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Zhou Y, Nakajima R, Shirasawa M, Fikriyanti M, Zhao L, Iwanaga R, Bradford AP, Kurayoshi K, Araki K, Ohtani K. Expanding Roles of the E2F-RB-p53 Pathway in Tumor Suppression. BIOLOGY 2023; 12:1511. [PMID: 38132337 PMCID: PMC10740672 DOI: 10.3390/biology12121511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023]
Abstract
The transcription factor E2F links the RB pathway to the p53 pathway upon loss of function of pRB, thereby playing a pivotal role in the suppression of tumorigenesis. E2F fulfills a major role in cell proliferation by controlling a variety of growth-associated genes. The activity of E2F is controlled by the tumor suppressor pRB, which binds to E2F and actively suppresses target gene expression, thereby restraining cell proliferation. Signaling pathways originating from growth stimulative and growth suppressive signals converge on pRB (the RB pathway) to regulate E2F activity. In most cancers, the function of pRB is compromised by oncogenic mutations, and E2F activity is enhanced, thereby facilitating cell proliferation to promote tumorigenesis. Upon such events, E2F activates the Arf tumor suppressor gene, leading to activation of the tumor suppressor p53 to protect cells from tumorigenesis. ARF inactivates MDM2, which facilitates degradation of p53 through proteasome by ubiquitination (the p53 pathway). P53 suppresses tumorigenesis by inducing cellular senescence or apoptosis. Hence, in almost all cancers, the p53 pathway is also disabled. Here we will introduce the canonical functions of the RB-E2F-p53 pathway first and then the non-classical functions of each component, which may be relevant to cancer biology.
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Affiliation(s)
- Yaxuan Zhou
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan; (Y.Z.); (R.N.); (M.S.); (M.F.); (L.Z.)
| | - Rinka Nakajima
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan; (Y.Z.); (R.N.); (M.S.); (M.F.); (L.Z.)
| | - Mashiro Shirasawa
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan; (Y.Z.); (R.N.); (M.S.); (M.F.); (L.Z.)
| | - Mariana Fikriyanti
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan; (Y.Z.); (R.N.); (M.S.); (M.F.); (L.Z.)
| | - Lin Zhao
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan; (Y.Z.); (R.N.); (M.S.); (M.F.); (L.Z.)
| | - Ritsuko Iwanaga
- Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA; (R.I.); (A.P.B.)
| | - Andrew P. Bradford
- Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045, USA; (R.I.); (A.P.B.)
| | - Kenta Kurayoshi
- Division of Molecular Genetics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan;
| | - Keigo Araki
- Department of Morphological Biology, Ohu University School of Dentistry, 31-1 Misumido Tomitamachi, Koriyama, Fukushima 963-8611, Japan;
| | - Kiyoshi Ohtani
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo 669-1330, Japan; (Y.Z.); (R.N.); (M.S.); (M.F.); (L.Z.)
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Montano E, Pollice A, Lucci V, Falco G, Affinito O, La Mantia G, Vivo M, Angrisano T. Pancreatic Progenitor Commitment Is Marked by an Increase in Ink4a/Arf Expression. Biomolecules 2021; 11:biom11081124. [PMID: 34439790 PMCID: PMC8392192 DOI: 10.3390/biom11081124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/20/2021] [Accepted: 07/28/2021] [Indexed: 01/06/2023] Open
Abstract
The identification of the molecular mechanisms controlling early cell fate decisions in mammals is of paramount importance as the ability to determine specific lineage differentiation represents a significant opportunity for new therapies. Pancreatic Progenitor Cells (PPCs) constitute a regenerative reserve essential for the maintenance and regeneration of the pancreas. Besides, PPCs represent an excellent model for understanding pathological pancreatic cellular remodeling. Given the lack of valid markers of early endoderm, the identification of new ones is of fundamental importance. Both products of the Ink4a/Arf locus, in addition to being critical cell-cycle regulators, appear to be involved in several disease pathologies. Moreover, the locus' expression is epigenetically regulated in ES reprogramming processes, thus constituting the ideal candidates to modulate PPCs homeostasis. In this study, starting from mouse embryonic stem cells (mESCs), we analyzed the early stages of pancreatic commitment. By inducing mESCs commitment to the pancreatic lineage, we observed that both products of the Cdkn2a locus, Ink4a and Arf, mark a naïve pancreatic cellular state that resembled PPC-like specification. Treatment with epi-drugs suggests a role for chromatin remodeling in the CDKN2a (Cycline Dependent Kinase Inhibitor 2A) locus regulation in line with previous observations in other cellular systems. Our data considerably improve the comprehension of pancreatic cellular ontogeny, which could be critical for implementing pluripotent stem cells programming and reprogramming toward pancreatic lineage commitment.
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Affiliation(s)
- Elena Montano
- Department of Biology, University of Naples “Federico II”, 80147 Naples, Italy; (E.M.); (A.P.); (V.L.); (G.F.); (G.L.M.)
| | - Alessandra Pollice
- Department of Biology, University of Naples “Federico II”, 80147 Naples, Italy; (E.M.); (A.P.); (V.L.); (G.F.); (G.L.M.)
| | - Valeria Lucci
- Department of Biology, University of Naples “Federico II”, 80147 Naples, Italy; (E.M.); (A.P.); (V.L.); (G.F.); (G.L.M.)
- Department of Nuclear Medicine, IRCCS—Referral Cancer Center of Basilicata (CROB), 85028 Rionero in Vulture, Italy
| | - Geppino Falco
- Department of Biology, University of Naples “Federico II”, 80147 Naples, Italy; (E.M.); (A.P.); (V.L.); (G.F.); (G.L.M.)
