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Scarola M.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie
Oncogene | Year: 2017

OCT4 (Octamer-binding transcription factor 4) is essential for embryonic stem cell self-renewal. Here we show that OCT4 increases the aggressiveness of high-grade serous ovarian cancer (HG-SOC) by inactivating the Retinoblastoma tumor suppressor pathway and enhancing mitotic stability in cancer cells. OCT4 drives the expression of Nuclear Inhibitor of Protein Phosphatase type 1 (NIPP1) and Cyclin F (CCNF) that together inhibit Protein Phosphatase 1 (PP1). This results in pRB hyper-phosphorylation, accelerated cell proliferation and increased in vitro tumorigenicity of ovarian cancer cells. In parallel, OCT4 and NIPP1/CCNF drive the expression of the central Chromosomal Passenger Complex (CPC) components, Borealin, Survivin and the mitotic kinase Aurora B, promoting the clustering of supernumerary centrosomes to increase mitotic stability. Loss of OCT4 or NIPP1/CCNF results in severe mitotic defects, multipolar spindles and supernumerary centrosomes, finally leading to the induction of apoptosis. These phenotypes were recapitulated in different cancer models indicating general relevance for human cancer. Importantly, activation of these parallel pathways leads to dramatically reduced overall survival of HG-SOC patients. Altogether, our data highlights an unprecedented role for OCT4 as central regulator of mitotic fidelity and RB tumor suppressor pathway activity. Disrupting this pathway represents a promising strategy to target an aggressive subpopulation of HG-SOC cells.Oncogene advance online publication, 20 March 2017; doi:10.1038/onc.2017.20. © 2017 Macmillan Publishers Limited, part of Springer Nature.


Vilotti S.,International School for Advanced Studies | Vilotti S.,Giovanni Armenise Harvard Foundation Laboratory | Biagioli M.,International School for Advanced Studies | Foti R.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | And 13 more authors.
Cell Death and Differentiation | Year: 2012

TRAF and TNF receptor-associated protein (TTRAP) is a multifunctional protein that can act in the nucleus as a 5′-tyrosyl DNA phosphodiesterase and in the cytoplasm as a regulator of cell signaling. In this paper we show that in response to proteasome inhibition TTRAP accumulates in nucleolar cavities in a promyelocytic leukemia protein-dependent manner. In the nucleolus, TTRAP contributes to control levels of ribosomal RNA precursor and processing intermediates, and this phenotype is independent from its 5′-tyrosyl DNA phosphodiesterase activity. Our findings suggest a previously unidentified function for TTRAP and nucleolar cavities in ribosome biogenesis under stress. © 2012 Macmillan Publishers Limited All rights reserved.


Vilotti S.,International School for Advanced Studies | Codrich M.,International School for Advanced Studies | dal Ferro M.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | dal Ferro M.,University of Trieste | And 9 more authors.
PLoS ONE | Year: 2012

Mutations in PARK7/DJ-1 gene are associated to autosomal recessive early onset forms of Parkinson's disease (PD). Although large gene deletions have been linked to a loss-of-function phenotype, the pathogenic mechanism of missense mutations is less clear. The L166P mutation causes misfolding of DJ-1 protein and its degradation. L166P protein may also accumulate into insoluble cytoplasmic aggregates with a mechanism facilitated by the E3 ligase TNF receptor associated factor 6 (TRAF6). Upon proteasome impairment L166P activates the JNK/p38 MAPK apoptotic pathway by its interaction with TRAF and TNF Receptor Associated Protein (TTRAP). When proteasome activity is blocked in the presence of wild-type DJ-1, TTRAP forms aggregates that are localized to the cytoplasm or associated to nucleolar cavities, where it is required for a correct rRNA biogenesis. In this study we show that in post-mortem brains of sporadic PD patients TTRAP is associated to the nucleolus and to Lewy Bodies, cytoplasmic aggregates considered the hallmark of the disease. In SH-SY5Y neuroblastoma cells, misfolded mutant DJ-1 L166P alters rRNA biogenesis inhibiting TTRAP localization to the nucleolus and enhancing its recruitment into cytoplasmic aggregates with a mechanism that depends in part on TRAF6 activity. This work suggests that TTRAP plays a role in the molecular mechanisms of both sporadic and familial PD. Furthermore, it unveils the existence of an interplay between cytoplasmic and nucleolar aggregates that impacts rRNA biogenesis and involves TRAF6. © 2012 Vilotti et al.


