Publications by authors named "Marta Colletti"

20 Publications

  • Page 1 of 1

Establishment and Characterization of a Cell Line (S-RMS1) Derived from an Infantile Spindle Cell Rhabdomyosarcoma with Fusion Transcript.

Int J Mol Sci 2021 May 22;22(11). Epub 2021 May 22.

Department of Pediatric Hematology/Oncology and Cell and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy.

: Spindle cell rhabdomyosarcoma (S-RMS) is a rare tumor that was previously considered as an uncommon variant of embryonal RMS (ERMS) and recently reclassified as a distinct RMS subtype with NCOA2, NCOA1, and VGLL2 fusion genes. In this study, we established a cell line (S-RMS1) derived from a four-month-old boy with infantile spindle cell RMS harboring gene fusion. : Morphological and molecular characteristics of S-RMS1 were analyzed and compared with two RMS cell lines, RH30 and RD18. Whole genome sequencing of S-RMS1 and clinical exome sequencing of genomic DNA were performed. : S-RMS1 showed cells small in size, with a fibroblast-like morphology and positivity for MyoD-1, myogenin, desmin, and smooth muscle actin. The population doubling time was 3.7 days. Whole genome sequencing demonstrated that S-RMS1 retained the same genetic profile of the tumor at diagnosis. A Western blot analysis showed downregulation of AKT-p and YAP-p while RT-qPCR showed upregulation of endoglin and GATA6 as well as downregulation of TGFßR1 and Mef2C transcripts. : This is the first report of the establishment of a cell line from an infantile spindle cell RMS with SRF-NCOA2 gene fusion. S-RMS1 should represent a useful tool for the molecular characterization of this rare and almost unknown tumor.
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http://dx.doi.org/10.3390/ijms22115484DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8196948PMC
May 2021

Autophagy and Exosomes Relationship in Cancer: Friends or Foes?

Front Cell Dev Biol 2020 12;8:614178. Epub 2021 Jan 12.

Department of Pediatric Hemato-Oncology and Cell and Gene Therapy, IRCCS, Bambino Gesù Children's Hospital, Rome, Italy.

Autophagy is an intracellular degradation process involved in the removal of proteins and damaged organelles by the formation of a double-membrane vesicle named autophagosome and degraded through fusion with lysosomes. An intricate relationship between autophagy and the endosomal and exosomal pathways can occur at different stages with important implications for normal physiology and human diseases. Recent researches have revealed that extracellular vesicles (EVs), such as exosomes, could have a cytoprotective role by inducing intracellular autophagy; on the other hand, autophagy plays a crucial role in the biogenesis and degradation of exosomes. Although the importance of these processes in cancer is well established, their interplay in tumor is only beginning to be documented. In some tumor contexts (1) autophagy and exosome-mediated release are coordinately activated, sharing the molecular machinery and regulatory mechanisms; (2) cancer cell-released exosomes impact on autophagy in recipient cells through mechanisms yet to be determined; (3) exosome-autophagy relationship could affect drug resistance and tumor microenvironment (TME). In this review, we survey emerging discoveries relevant to the exosomes and autophagy crosstalk in the context of cancer initiation, progression and recurrence. Consequently, we discuss clinical implications by targeting autophagy-exosomal pathway interaction and how this could lay a basis for the purpose of novel cancer therapeutics.
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http://dx.doi.org/10.3389/fcell.2020.614178DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7835528PMC
January 2021

Neuroblastoma-secreted exosomes carrying miR-375 promote osteogenic differentiation of bone-marrow mesenchymal stromal cells.

J Extracell Vesicles 2020 Jun 3;9(1):1774144. Epub 2020 Jun 3.

Department of Pediatric Onco-Hematology and Cell and Gene Therapy, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.

Bone marrow (BM) is the major target organ for neuroblastoma (NB) metastasis and its involvement is associated with poor outcome. Yet, the mechanism by which NB cells invade BM is largely unknown. Tumour microenvironment represents a key element in tumour progression and mesenchymal stromal cells (MSCs) have been recognized as a fundamental part of the associated tumour stroma. Here, we show that BM-MSCs isolated from NB patients with BM involvement exhibit a greater osteogenic potential than MSCs from non-infiltrated BM. We show that BM metastasis-derived NB-cell lines secrete higher levels of exosomal miR-375, which promotes osteogenic differentiation in MSCs. Of note, clinical data demonstrate that high level of miR-375 correlates with BM metastasis in NB patients. Our findings suggest, indeed, a potential role for exosomal miR-375 in determining a favourable microenvironment in BM to promote metastatic progression. MiR-375 may, thus, represent a novel biomarker and a potential target for NB patients with BM involvement.
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http://dx.doi.org/10.1080/20013078.2020.1774144DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7448845PMC
June 2020

Proteomic Profiling of Retinoblastoma-Derived Exosomes Reveals Potential Biomarkers of Vitreous Seeding.