- Department of Nuclear Medicine, IRCCS—Referral Cancer Center of Basilicata (CROB), 85028 Rionero in Vulture, Italy
- Biogem Scarl, Istituto di Ricerche Genetiche “Gaetano Salvatore”, 83031 Ariano Irpino, Italy
| | | | - Girolama La Mantia
- Department of Biology, University of Naples “Federico II”, 80147 Naples, Italy; (E.M.); (A.P.); (V.L.); (G.F.); (G.L.M.)
| | - Maria Vivo
- Department of Chemistry and Biology, University of Salerno, 84084 Fisciano, Italy
- Correspondence: (M.V.); (T.A.); Tel.: +39-081-679721 (T.A.)
| | - Tiziana Angrisano
- Department of Biology, University of Naples “Federico II”, 80147 Naples, Italy; (E.M.); (A.P.); (V.L.); (G.F.); (G.L.M.)
- Correspondence: (M.V.); (T.A.); Tel.: +39-081-679721 (T.A.)
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Non-Canonical Functions of the ARF Tumor Suppressor in Development and Tumorigenesis. Biomolecules 2021; 11:biom11010086. [PMID: 33445626 PMCID: PMC7827855 DOI: 10.3390/biom11010086] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/12/2022] Open
Abstract
P14ARF (ARF; Alternative Reading Frame) is an extensively characterized tumor suppressor which, in response to oncogenic stimuli, mediates cell cycle arrest and apoptosis via p53-dependent and independent routes. ARF has been shown to be frequently lost through CpG island promoter methylation in a wide spectrum of human malignancies, such as colorectal, prostate, breast, and gastric cancers, while point mutations and deletions in the p14ARF locus have been linked with various forms of melanomas and glioblastomas. Although ARF has been mostly studied in the context of tumorigenesis, it has been also implicated in purely developmental processes, such as spermatogenesis, and mammary gland and ocular development, while it has been additionally involved in the regulation of angiogenesis. Moreover, ARF has been found to hold important roles in stem cell self-renewal and differentiation. As is often the case with tumor suppressors, ARF functions as a pleiotropic protein regulating a number of different mechanisms at the crossroad of development and tumorigenesis. Here, we provide an overview of the non-canonical functions of ARF in cancer and developmental biology, by dissecting the crosstalk of ARF signaling with key oncogenic and developmental pathways.
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Daher MT, Bausero P, Agbulut O, Li Z, Parlakian A. Bcl11b/Ctip2 in Skin, Tooth, and Craniofacial System. Front Cell Dev Biol 2020; 8:581674. [PMID: 33363142 PMCID: PMC7758212 DOI: 10.3389/fcell.2020.581674] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/19/2020] [Indexed: 12/20/2022] Open
Abstract
Ctip2/Bcl11b is a zinc finger transcription factor with dual action (repression/activation) that couples epigenetic regulation to gene transcription during the development of various tissues. It is involved in a variety of physiological responses under healthy and pathological conditions. Its role and mechanisms of action are best characterized in the immune and nervous systems. Furthermore, its implication in the development and homeostasis of other various tissues has also been reported. In the present review, we describe its role in skin development, adipogenesis, tooth formation and cranial suture ossification. Experimental data from several studies demonstrate the involvement of Bcl11b in the control of the balance between cell proliferation and differentiation during organ formation and repair, and more specifically in the context of stem cell self-renewal and fate determination. The impact of mutations in the coding sequences of Bcl11b on the development of diseases such as craniosynostosis is also presented. Finally, we discuss genome-wide association studies that suggest a potential influence of single nucleotide polymorphisms found in the 3’ regulatory region of Bcl11b on the homeostasis of the cardiovascular system.
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Affiliation(s)
- Marie-Thérèse Daher
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Pedro Bausero
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Onnik Agbulut
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Zhenlin Li
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
| | - Ara Parlakian
- Biological Adaptation and Ageing, Inserm ERL U1164, UMR CNRS 8256, Institut de Biologie Paris-Seine, Sorbonne Université, Paris, France
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5
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Higginsianins A and B, two fungal diterpenoid α-pyrones with cytotoxic activity against human cancer cells. Toxicol In Vitro 2019; 61:104614. [DOI: 10.1016/j.tiv.2019.104614] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/12/2019] [Accepted: 07/28/2019] [Indexed: 01/12/2023]
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6
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Montano E, Vivo M, Guarino AM, di Martino O, Di Luccia B, Calabrò V, Caserta S, Pollice A. Colloidal Silver Induces Cytoskeleton Reorganization and E-Cadherin Recruitment at Cell-Cell Contacts in HaCaT Cells. Pharmaceuticals (Basel) 2019; 12:E72. [PMID: 31096606 PMCID: PMC6631624 DOI: 10.3390/ph12020072] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/08/2019] [Accepted: 05/14/2019] [Indexed: 12/14/2022] Open
Abstract
Up until the first half of the 20th century, silver found significant employment in medical applications, particularly in the healing of open wounds, thanks to its antibacterial and antifungal properties. Wound repair is a complex and dynamic biological process regulated by several pathways that cooperate to restore tissue integrity and homeostasis. To facilitate healing, injuries need to be promptly treated. Recently, the interest in alternatives to antibiotics has been raised given the widespread phenomenon of antibiotic resistance. Among these alternatives, the use of silver appears to be a valid option, so a resurgence in its use has been recently observed. In particular, in contrast to ionic silver, colloidal silver, a suspension of metallic silver particles, shows antibacterial activity displaying less or no toxicity. However, the human health risks associated with exposure to silver nanoparticles (NP) appear to be conflicted, and some studies have suggested that it could be toxic in different cellular contexts. These potentially harmful effects of silver NP depend on various parameters including NP size, which commonly range from 1 to 100 nm. In this study, we analyzed the effect of a colloidal silver preparation composed of very small and homogeneous nanoparticles of 0.62 nm size, smaller than those previously tested. We found no adverse effect on the cell proliferation of HaCaT cells, even at high NP concentration. Time-lapse microscopy and indirect immunofluorescence experiments demonstrated that this preparation of colloidal silver strongly increased cell migration, re-modeled the cytoskeleton, and caused recruitment of E-cadherin at cell-cell junctions of human cultured keratinocytes.
