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Fischer M, Sammons MA. Determinants of p53 DNA binding, gene regulation, and cell fate decisions. Cell Death Differ 2024:10.1038/s41418-024-01326-1. [PMID: 38951700 DOI: 10.1038/s41418-024-01326-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 06/05/2024] [Accepted: 06/10/2024] [Indexed: 07/03/2024] Open
Abstract
The extent to which transcription factors read and respond to specific information content within short DNA sequences remains an important question that the tumor suppressor p53 is helping us answer. We discuss recent insights into how local information content at p53 binding sites might control modes of p53 target gene activation and cell fate decisions. Significant prior work has yielded data supporting two potential models of how p53 determines cell fate through its target genes: a selective target gene binding and activation model and a p53 level threshold model. Both of these models largely revolve around an analogy of whether p53 is acting in a "smart" or "dumb" manner. Here, we synthesize recent and past studies on p53 decoding of DNA sequence, chromatin context, and cellular signaling cascades to elicit variable cell fates critical in human development, homeostasis, and disease.
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Affiliation(s)
- Martin Fischer
- Computational Biology Group, Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstraße 11, 07745, Jena, Germany.
| | - Morgan A Sammons
- Department of Biological Sciences and The RNA Institute, The State University of New York at Albany, 1400 Washington Avenue, Albany, NY, 12222, USA.
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2
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Nano M, Montell DJ. Apoptotic signaling: Beyond cell death. Semin Cell Dev Biol 2024; 156:22-34. [PMID: 37988794 DOI: 10.1016/j.semcdb.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/02/2023] [Accepted: 11/04/2023] [Indexed: 11/23/2023]
Abstract
Apoptosis is the best described form of regulated cell death, and was, until relatively recently, considered irreversible once particular biochemical points-of-no-return were activated. In this manuscript, we examine the mechanisms cells use to escape from a self-amplifying death signaling module. We discuss the role of feedback, dynamics, propagation, and noise in apoptotic signaling. We conclude with a revised model for the role of apoptosis in animal development, homeostasis, and disease.
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Affiliation(s)
- Maddalena Nano
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA; Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA.
| | - Denise J Montell
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA; Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA.
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Rahmé R, Braun T. Venetoclax Combined with Intensive Chemotherapy: A New Hope for Refractory and/or Relapsed Acute Myeloid Leukemia? J Clin Med 2024; 13:549. [PMID: 38256681 PMCID: PMC10816428 DOI: 10.3390/jcm13020549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/08/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
Background. Primary resistance of acute myeloid leukemia (AML) to the conventional 3 + 7 intensive chemotherapy and relapses after first-line chemotherapy are two highly challenging clinical scenarios. In these cases, when allogeneic stem cell transplantation is feasible, patients are usually retreated with other chemotherapeutic regimens, as transplantation is still considered, nowadays, the only curative option. Methods. We discuss the mechanisms behind resistance to chemotherapy and offer a comprehensive review on current treatments of refractory/relapsed AML with a focus on novel approaches incorporating the BCL-2 inhibitor venetoclax. Results. Alas, complete remission rates after salvage chemotherapy remain relatively low, between 30 and 60% at best. More recently, the BCL-2 inhibitor venetoclax was combined either with hypomethylating agents or chemotherapy in refractory/relapsed patients. In particular, its combination with chemotherapy offered promising results by achieving higher rates of remission and bridging a substantial number of patients to transplantation. Conclusions. Venetoclax-based approaches might become, in the near future, the new standard of care for refractory/relapsed AML.
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Affiliation(s)
- Ramy Rahmé
- Hematology Department, Avicenne Hospital, Assistance Publique-Hôpitaux de Paris, 93000 Bobigny, France
- Faculty of Medicine, Université Sorbonne Paris Nord, 93017 Bobigny, France;
| | - Thorsten Braun
- Hematology Department, Avicenne Hospital, Assistance Publique-Hôpitaux de Paris, 93000 Bobigny, France
- Faculty of Medicine, Université Sorbonne Paris Nord, 93017 Bobigny, France;
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4
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Fisher EM, Greensmith L, Malaspina A, Fratta P, Hanna MG, Schiavo G, Isaacs AM, Orrell RW, Cunningham TJ, Arozena AA. Opinion: more mouse models and more translation needed for ALS. Mol Neurodegener 2023; 18:30. [PMID: 37143081 PMCID: PMC10161557 DOI: 10.1186/s13024-023-00619-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 04/11/2023] [Indexed: 05/06/2023] Open
Abstract
Amyotrophic lateral sclerosis is a complex disorder most of which is 'sporadic' of unknown origin but approximately 10% is familial, arising from single mutations in any of more than 30 genes. Thus, there are more than 30 familial ALS subtypes, with different, often unknown, molecular pathologies leading to a complex constellation of clinical phenotypes. We have mouse models for many genetic forms of the disorder, but these do not, on their own, necessarily show us the key pathological pathways at work in human patients. To date, we have no models for the 90% of ALS that is 'sporadic'. Potential therapies have been developed mainly using a limited set of mouse models, and through lack of alternatives, in the past these have been tested on patients regardless of aetiology. Cancer researchers have undertaken therapy development with similar challenges; they have responded by producing complex mouse models that have transformed understanding of pathological processes, and they have implemented patient stratification in multi-centre trials, leading to the effective translation of basic research findings to the clinic. ALS researchers have successfully adopted this combined approach, and now to increase our understanding of key disease pathologies, and our rate of progress for moving from mouse models to mechanism to ALS therapies we need more, innovative, complex mouse models to address specific questions.
