved in the increased expression of KLF4 induced by 5-ASA.

2016 - A novel 2,3-benzodiazepine-4-one derivative AMPA antagonist inhibits G2/M transition and induces apoptosis in human leukemia Jurkat T cell line [Articolo su rivista]
Parenti, Sandra; Casagrande, Giacomo; Montanari, Monica; Espahbodinia, M.; Ettari, R.; Grande, Alexis; Corsi, Lorenzo
abstract

It has been shown that the antagonism of glutamate receptors activity was able inhibit proliferation and induce apoptosis in several neuronal and non-neuronal cancer cell lines. In addition, it has been shown that glutamate might facilitate the spread and growth of leukemia T cells through interactions with AMPA receptors. The aim of the present study was to investigate the modulation of cell cycle elicited by a novel 2,3-benzodiazepine-4- one non-competitive AMPA antagonist derivative in the human leukemia Jurkat T cells. Our results indicated that the 1-(4-amino-3,5-dimethylphenyl)-3,5-dihydro-7,8-ethylenedioxy-4 h-2,3- benzodiazepin-4-one, named 1 g, exerted a significant growth inhibition of leukemia Jurkat T cells in a time and dose dependent manner, arresting the transition of G2/M phase through activation of Myt-1. The molecule also induced apoptosis through the enhanced expression of the pro-apoptotic p53, and the inhibition of Bcl-2, and Bcl-xl, followed by the activation of caspase-3. The results suggested that compound 1 g might act mostly as a cytostatic rather than cytotoxic compound. Al- though further studies are necessary, in order to identify others specific pathways involved in the activity of the present molecule, the presented results identified a novel molecule acting on specific G2/M checkpoint reg- ulation pathway. Finally, our data suggest that compound 1 g might be a good molecule for future development in the cancer research

2016 - Expression of μ-protocadherin is negatively regulated by the activation of the β-catenin signaling pathway in normal and cancer colorectal enterocytes [Articolo su rivista]
Montorsi, Lucia; Parenti, Sandra; Losi, Lorena; Ferrarini, F; Gemelli, Claudia; Rossi, A; Manco, Gianrocco; Ferrari, Sergio; Calabretta, Bruno; Tagliafico, Enrico; ZANOCCO MARANI, Tommaso; Grande, Alexis
abstract

Mu-protocadherin (MUCDHL) is an adhesion molecule predominantly expressed by colorectal epithelial cells which is markedly downregulated upon malignant transformation. Notably, treatment of colorectal cancer (CRC) cells with mesalazine lead to increased expression of MUCDHL, and is associated with sequestration of β-catenin on the plasma membrane and inhibition of its transcriptional activity. To better characterize the causal relationship between β-catenin and MUCDHL expression, we performed various experiments in which CRC cell lines and normal colonic organoids were subjected to culture conditions inhibiting (FH535 treatment, transcription factor 7-like 2 siRNA inactivation, Wnt withdrawal) or stimulating (LiCl treatment) β-catenin activity. We show here that expression of MUCDHL is negatively regulated by functional activation of the β-catenin signaling pathway. This finding was observed in cell culture systems representing conditions of physiological stimulation and upon constitutive activation of β-catenin in CRC. The ability of MUCDHL to sequester and inhibit β-catenin appears to provide a positive feedback enforcing the effect of β-catenin inhibitors rather than serving as the primary mechanism responsible for β-catenin inhibition. Moreover, MUCDHL might have a role as biomarker in the development of CRC chemoprevention drugs endowed with β-catenin inhibitory activity.