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Affiliation(s)
- Elena Montano
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy.
| | - Maria Vivo
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy.
| | - Andrea Maria Guarino
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy.
| | - Orsola di Martino
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy.
| | - Blanda Di Luccia
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy.
| | - Viola Calabrò
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy.
| | - Sergio Caserta
- Dipartimento di Ingegneria Chimica dei Materiali e della Produzione Industriale (DICMAPI) Università degli Studi Napoli Federico II, P.le Tecchio, 80, 80125 Napoli, Italy.
| | - Alessandra Pollice
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy.
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Fontana R, Ranieri M, La Mantia G, Vivo M. Dual Role of the Alternative Reading Frame ARF Protein in Cancer. Biomolecules 2019; 9:E87. [PMID: 30836703 PMCID: PMC6468759 DOI: 10.3390/biom9030087] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/20/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023] Open
Abstract
The CDKN2a/ARF locus expresses two partially overlapping transcripts that encode two distinct proteins, namely p14ARF (p19Arf in mouse) and p16INK4a, which present no sequence identity. Initial data obtained in mice showed that both proteins are potent tumor suppressors. In line with a tumor-suppressive role, ARF-deficient mice develop lymphomas, sarcomas, and adenocarcinomas, with a median survival rate of one year of age. In humans, the importance of ARF inactivation in cancer is less clear whereas a more obvious role has been documented for p16INK4a. Indeed, many alterations in human tumors result in the elimination of the entire locus, while the majority of point mutations affect p16INK4a. Nevertheless, specific mutations of p14ARF have been described in different types of human cancers such as colorectal and gastric carcinomas, melanoma and glioblastoma. The activity of the tumor suppressor ARF has been shown to rely on both p53-dependent and independent functions. However, novel data collected in the last years has challenged the traditional and established role of this protein as a tumor suppressor. In particular, tumors retaining ARF expression evolve to metastatic and invasive phenotypes and in humans are associated with a poor prognosis. In this review, the recent evidence and the molecular mechanisms of a novel role played by ARF will be presented and discussed, both in pathological and physiological contexts.
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Affiliation(s)
- Rosa Fontana
- Department of Pharmacology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Michela Ranieri
- Division of Hematology and Medical Oncology, Laura and Isaac Perlmutter Cancer Center, NYU Langone Medical Center, New York, NY 10016, USA.
| | - Girolama La Mantia
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy.
| | - Maria Vivo
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy.
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8
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Guarino AM, Troiano A, Pizzo E, Bosso A, Vivo M, Pinto G, Amoresano A, Pollice A, La Mantia G, Calabrò V. Oxidative Stress Causes Enhanced Secretion of YB-1 Protein that Restrains Proliferation of Receiving Cells. Genes (Basel) 2018; 9:genes9100513. [PMID: 30360431 PMCID: PMC6210257 DOI: 10.3390/genes9100513] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 10/16/2018] [Accepted: 10/18/2018] [Indexed: 01/03/2023] Open
Abstract
The prototype cold-shock Y-box binding protein 1 (YB-1) is a multifunctional protein that regulates a variety of fundamental biological processes including cell proliferation and migration, DNA damage, matrix protein synthesis and chemotaxis. The plethora of functions assigned to YB-1 is strictly dependent on its subcellular localization. In resting cells, YB-1 localizes to cytoplasm where it is a component of messenger ribonucleoprotein particles. Under stress conditions, YB-1 contributes to the formation of stress granules (SGs), cytoplasmic foci where untranslated messenger RNAs (mRNAs) are sorted or processed for reinitiation, degradation, or packaging into ribonucleoprotein particles (mRNPs). Following DNA damage, YB-1 translocates to the nucleus and participates in DNA repair thereby enhancing cell survival. Recent data show that YB-1 can also be secreted and YB-1-derived polypeptides are found in plasma of patients with sepsis and malignancies. Here we show that in response to oxidative insults, YB-1 assembly in SGs is associated with an enhancement of YB-1 protein secretion. An enriched fraction of extracellular YB-1 (exYB-1) significantly inhibited proliferation of receiving cells and such inhibition was associated to a G2/M cell cycle arrest, induction of p21WAF and reduction of ΔNp63α protein level. All together, these data show that acute oxidative stress causes sustained release of YB-1 as a paracrine/autocrine signal that stimulate cell cycle arrest.
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Affiliation(s)
- Andrea Maria Guarino
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Annaelena Troiano
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Elio Pizzo
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Andrea Bosso
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Maria Vivo
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Gabriella Pinto
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Angela Amoresano
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Alessandra Pollice
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Girolama La Mantia
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
| | - Viola Calabrò
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, 80126 Napoli, Italy.