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Affiliation(s)
- Elizabeth M.C. Fisher
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Linda Greensmith
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Andrea Malaspina
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Pietro Fratta
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Michael G. Hanna
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Giampietro Schiavo
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- UK Dementia Research Institute at UCL, London, WC1E 6BT UK
| | - Adrian M. Isaacs
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- UK Dementia Research Institute at UCL, London, WC1E 6BT UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Richard W. Orrell
- UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG UK
| | - Thomas J. Cunningham
- MRC Prion Unit at UCL, Courtauld Building, 33 Cleveland Street, London, W1W 7FF UK
| | - Abraham Acevedo Arozena
- Research Unit, Hospital Universitario de Canarias, ITB-ULL and CIBERNED, La Laguna, 38320 Spain
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Abstract
Mutations in the TP53 tumour suppressor gene are very frequent in cancer, and attempts to restore the functionality of p53 in tumours as a therapeutic strategy began decades ago. However, very few of these drug development programmes have reached late-stage clinical trials, and no p53-based therapeutics have been approved in the USA or Europe so far. This is probably because, as a nuclear transcription factor, p53 does not possess typical drug target features and has therefore long been considered undruggable. Nevertheless, several promising approaches towards p53-based therapy have emerged in recent years, including improved versions of earlier strategies and novel approaches to make undruggable targets druggable. Small molecules that can either protect p53 from its negative regulators or restore the functionality of mutant p53 proteins are gaining interest, and drugs tailored to specific types of p53 mutants are emerging. In parallel, there is renewed interest in gene therapy strategies and p53-based immunotherapy approaches. However, major concerns still remain to be addressed. This Review re-evaluates the efforts made towards targeting p53-dysfunctional cancers, and discusses the challenges encountered during clinical development.
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Affiliation(s)
- Ori Hassin
- grid.13992.300000 0004 0604 7563Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Moshe Oren
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
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Ma T, Zhou J, Li J, Chen Q. Hyaluronic Acid-modified Liposomes for Ursolic Acid-targeted Delivery Treat Lung Cancer Based on p53/ARTS-mediated Mitochondrial Apoptosis. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2023; 22:e131758. [PMID: 38116552 PMCID: PMC10728842 DOI: 10.5812/ijpr-131758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 02/08/2023] [Accepted: 02/20/2023] [Indexed: 12/21/2023]
Abstract
Background Chemotherapy drugs can cause drug resistance and other problems when treating lung cancer, which leads to treatment failure. Ursolic acid (UA) is used in formulations based on traditional Chinese medicine. UA has excellent anti-tumor effects, but they are limited by solubility and non-specificity to tumor cells. Objectives To overcome these issues, we created a novel hyaluronic acid (HA)-targeted liposome system for delivering UA (HA-Lipo/UA) to explore the targeting and anti-tumor effects of UA. Methods We constructed the HA-Lipo/UA delivery system by the thin film hydration method. The uptake and localization of UA were detected by flow cytometry and microscope. Cell proliferation of A549 cells was detected by MTT assays. Apoptosis and reactive oxygen species (ROS) expression of A549 cells were also evaluated after being treated with HA-Lipo/UA. Western blot analysis evaluated the anti-tumor mechanism of HA-Lipo/UA. Results HA-Lipo/UA exhibited favorable targeting of the cluster of differentiation (CD)44-overexpressing A549 cells. HA-Lipo/UA exhibited significant inhibition of the proliferation of A549 cells and induced their apoptosis compared with the corresponding monotherapies. HA-Lipo/UA induced overexpression of reactive oxygen species and upregulated expression of p53 and apoptosis-related protein in the transforming growth factor-β signaling (ARTS) pathway, which induced cytochrome-c release, activation of caspase-3, and promoted mitochondrial apoptosis in A549 cells. Conclusions Taken together, these data suggested that HA-Lipo/UA could be used to target tumor cells.