Cancers (Basel) 2020 06 12;12(6). Epub 2020 Jun 12.

Department of Pediatric Hematology/Oncology and Cell and Gene Therapy, IRCCS, Ospedale Pediatrico Bambino Gesù, Piazza Sant'Onofrio 4, 00165 Rome, Italy.

Retinoblastoma (RB) is the most common tumor of the eye in early childhood. Although recent advances in conservative treatment have greatly improved the visual outcome, local tumor control remains difficult in the presence of massive vitreous seeding. Traditional biopsy has long been considered unsafe in RB, due to the risk of extraocular spread. Thus, the identification of new biomarkers is crucial to design safer diagnostic and more effective therapeutic approaches. Exosomes, membrane-derived nanovesicles that are secreted abundantly by aggressive tumor cells and that can be isolated from several biological fluids, represent an interesting alternative for the detection of tumor-associated biomarkers. In this study, we defined the protein signature of exosomes released by RB tumors (RBT) and vitreous seeding (RBVS) primary cell lines by high resolution mass spectrometry. A total of 5666 proteins were identified. Among these, 5223 and 3637 were expressed in exosomes RBT and one RBVS group, respectively. Gene enrichment analysis of exclusively and differentially expressed proteins and network analysis identified in RBVS exosomes upregulated proteins specifically related to invasion and metastasis, such as proteins involved in extracellular matrix (ECM) remodeling and interaction, resistance to anoikis and the metabolism/catabolism of glucose and amino acids.
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http://dx.doi.org/10.3390/cancers12061555DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352325PMC
June 2020

Exosomal MiRNAs in Pediatric Cancers.

Int J Mol Sci 2019 Sep 17;20(18). Epub 2019 Sep 17.

Department of Pediatric Hematology/Oncology, IRCCS, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy.

MicroRNAs (miRNAs) have generated great attention in oncology as they play a fundamental role in the regulation of gene expression and their aberrant expression is present in almost all types of tumors including pediatric ones. The discovery that miRNAs can be transported by exosomes, which are vesicles of 40-120 nm involved in cellular communication, that are produced by different cell types, and that are present in different biological fluids, has opened the possibility of using exosomal miRNAs as biomarkers. The possibility to diagnose and monitor the progression and response to drugs through molecules that can be easily isolated from biological fluids represents a particularly important aspect in the pediatric context where invasive techniques are often used. In recent years, the idea of liquid biopsy as well as studies on the possible role of exosomal miRNAs as biomarkers have developed greatly. In this review, we report an overview of all the evidences acquired in recent years on the identification of exosomal microRNAs with biomarker potential in pediatric cancers. We discuss the following herein: neuroblastoma, hepatoblastoma, sarcomas (osteosarcoma, Ewing's sarcoma and rhabdoid tumors, and non-rhabdomyosarcoma soft tissue sarcoma), brain tumors, lymphomas, and leukemias.
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http://dx.doi.org/10.3390/ijms20184600DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770697PMC
September 2019

Exosomes in Systemic Sclerosis: Messengers Between Immune, Vascular and Fibrotic Components?

Int J Mol Sci 2019 09 4;20(18). Epub 2019 Sep 4.

Unit of Endocrinology, Department of Movement, Human and Health Sciences, Università degli Studi di Roma "Foro Italico", Piazza Lauro de Bosis, 600135 Rome, Italy.

