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Cameron DP, Sornkom J, Alsahafi S, Drygin D, Poortinga G, McArthur GA, Hein N, Hannan R, Panov KI. CX-5461 Preferentially Induces Top2α-Dependent DNA Breaks at Ribosomal DNA Loci. Biomedicines 2024; 12:1514. [PMID: 39062087 PMCID: PMC11275095 DOI: 10.3390/biomedicines12071514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 06/21/2024] [Accepted: 06/22/2024] [Indexed: 07/28/2024] Open
Abstract
While genotoxic chemotherapeutic agents are among the most effective tools to combat cancer, they are often associated with severe adverse effects caused by indiscriminate DNA damage in non-tumor tissue as well as increased risk of secondary carcinogenesis. This study builds on our previous work demonstrating that the RNA Polymerase I (Pol I) transcription inhibitor CX-5461 elicits a non-canonical DNA damage response and our discovery of a critical role for Topoisomerase 2α (Top2α) in the initiation of Pol I-dependent transcription. Here, we identify Top2α as a mediator of CX-5461 response in the murine Eµ-Myc B lymphoma model whereby sensitivity to CX-5461 is dependent on cellular Top2α expression/activity. Most strikingly, and in contrast to canonical Top2α poisons, we found that the Top2α-dependent DNA damage induced by CX-5461 is preferentially localized at the ribosomal DNA (rDNA) promoter region, thereby highlighting CX-5461 as a loci-specific DNA damaging agent. This mechanism underpins the efficacy of CX-5461 against certain types of cancer and can be used to develop effective non-genotoxic anticancer drugs.
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Affiliation(s)
- Donald P. Cameron
- ACRF Department of Cancer Biology and Therapeutics, Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The College of Health and Medicine, The Australian National University, Canberra, ACT 2601, Australia; (D.P.C.); (N.H.)
- Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.S.); (G.P.)
| | - Jirawas Sornkom
- Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.S.); (G.P.)
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3000, Australia;
| | - Sameerh Alsahafi
- School of Biological Sciences, Queen’s University Belfast, Belfast BT9 5DL, UK;
| | - Denis Drygin
- Pimera Therapeutics, 7875 Highland Village Place, Suite 412, San Diego, CA 92129, USA;
| | - Gretchen Poortinga
- Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.S.); (G.P.)
| | - Grant A. McArthur
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3000, Australia;
| | - Nadine Hein
- ACRF Department of Cancer Biology and Therapeutics, Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The College of Health and Medicine, The Australian National University, Canberra, ACT 2601, Australia; (D.P.C.); (N.H.)
| | - Ross Hannan
- ACRF Department of Cancer Biology and Therapeutics, Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The College of Health and Medicine, The Australian National University, Canberra, ACT 2601, Australia; (D.P.C.); (N.H.)
- Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia; (J.S.); (G.P.)
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC 3053, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Konstantin I. Panov
- School of Biological Sciences, Queen’s University Belfast, Belfast BT9 5DL, UK;
- Patrick G Johnston Centre for Cancer Research, Queen’s University Belfast, Belfast BT9 7AE, UK
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2
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Koll FJ, Metzger E, Hamann J, Ramos-Triguero A, Bankov K, Köllermann J, Döring C, Chun FKH, Schüle R, Wild PJ, Reis H. Overexpression of KMT9α Is Associated with Aggressive Basal-like Muscle-Invasive Bladder Cancer. Cells 2023; 12:cells12040589. [PMID: 36831256 PMCID: PMC9954512 DOI: 10.3390/cells12040589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Muscle-invasive bladder cancer (MIBC) is associated with limited response rates to systemic therapy leading to a significant risk of recurrence and death. A recently discovered histone methyltransferase KMT9, acts as an epigenetic regulator of carcinogenesis in different tumor entities. In this study, we investigated the presence and association of histological and molecular subtypes and their impact on the survival of KMT9α in MIBC. We performed an immunohistochemical (IHC) analysis of KMT9α in 135 MIBC patients undergoing radical cystectomy. KMT9α was significantly overexpressed in the nucleus in MIBC compared to normal urothelium and low-grade urothelial cancer. Using the HTG transcriptome panel, we assessed mRNA expression profiles to determine molecular subtypes and identify differentially expressed genes. Patients with higher nuclear and nucleolar KMT9α expression showed basal/squamous urothelial cancer characteristics confirmed by IHC and differentially upregulated KRT14 expression. We identified a subset of patients with nucleolar expression of KMT9α, which was associated with an increased risk of death in uni- and multivariate analyses (HR 2.28, 95%CI 1.28-4.03, p = 0.005). In conclusion, basal-like MIBC and the squamous histological subtype are associated with high nuclear KMT9α expression. The association with poor survival makes it a potential target for the treatment of bladder cancer.