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Affiliation(s)
- TingTing Ma
- Department of Infectious Diseases, Ningbo Yinzhou No.2 Hospital, Ningbo, China
| | - Jiasi Zhou
- Department of Respiratory and Critical Care Medicine, Ningbo Yinzhou No.2 Hospital, Ningbo, China
| | - Jiajie Li
- The Affiliated Hospital of Medical School, University of Ningbo, Ningbo, China
| | - Qi Chen
- Department of Infectious Diseases, Ningbo Yinzhou No.2 Hospital, Ningbo, China
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Bharti V, Watkins R, Kumar A, Shattuck-Brandt RL, Mossing A, Mittra A, Shen C, Tsung A, Davies AE, Hanel W, Reneau JC, Chung C, Sizemore GM, Richmond A, Weiss VL, Vilgelm AE. BCL-xL inhibition potentiates cancer therapies by redirecting the outcome of p53 activation from senescence to apoptosis. Cell Rep 2022; 41:111826. [PMID: 36543138 PMCID: PMC10030045 DOI: 10.1016/j.celrep.2022.111826] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 10/26/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
Cancer therapies trigger diverse cellular responses, ranging from apoptotic death to acquisition of persistent therapy-refractory states such as senescence. Tipping the balance toward apoptosis could improve treatment outcomes regardless of therapeutic agent or malignancy. We find that inhibition of the mitochondrial protein BCL-xL increases the propensity of cancer cells to die after treatment with a broad array of oncology drugs, including mitotic inhibitors and chemotherapy. Functional precision oncology and omics analyses suggest that BCL-xL inhibition redirects the outcome of p53 transcriptional response from senescence to apoptosis, which likely occurs via caspase-dependent down-modulation of p21 and downstream cytostatic proteins. Consequently, addition of a BCL-2/xL inhibitor strongly improves melanoma response to the senescence-inducing drug targeting mitotic kinase Aurora kinase A (AURKA) in mice and patient-derived organoids. This study shows a crosstalk between the mitochondrial apoptotic pathway and cell cycle regulation that can be targeted to augment therapeutic efficacy in cancers with wild-type p53.
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Affiliation(s)
- Vijaya Bharti
- Department of Pathology, The Ohio State University, 460 W. 12th Avenue, Office 496, Columbus, OH, USA; The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA
| | - Reese Watkins
- Department of Pathology, The Ohio State University, 460 W. 12th Avenue, Office 496, Columbus, OH, USA; The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA
| | - Amrendra Kumar
- Department of Pathology, The Ohio State University, 460 W. 12th Avenue, Office 496, Columbus, OH, USA; The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA
| | - Rebecca L Shattuck-Brandt
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Alexis Mossing
- The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA; Department of Radiation Oncology, The Ohio State University, Columbus, OH, USA
| | - Arjun Mittra
- The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA; Division of Medical Oncology, The Ohio State University, Columbus, OH, USA
| | - Chengli Shen
- Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Allan Tsung
- Department of Surgery, University of Virginia, Charlottesville, VA, USA
| | - Alexander E Davies
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Walter Hanel
- The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA
| | - John C Reneau
- The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA
| | - Catherine Chung
- Department of Pathology, The Ohio State University, 460 W. 12th Avenue, Office 496, Columbus, OH, USA; The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA
| | - Gina M Sizemore
- The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA; Department of Radiation Oncology, The Ohio State University, Columbus, OH, USA
| | - Ann Richmond
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Vivian L Weiss
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Anna E Vilgelm
- Department of Pathology, The Ohio State University, 460 W. 12th Avenue, Office 496, Columbus, OH, USA; The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, Columbus, OH, USA.