2016 - Loss of zfp36 expression in colorectal cancer correlates to wnt/ ß-catenin activity and enhances epithelial-to-mesenchymal transition through upregulation of zeb1, sox9 and macc1 [Articolo su rivista]
Montorsi, Lucia; Guizzetti, Filippo; Alecci, Claudia; Caporali, Andrea; Martello, Andrea; Giacinto Atene, Claudio; Parenti, Sandra; Pizzini, Silvia; Zanovello, Paola; Bortoluzzi, Stefania; Ferrari, Sergio; Grande, Alexis; ZANOCCO MARANI, Tommaso
abstract

The mRNA-destabilizing protein ZFP36 has been previously described as a tumor suppressor whose expression is lost during colorectal cancer development. In order to evaluate its role in this disease, we restored ZFP36 expression in different cell contexts, showing that the presence of this protein impairs the epithelial-to-mesenchymal transition (EMT) and induces a higher susceptibility to anoikis. Consistently, we found that ZFP36 inhibits the expression of three key transcription factors involved in EMT: ZEB1, MACC1 and SOX9. Finally, we observed for the first time that its expression negatively correlates with the activity of Wnt/β-catenin pathway, which is constitutively activated in colorectal cancer. This evidence provides a clue on the mechanism leading to the loss of ZFP36 in CRC.

2016 - STRATEGIES TO PREDICT TREATMENT RESPONSE AND SELECT THERAPIES IN METASTATIC BREAST CANCER PATIENTS USING A NEXT GENERATION SEQUENCING (NGS) MULTI-GENE PANEL [Poster]
Toss, Angela; Cortesi, Laura; Artuso, Lucia; Tenedini, Elena; Bernardis, Isabella; Parenti, Sandra; Ficarra, Guido; Piacentini, Federico; Federico, Massimo; Tagliafico, Enrico
abstract

The standard of care for many patients with advanced breast cancer (BC )is gradually evolving from empirical treatment based on clinicalpathological characteristics to the use of targeted approaches based on the molecular profile of the tumor. In the last decade, an increasing number of molecularly targeted drugs have been developed for the treatment of metastatic BC. These drugs target specific molecular abnormalities that confer to cancer cells a survival advantage [1]. Interestingly, the ability to perform multigene testing for a range of molecular alterations may provide an opportunity to clarify the mechanisms of treatment response, to find the strategies to overcome treatment resistance and thus, to identify patients who are more likely to develop relapse and who may be candidates for matched targeted therapies [2-3]. The main aim of this study is to find prognostic and predictive molecular biomarkers for the management of metastatic BC patients in clinical practice. MATERIALS AND METHODS The amplicon-sequencing analyses took advantage of the Ion AmpliSeq™ technology (Thermo Fisher, Waltham, MA, USA). A custom panel was designed with the help of the Designer online tool (www.ampliseq.com), which was employed to generate optimized primers encompassing the coding DNA sequences (with 100bp of exon padding and the UTRs regions) of 25 genes in the Human Reference Genome (hg19); these genes were selected searching and screening scientific literature for treatments resistance in BC and are reported in Table 1. Primer pairs were divided into two pools to optimize multiplex PCR conditions and the coverage, that assessed to 89.02%. The customized Ion AmpliSeq panel was employed on samples from 7 primary BC samples and matched metastatic sites (3 skin, 3 lymph node and 1 lung metastases). They were all processed using the Ion AmpliSeq Library Kit 2.0, starting from 15 nanograms of FFPE extracted DNA/pool. Samples were barcoded with the Ion Express Kit to optimize matched patients pooling on the same 318 Chip v2 sequencing chip. The template-positive Ion Sphere Particles were sequenced on a Personal Genome Machine (Thermo Fisher, Waltham, MA, USA). RESULTS The mutation profiles of paired primary and secondary tumors of the seven patients enrolled in this study are presented in Table 2. Ten different genes (PTEN, PIK3CA, mTOR, ERBB2, ERBB3, MET, INPP4B, MAP2K1, CDK6, KRAS) in 6 different patients showed possible damaging variants as shown in Table 2. • Four patients (number 1, 3, 5 and 6) showed no additional or different mutations in secondary tumors if compared to primary samples. • In patient number 2, the metastatic site presented new mutations if compared to the primary tumor. • Finally in patient number 4 and 7 we did not detect in metastases some of the mutations found in the primary tumor. DISCUSSION In 5 patients (71,4%) the mutational status of primary tumor could explain treatment resistance and thus predict relapse, in one patient the mutational status of the new subclones could be relevant for guiding differently the subsequent treatment choices. In 2 patients (28,5%) we were not able to detect in metastases some of the mutations found in the primary tumor. This could be explained by considering the clonal evolution of metastases. These preliminary data suggest that the multi-gene panel analysis of primary and secondary tumors may help clinicians: • in discriminating BC patients HR+ and/or HER2+ with mutations predicting an increased risk of adjuvant treatment resistance and thus relapse • in guiding treatment selection strategies in the metastatic setting. The study is still open and we are currently recruiting other patients.