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PKC Dependent p14ARF Phosphorylation on Threonine 8 Drives Cell Proliferation. Sci Rep 2018; 8:7056. [PMID: 29728595 PMCID: PMC5935756 DOI: 10.1038/s41598-018-25496-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 04/24/2018] [Indexed: 01/11/2023] Open
Abstract
ARF role as tumor suppressor has been challenged in the last years by several findings of different groups ultimately showing that its functions can be strictly context dependent. We previously showed that ARF loss in HeLa cells induces spreading defects, evident as rounded morphology of depleted cells, accompanied by a decrease of phosphorylated Focal Adhesion Kinase (FAK) protein levels and anoikis. These data, together with previous finding that a PKC dependent signalling pathway can lead to ARF stabilization, led us to the hypothesis that ARF functions in cell proliferation might be regulated by phosphorylation. In line with this, we show here that upon spreading ARF is induced through PKC activation. A constitutive-phosphorylated ARF mutant on the conserved threonine 8 (T8D) is able to mediate both cell spreading and FAK activation. Finally, ARF-T8D expression confers growth advantage to cells thus leading to the intriguing hypothesis that ARF phosphorylation could be a mechanism through which pro-proliferative or anti proliferative signals could be transduced inside the cells in both physiological and pathological conditions.
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10
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Ranieri M, Vivo M, De Simone M, Guerrini L, Pollice A, La Mantia G, Calabrò V. Sumoylation and ubiquitylation crosstalk in the control of ΔNp63α protein stability. Gene 2017; 645:34-40. [PMID: 29246538 DOI: 10.1016/j.gene.2017.12.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 12/05/2017] [Accepted: 12/11/2017] [Indexed: 12/20/2022]
Abstract
ΔNp63α is finely and strictly regulated during embryogenesis and differentiation. ΔNp63α is the only p63 isoform degraded by the proteasome after Ubiquitin and SUMO (Small Ubiquitin-like MOdifier) conjugation. Here, we show that p63 ubiquitylation per se is not the signal triggering p63 proteasomal degradation. Taking advantage of natural ΔNp63α mutants isolated by patients with Split Hand and Foot Malformation IV syndrome, we found that SUMO and Ub modifications are not redundant and both are required to guarantee efficient ΔNp63α degradation. Here, we present evidence that sumoylation and ubiquitylation of ΔNp63α are strongly intertwined, and none of the two can efficiently occur if the other is impaired.
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Affiliation(s)
- Michela Ranieri
- Department of Developmental and Molecular Biology Albert Einstein College of Medicine, United States
| | - Maria Vivo
- Dipartimento di Biologia, Università degli Studi di Napoli "Federico II", Italy.
| | | | | | - Alessandra Pollice
- Dipartimento di Biologia, Università degli Studi di Napoli "Federico II", Italy
| | - Girolama La Mantia
- Dipartimento di Biologia, Università degli Studi di Napoli "Federico II", Italy
| | - Viola Calabrò
- Dipartimento di Biologia, Università degli Studi di Napoli "Federico II", Italy
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11
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p14ARF interacts with the focal adhesion kinase and protects cells from anoikis. Oncogene 2017; 36:4913-4928. [PMID: 28436949 PMCID: PMC5582215 DOI: 10.1038/onc.2017.104] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 03/01/2017] [Accepted: 03/06/2017] [Indexed: 12/13/2022]
Abstract
The ARF protein functions as an important sensor of hyper-proliferative stimuli restricting cell proliferation through both p53-dependent and -independent pathways. Although to date the majority of studies on ARF have focused on its anti-proliferative role, few studies have addressed whether ARF may also have pro-survival functions. Here we show for the first time that during the process of adhesion and spreading ARF re-localizes to sites of active actin polymerization and to focal adhesion points where it interacts with the phosphorylated focal adhesion kinase. In line with its recruitment to focal adhesions, we observe that hampering ARF function in cancer cells leads to gross defects in cytoskeleton organization resulting in apoptosis through a mechanism dependent on the Death-Associated Protein Kinase. Our data uncover a novel function for p14ARF in protecting cells from anoikis that may reflect its role in anchorage independence, a hallmark of malignant tumor cells.
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12
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PML IV/ARF interaction enhances p53 SUMO-1 conjugation, activation, and senescence. Proc Natl Acad Sci U S A 2015; 112:14278-83. [PMID: 26578773 DOI: 10.1073/pnas.1507540112] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Promyelocytic leukemia protein (PML) nuclear bodies (NBs) recruit multiple partners, including p53 and many of its regulators. NBs are believed to facilitate several posttranslational modifications and are key regulators of senescence. PML, the organizer of NBs, is expressed as a number of splice variants that all efficiently recruit p53 partners. However, overexpression of only one of them, PML IV, triggers p53-driven senescence. Here, we show that PML IV specifically binds ARF, a key p53 regulator. Similar to ARF, PML IV enhances global SUMO-1 conjugation, particularly that of p53, resulting in p53 stabilization and activation. ARF interacts with and stabilizes the NB-associated UBC9 SUMO-conjugating enzyme, possibly explaining PML IV-enhanced SUMOylation. These results unexpectedly link two key tumor suppressors, highlighting their convergence for global control of SUMO conjugation, p53 activation, and senescence induction.
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13
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Vivo M, Matarese M, Sepe M, Di Martino R, Festa L, Calabrò V, Mantia GL, Pollice A. MDM2-mediated degradation of p14ARF: a novel mechanism to control ARF levels in cancer cells. PLoS One 2015; 10:e0117252. [PMID: 25723571 PMCID: PMC4344200 DOI: 10.1371/journal.pone.0117252] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 12/19/2014] [Indexed: 01/22/2023] Open
Abstract
We here show a new relationship between the human p14ARF oncosuppressor and the MDM2 oncoprotein. MDM2 overexpression in various cancer cell lines causes p14ARF reduction inducing its degradation through the proteasome. The effect does not require the ubiquitin ligase activity of MDM2 and preferentially occurs in the cytoplasm. Interestingly, treatment with inhibitors of the PKC (Protein Kinase C) pathway and use of p14ARF phosphorylation mutants indicate that ARF phosphorylation could play a role in MDM2 mediated ARF degradation reinforcing our previous observations that ARF phosphorylation influences its stability and biological activity. Our study uncovers a new potentially important mechanism through which ARF and MDM2 can counterbalance each other during the tumorigenic process.