Systemic sclerosis (SSc) is a rare autoimmune disease, characterized by vasculopathy and fibrosis of the skin and internal organs. This disease is still considered incurable and is associated with a high risk of mortality, which is related to fibrotic events. An early diagnosis is useful for preventing complications, and targeted therapies reduce disease progression and ameliorate patients' quality of life. Nevertheless, there are no validated biomarkers for early diagnosis with predictive prognostic value. Exosomes are membrane vesicles, transporting proteins and nucleic acids that may be delivered to target cells, which influences cellular behavior. They play important roles in cell-cell communication, both in physiological and pathological conditions, and may be useful as circulating biomarkers. Recent evidences suggest a role for these microvesicles in the three main aspects related to the pathogenesis of SSc (immunity, vascular damage, and fibrosis). Moreover, exosomes are of particular interest in the field of nano-delivery and are used as biological carriers. In this review, we report the latest information concerning SSc pathogenesis, clinical aspects of SSc, and current approaches to the treatment of SSc. Furthermore, we indicate a possible role of exosomes in SSc pathogenesis and suggest their potential use as diagnostic and prognostic biomarkers, as well as therapeutic tools.
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http://dx.doi.org/10.3390/ijms20184337DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770454PMC
September 2019

Expression profiles of exosomal miRNAs isolated from plasma of patients with desmoplastic small round cell tumor.

Epigenomics 2019 04 20;11(5):489-500. Epub 2018 Dec 20.

Department of Pediatric Hematology/Oncology, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant' Onofrio, 4, 00165 Rome, Italy.

Aim: Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive mesenchymal tumor, lacking biomarkers for diagnosis, treatment stratification and prognosis. We investigated the exosomal miRNA profile in plasma samples collected from DSRCT patients, evaluating their potential as circulating biomarkers for this tumor.

Patients & Methods: We isolated exosomes from plasma of three DSRCT adolescents and four age-matched healthy controls; expression of circulating miRNAs was quantified by qPCR.

Results: We identified 55 miRNAs significantly modulated compared with healthy controls. Among these miRNAs, 14 were highly dysregulated in at least one patient and 5 were expressed in all patients.

Conclusion: To our knowledge, this is the first report describing exosomal miRNAs as promising biomarkers to characterize disease status in DSRCT patients.
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http://dx.doi.org/10.2217/epi-2018-0179DOI Listing
April 2019

Circulating Biomarkers for Tumor Angiogenesis: Where Are We?

Curr Med Chem 2020 ;27(14):2361-2380

Department of Hematology/Oncology and Stem Cell Transplantation, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant'Onofrio, 4-00165 Rome, Italy.

Background: In recent years, several anti-angiogenic drugs have been developed and their addition to standard treatment has been associated with clinical benefits. However, the response to anti-angiogenic therapy is characterized by considerable variability. In this context, the development of dynamic non-invasive biomarkers would be helpful to elucidate the emergence of anti-angiogenic resistance as well as to correctly address the treatment.

Objectives: The purpose of this review is to describe current reports on circulating diagnostic and prognostic biomarkers related to angiogenesis. We further discuss how this non-invasive strategy could improve the monitoring of tumor treatment and help clinical strategy.

Results: We discuss the latest evidence in the literature regarding circulating anti-angiogenic markers. Besides growth factor proteins, different circulating miRNAs could exert a pro- or anti-angiogenic activity so as to represent suitable candidates for a non-invasive strategy. Recent reports indicate that tumor-derived exosomes, which are small membrane vesicles abundant in biological fluids, also have an impact on vascular remodeling.

Conclusion: Numerous circulating biomarkers related to angiogenesis have been recently identified. Their use will allow identifying patients who are more likely to benefit from a specific anti-angiogenic treatment, as well as detecting those who will develop resistance and/or adverse effects. Nonetheless, further studies are required to elucidate the role of these biomarkers in clinical settings.
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http://dx.doi.org/10.2174/0929867325666180821151409DOI Listing
July 2020

Evaluation of Endoglin (CD105) expression in pediatric rhabdomyosarcoma.

BMC Cancer 2018 01 5;18(1):31. Epub 2018 Jan 5.

Department of Hematology/Oncology, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant'Onofrio, 4, 00165, Rome, Italy.

Background: The Intratumoral Microvessel Density (IMVD) is commonly used to quantify tumoral vascularization and is usually assessed by pan-endothelial markers, such as CD31. Endoglin (CD105) is a protein predominantly expressed in proliferating endothelium and the IMVD determined by this marker measures specifically the neovascularization. In this study, we investigated the CD105 expression in pediatric rhabdomyosarcoma and assessed the neovascularization by using the angiogenic ratio IMVD-CD105 to IMVD-CD31.