2015 - Monocyte-macrophage differentiation of acute myeloid leukemia cell lines by small molecules identified through interrogation of the Connectivity Map database [Articolo su rivista]
Manzotti, Gloria; Parenti, Sandra; Ferrari, Giovanna; Soliera, Angela Rachele; Cattelani, Sara; Montanari, Monica; Grande, Alexis; Calabretta, Bruno; Ertel, Adam; Cavalli, Daniel
abstract

The transcription factor C/EBPα is required for granulocytic differentiation of normal myeloid progenitors and is frequently inactivated in acute myeloid leukemia (AML) cells. Ectopic expression of C/EBPα in AML cells suppresses proliferation and induces differentiation suggesting that restoring C/EBPα expression/activity in AML cells could be therapeutically useful. Unfortunately, current approaches of gene or protein delivery in leukemic cells are unsatisfactory. However, "drug repurposing" is becoming a very attractive strategy to identify potential new uses for existing drugs. In this study, we assessed the biological effects of candidate C/EBPα-mimetics identified by interrogation of the Connectivity Map database. We found that amantadine, an antiviral and anti-Parkinson agent, induced a monocyte-macrophage-like differentiation of HL60, U937, Kasumi-1 myeloid leukemia cell lines, as indicated by morphology and differentiation antigen expression, when used in combination with suboptimal concentration of all trans retinoic acid (ATRA) or Vit D3. The effect of amantadine depends, in part, on increased activity of the vitamin D receptor (VDR), since it induced VDR expression and amantadine-dependent monocyte-macrophage differentiation of HL60 cells was blocked by expression of dominant-negative VDR. These results reveal a new function for amantadine and support the concept that screening of the Connectivity Map database can identify small molecules that mimic the effect of transcription factors required for myelo-monocytic differentiation.

2015 - ZFP36 stabilizes RIP1 via degradation of XIAP and cIAP2 thereby promoting ripoptosome assembly [Articolo su rivista]
Selmi, Tommaso; Alecci, Claudia; Dell' Aquila, Miriam; Montorsi, Lucia; Martello, Andrea; Guizzetti, Filippo; Volpi, Nicola; Parenti, Sandra; Ferrari, Sergio; Salomoni, Paolo; Grande, Alexis; ZANOCCO MARANI, Tommaso
abstract

BACKGROUND: ZFP36 is an mRNA binding protein that exerts anti-tumor activity in glioblastoma by triggering cell death, associated to an increase in the stability of the kinase RIP1. METHODS: We used cell death assays, size exclusion chromatography, Co-Immunoprecipitation, shRNA lentivectors and glioma neural stem cells to determine the effects of ZFP36 on the assembly of a death complex containing RIP1 and on the induction of necroptosis. RESULTS: Here we demonstrate that ZFP36 promotes the assembly of the death complex called Ripoptosome and induces RIP1-dependent death. This involves the depletion of the ubiquitine ligases cIAP2 and XIAP and leads to the association of RIP1 to caspase-8 and FADD. Moreover, we show that ZFP36 controls RIP1 levels in glioma neural stem cell lines. CONCLUSIONS: We provide a molecular mechanism for the tumor suppressor role of ZFP36, and the first evidence for Ripoptosome assembly following ZFP36 expression. These findings suggest that ZFP36 plays an important role in RIP1-dependent cell death in conditions where IAPs are depleted.