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Affiliation(s)
- Maria Vivo
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Maria Matarese
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
- Istituto di Genetica e Biofisica (IGB)—Consiglio Nazionale delle Ricerche (CNR), Naples, Italy
| | - Maria Sepe
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche- Università di Napoli Federico II, Naples, Italy
| | - Rosaria Di Martino
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
- Istituto di Biochimica delle Proteine (IBP)—Consiglio Nazionale delle Ricerche (CNR), Naples, Italy
| | - Luisa Festa
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
- Diagnostica e Farmaceutica Molecolare- Consiglio Nazionale delle Ricerche (CNR), Naples, Italy
| | - Viola Calabrò
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Girolama La Mantia
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Alessandra Pollice
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
- * E-mail:
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14
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Montariello D, Troiano A, Di Girolamo D, Beneke S, Calabrò V, Quesada P. Effect of poly(ADP-ribose)polymerase and DNA topoisomerase I inhibitors on the p53/p63-dependent survival of carcinoma cells. Biochem Pharmacol 2015; 94:212-9. [PMID: 25667043 DOI: 10.1016/j.bcp.2015.01.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/20/2015] [Accepted: 01/21/2015] [Indexed: 11/30/2022]
Abstract
Depending on their genetic background (p53(wt) versus p53(null)), carcinoma cells are more or less sensitive to drug-induced cell cycle arrest and/or apoptosis. Among the members of the p53 family, p63 is characterized by two N-terminal isoforms, TAp63 and ΔNp63. TAp63 isoform has p53-like functions, while ΔNp63 acts as a dominant negative inhibitor of p53. We have previously published that TAp63 is involved in poly(ADP-ribose)polymerase-1 (PARP-1) signaling of DNA damage deriving from DNA topoisomerase I (TOP I) inhibition in carcinoma cells. In the present study, we treated MCF7 breast carcinoma cells (p53(+)/ΔNp63(-)) or SCC022 (p53(-)/ΔNp63(+)) squamous carcinoma cells with the TOP I inhibitor topotecan (TPT) and the PJ34 PARP inhibitor, to compare their effects in the two different cell contexts. In MCF7 cells, we found that PJ34 addition reverts TPT-dependent PARP-1 auto-modification and triggers caspase-dependent PARP-1 proteolysis. Moreover, TPT as single agent stimulates p53(ser15) phosphorylation, p53 PARylation and occupancy of the p21WAF promoter by p53 resulting in an increase of p21WAF expression. Interestingly, PJ34 in combination with TPT enhances p53 occupancy at the BAX promoter and is associated with increased BAX protein level. In SCC022 cells, instead, TPT+PJ34 combined treatment reduces the level of the anti-apoptotic ΔNp63α protein without inducing apoptosis. Remarkably, in such cells, either exogenous p53 or TAp63 can rescue the apoptotic program in response to the treatment. All together our results suggest that in cancer cells PARP inhibitor(s) can operate in the choice between growth arrest and apoptosis by modulating p53 family-dependent signal.
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Affiliation(s)
| | - Annaelena Troiano
- Department of Biology, University of Naples "Federico II", Naples, Italy
| | | | - Sascha Beneke
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Viola Calabrò
- Department of Biology, University of Naples "Federico II", Naples, Italy
| | - Piera Quesada
- Department of Biology, University of Naples "Federico II", Naples, Italy.
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15
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Di Luccia B, Manzo N, Baccigalupi L, Calabrò V, Crescenzi E, Ricca E, Pollice A. Lactobacillus gasseri SF1183 affects intestinal epithelial cell survival and growth. PLoS One 2013; 8:e69102. [PMID: 23894414 PMCID: PMC3720908 DOI: 10.1371/journal.pone.0069102] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/06/2013] [Indexed: 01/01/2023] Open
Abstract
It is now commonly accepted that the intestinal microbiota plays a crucial role in the gut physiology and homeostasis, and that both qualitative and quantitative alterations in the compositions of the gut flora exert profound effects on the host’s intestinal cells. In spite of this, the details of the interaction between commensal bacteria and intestinal cells are still largely unknown and only in few cases the molecular mechanisms have been elucidated. Here we analyze the effects of molecules produced and secreted by Lactobacillus gasseri SF1183 on human intestinal HCT116 cells. L. gasseri is a well known species of lactic acid bacteria, commonly associated to the human intestine and SF1183 is a human strain previously isolated from an ileal biopsy of an healthy volunteer. SF1183 produces and secretes, in a growth phase-dependent way, molecule(s) able to drastically interfere with HCT116 cell proliferation. Although several attempts to purify and identify the bioactive molecule(s) have been so far unsuccessful, a partial characterization has indicated that it is smaller than 3 kDa, thermostable and of proteinaceous nature. L. gasseri molecule(s) stimulate a G1-phase arrest of the cell cycle by up-regulation of p21WAF1 rendering cells protected from intrinsic and extrinsic apoptosis. A L. gasseri-mediated reduction of apoptosis and of cell proliferation could be relevant in protecting epithelial barrier integrity and helping in reconstituting tissutal homeostasis.