Methods: Paraffin-embedded archival tumor specimens were selected from 65 pediatric patients affected by rhabdomyosarcoma. The expression levels of CD105, CD31 and Vascular Endothelial Growth Factor (VEGF) were investigated in 30 cases (18 embryonal and 12 alveolar) available for this study. The IMVD-CD105 to IMVD-CD31 expression ratio was correlated with clinical and pathologic features of these patients.

Results: We found a specific expression of endoglin (CD105) in endothelial cells of all the rhabdomyosarcoma specimens analyzed. We observed a significant positive correlation between the IMVD individually measured by CD105 and CD31. The CD105/CD31 expression ratio was significantly higher in patients with lower survival and embryonal histology. Indeed, patients with a CD105/CD31 expression ratio < 1.3 had a significantly increased OS (88%, 95%CI, 60%-97%) compared to patients with higher values (40%, 95%CI, 12%-67%). We did not find any statistical correlation among VEGF and EFS, OS and CD105/CD31 expression ratio.

Conclusion: CD105 is expressed on endothelial cells of rhabdomyosarcoma and represent a useful tool to quantify neovascularization in this tumor. If confirmed by further studies, these results will indicate that CD105 is a potential target for combined therapies in rhabdomyosarcoma.
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http://dx.doi.org/10.1186/s12885-017-3947-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5755407PMC
January 2018

Intraspinal mesenchymal chondrosarcoma: report of a pediatric case and literature review.

Tumori 2017 Nov 15;103(Suppl. 1):e66-e72. Epub 2017 Nov 15.

Department of hematology/Oncology and Stem Cell Transplantation, Bambino Gesù Children's Hospital, IRCCS, Rome - Italy.

Purpose: Mesenchymal chondrosarcoma (MCS) is an aggressive variant of chondrosarcoma and is a rare tumor, particularly within the pediatric population. Commonly, MCS originates in the bone, but it can also arise in extraskeletal sites, such as the brain and the intraspinal area. Due to the rarity of this tumor, there are no guidelines for its optimal treatment.

Methods: We report a case of intradural extramedullary MCS, located at the T11-T12 level, in a 14-year-old male. The tumor was documented by magnetic resonance imaging and treated with gross total resection (GTR) without adjuvant treatment. We further reviewed the relevant pediatric literature and discussed the management and outcome of intracranial and intraspinal MCS.

Results: The patient's follow-up showed no evidence of disease 2 years from diagnosis. A total of 51 cases of intracranial and intraspinal MCS have been reported (24 intraspinal and 27 intracranial). Recurrence has been described in only 4 patients with intraspinal MSC, and among them 3 received adjuvant chemotherapy and radiotherapy. GTR seems to reduce the risk of recurrence and, due to a higher cancer-mortality rate for these patients, adjuvant chemotherapy and radiotherapy are recommended in case aggressive surgery is not possible.

Conclusions: According to our single experience, we would suggest that adjuvant therapy might be unnecessary in cases where a localized MCS undergoes GTR. Chemotherapy and radiotherapy should be recommended when GTR cannot be obtained. Further studies are needed to investigate a standard treatment approach for this rare tumor.
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http://dx.doi.org/10.5301/tj.5000689DOI Listing
November 2017

MicroRNAs in Neuroblastoma: Biomarkers with Therapeutic Potential.

Curr Med Chem 2018 Feb;25(5):584-600

Department of Hematology/Oncology, Bambino Gesu Children's Hospital, IRCCS, Rome, Italy.

Background: Neuroblastoma is the most common extracranial solid tumor in infancy. The majority of children have a disseminated disease at diagnosis with bone marrow as the most common site of metastasis. Although several prognostic factors have been defined (i.e. age, stage, histology, recurrent genetic anomalies), the identification of non-invasive biomarkers for disease follow-up and therapy monitoring is indeed still a clinical need. Aberrant regulation of microRNAs (miRNAs) expression has been implicated in several malignancies.

Objectives: In this mini-review, we describe the recent findings about miRNAs in neuroblastoma, both in the tumor and circulation, with particular focus on those involved in tumor progression and drug resistance. Furthermore, we will discuss the use of specific miRNAs as potential therapeutic tools in this tumor.

Results: Several miRNAs have been identified to be down- or up-regulated in primary tumors and have been associated with MYCN amplification, differentiation, dissemination and chemoresistance. Little evidence is available in the literature about circulating miRNAs which are of particular interest as potential biomarkers for liquid biopsy.