2014 - MafB is a downstream target of the IL-10/STAT3 signaling pathway, involved in the regulation of macrophage de-activation [Articolo su rivista]
Gemelli, C.; Zanocco Marani, T.; Bicciato, S.; Mazza, E. M. C.; Boraschi, D.; Salsi, V.; Zappavigna, V.; Parenti, S.; Selmi, T.; Tagliafico, E.; Ferrari, S.; Grande, A.
abstract

In spite of the numerous reports implicating MafB transcription factor in the molecular control of monocyte-macrophage differentiation, the precise genetic program underlying this activity has been, to date, poorly understood. To clarify this issue, we planned a number of experiments that were mainly conducted on human primary macrophages. In this regard, a preliminary gene function study, based on MafB inactivation and over-expression, indicated MMP9 and IL-. 7R genes as possible targets of the investigated transcription factor. Bioinformatics analysis of their promoter regions disclosed the presence of several putative MARE elements and a combined approach of EMSA and luciferase assay subsequently demonstrated that expression of both genes is indeed activated by MafB through a direct transcription mechanism. Additional investigation, performed with similar procedures to elucidate the biological relevance of our observation, revealed that MafB is a downstream target of the IL-10/STAT3 signaling pathway, normally inducing the macrophage de-activation process. Taken together our data support the existence of a signaling cascade by which stimulation of macrophages with the IL-10 cytokine determines a sequential activation of STAT3 and MafB transcription factors, in turn leading to an up-regulated expression of MMP9 and IL-. 7R genes. © 2014 Elsevier B.V.

2013 - The Orosomucoid1 protein is involved in the vitamin D – mediated macrophage de-activation process [Articolo su rivista]
Gemelli, Claudia; Martello, Andrea; Montanari, Monica; ZANOCCO MARANI, Tommaso; Salsi, Valentina; Zappavigna, Vincenzo; Parenti, Sandra; Vignudelli, Tatiana; Selmi, Tommaso; Ferrari, Sergio; Grande, Alexis
abstract

Orosomucoid 1 (ORM1), also named Alpha 1 acid glycoprotein A (AGP-A), is an abundant plasma protein characterized by anti-inflammatory and immune-modulating properties. The present study was designed to identify a possible correlation between ORM1 and Vitamin D3 (1,25(OH)2D3), a hormone exerting a widespread effect on cell proliferation, differentiation and regulation of the immune system. In particular, the data described here indicated that ORM1 is a 1,25(OH)2D3 primary response gene, characterized by the presence of a VDRE element inside the 1kb sequence of its proximal promoter region. This finding was demonstrated with gene expression studies, Chromatin Immunoprecipitation and luciferase transactivation experiments and confirmed by VDR full length and dominant negative over-expression. In addition, several experiments carried out in human normal monocytes demonstrated that the 1,25(OH)2D3 - VDR – ORM1 pathway plays a functional role inside the macrophage de-activation process and that ORM1 may be considered as a signaling molecule involved in the maintenance of tissue homeostasis and remodeling.

2012 - Chemoprevention of colorectal cancer [Brevetto]
Grande, Alexis; Ferrarini, Fabrizio; Parenti, Sandra
abstract

In the present invention, a new combination is disclosed comprising (i) 5 -aminosalicylic acid (5 -ASA) or a derivative thereof, or a pharmacologically acceptable salt thereof, and (ii) a group D vitamin, a derivative thereof, a metabolite or analogue, for use in the prevention and/or treatment of colorectal cancer (CRC). A further aspect of the invention is directed to pharmaceutical compositions comprising said combination together with at least one physiologically acceptable excipient and the use thereof in the prevention and/or in the treatment of the colorectal cancer.