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Grubb T, Maganti S, Krill-Burger JM, Fraser C, Stransky L, Radivoyevitch T, Sarosiek KA, Vazquez F, Kaelin WG, Chakraborty AA. A Mesenchymal Tumor Cell State Confers Increased Dependency on the BCL-XL Antiapoptotic Protein in Kidney Cancer. Clin Cancer Res 2022; 28:4689-4701. [PMID: 35776130 PMCID: PMC9633392 DOI: 10.1158/1078-0432.ccr-22-0669] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/07/2022] [Accepted: 06/28/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE Advanced/metastatic forms of clear-cell renal cell carcinomas (ccRCC) have limited therapeutic options. Genome-wide genetic screens have identified cellular dependencies in many cancers. Using the Broad Institute/Novartis combined short hairpin RNA (shRNA) dataset, and cross-validation with the CRISPR/Cas9 DepMap (21Q3) dataset, we sought therapeutically actionable dependencies in kidney lineage cancers. EXPERIMENTAL DESIGN We identified preferential genetic dependencies in kidney cancer cells versus other lineages. BCL2L1, which encodes the BCL-XL antiapoptotic protein, scored as the top actionable dependency. We validated this finding using genetic and pharmacologic tools in a panel of ccRCC cell lines. Select BCL-XL-dependent (versus independent) cell lines were then transcriptionally profiled to identify biomarkers and mechanistic drivers of BCL-XL dependence. Cell-based studies (in vitro and in vivo) and clinical validations were used to address physiologic relevance. RESULTS Inactivation of BCL-XL, but not BCL-2, led to fitness defects in renal cancer cells, and sensitized them to chemotherapeutics. Transcriptomic profiling identified a "BCL-XL dependency" signature, including an elevated mesenchymal gene signature. A mesenchymal state was both necessary and sufficient to confer increased BCL-XL dependence. The "BCL-XL dependency" signature was observed in approximately 30% of human ccRCCs, which were also associated with worse clinical outcomes. Finally, an orally bioavailable BCL-XL inhibitor, A-1331852, showed antitumor efficacy in vivo. CONCLUSIONS Our studies uncovered an unexpected link between cell state and BCL-XL dependence in ccRCC. Therapeutic agents that specifically target BCL-XL are available. Our work justifies testing the utility of BCL-XL blockade to target, likely, a clinically aggressive subset of human kidney cancers. See related commentary by Wang et al., p. 4600.
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Affiliation(s)
- Treg Grubb
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Smruthi Maganti
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | - Cameron Fraser
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.,Molecular and Integrative Physiology Program, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Laura Stransky
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Tomas Radivoyevitch
- Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kristopher A. Sarosiek
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.,Molecular and Integrative Physiology Program, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | | | - William G. Kaelin
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02215, USA.,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.,Corresponding Authors: William G. Kaelin, Jr., Dana-Farber Cancer Institute and Harvard Medical School, 450 Brookline Ave, Boston, MA 02115. . Phone: 617-632-3975; Abhishek A. Chakraborty, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195. . Phone: 216-445-6620
| | - Abhishek A. Chakraborty
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA.,Corresponding Authors: William G. Kaelin, Jr., Dana-Farber Cancer Institute and Harvard Medical School, 450 Brookline Ave, Boston, MA 02115. . Phone: 617-632-3975; Abhishek A. Chakraborty, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195. . Phone: 216-445-6620
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L'Hôte V, Mann C, Thuret JY. From the divergence of senescent cell fates to mechanisms and selectivity of senolytic drugs. Open Biol 2022; 12:220171. [PMID: 36128715 PMCID: PMC9490338 DOI: 10.1098/rsob.220171] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Senescence is a cellular stress response that involves prolonged cell survival, a quasi-irreversible proliferative arrest and a modification of the transcriptome that sometimes includes inflammatory gene expression. Senescent cells are resistant to apoptosis, and if not eliminated by the immune system they may accumulate and lead to chronic inflammation and tissue dysfunction. Senolytics are drugs that selectively induce cell death in senescent cells, but not in proliferative or quiescent cells, and they have proved a viable therapeutic approach in multiple mouse models of pathologies in which senescence is implicated. As the catalogue of senolytic compounds is expanding, novel survival strategies of senescent cells are uncovered, and variations in sensitivity to senolysis between different types of senescent cells emerge. We propose herein a mechanistic classification of senolytic drugs, based on the level at which they target senescent cells: directly disrupting BH3 protein networks that are reorganized upon senescence induction; downregulating survival-associated pathways essential to senescent cells; or modulating homeostatic processes whose regulation is challenged in senescence. With this approach, we highlight the important diversity of senescent cells in terms of physiology and pathways of apoptosis suppression, and we describe possible avenues for the development of more selective senolytics.