Dinami R.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Dinami R.,University of Trieste | Dinami R.,Telomeres in Cancer and Aging Unit | Ercolani C.,Regina Elena Cancer Institute | And 19 more authors.
Cancer Research | Year: 2014

Telomeres consist of DNA tandemrepeats that recruit the multiprotein complex shelterin to build a chromatin structure that protects chromosome ends. Although cancer formation is linked to alterations in telomere homeostasis, there is little understanding of how shelterin function is limited in cancer cells. Using a small-scale screening approach, we identified miR-155 as a key regulator in breast cancer cell expression of the shelterin component TERF1 (TRF1). miR-155 targeted a conserved sequence motif in the 30UTR of TRF1, resulting in its translational repression. miR-155 was upregulated commonly in breast cancer specimens, as associated with reduced TRF1 protein expression, metastasis-free survival, and relapse-free survival in estrogen receptor-positive cases. Modulating miR-155 expression in cells altered TRF1 levels and TRF1 abundance at telomeres. Compromising TRF1 expression by elevating miR-155 increased telomere fragility and altered the structure of metaphase chromosomes. In contrast, reducing miR-155 levels improved telomere function and genomic stability. These results implied that miR-155 upregulation antagonizes telomere integrity in breast cancer cells, increasing genomic instability linked to poor clinical outcome in estrogen receptor-positive disease. Our work argued that miRNAdependent regulation of shelterin function has a clinically significant impact on telomere function, suggesting the existence of "telo-miRNAs" that have an impact on cancer and aging. © 2014 American Association for Cancer Research.


Verardo R.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Piazza S.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Klaric E.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Ciani Y.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | And 15 more authors.
Stem Cells | Year: 2014

Mesenchymal stem/stromal cells (MSCs) are the precursors of various cell types that compose both normal and cancer tissue microenvironments. In order to support the widely diversified parenchymal cells and tissue organization, MSCs are characterized by a large degree of heterogeneity, although available analyses of molecular and transcriptional data do not provide clear evidence. We have isolated MSCs from high-grade serous ovarian cancers (HG-SOCs) and various normal tissues (N-MSCs), demonstrated their normal genotype and analyzed their transcriptional activity with respect to the large comprehensive FANTOM5 sample dataset. Our integrative analysis conducted against the extensive panel of primary cells and tissues of the FANTOM5 project allowed us to mark the HG-SOC-MSCs CAGE-seq transcriptional heterogeneity and to identify a cell-type-specific transcriptional activity showing a significant relationship with primary mesothelial cells. Our analysis shows that MSCs isolated from different tissues are highly heterogeneous. The mesothelial-related gene signature identified in this study supports the hypothesis that HG-SOC-MSCs are bona fide representatives of the ovarian district. This finding indicates that HG-SOC-MSCs could actually derive from the coelomic mesothelium, suggesting that they might be linked to the epithelial tumor through common embryological precursors. © 2014 AlphaMed Press.


Schoeftner S.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Schoeftner S.,Italian National Cancer Institute | Scarola M.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Comisso E.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | And 4 more authors.
Stem Cells | Year: 2013

The pluripotency of mouse embryonic stem cells (mESCs) is controlled by a network of transcription factors, mi-RNAs, and signaling pathways. Here, we present a new regulatory circuit that connects miR-335, Oct4, and the Retinoblastoma pathway to control mESC self-renewal and differentiation. Oct4 drives the expression of Nipp1 and Ccnf that inhibit the activity of the protein phosphatase 1 (PP1) complex to establish hyperphosphorylation of the retinoblastoma protein 1 (pRb) as a hallmark feature of self-renewing mESCs. The Oct4-Nipp1/Ccnf-PP1-pRb axis promoting mESC self-renewal is under control of miR-335 that regulates Oct4 and Rb expression. During mESC differentiation, miR-335 upregulation co-operates with the transcriptional repression of Oct4 to facilitate the collapse of the Oct4-Nipp1/Ccnf-PP1-pRb axis, pRb dephosphorylation, the exit from self-renewal, and the establishment of a pRb-regulated cell cycle program. Our results introduce Oct4-dependent control of the Rb pathway as novel regulatory circuit controlling mESC self-renewal and differentiation. © AlphaMed Press.