2011 - Alpha – 1 – acid glycoprotein-A is a new VDR transcriptional target involved in monocyte differentiation and activation processes. [Poster]
Gemelli, Claudia; Martello, Andrea; Montanari, Monica; Parenti, Sandra; Vignudelli, Tatiana; Selmi, Tommaso; ZANOCCO MARANI, Tommaso; Ferrari, Sergio; Grande, Alexis
abstract

Orosomucoid 1 (ORM1), also named Alpha 1 acid glycoprotein A (AGP-A), is an abundant plasma protein characterized by anti-inflammatory and immune-modulating properties. The present study was designed to identify a possible correlation between ORM1 and Vitamin D3 (1,25(OH)2D3), a hormone exerting a widespread effect on cell proliferation, differentiation and regulation of the immune system. In particular, the data described here indicated that ORM1 is a 1,25(OH)2D3 primary response gene, characterized by the presence of a VDRE element inside the 1kb sequence of its proximal promoter region. This finding was demonstrated with gene expression studies, Chromatin Immunoprecipitation and luciferase transactivation experiments and confirmed by VDR full length and dominant negative over-expression. In addition, several experiments carried out in human normal monocytes demonstrated that the 1,25(OH)2D3--VDR--ORM1 pathway plays a functional role inside the macrophage de-activation process and that ORM1 may be considered as a signaling molecule involved in the maintenance of tissue homeostasis and remodeling.

2011 - Down-regulation of μ-protocadherin expression is a common event in colorectal carcinogenesis [Articolo su rivista]
Losi, Lorena; Parenti, Sandra; Fabrizio, Ferrarini; Rivasi, Francesco; Margherita, Gavioli; Gianni, Natalini; Ferrari, Sergio; Grande, Alexis
abstract

We have previously reported that treatment of colorectal cancer cells with mesalazine results in the up-regulated expression of a novel member of the cadherin protein superfamily, named μ-protocadherin, which is able to sequester β-catenin on plasmatic membrane of treated cells inhibiting its proliferation signalling pathway. This finding suggests that μ-protocadherin could exert an oncosuppressive effect on colorectal epithelium. The purpose of our study was to assess whether μ-protocadherin expression is down-regulated during colorectal carcinogenesis. This issue was addressed by analyzing the messenger RNA and protein expression of μ-protocadherin in normal and tumor colorectal cell samples using a combination of quantitative real-time polymerase chain reaction, microarray analysis, and immunohistochemical examination. To better contextualize the role played by μ-protocadherin in the pathogenesis of colorectal cancer, this last assay was also extended to β-catenin, E-cadherin, and Ki-67 proteins. The results obtained evidenced that (1) levels of μ-protocadherin transcript were down-regulated in all the analyzed colorectal cancer samples as compared with normal mucosa; (2) expression of μ-protocadherin protein was completely lost in most analyzed colorectal cancer samples (71%); (3) μ-protocadherin retains β-catenin on the plasmatic membrane of normal colon enterocytes, which implies that β-catenin is released from this site and translocated to the nucleus in colorectal cancer cells. Our data consequently suggest that down-regulation of μ-protocadherin expression is a common event in colorectal carcinogenesis and might therefore play an important role in this pathologic process.

2010 - Mesalazine inhibits the beta-catenin signalling pathway acting through the upregulation of mu-protocadherin gene in colo-rectal cancer cells [Articolo su rivista]
Parenti, Sandra; Ferrarini, F; Zini, Roberta; Montanari, Monica; Losi, Lorena; Canovi, B; Ferrari, Sergio; Grande, Alexis
abstract

BACKGROUND: Several reports indicate that mesalazine (5-aminosalicylic acid, 5-ASA) is a promising candidate for the chemoprevention of colo-rectal cancer because of its ability to reach the purpose avoiding the unwanted side effects usually associated with prolonged administration of nonsteroidal anti-inflammatory drugs. This activity of 5-ASA is probably the consequence of a number of effects determined on colo-rectal cancer cells, consisting of reduced proliferation, increased apoptosis and activation of cell cycle checkpoints and DNA repair processes. A recent observation has suggested that inhibition of beta-catenin signalling could induce these cellular effects. AIM: To characterize better the capacity of 5-ASA to inhibit the beta-catenin signalling pathway. METHODS: Genes belonging to the beta-catenin signalling pathway were analysed in colo-rectal cancer cell lines treated with 5-ASA using a combination of laboratory assays that are able to detect their phenotypic expression and functional activity. RESULTS: The results obtained indicated that 5-ASA induces the expression of a protein called mu-protocadherin that belongs to the cadherin superfamily and is able to sequester beta-catenin on the plasmatic membrane of treated cells hampering its function. CONCLUSION: These findings suggest that mu-protocadherin might be employed as a biological marker to monitor the chemopreventive efficacy of 5-ASA.