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Affiliation(s)
- Valentin L'Hôte
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Carl Mann
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Jean-Yves Thuret
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette cedex, France
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10
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Chang H, Wang Q, Meng X, Chen X, Deng Y, Li L, Yang Y, Song G, Jia H. Effect of Titanium Dioxide Nanoparticles on Mammalian Cell Cycle In Vitro: A Systematic Review and Meta-Analysis. Chem Res Toxicol 2022; 35:1435-1456. [PMID: 35998370 DOI: 10.1021/acs.chemrestox.1c00402] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although most studies that explore the cytotoxicity of titanium dioxide nanoparticles (nano-TiO2) have focused on cell viability and oxidative stress, the cell cycle, a basic process of cell life, can also be affected. However, the results on the effects of nano-TiO2 on mammalian cell cycle are still inconsistent. A systematic review and meta-analysis were therefore performed in this research based on the effects of nano-TiO2 on the mammalian cell cycle in vitro to explore whether nano-TiO2 can induce cell cycle arrest. Meanwhile, the impact of physicochemical properties of nano-TiO2 on the cell cycle in vitro was investigated, and the response of normal cells and cancer cells was compared. A total of 33 articles met the eligibility criteria after screening. We used Review Manager 5.4 and Stata 15.1 for analysis. The results showed an increased percentage of cells in the sub-G1 phase and an upregulation of the p53 gene after being exposed to nano-TiO2. Nevertheless, nano-TiO2 had no effect on cell percentage in other phases of the cell cycle. Furthermore, subgroup analysis revealed that the cell percentage in both the sub-G1 phase of normal cells and S phase of cancer cells were significantly increased under anatase-form nano-TiO2 treatment. Moreover, nano-TiO2 with a particle size <25 nm or exposure duration of nano-TiO2 more than 24 h induced an increased percentage of normal cells in the sub-G1 phase. In addition, the cell cycle of cancer cells was arrested in the S phase no matter if the exposure duration of nano-TiO2 was more than 24 h or the exposure concentration was over 50 μg/mL. In conclusion, this study demonstrated that nano-TiO2 disrupted the cell cycle in vitro. The cell cycle arrest induced by nano-TiO2 varies with cell status and physicochemical properties of nano-TiO2.
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Affiliation(s)
- Hongmei Chang
- Department of Preventive Medicine/the Key Laboratories for Xinjiang Endemic and Ethnic Diseases, School of Medicine, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Qianqian Wang
- Department of Preventive Medicine/the Key Laboratories for Xinjiang Endemic and Ethnic Diseases, School of Medicine, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Xiaojia Meng
- Department of Preventive Medicine/the Key Laboratories for Xinjiang Endemic and Ethnic Diseases, School of Medicine, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Xinyu Chen
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, 210019 Nanjing, China
| | - Yaxin Deng
- Department of Preventive Medicine/the Key Laboratories for Xinjiang Endemic and Ethnic Diseases, School of Medicine, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Li Li
- Department of Preventive Medicine/the Key Laboratories for Xinjiang Endemic and Ethnic Diseases, School of Medicine, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Yaqian Yang
- Department of Preventive Medicine/the Key Laboratories for Xinjiang Endemic and Ethnic Diseases, School of Medicine, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Guanling Song
- Department of Preventive Medicine/the Key Laboratories for Xinjiang Endemic and Ethnic Diseases, School of Medicine, Shihezi University, Shihezi 832003, Xinjiang, China
| | - Huaimiao Jia
- Department of Endemic Disease, Shihezi Center for Disease Control and Prevention, Shihezi 832003, Xinjiang, China
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11
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Mechanism of vitamin B6 benzoyl hydrazone platinum(II) complexes overcomes multidrug resistance in lung cancer. Eur J Med Chem 2022; 237:114415. [DOI: 10.1016/j.ejmech.2022.114415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/20/2022] [Accepted: 04/24/2022] [Indexed: 11/16/2022]
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Lee AH, Mejia Peña C, Dawson MR. Comparing the Secretomes of Chemorefractory and Chemoresistant Ovarian Cancer Cell Populations. Cancers (Basel) 2022; 14:1418. [PMID: 35326569 PMCID: PMC8946241 DOI: 10.3390/cancers14061418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/04/2022] [Accepted: 03/08/2022] [Indexed: 12/13/2022] Open
Abstract
High-grade serous ovarian cancer (HGSOC) constitutes the majority of all ovarian cancer cases and has staggering rates of both refractory and recurrent disease. While most patients respond to the initial treatment with paclitaxel and platinum-based drugs, up to 25% do not, and of the remaining that do, 75% experience disease recurrence within the subsequent two years. Intrinsic resistance in refractory cases is driven by environmental stressors like tumor hypoxia which alter the tumor microenvironment to promote cancer progression and resistance to anticancer drugs. Recurrent disease describes the acquisition of chemoresistance whereby cancer cells survive the initial exposure to chemotherapy and develop adaptations to enhance their chances of surviving subsequent treatments. Of the environmental stressors cancer cells endure, exposure to hypoxia has been identified as a potent trigger and priming agent for the development of chemoresistance. Both in the presence of the stress of hypoxia or the therapeutic stress of chemotherapy, cancer cells manage to cope and develop adaptations which prime populations to survive in future stress. One adaptation is the modification in the secretome. Chemoresistance is associated with translational reprogramming for increased protein synthesis, ribosome biogenesis, and vesicle trafficking. This leads to increased production of soluble proteins and extracellular vesicles (EVs) involved in autocrine and paracrine signaling processes. Numerous studies have demonstrated that these factors are largely altered between the secretomes of chemosensitive and chemoresistant patients. Such factors include cytokines, growth factors, EVs, and EV-encapsulated microRNAs (miRNAs), which serve to induce invasive molecular, biophysical, and chemoresistant phenotypes in neighboring normal and cancer cells. This review examines the modifications in the secretome of distinct chemoresistant ovarian cancer cell populations and specific secreted factors, which may serve as candidate biomarkers for aggressive and chemoresistant cancers.