Gurian E.,University of Trieste | Gurian E.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Bellich B.,University of Trieste | Cesaro A.,University of Trieste | Cesaro A.,Elettra - Sincrotrone Trieste
Food Hydrocolloids | Year: 2016

The isothermal dehydration of aqueous biosystems is a relevant topic in food, pharmaceutical and cosmetic industry and has been recently investigated for the assessment of a model calorimetric set-up and for the characterization of the parameters featuring the experimental calorimetric curve.In this study, the experimental Differential Scanning Calorimetry (DSC) data obtained under controlled conditions in isothermal mode have been collected on the dehydration of films consisting of solutions and gels of alginate, hydroxypropylmethylcellulose (HPMC), trehalose and mixtures thereof. Based on the proportionality between the calorimetric heat flow and water activity (aw) of solutions of known aw, the values calculated from calorimetry have been compared to those obtained with classic hygrometric measurements revealing a good consistency between the methods. Furthermore, the experimental data were mathematically turned into desorption isotherms, providing a continuous description of the water activity down to the low water activity limit. This experimental method represents an innovative approach to support other consolidated analytical techniques in the physico-chemical characterization of aqueous systems and, more importantly, a step forward in the determination of water activity as a continuous measurement in a timeframe far shorter than that necessary with other instruments (e.g., hygrometers). © 2016 Elsevier Ltd.


Foronda M.,Telomeres and Telomerase Group | Martinez P.,Telomeres and Telomerase Group | Schoeftner S.,Telomeres and Telomerase Group | Schoeftner S.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | And 5 more authors.
Cell Reports | Year: 2014

Sox4 expression is restricted in mammals to embryonic structures and some adult tissues, such as lymphoid organs, pancreas, intestine, and skin. During embryogenesis, Sox4 regulates mesenchymal and neural progenitor survival, as well as lymphocyte and myeloid differentiation, and contributes to pancreas, bone, and heart development. Aberrant Sox4 expression is linked to malignant transformation and metastasis in several types of cancer. To understand the roleof Sox4 in the adult organism, we first generated mice with reduced whole-body Sox4 expression. These mice display accelerated aging and reduced cancer incidence. To specifically address a role for Sox4 in adult stem cells, we conditionally deleted Sox4 (Sox4cKO) in stratified epithelia. Sox4cKO mice show increased skin stem cell quiescence and resistance to chemical carcinogenesis concomitantly with downregulation of cell cycle, DNA repair, and activated hair follicle stem cell pathways. Altogether, these findings highlight the importance of Sox4 in regulating adult tissue homeostasis and cancer. © 2014 The Authors.


Scarola M.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Schoeftner S.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Schneider C.,Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie | Schneider C.,University of Udine | And 2 more authors.
Cancer Research | Year: 2010

Loss-of-function mutations of retinoblastoma family (Rb) proteins drive tumorigenesis by overcoming barriers to cellular proliferation. Consequently, factors modulating Rb function are of great clinical import. Here, we show that miR-335 is differentially expressed in human cancer cells and that it tightly regulates the expression of Rb1 (pRb/p105) by specifically targeting a conserved sequence motif in its 3′ untranslated region. We found that by altering Rb1 (pRb/p105) levels, miR-335 activates the p53 tumor suppressor pathway to limit cell proliferation and neoplastic cell transformation. DNA damage elicited an increase in miR-335 expression in a p53-dependent manner. miR-335 and p53 cooperated in a positive feedback loop to drive cell cycle arrest. Together, these results indicate that miR-335 helps control proliferation by balancing the activities of the Rb and p53 tumor suppressor pathways. Further, they establish that miR-335 activation plays an important role in the induction of p53-dependent cell cycle arrest after DNA damage. ©2010 AACR.


PubMed | Saint Louis University, Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie, International Center for Genetic Engineering and Biotechnology and University of Trieste
Type: Journal Article | Journal: PloS one | Year: 2016

The HMGA1 architectural transcription factor is an oncogene overexpressed in the vast majority of human cancers. HMGA1 is a highly connected node in the nuclear molecular network and the key aspect of HMGA1 involvement in cancer development is that HMGA1 simultaneously confers cells multiple oncogenic hits, ranging from global chromatin structural and gene expression modifications up to the direct functional alterations of key cellular proteins. Interestingly, HMGA1 also modulates DNA damage repair pathways. In this work, we provide evidences linking HMGA1 with Non-Homologous End Joining DNA repair. We show that HMGA1 is in complex with and is a substrate for DNA-PK. HMGA1 enhances Ligase IV activity and it counteracts the repressive histone H1 activity towards DNA ends ligation. Moreover, breast cancer cells overexpressing HMGA1 show a faster recovery upon induction of DNA double-strand breaks, which is associated with a higher survival. These data suggest that resistance to DNA-damaging agents in cancer cells could be partially attributed to HMGA1 overexpression thus highlighting the relevance of considering HMGA1 expression levels in the selection of valuable and effective pharmacological regimens.

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