Conclusion: Identification of body-fluid markers for non-invasive diagnosis, risk stratification, treatment monitoring and tumor follow-up, is gaining growing interest, especially in the pediatric field. miRNAs are suitable candidates as biomarkers in neuroblastoma but further investigations are needed to expand knowledge regarding their role in this malignancy to design specific approaches of miRNAs-mediated therapies.
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http://dx.doi.org/10.2174/0929867324666171003120335DOI Listing
February 2018

Proteomic Analysis of Neuroblastoma-Derived Exosomes: New Insights into a Metastatic Signature.

Proteomics 2017 Dec 12;17(23-24). Epub 2017 Sep 12.

Department of Hematology/Oncology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.

Neuroblastoma (NB) is the most common extracranial pediatric solid tumor. Around 70% of patients with metastatic disease at diagnosis present bone-marrow infiltration, which is considered a marker of poor outcome; however, the mechanism underlying this specific tropism has to be elucidated. Tumor-derived exosomes may support metastatic progression in several tumors by interacting with the microenvironment, and may serve as tumor biomarkers. The main objective of this study is to identify an exosomal signature associated with NB metastatic bone-marrow dissemination. Therefore, the proteomic cargo of exosomes isolated from NB cell lines derived from primary tumor and bone-marrow metastasis is characterized. The comparison among exosomal proteins show 15 proteins exclusively present in primary tumor-derived exosomes, mainly involved in neuronal development, and 6 proteins in metastasis-derived exosomes related to cancer progression. Significant proteins obtain with statistical analysis performed between the two groups, reveal that primary tumor exosomes contain a higher level of proteins involved in extra-cellular matrix (ECM) assembly and adhesion, as well as in neuronal development. Exosomes isolated from bone-marrow metastasis exhibit proteins involved in ameboidal cell migration and mitochondrial activity. This work suggests that proteomic profiling of NB-derived exosomes reflects the tumor stage and may be considered as potential tumor biomarker.
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http://dx.doi.org/10.1002/pmic.201600430DOI Listing
December 2017

Nano-Delivery in Pediatric Tumors: Looking Back, Moving Forward.

Anticancer Agents Med Chem 2017 ;17(10):1328-1343

Bambino Gesu Children's Hospital, IRCCS-Department of Pediatric Hematology/Oncology and Stem Cell Transplantation Rome. Italy.

Recent advances in the treatment of pediatric tumors led to an improvement of survival in this population. As a result, many pediatric survivors experience long-term effects that impact their quality of life. Therefore, it is extremely important to identify new treatment approaches that may target the tumor minimizing the drug-related side effects. Over the past 10 years, remarkable advances in nanomedicine have provided several potential tools for cancer treatment. Recently, there has been a growing interest towards therapeutic nanocarriers in the pediatric field, since they represent a new strategy to enhance the drug efficacy and reduce the toxicity. Various nanoformulations have been developed to improve the targeting and the release of antitumor compound to cancer cells in pediatric tumors and clinical trials have been conducted or are ongoing. Exosomes are nanometer-sized vesicles that play a crucial role in mediating intercellular communication. Thanks to to their intrinsic cell targeting properties, stability in the circulation, and bio-compatibility, they are emerging as new promising vehicles both for drugs and biological therapeutics. Moreover, these nanovesicles are a reservoir of potential diagnostic and prognostic markers. In this review, we describe recent advances in the treatment of pediatric tumors through nanodelivery system with particular attention to neuroblastoma, soft-tissues/bone sarcomas and pediatric brain tumors. Furthermore, we explore the potential role of exosomes as an effective option of nanodelivery providing insights into their characteristics in pediatric tumors and their use in adult clinical trials.
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http://dx.doi.org/10.2174/1871520617666170103101141DOI Listing
October 2017

Phosphodiesterase Type 5 Inhibitor Sildenafil Decreases the Proinflammatory Chemokine CXCL10 in Human Cardiomyocytes and in Subjects with Diabetic Cardiomyopathy.

Inflammation 2016 Jun;39(3):1238-52

Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Rome, Italy.