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Affiliation(s)
- Amy H. Lee
- Center for Biomedical Engineering, Brown University, Providence, RI 02912, USA;
| | - Carolina Mejia Peña
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA;
| | - Michelle R. Dawson
- Center for Biomedical Engineering, Brown University, Providence, RI 02912, USA;
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA;
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Klimovich B, Meyer L, Merle N, Neumann M, König AM, Ananikidis N, Keber CU, Elmshäuser S, Timofeev O, Stiewe T. Partial p53 reactivation is sufficient to induce cancer regression. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2022; 41:80. [PMID: 35232479 PMCID: PMC8889716 DOI: 10.1186/s13046-022-02269-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 01/20/2022] [Indexed: 01/21/2023]
Abstract
Background Impaired p53 function is one of the central molecular features of a tumor cell and even a partial reduction in p53 activity can increase the cancer risk in mice and men. From a therapeutic perspective it is noteworthy that tumor cells often become addicted to the absence of p53 providing a rationale for developing p53 reactivating compounds to treat cancer patients. Unfortunately, many of the compounds that are currently undergoing preclinical and clinical testing fail to fully reactivate mutant p53 proteins, raising the crucial question: how much p53 activity is needed to elicit a therapeutic effect? Methods We have genetically modelled partial p53 reactivation using knock-in mice with inducible expression of the p53 variant E177R. This variant has a reduced ability to bind and transactivate target genes and consequently causes moderate cancer susceptibility. We have generated different syngeneically transplanted and autochthonous mouse models of p53-deficient acute myeloid leukemia and B or T cell lymphoma. After cancer manifestation we have activated E177R expression and analyzed the in vivo therapy response by bioluminescence or magnetic resonance imaging. The molecular response was further characterized in vitro by assays for gene expression, proliferation, senescence, differentiation, apoptosis and clonogenic growth. Results We report the conceptually intriguing observation that the p53 variant E177R, which promotes de novo leukemia and lymphoma formation, inhibits proliferation and viability, induces immune cell infiltration and triggers cancer regression in vivo when introduced into p53-deficient leukemia and lymphomas. p53-deficient cancer cells proved to be so addicted to the absence of p53 that even the low-level activity of E177R is detrimental to cancer growth. Conclusions The observation that a partial loss-of-function p53 variant promotes tumorigenesis in one setting and induces regression in another, underlines the highly context-specific effects of individual p53 mutants. It further highlights the exquisite sensitivity of cancer cells to even small changes in p53 activity and reveals that changes in activity level are more important than the absolute level. As such, the study encourages ongoing research efforts into mutant p53 reactivating drugs by providing genetic proof-of-principle evidence that incomplete p53 reactivation may suffice to elicit a therapeutic response. Supplementary Information The online version contains supplementary material available at 10.1186/s13046-022-02269-6.
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Affiliation(s)
- Boris Klimovich
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany
| | - Laura Meyer
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany
| | - Nastasja Merle
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany
| | - Michelle Neumann
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany
| | - Alexander M König
- Clinic of Diagnostic and Interventional Radiology, Core Facility 7T-small animal MRI, Philipps-University, Marburg, Germany
| | - Nikolaos Ananikidis
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany
| | - Corinna U Keber
- Institute for Pathology, University Hospital Marburg, Philipps-University, Marburg, Germany
| | - Sabrina Elmshäuser
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany
| | - Oleg Timofeev
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany. .,German Center for Lung Research (DZL), Philipps-University, Marburg, Germany.
| | - Thorsten Stiewe
- Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany. .,German Center for Lung Research (DZL), Philipps-University, Marburg, Germany. .,Genomics Core Facility, Philipps-University, Marburg, Germany.