2010 - ZFP36L1 Negatively Regulates Erythroid Differentiation of CD34+ Hematopoietic Stem Cells by Interfering with Stat5b Pathway. [Articolo su rivista]
Vignudelli, Tatiana; Selmi, Tommaso; A., Martello; Parenti, Sandra; Grande, Alexis; Gemelli, Claudia; ZANOCCO MARANI, Tommaso; Ferrari, Sergio
abstract

ZFP36L1 is a member of a family of CCCH tandem zinc finger proteins (TTP family) able to bind to AU-rich elements in the 3'-untranslated region of mRNAs, thereby triggering their degradation. The present study suggests that such mechanism is used during hematopoiesis to regulate differentiation by post-transcriptionally modulating the expression of specific target genes. In particular, it demonstrates that ZFP36L1 negatively regulates erythroid differentiation by directly binding the 3' untranslated region of Stat5b encoding mRNA. Stat5b down-regulation obtained by ZFP36L1 overexpression results, in human hematopoietic progenitors, in a drastic decrease of erythroid colonies formation. These observations have been confirmed by silencing experiments targeting Stat5b and by treating hematopoietic stem/progenitor cells with drugs able to induce ZFP36L1 expression. Moreover, this study shows that different members of ZFP36L1 family act redundantly, since cooverexpression of ZFP36L1 and family member ZFP36 determines a cumulative effect on Stat5b down-regulation. This work describes a mechanism underlying ZFP36L1 capability to regulate hematopoietic differentiation and suggests a new target for the therapy of hematopoietic diseases involving Stat5b/JAK2 pathway, such as chronic myeloproliferative disorders.

2009 - TFE3 transcription factor regulates the expression of MAFB during macrophage differentiation [Articolo su rivista]
ZANOCCO MARANI, Tommaso; Vignudelli, Tatiana; Parenti, Sandra; Gemelli, Claudia; Condorelli, F; Martello, A; Selmi, Tommaso; Grande, Alexis; Ferrari, Sergio
abstract

Transcription Factor for Immunoglobulin Heavy-Chain Enhancer 3 (Tfe3) is a transactivator of metabolic genes that are regulated through an EBox located in their promoters. It is involved in physiological processes such as osteoclast and macrophage differentiation, as well as in pathological processes such as translocations underlying different cancer diseases. MAFB is a basic region/leucine zipper transcription factor that affects transcription by binding specific DNA regions known as MARE. It plays a pivotal role in regulating lineage-specific hematopoiesis by repressing transcription of erythroid specific genes in myeloid cells and enhancing expression of macrophage and megakaryocytic genes. Here we have shown MAFB to be highly induced in human hematopoietic cells undergoing macrophage differentiation following Tfe3 ectopic expression, and to be down regulated, compared to the controls, in the same cell population following Phorbol Esters (PMA) dependent differentiation coupled to Tfe3 gene silencing. Electrophoretic mobility shift assays identified a Tfe3-binding site (EBox) in the MAFB promoter region that is conserved in different mammalian species. MAFB promoter was transactivated by co-expression of Tfe3 in reporter gene assays while deletion or mutation of the MAFB EBox prevented transactivation by Tfe3. Both of these genes were previously included in the group of transcription factors able to drive macrophage differentiation. The observation that MAFB belongs to the Tfe3 regulon suggests the existence of a pathway where these two gene families act synergistically to determine differentiation.