T helper 1 (Th1) type cytokines and chemokines are bioactive mediators in inflammation underling several diseases and co-morbid conditions, such as cardiovascular and metabolic disorders. Th1 chemokine CXCL10 participates in heart damage initiation/progression; cardioprotection has been recently associated with sildenafil, a type 5 phosphodiesterase inhibitor. We aimed to evaluate the effect of sildenafil on CXCL10 in inflammatory conditions associated with diabetic cardiomyopathy. We analyzed: CXCL10 gene and protein in human cardiac, endothelial, and immune cells challenged by pro-inflammatory stimuli with and without sildenafil; serum CXCL10 in diabetic subjects at cardiomyopathy onset, before and after 3 months of treatment with sildenafil vs. placebo. Sildenafil significantly decreased CXCL10 protein secretion (IC50 = 2.6 × 10(-7)) and gene expression in human cardiomyocytes and significantly decreased circulating CXCL10 in subjects with chemokine basal level ≥ 930 pg/ml, the cut-off value as assessed by ROC analysis. In conclusion, sildenafil could be a pharmacologic tool to control CXCL10-associated inflammation in diabetic cardiomyopathy.
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http://dx.doi.org/10.1007/s10753-016-0359-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4883282PMC
June 2016

MicroRNA-101 is repressed by EZH2 and its restoration inhibits tumorigenic features in embryonal rhabdomyosarcoma.

Clin Epigenetics 2015 6;7:82. Epub 2015 Aug 6.

Department of Oncohematology, Laboratory of Angiogenesis, Ospedale Pediatrico Bambino Gesù, IRCCS, Piazza S. Onofrio 4, 00165 Rome, Italy.

Background: Rhabdomyosarcoma (RMS) is a pediatric soft tissue sarcoma arising from myogenic precursors that have lost their capability to differentiate into skeletal muscle. The polycomb-group protein EZH2 is a Lys27 histone H3 methyltransferase that regulates the balance between cell proliferation and differentiation by epigenetically silencing muscle-specific genes. EZH2 is often over-expressed in several human cancers acting as an oncogene. We previously reported that EZH2 inhibition induces cell cycle arrest followed by myogenic differentiation of RMS cells of the embryonal subtype (eRMS). MiR-101 is a microRNA involved in a negative feedback circuit with EZH2 in different normal and tumor tissues. To that, miR-101 can behave as a tumor suppressor in several cancers by repressing EZH2 expression. We, therefore, evaluated whether miR-101 is de-regulated in eRMS and investigated its interplaying with EZH2 as well as its role in the in vitro tumorigenic potential of these tumor cells.

Results: Herein, we report that miR-101 is down-regulated in eRMS patients and in tumor cell lines compared to their controls showing an inverse pattern of expression with EZH2. We also show that miR-101 is up-regulated in eRMS cells following both genetic and pharmacological inhibition of EZH2. In turn, miR-101 forced expression reduces EZH2 levels as well as restrains the migratory potential of eRMS cells and impairs their clonogenic and anchorage-independent growth capabilities. Finally, EZH2 recruitment to regulatory region of miR-101-2 gene decreases in EZH2-silenced eRMS cells. This phenomenon is associated to reduced H3K27me3 levels at the same regulatory locus, indicating that EZH2 directly targets miR-101 for repression in eRMS cells.

Conclusions: Altogether, our data show that, in human eRMS, miR-101 is involved in a negative feedback loop with EZH2, whose targeting has been previously shown to halt eRMS tumorigenicity. They also demonstrate that the re-induction of miR-101 hampers the tumor features of eRMS cells. In this scenario, epigenetic dysregulations confirm their crucial role in the pathogenesis of this soft tissue sarcoma.
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http://dx.doi.org/10.1186/s13148-015-0107-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4527101PMC
August 2015

Vitamin D receptor agonists target CXCL10: new therapeutic tools for resolution of inflammation.

Mediators Inflamm 2013 17;2013:876319. Epub 2013 Apr 17.

Department of Medical Biotechnologies, University of Siena, Siena, Italy.