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14
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Kung CP, Weber JD. It’s Getting Complicated—A Fresh Look at p53-MDM2-ARF Triangle in Tumorigenesis and Cancer Therapy. Front Cell Dev Biol 2022; 10:818744. [PMID: 35155432 PMCID: PMC8833255 DOI: 10.3389/fcell.2022.818744] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/07/2022] [Indexed: 01/31/2023] Open
Abstract
Anti-tumorigenic mechanisms mediated by the tumor suppressor p53, upon oncogenic stresses, are our bodies’ greatest weapons to battle against cancer onset and development. Consequently, factors that possess significant p53-regulating activities have been subjects of serious interest from the cancer research community. Among them, MDM2 and ARF are considered the most influential p53 regulators due to their abilities to inhibit and activate p53 functions, respectively. MDM2 inhibits p53 by promoting ubiquitination and proteasome-mediated degradation of p53, while ARF activates p53 by physically interacting with MDM2 to block its access to p53. This conventional understanding of p53-MDM2-ARF functional triangle have guided the direction of p53 research, as well as the development of p53-based therapeutic strategies for the last 30 years. Our increasing knowledge of this triangle during this time, especially through identification of p53-independent functions of MDM2 and ARF, have uncovered many under-appreciated molecular mechanisms connecting these three proteins. Through recognizing both antagonizing and synergizing relationships among them, our consideration for harnessing these relationships to develop effective cancer therapies needs an update accordingly. In this review, we will re-visit the conventional wisdom regarding p53-MDM2-ARF tumor-regulating mechanisms, highlight impactful studies contributing to the modern look of their relationships, and summarize ongoing efforts to target this pathway for effective cancer treatments. A refreshed appreciation of p53-MDM2-ARF network can bring innovative approaches to develop new generations of genetically-informed and clinically-effective cancer therapies.
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Affiliation(s)
- Che-Pei Kung
- ICCE Institute, St. Louis, MO, United States
- Division of Molecular Oncology, Department of Medicine, St. Louis, MO, United States
- *Correspondence: Che-Pei Kung, ; Jason D. Weber,
| | - Jason D. Weber
- ICCE Institute, St. Louis, MO, United States
- Division of Molecular Oncology, Department of Medicine, St. Louis, MO, United States
- Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, United States
- *Correspondence: Che-Pei Kung, ; Jason D. Weber,
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15
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Wang S, Xie Z, Wu Z. Establishment and Validation of a Ferroptosis-Related Gene Signature to Predict Overall Survival in Lung Adenocarcinoma. Front Genet 2022; 12:793636. [PMID: 35096011 PMCID: PMC8795866 DOI: 10.3389/fgene.2021.793636] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/01/2021] [Indexed: 12/16/2022] Open
Abstract
Background: Lung adenocarcinoma (LUAD) is the most common and lethal subtype of lung cancer. Ferroptosis, an iron-dependent form of regulated cell death, has emerged as a target in cancer therapy. However, the prognostic value of ferroptosis-related genes (FRGs)x in LUAD remains to be explored. Methods: In this study, we used RNA sequencing data and relevant clinical data from The Cancer Genome Atlas (TCGA) dataset and Gene Expression Omnibus (GEO) dataset to construct and validate a prognostic FRG signature for overall survival (OS) in LUAD patients and defined potential biomarkers for ferroptosis-related tumor therapy. Results: A total of 86 differentially expressed FRGs were identified from LUAD tumor tissues versus normal tissues, of which 15 FRGs were significantly associated with OS in the survival analysis. Through the LASSO Cox regression analysis, a prognostic signature including 11 FRGs was established to predict OS in the TCGA tumor cohort. Based on the median value of risk scores calculated according to the signature, patients were divided into high-risk and low-risk groups. Kaplan–Meier analysis indicated that the high-risk group had a poorer OS than the low-risk group. The area under the curve of this signature was 0.74 in the TCGA tumor set, showing good discrimination. In the GEO validation set, the prognostic signature also had good predictive performance. Functional enrichment analysis showed that some immune-associated gene sets were significantly differently enriched in two risk groups. Conclusion: Our study unearthed a novel ferroptosis-related gene signature for predicting the prognosis of LUAD, and the signature may provide useful prognostic biomarkers and potential treatment targets.
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Affiliation(s)
- Su Wang
- Department of Emergency Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhen Xie
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zenghong Wu
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Zenghong Wu,
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16
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Bartalucci N, Galluzzi L. Philadelphia-negative myeloproliferative neoplasms: From origins to new perspectives. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2022; 366:ix-xx. [PMID: 35153008 DOI: 10.1016/s1937-6448(22)00019-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Affiliation(s)
- Niccolò Bartalucci
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; DENOThe Excellence Center, University of Florence, Florence, Italy.