2008 - The vitamin D3/Hox-A10 pathway supports MafB function during the monocyte differentiation of human CD34+ hemopoietic progenitors [Articolo su rivista]
Gemelli, Claudia; Orlandi, Claudia; ZANOCCO MARANI, Tommaso; Martello, A; Vignudelli, Tatiana; Ferrari, Francesco; Montanari, Monica; Parenti, Sandra; Testa, Anna; Grande, Alexis; Ferrari, Sergio
abstract

Although a considerable number of reports indicate an involvement of the Hox-A10 gene in the molecular control of hemopoiesis, the conclusions of such studies are quite controversial given that they support, in some cases, a role in the stimulation of stem cell self-renewal and myeloid progenitor expansion, whereas in others they implicate this transcription factor in the induction of monocyte-macrophage differentiation. To clarify this issue, we analyzed the biological effects and the transcriptome changes determined in human primary CD34+ hemopoietic progenitors by retroviral transduction of a full-length Hox-A10 cDNA. The results obtained clearly indicated that this homeogene is an inducer of monocyte differentiation, at least partly acting through the up-regulation of the MafB gene, recently identified as the master regulator of such a maturation pathway. By using a combined approach based on computational analysis, EMSA experiments, and luciferase assays, we were able to demonstrate the presence of a Hox-A10-binding site in the promoter region of the MafB gene, which suggested the likely molecular mechanism underlying the observed effect. Stimulation of the same cells with the vitamin D3 monocyte differentiation inducer resulted in a clear increase of Hox-A10 and MafB transcripts, indicating the existence of a precise transactivation cascade involving vitamin D3 receptor, Hox-A10, and MafB transcription factors. Altogether, these data allow one to conclude that the vitamin D3/Hox-A10 pathway supports MafB function during the induction of monocyte differentiation.

2006 - IDENTIFICATION OF A MOLECULAR SIGNATURE PREDICTIVE OF REFRACTORINESS IN ACUTE MYELOID LEUKEMIA [Abstract in Atti di Convegno]
Tenedini, Elena; Tagliafico, Enrico; Manfredini, Rossella; Ferrari, Francesco; Roncaglia, Enrica; Fantoni, Luca; Grande, Alexis; Parenti, Sandra; ZANOCCO MARANI, Tommaso; Gemelli, Claudia; Tatiana Vignudelli, Tatiana; Montanari, Monica; Zini, Roberta; Salati, Simona; Bianchi, Elisa; Bicciato, Silvio; Ferrari, Sergio
abstract

Acute Myeloid Leukemia (AML) blast cells are immature committed myeloid cells unable to spontaneously undergo terminal maturation, characterized by heterogeneous sensitivity to natural differentiation inducers. No data are available so far by which infer the AML’s response to differentiating therapy. Thus, we have initially profiled by GeneChip arrays the gene expression of several AML cell lines: they derived by the original blast cell populations and are still characterized by the same immunophenotype, retain a different sensitivity or resistance to All-Trans Retinoic-Acid (ATRA) and Vitamin-D3 (VD) and never undergo spontaneously terminal maturation. Here we show that differences exist by which predict the cell line differentiation fate. Next we constructed a signature able to predict resistance or sensitivity to the differentiation induction and tested it, using a TaqMan platform, for its capability to predict the in-vitro response of 28 VD or ATRA treated AML blast cell populations. Finally, by a meta-analysis of public available microarray data we demonstrated that our signature of 11 genes, among them is particularly intriguing the presence of Meis1 and ID3, that was formerly designed to identify differentiation therapy resistant populations, turned out to be a good classifier for clusters of patients known to have poor prognostic significance.

2006 - Identification of a molecular signature predictive of sensitivity to differentiation induction in acute myeloid leukemia [Articolo su rivista]
Tagliafico, Enrico; Tenedini, Elena; Manfredini, Rossella; Grande, Alexis; Ferrari, F.; Roncaglia, Enrica; Bicciato, Silvio; Zini, Roberta; Salati, Simona; Bianchi, Elisa; Gemelli, Claudia; Montanari, Monica; Vignudelli, Tatiana; ZANOCCO MARANI, Tommaso; Parenti, Sandra; Paolucci, Paolo; Martinelli, G.; Piccaluga, P. P.; Baccarani, M.; Specchia, G.; Torelli, U.; Ferrari, Sergio
abstract