Understanding the many biological extraskeletal actions of vitamin D has increased in the past decades. Indeed, vitamin D and analogue molecules, besides the classical actions on bone metabolism, exert several beneficial effects on metabolic homeostasis, heart-cardiovascular, brain, and muscle physiological functions, throughout the interaction with the specific vitamin D receptor (VDR). In particular, VDR agonists powerfully control innate and adaptive immune system with favorable effects on human health. VDR ligands act as immunomodulators that are potent enough to retain anti-inflammatory effects, even though the mechanism underlying those effects is not yet fully elucidated. VDR agonists exert a significant suppression of inflammatory processes switching the immune response from T helper 1 (Th1) to T helper 2 (Th2) dominance and counteracting the self-enhancing inflammatory loop between immune and resident cells, especially by cytokine release impairment. Those molecules are able, indeed, to reduce the release of the interferon (IFN)γ-induced 10 kDa protein IP-10/CXCL10, a powerful chemokine driving Th1-mediated inflammation. Based on their features, VDR ligands show the potentiality to be included in immunosuppressive regimens, aimed to control auto- and alloimmune Th1-driven overreactivity, occurring, for example, in autoimmune disease or graft rejection.
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http://dx.doi.org/10.1155/2013/876319DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3652186PMC
December 2013

Role of the ductal transcription factors HNF6 and Sox9 in pancreatic acinar-to-ductal metaplasia.

Gut 2012 Dec 22;61(12):1723-32. Epub 2012 Jan 22.

Université catholique de Louvain, de Duve Institute, Avenue Hippocrate 75/B1-7503, B-1200 Brussels, Belgium.

Objective: Growing evidence suggests that a phenotypic switch converting pancreatic acinar cells to duct-like cells can lead to pancreatic intraepithelial neoplasia and eventually to invasive pancreatic ductal adenocarcinoma. Histologically, the onset of this switch is characterised by the co-expression of acinar and ductal markers in acini, a lesion called acinar-to-ductal metaplasia (ADM). The transcriptional regulators required to initiate ADM are unknown, but need to be identified to characterise the regulatory networks that drive ADM. In this study, the role of the ductal transcription factors hepatocyte nuclear factor 6 (HNF6, also known as Onecut1) and SRY-related HMG box factor 9 (Sox9) in ADM was investigated.

Design: Expression of HNF6 and Sox9 was measured by immunostaining in normal and diseased human pancreas. The function of the factors was tested in cultured cells and in mouse models of ADM by a combination of gain and loss of function experiments.

Results: Expression of HNF6 and Sox9 was ectopically induced in acinar cells in human ADM as well as in mouse models of ADM. HNF6 and, to a lesser extent, Sox9 were required for repression of acinar genes, for modulation of ADM-associated changes in cell polarity and for activation of ductal genes in metaplastic acinar cells.

Conclusions: HNF6 and Sox9 are new biomarkers of ADM and constitute candidate targets for preventive treatment in cases when ADM may lead to cancer. This work also shows that ectopic activation of transcription factors may underlie metaplastic processes occurring in other organs.
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http://dx.doi.org/10.1136/gutjnl-2011-300266DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898034PMC
December 2012

Inflammatory response in human skeletal muscle cells: CXCL10 as a potential therapeutic target.

Eur J Cell Biol 2012 Feb 15;91(2):139-49. Epub 2011 Dec 15.

Department of Health Sciences, University of Rome Foro Italico, 00135 Rome, Italy.

Inflammatory myopathies (IMs) are systemic diseases characterized by a T helper (Th) 1 type inflammatory response and cell infiltrates within skeletal muscles. The mainstay of treatment is drugs aimed at suppressing the immune system - corticosteroids and immunosuppressants. About 25% of patients are non-responders. Skeletal muscle cells seem actively involved in the immune-inflammatory response and not only a target; understanding the molecular bases of IMs might help drug development strategies. Within muscles the interaction between the chemokine interferon (IFN)γ inducible 10 kDa protein, CXCL10 or IP-10, and its specific receptor CXCR3, present on Th1 type infiltrating cells, likely plays a pivotal role, potentially offering the opportunity for therapeutic intervention. We aimed to clarify the involvement of human skeletal muscle cells in inflammatory processes in terms of CXCL10 secretion, to elucidate the engaged molecular mechanism(s) and, finally, to evaluate muscular cell responses, if any, to some immunosuppressants routinely used in IM treatment, such as methylprednisolone, methotrexate, cyclosporin A and Infliximab. We first isolated and characterized human fetal skeletal muscle cells (Hfsmc), which expressed the specific lineage markers and showed the competence to react in the context of an in vitro alloresponse. CXCL10 protein secretion by Hfsmc was similarly induced by the inflammatory cytokines interferon (IFN)γ and tumor necrosis factor (TNF)α, above undetectable control levels, through the activation of Stat1 and NF-kB pathways, respectively; CXCL10 secretion was significantly magnified by cytokine combination, and this synergy was associated to a significant up-regulation of TNFαRII; cytokine-induced CXCL10 secretion was considerably affected only by Infliximab. Our data suggested that human skeletal muscle cells might actively self-promote muscular inflammation by eliciting CXCL10 secretion, which is known to amplify Th1 cell tissue infiltration in vivo. In conclusion, we sustain that pharmacological targeting of CXCL10 within muscular cells might contribute to keep in control pro-Th1 polarization of the immune/inflammatory response.
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http://dx.doi.org/10.1016/j.ejcb.2011.09.011DOI Listing
February 2012