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Affiliation(s)
- Blanda Di Luccia
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
| | - Nicola Manzo
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
| | - Loredana Baccigalupi
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
| | - Viola Calabrò
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
| | - Elvira Crescenzi
- Istituto di Endocrinologia ed Oncologia Sperimentale-CNR-via S. Pansini, Naples, Italy
| | - Ezio Ricca
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
| | - Alessandra Pollice
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
- * E-mail:
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16
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Di Luccia B, Manzo N, Baccigalupi L, Calabrò V, Crescenzi E, Ricca E, Pollice A. Lactobacillus gasseri SF1183 affects intestinal epithelial cell survival and growth. PLoS One 2013. [PMID: 23894414 DOI: 10.1016/j.jff.2017.12.049] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
It is now commonly accepted that the intestinal microbiota plays a crucial role in the gut physiology and homeostasis, and that both qualitative and quantitative alterations in the compositions of the gut flora exert profound effects on the host's intestinal cells. In spite of this, the details of the interaction between commensal bacteria and intestinal cells are still largely unknown and only in few cases the molecular mechanisms have been elucidated. Here we analyze the effects of molecules produced and secreted by Lactobacillus gasseri SF1183 on human intestinal HCT116 cells. L. gasseri is a well known species of lactic acid bacteria, commonly associated to the human intestine and SF1183 is a human strain previously isolated from an ileal biopsy of an healthy volunteer. SF1183 produces and secretes, in a growth phase-dependent way, molecule(s) able to drastically interfere with HCT116 cell proliferation. Although several attempts to purify and identify the bioactive molecule(s) have been so far unsuccessful, a partial characterization has indicated that it is smaller than 3 kDa, thermostable and of proteinaceous nature. L. gasseri molecule(s) stimulate a G1-phase arrest of the cell cycle by up-regulation of p21WAF1 rendering cells protected from intrinsic and extrinsic apoptosis. A L. gasseri-mediated reduction of apoptosis and of cell proliferation could be relevant in protecting epithelial barrier integrity and helping in reconstituting tissutal homeostasis.
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Affiliation(s)
- Blanda Di Luccia
- Department of Biology, University of Naples Federico II-MSA-Via Cinthia, Naples, Italy
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17
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Ivanschitz L, De Thé H, Le Bras M. PML, SUMOylation, and Senescence. Front Oncol 2013; 3:171. [PMID: 23847762 PMCID: PMC3701148 DOI: 10.3389/fonc.2013.00171] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 06/14/2013] [Indexed: 11/15/2022] Open
Abstract
Since its discovery, 25 years ago, promyelocytic leukemia (PML) has been an enigma. Implicated in the oncogenic PML/RARA fusion, forming elusive intranuclear domains, triggering cell death or senescence, controlled by and perhaps controlling SUMOylation… there are multiple PML-related issues. Here we review the reciprocal interactions between PML, senescence, and SUMOylation, notably in the context of cellular transformation.
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Affiliation(s)
- Lisa Ivanschitz
- University Paris Diderot, Sorbonne Paris Cité, Hôpital St. Louis , Paris , France ; INSERM UMR 944, Equipe labellisée par la Ligue Nationale contre le Cancer, Institut Universitaire d'Hématologie, Hôpital St. Louis , Paris , France ; CNRS UMR 7212, Hôpital St. Louis , Paris , France
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18
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Vivo M, Ranieri M, Sansone F, Santoriello C, Calogero RA, Calabrò V, Pollice A, La Mantia G. Mimicking p14ARF phosphorylation influences its ability to restrain cell proliferation. PLoS One 2013; 8:e53631. [PMID: 23308265 PMCID: PMC3538741 DOI: 10.1371/journal.pone.0053631] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 12/03/2012] [Indexed: 11/29/2022] Open
Abstract
The INK4a/ARF locus on the short arm of chromosome 9 is one of the most frequently altered loci in human cancer. It is generally accepted that ARF is involved in oncogenic checkpoint pathways by sensitizing incipient cancer cells to undergo growth arrest or apoptosis through both p53-dependent and independent pathways. While intensive studies have been focused on ARF activation at the transcriptional level, only recently mechanisms governing ARF turnover have been identified. Here, we show for the first time that p14ARF is a PKC target. Prediction analysis showed many potential phosphorylation sites in PKC consensus sequences within ARF protein, and, among them, the threonine at position 8 was the most conserved. Substitution of this threonine influences both ARF stability and localization. Furthermore, a phosphomimetic ARF mutation reduces the ability to arrest cell growth although the ability to bind MDM2 and stabilize p53 result unaffected. Thus we propose that phosphorylation of ARF in both immortalized and tumor cell lines could be a mechanism to escape ARF surveillance following proliferative and oncogenic stress.
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Affiliation(s)
- Maria Vivo
- Department of Structural and Functional Biology, University of Naples “Federico II”, Naples, Italy
- * E-mail: (MV); (GLM)
| | - Michela Ranieri
- Department of Structural and Functional Biology, University of Naples “Federico II”, Naples, Italy
| | - Federica Sansone
- Department of Structural and Functional Biology, University of Naples “Federico II”, Naples, Italy
| | - Cristina Santoriello
- Harvard Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | | | - Viola Calabrò
- Department of Structural and Functional Biology, University of Naples “Federico II”, Naples, Italy
| | - Alessandra Pollice
- Department of Structural and Functional Biology, University of Naples “Federico II”, Naples, Italy
| | - Girolama La Mantia
- Department of Structural and Functional Biology, University of Naples “Federico II”, Naples, Italy
- * E-mail: (MV); (GLM)
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Zhang LJ, Bhattacharya S, Leid M, Ganguli-Indra G, Indra AK. Ctip2 is a dynamic regulator of epidermal proliferation and differentiation by integrating EGFR and Notch signaling. J Cell Sci 2012; 125:5733-44. [PMID: 23015591 DOI: 10.1242/jcs.108969] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Epidermal morphogenesis results from a delicate balance between keratinocyte proliferation and differentiation, and this balance is perturbed upon deletion of transcription factor Ctip2. Here we demonstrate that Ctip2, in a cell autonomous manner, controls keratinocyte proliferation and cytoskeletal organization, and regulates the onset and maintenance of differentiation in keratinocytes in culture. Ctip2 integrates keratinocyte proliferation and the switch to differentiation by directly and positively regulating EGFR transcription in proliferating cells and Notch1 transcription in differentiating cells. In proliferative cells, the EGFR promoter is occupied by Ctip2, whereas Ctip2 is only recruited to the Notch1 promoter under differentiating conditions. Activation of EGFR signaling downregulates Ctip2 at the transcript level, whereas high calcium signaling triggers SUMOylation, ubiquitination and proteasomal degradation of Ctip2 at the protein level. Together, our findings demonstrate a novel mechanism(s) of Ctip2-mediated, coordinated control of epidermal proliferation and terminal differentiation, and identify a pathway of negative feedback regulation of Ctip2 during epidermal development.