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, United States; Sandra and Edward Meyer Cancer Center, New York, NY, United States; Caryl and Israel Englander Institute for Precision Medicine, New York, NY, United States; Department of Dermatology, Yale School of Medicine, New Haven, CT, United States; Université de Paris, Paris, France.
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Arafat EA, Youssef EMI, Khalaf HA. The possible alleviating effect of garlic supplement on the neural retina in a rat model of hypercholesterolemia: a histological and immunohistochemical study. Eur J Histochem 2021; 65:3322. [PMID: 34911286 PMCID: PMC8696193 DOI: 10.4081/ejh.2021.3322] [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: 09/04/2021] [Accepted: 12/01/2021] [Indexed: 11/23/2022] Open
Abstract
The purpose of this work was to prove that oxidative stress is the main mechanism responsible for retinal neurodegenerative changes, subsequent apoptosis, and inflammatory cytokine release in rats fed with a high cholesterol diet (HCD) and determine the role of garlic in alleviating these changes. Forty rats were equally divided into four groups: control, garlic-treated (positive control), HCD, and HCD + garlic-treated (HCD + G). By the end of the experiment (24 weeks) blood samples were collected for assessment of serum lipid profile, oxidative stress parameters, and plasma levels of IL-6 and TNF-α. Both eyes of the rats were enucleated; one was used for light microscopic examination and the other for electron microscopic examination. There was a significant increase in the levels of serum lipids, oxidative stress parameters, IL-6 and TNF-α, and area of expression of caspase-3 in the HCD group compared to both the control and HCD + G groups. Histological examination revealed degenerative changes in all layers of the neural retina in the HCD group. Garlic administration resulted in a significant improvement in the biochemical, immunohistochemical, and histological characteristics of hypercholesterolemic rats. These findings support the hypotheses that garlic has strong antioxidant, anti-apoptotic, and anti-inflammatory properties. Garlic ameliorates the neurodegenerative changes in the neural retina of hypercholesteremic rats.
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Affiliation(s)
- Eetmad A Arafat
- Histology and Cell Biology Department, Faculty of Medicine, Mansoura University, Mansoura.
| | - Eman M I Youssef
- Department of Biochemistry, Faculty of Medicine, Al-Azhar University, Cairo.
| | - Hanaa A Khalaf
- Histology and Cell Biology Department, Faculty of Medicine, Mansoura University, Mansoura.
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The p53 transcriptional response across tumor types reveals core and senescence-specific signatures modulated by long noncoding RNAs. Proc Natl Acad Sci U S A 2021; 118:2025539118. [PMID: 34326251 PMCID: PMC8346867 DOI: 10.1073/pnas.2025539118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The work by Tesfaye and colleagues defines universal and tumor type–specific features of the p53 tumor suppressor transcriptional network. This study determines a “core” signature of the p53 response across different oncogenic contexts, which defines a universal set of p53 target genes. In addition, this study clarifies the basis for outcome specificity downstream of p53 activation in different oncogenic contexts. We observe that while apoptosis in lymphoma cells is not primarily determined by p53’s transcriptional activity, p53 indirectly promotes senescence in lung adenocarcinoma and sarcoma cells by activating the cis-regulatory long noncoding RNA Pvt1b, which represses Myc levels and its proliferative function. The p53 pathway is a universal tumor suppressor mechanism that limits tumor progression by triggering apoptosis or permanent cell cycle arrest, called senescence. In recent years, efforts to reactivate p53 function in cancer have proven to be a successful therapeutic strategy in murine models and have gained traction with the development of a range of small molecules targeting mutant p53. However, knowledge of the downstream mediators of p53 reactivation in different oncogenic contexts has been limited. Here, we utilized a panel of murine cancer cell lines from three distinct tumor types susceptible to alternative outcomes following p53 restoration to define unique and shared p53 transcriptional signatures. While we found that the majority of p53-bound sites and p53-responsive transcripts are tumor-type specific, analysis of shared targets identified a core signature of genes activated by p53 across all contexts. Furthermore, we identified repression of E2F and Myc target genes as a key feature of senescence. Characterization of p53-induced transcripts revealed core and senescence-specific long noncoding RNAs (lncRNAs) that are predominantly chromatin associated and whose production is coupled to cis-regulatory activities. Functional investigation of the contributions of p53-induced lncRNAs to p53-dependent outcomes highlighted Pvt1b, the p53-dependent isoform of Pvt1, as a mediator of p53-dependent senescence via Myc repression. Inhibition of Pvt1b led to decreased activation of senescence markers and increased levels of markers of proliferation. These findings shed light on the core and outcome-specific p53 restoration signatures across different oncogenic contexts and underscore the key role of the p53-Pvt1b-Myc regulatory axis in mediating proliferative arrest.
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