Convergence of Wnt signaling on the HNF4alpha-driven transcription in controlling liver zonation.

Gastroenterology 2009 Aug 18;137(2):660-72. Epub 2009 May 18.

Department of Cellular Biotechnologies and Haematology, Istituto Pasteur-Fondazione Cenci Bolognetti, University Sapienza of Rome, Italy.

Background & Aims: In each hepatocyte, the specific repertoire of gene expression is influenced by its exact location along the portocentrovenular axis of the hepatic lobule and provides a reason for the liver functions compartmentalization defined "metabolic zonation." So far, few molecular players controlling genetic programs of periportal (PP) and perivenular (PV) hepatocytes have been identified; the elucidation of zonation mechanisms remains a challenge for experimental hepatology. Recently, a key role in induction and maintenance of the hepatocyte heterogeneity has been ascribed to Wnt/beta-catenin pathway. We sought to clarify how this wide-ranging stimulus integrates with hepatocyte specificity.

Methods: Reverse transcriptase polymerase chain reaction (RT-PCR) allowed the transcriptional profiling of hepatocytes derived from in vitro differentiation of liver stem cells. The GSK3beta inhibitor 6-bromoindirubin-3'-oxime (BIO) was used for beta-catenin stabilization. Co-immunoprecipitations were used to study biochemical protein interactions while ChIP assays allowed the in vivo inspection of PV and PP genes regulatory regions.

Results: We found that spontaneous differentiation of liver stem cells gives rise to PP hepatocytes that, after Wnt pathway activation, switch into PV hepatocytes. Next, we showed that the Wnt downstream player LEF1 interacts with the liver-enriched transcriptional factor HNF4alpha. Finally, we unveiled that the BIO induced activation of PV genes correlates with LEF1 binding to both its own and HNF4alpha consensus, and the repression of PP genes correlates with HNF4alpha displacement from its own consensus.

Conclusion: Our data show a direct and hitherto unknown convergence of the canonical Wnt signaling on the HNF4alpha-driven transcription providing evidences of a mechanism controlling liver zonated gene expression.
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http://dx.doi.org/10.1053/j.gastro.2009.05.038DOI Listing
August 2009

ERK5/MAPK is activated by TGFbeta in hepatocytes and required for the GSK-3beta-mediated Snail protein stabilization.

Cell Signal 2008 Nov 8;20(11):2113-8. Epub 2008 Aug 8.

Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biotecnologie Cellulari ed Ematologia, University La Sapienza, Rome, Italy.

Extracellular signal-regulated protein kinase 5 (ERK5) is a mitogen-activated protein kinase, specifically activated by MEK5, and involved in the regulation of many cellular functions including proliferation, survival, differentiation and apoptosis. MEK5/ERK5 module is an important element of different signal transduction pathways. The aim of this study was to investigate whether ERK5 participates to the signalling of the multifunctional cytokine TGFbeta, known to play an important role in the regulation of hepatic growth. Here, we reported that ERK5 is phosphorylated and activated by TGFbeta in hepatocytes, with a rapid and sustained kinetic, through a Src-dependent pathway. Moreover, we demonstrated that ERK5 participates to the TGFbeta-induced Snail protein regulation being required for its stabilization. We also found that the functional inactivation of ERK5 impedes the TGFbeta-mediated glycogen synthase kinase-3beta inactivation suggesting this as mechanism responsible for ERK5-mediated Snail stabilization. Thus, results presented in this study uncovered for the first time a role for ERK5 in the TGFbeta-induced cellular responses.
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http://dx.doi.org/10.1016/j.cellsig.2008.08.002DOI Listing
November 2008
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