Acute myeloid leukemia (AML) blasts are immature committed myeloid cells unable to spontaneously undergo terminal maturation, and characterized by heterogeneous sensitivity to natural differentiation inducers. Here, we show a molecular signature predicting the resistance or sensitivity of six myeloid cell lines to differentiation induced in vitro with retinoic acid or vitamin D. The identified signature was further validated by TaqMan assay for the prediction of response to an in vitro differentiation assay performed on 28 freshly isolated AML blast populations. The TaqMan assay successfully predicts the in vitro resistance or responsiveness of AML blasts to differentiation inducers. Furthermore, performing a meta-analysis of publicly available microarray data sets, we also show the accuracy of our prediction on known phenotypes and suggest that our signature could become useful for the identification of patients eligible for new therapeutic strategies.

2006 - Tfe3 expression is closely associated to macrophage terminal differentiation of human hematopoietic myeloid precursors. [Articolo su rivista]
ZANOCCO MARANI, Tommaso; Vignudelli, Tatiana; Gemelli, Claudia; Pirondi, Sara; Testa, Anna; Montanari, Monica; Parenti, Sandra; Tenedini, Elena; Grande, Alexis; Ferrari, Sergio
abstract

The MItf-Tfe family of basic helix–loop–helix leucine zipper (bHLH-Zip) transcription factors encodes four family members: MItf, Tfe3, TfeB and TfeC. In vitro, each protein of the family binds DNA in a homo- or heterodimeric form with other family members. Tfe3 is involved in chromosomal translocations recurrent in different tumors and it has been demonstrated, by in vivo studies, that it plays, redundantly with MItf, an important role in the process of osteoclast formation, in particular during the transition from mono-nucleated to multi-nucleated osteoclasts. Since mono-nucleated osteoclasts derive from macrophages we investigated whether Tfe3 might play a role upstream during hematopoietic differentiation. Here we show that Tfe3 is able to induce mono-macrophagic differentiation of U937 cells, in association with a decrease of cell proliferation and an increase of apoptosis. We also show that Tfe3 does not act physiologically during commitment of CD34+ hematopoietic stem cells (HSCs), since it is not able to direct HSCs toward a specific lineage as observed by clonogenic assay, but is a strong actor of terminal differentiation since it allows human primary myeloblasts' maturation toward the macrophage lineage.

2005 - IDENTIFICATION OF A MOLECULAR SIGNATURE PREDICTIVE OF REFRACTORINESS IN ACUTE MYELOID LEUKEMIA [Abstract in Atti di Convegno]
Tagliafico, Enrico; Tenedini, Elena; Manfredini, Rossella; Ferrari, Sergio; Roncaglia, Enrica; Fantoni, Luca; Grande, Alexis; Parenti, Sandra; ZANOCCO MARANI, Tommaso; Gemelli, Claudia; Vignudelli, Tatiana; Montanari, Monica; Zini, Roberta; Salati, Simona; Bianchi, Elisa; Bicciato, Silvio; Specchia, Giorgina; Martinelli, Giovanni; Baccarani, Michele; Piccaluga, Pier Paolo; Torelli, Umberto; Ferrari, Sergio
abstract

Acute Myeloid Leukemia (AML) blast cells are immature committed myeloid cells unable to spontaneously undergo terminal maturation, characterized by heterogeneous sensitivity to natural differentiation inducers. No data are available so far by which infer the AML’s response to differentiating therapy. Thus, we have initially profiled by GeneChip arrays the gene expression of several AML cell lines: they derived by the original blast cell populations and are still characterized by the same immunophenotype, retain a different sensitivity or resistance to ATRA and VD and never undergo spontaneously terminal maturation. Here we show that differences exist by which predict the cell line differentiation fate. Next we constructed a signature able to predict resistance or sensitivity to the differentiation induction and tested it, using a TaqMan platform, for its capability to predict the in-vitro response of 28 VD or ATRA treated AML blast cell populations. Finally, by a meta-analysis of public available microarray data we demonstrated that our signature, that was formerly designed to identify differentiation therapy resistant populations, turned out to be a good classifier for clusters of patients with citogenetically and molecularly defined lesions that are known to have poor prognostic significance.