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Affiliation(s)
- Ling-juan Zhang
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331, USA
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20
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Lentini L, Barra V, Schillaci T, Di Leonardo A. MAD2 depletion triggers premature cellular senescence in human primary fibroblasts by activating a P53 pathway preventing aneuploid cells propagation. J Cell Physiol 2012; 227:3324-32. [DOI: 10.1002/jcp.24030] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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21
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Barra V, Schillaci T, Lentini L, Costa G, Di Leonardo A. Bypass of cell cycle arrest induced by transient DNMT1 post-transcriptional silencing triggers aneuploidy in human cells. Cell Div 2012; 7:2. [PMID: 22305267 PMCID: PMC3292948 DOI: 10.1186/1747-1028-7-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 02/03/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aneuploidy has been acknowledged as a major source of genomic instability in cancer, and it is often considered the result of chromosome segregation errors including those caused by defects in genes controlling the mitotic spindle assembly, centrosome duplication and cell-cycle checkpoints. Aneuploidy and chromosomal instability has been also correlated with epigenetic alteration, however the molecular basis of this correlation is poorly understood. RESULTS To address the functional connection existing between epigenetic changes and aneuploidy, we used RNA-interference to silence the DNMT1 gene, encoding for a highly conserved member of the DNA methyl-transferases. DNMT1 depletion slowed down proliferation of near-diploid human tumor cells (HCT116) and triggered G1 arrest in primary human fibroblasts (IMR90), by inducing p53 stabilization and, in turn, p21waf1 transactivation. Remarkably, p53 increase was not caused by DNA damage and was not observed after p14-ARF post-transcriptional silencing. Interestingly, DNMT1 silenced cells with p53 or p14-ARF depleted did not arrest in G1 but, instead, underwent DNA hypomethylation and became aneuploid. CONCLUSION Our results suggest that DNMT1 depletion triggers a p14ARF/p53 dependent cell cycle arrest to counteract the aneuploidy induced by changes in DNA methylation.
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Affiliation(s)
- Viviana Barra
- Department of Molecular and Biomolecular Science and Technology (STEMBIO) University of Palermo, Italy.
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22
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Taylor JR, Lehmann BD, Chappell WH, Abrams SL, Steelman LS, McCubrey JA. Cooperative effects of Akt-1 and Raf-1 on the induction of cellular senescence in doxorubicin or tamoxifen treated breast cancer cells. Oncotarget 2012; 2:610-26. [PMID: 21881167 PMCID: PMC3248208 DOI: 10.18632/oncotarget.315] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Escape from cellular senescence induction is a potent mechanism for chemoresistance. Cellular senescence can be induced in breast cancer cell lines by the removal of estrogen signaling with tamoxifen or by the accumulation of DNA damage induced by the chemotherapeutic drug doxorubicin. Long term culturing of the hormone-sensitive breast cancer cell line MCF-7 in doxorubicin (MCF-7/DoxR) reduced the ability of doxorubicin, but not tamoxifen, to induce senescence. Two pathways that are often upregulated in chemo- and hormonal-resistance are the PI3K/PTEN/Akt/mTOR and Ras/Raf/MEK/ERK pathways. To determine if active Akt-1 and Raf-1 can influence drug-induced senescence, we stably introduced activated ΔAkt-1(CA) and ΔRaf-1(CA) into drug-sensitive and doxorubicin-resistant cells. Expression of a constitutively-active Raf-1 construct resulted in higher baseline senescence, indicating these cells possessed the ability to undergo oncogene-induced-senescence. Constitutive activation of the Akt pathway significantly decreased drug-induced senescence in response to doxorubicin but not tamoxifen in MCF-7 cells. However, constitutive Akt-1 activation in drug-resistant cells containing high levels of active ERK completely escaped cellular senescence induced by doxorubicin and tamoxifen. These results indicate that up regulation of the Ras/PI3K/PTEN/Akt/mTOR pathway in the presence of elevated Ras/Raf/MEK/ERK signaling together can contribute to drug-resistance by diminishing cell senescence in response to chemotherapy. Understanding how breast cancers containing certain oncogenic mutations escape cell senescence in response to chemotherapy and hormonal based therapies may provide insights into the design of more effective drug combinations for the treatment of breast cancer.
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Affiliation(s)
- Jackson R Taylor
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University Greenville, NC 27858 USA
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23
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Heaton PR, Santos A, Rosas-Acosta G, Wilson VG. Analysis of global sumoylation changes occurring during keratinocyte differentiation. PLoS One 2012; 7:e30165. [PMID: 22291911 PMCID: PMC3264615 DOI: 10.1371/journal.pone.0030165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 12/11/2011] [Indexed: 11/22/2022] Open
Abstract
Sumoylation is a highly dynamic process that plays a role in a multitude of processes ranging from cell cycle progression to mRNA processing and cancer. A previous study from our lab demonstrated that SUMO plays an important role in keratinocyte differentiation. Here we present a new method of tracking the sumoylation state of proteins by creating a stably transfected HaCaT keratinocyte cell line expressing an inducible SNAP-SUMO3 protein. The SNAP-tag allows covalent fluorescent labeling that is denaturation resistant. When combined with two-dimensional gel electrophoresis, the SNAP-tag technology provides direct visualization of sumoylated targets and can be used to follow temporal changes in the global cohort of sumoylated proteins during dynamic processes such as differentiation. HaCaT keratinocyte cells expressing SNAP-SUMO3 displayed normal morphological and biochemical features that are consistent with typical keratinocyte differentiation. SNAP-SUMO3 also localized normally in these cells with a predominantly nuclear signal and some minor cytoplasmic staining, consistent with previous reports for untagged SUMO2/3. During keratinocyte differentiation the total number of proteins modified by SNAP-SUMO3 was highest in basal cells, decreased abruptly after induction of differentiation, and slowly rebounded beginning between 48 and 72 hours as differentiation progressed. However, within this overall trend the pattern of change for individual sumoylated proteins was highly variable with both increases and decreases in amount over time. From these results we conclude that sumoylation of proteins during keratinocyte differentiation is a complex process which likely reflects and contributes to the biochemical changes that drive differentiation.
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Affiliation(s)
- Phillip R. Heaton
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Andres Santos
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Germán Rosas-Acosta
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Van G. Wilson
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
- * E-mail:
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Stindt MH, Carter S, Vigneron AM, Ryan KM, Vousden KH. MDM2 promotes SUMO-2/3 modification of p53 to modulate transcriptional activity. Cell Cycle 2011; 10:3176-88. [PMID: 21900752 PMCID: PMC3218624 DOI: 10.4161/cc.10.18.17436] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 07/28/2011] [Accepted: 07/28/2011] [Indexed: 01/02/2023] Open
Abstract
The tumor suppressor p53 is extensively regulated by post-translational modification, including modification by the small ubiquitin-related modifier SUMO. We show here that MDM2, previously shown to promote ubiquitin, Nedd8 and SUMO-1 modification of p53, can also enhance conjugation of endogenous SUMO-2/3 to p53. Sumoylation activity requires p53-MDM2 binding but does not depend on an intact RING finger. Both ARF and L11 can promote SUMO-2/3 conjugation of p53. However, unlike the previously described SUMO-1 conjugation of p53 by an MDM2-ARF complex, this activity does not depend on the ability of MDM2 to relocalize to the nucleolus. Interestingly, the SUMO consensus is not conserved in mouse p53, which is therefore not modified by SUMO-2/3. Finally, we show that conjugation of SUMO-2/3 to p53 correlates with a reduction of both activation and repression of a subset of p53-target genes.
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Abstract
The tumour suppressor ARF (alternative reading frame) is one of the most important oncogenic stress sensors. ARF provides an 'oncogenic checkpoint' function through both p53-dependent and p53-independent mechanisms. In the present study, we demonstrate a novel p53-independent interaction between p14(ARF) and the adenovirus oncoprotein E1A. p14(ARF) inhibits E1A transcriptional function and promotes ubiquitination-dependent degradation of E1A. p14(ARF) overexpression relocalizes E1A into the nucleolus and inhibits E1A-induced cellular DNA replication independent of p53. Knockdown of endogenous p14(ARF) increases E1A transactivation. In addition, E1A can competitively inhibit ARF-Mdm2 (murine double minute 2) complex formation. These results identify a novel binding partner of p14(ARF) and reveal a mutually inhibitory interaction between p14(ARF) and E1A. We speculate that the ARF-E1A interaction may represent an additional host defence mechanism to limit viral replication. Alternatively, the interaction may allow adenovirus to sense the functional state of p53 in host cells, and fine-tune its own replication activity to prevent the triggering of a detrimental host response.
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26
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Role of p63 in cancer development. Biochim Biophys Acta Rev Cancer 2011; 1816:57-66. [PMID: 21515338 DOI: 10.1016/j.bbcan.2011.04.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 04/05/2011] [Accepted: 04/08/2011] [Indexed: 12/22/2022]
Abstract
Since their initial identification p53 homologues p63 and p73 have been expected to play a role in cancer development due to their close homology to p53, notoriously one of the most mutated genes in cancer. However soon after their discovery the awareness that these genes were rarely mutated in cancer seemed to indicate that they did not play a role in its development. However a large number of data collected in the following years indicated that altered expression rather than mutation could be found in different neoplasia and play a role in its biology. In particular p63 due to its fundamental role in epithelial development seems to play a role in a number of tumors of epithelial origin. In this review we summarize some of the evidence linking p63 to carcinogenesis.
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Abstract
The transcription factor p63 is critically important for skin development and maintenance. Processes that require p63 include epidermal lineage commitment, epidermal differentiation, cell adhesion, and basement membrane formation. Not surprisingly, alterations in the p63 pathway underlie a subset of ectodermal dysplasias, developmental syndromes in which the skin and skin appendages do not develop normally. This review summarizes the current understanding of the role of p63 in normal development and ectodermal dysplasias.
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Affiliation(s)
- Maranke I Koster
- Department of Dermatology, Charles C. Gates Regenerative Medicine and Stem Cell Biology Program, University of Colorado Denver, Aurora, Colorado 80045, USA.
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