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Affiliation(s)
- Florestan J. Koll
- Department of Urology, University Hospital Frankfurt, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
- Frankfurt Cancer Institute (FCI), University Hospital, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
- University Cancer Center (UCT) Frankfurt, University Hospital, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
- Correspondence: ; Tel.: +49-69-6301-86496
| | - Eric Metzger
- Klinik für Urologie und Zentrale Klinische Forschung, Klinikum der Albert-Ludwigs-Universität Freiburg, 79106 Freiburg, Germany
- Deutsches Konsortium für Translationale Krebsforschung (DKTK), 79106 Freiburg, Germany
| | - Jana Hamann
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, 60590 Frankfurt am Main, Germany
| | - Anna Ramos-Triguero
- Klinik für Urologie und Zentrale Klinische Forschung, Klinikum der Albert-Ludwigs-Universität Freiburg, 79106 Freiburg, Germany
| | - Katrin Bankov
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, 60590 Frankfurt am Main, Germany
| | - Jens Köllermann
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, 60590 Frankfurt am Main, Germany
| | - Claudia Döring
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, 60590 Frankfurt am Main, Germany
| | - Felix K. H. Chun
- Department of Urology, University Hospital Frankfurt, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
| | - Roland Schüle
- Klinik für Urologie und Zentrale Klinische Forschung, Klinikum der Albert-Ludwigs-Universität Freiburg, 79106 Freiburg, Germany
- Deutsches Konsortium für Translationale Krebsforschung (DKTK), 79106 Freiburg, Germany
| | - Peter J. Wild
- Frankfurt Cancer Institute (FCI), University Hospital, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, 60590 Frankfurt am Main, Germany
- Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main, Germany
| | - Henning Reis
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, 60590 Frankfurt am Main, Germany
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Wang B, Gao J, Zhao Z, Zhong X, Cui H, Hou H, Zhang Y, Zheng J, Di J, Liu Y. Identification of a small-molecule RPL11 mimetic that inhibits tumor growth by targeting MDM2-p53 pathway. Mol Med 2022; 28:109. [PMID: 36071402 PMCID: PMC9450376 DOI: 10.1186/s10020-022-00537-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/29/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Targeting ribosome biogenesis to activate p53 has recently emerged as a therapeutic strategy in human cancer. Among various ribosomal proteins, RPL11 centralizes the nucleolar stress-sensing pathway by binding MDM2, leading to MDM2 inactivation and p53 activation. Therefore, the identification of MDM2-binding RPL11-mimetics would be valuable for anti-cancer therapeutics. METHODS Based on the crystal structure of the interface between RPL11 and MDM2, we have identified 15 potential allosteric modulators of MDM2 through the virtual screening. RESULTS One of these compounds, named S9, directly binds MDM2 and competitively inhibits the interaction between RPL11 and MDM2, leading to p53 stabilization and activation. Moreover, S9 inhibits cancer cell proliferation in vitro and in vivo. Mechanistic study reveals that MDM2 is required for S9-induced G2 cell cycle arrest and apoptosis, whereas p53 contributes to S9-induced apoptosis. CONCLUSIONS Putting together, S9 may serve as a lead compound for the development of an anticancer drug that specifically targets RPL11-MDM2-p53 pathway.
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Affiliation(s)
- Bingwu Wang
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.,Department of Oncology, The Second Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221000, China
| | - Jian Gao
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China.,Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, 221000, China
| | - Zhongjun Zhao
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Xuefei Zhong
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Hao Cui
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Hui Hou
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China.,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Yanping Zhang
- Department of Radiation and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, 450 West Drive, Chapel Hill, USA
| | - Junnian Zheng
- Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China. .,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China.
| | - Jiehui Di
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China. .,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China. .,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China.
| | - Yong Liu
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, China. .,Center of Clinical Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China. .,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, China. .,The State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
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4
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Temaj G, Saha S, Dragusha S, Ejupi V, Buttari B, Profumo E, Beqa L, Saso L. Ribosomopathies and cancer: pharmacological implications. Expert Rev Clin Pharmacol 2022; 15:729-746. [PMID: 35787725 DOI: 10.1080/17512433.2022.2098110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION The ribosome is a ribonucleoprotein organelle responsible for protein synthesis, and its biogenesis is a highly coordinated process that involves many macromolecular components. Any acquired or inherited impairment in ribosome biogenesis or ribosomopathies is associated with the development of different cancers and rare genetic diseases. Interference with multiple steps of protein synthesis has been shown to promote tumor cell death. AREAS COVERED We discuss the current insights about impaired ribosome biogenesis and their secondary consequences on protein synthesis, transcriptional and translational responses, proteotoxic stress, and other metabolic pathways associated with cancer and rare diseases. Studies investigating the modulation of different therapeutic chemical entities targeting cancer in in vitro and in vivo models have also been detailed. EXPERT OPINION Despite the association between inherited mutations affecting ribosome biogenesis and cancer biology, the development of therapeutics targeting the essential cellular machinery has only started to emerge. New chemical entities should be designed to modulate different checkpoints (translating oncoproteins, dysregulation of specific ribosome-assembly machinery, ribosomal stress, and rewiring ribosomal functions). Although safe and effective therapies are lacking, consideration should also be given to using existing drugs alone or in combination for long-term safety, with known risks for feasibility in clinical trials and synergistic effects.
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Affiliation(s)
| | - Sarmistha Saha
- Department of Cardiovascular, Endocrine-metabolic Diseases, and Aging, Italian National Institute of Health, Rome, Italy
| | | | - Valon Ejupi
- College UBT, Faculty of Pharmacy, Prishtina, Kosovo
| | - Brigitta Buttari
- Department of Cardiovascular, Endocrine-metabolic Diseases, and Aging, Italian National Institute of Health, Rome, Italy
| | - Elisabetta Profumo
- Department of Cardiovascular, Endocrine-metabolic Diseases, and Aging, Italian National Institute of Health, Rome, Italy
| | - Lule Beqa
- College UBT, Faculty of Pharmacy, Prishtina, Kosovo
| | - Luciano Saso
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Italy
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Yin A, Feng M, Zhang L, Cheng Z, Li Y, Qian L. Identification of a novel native peptide derived from 60S ribosomal protein L23a that translationally regulates p53 to reduce myocardial ischemia-reperfusion. Pharmacol Res 2022; 175:105988. [PMID: 34808368 DOI: 10.1016/j.phrs.2021.105988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/22/2021] [Accepted: 11/11/2021] [Indexed: 11/22/2022]
Abstract
Myocardial ischemia-reperfusion (I/R) is a severe disease,but its underlying mechanism is not fully elucidated and no effective clinical treatment is available. Utilizing intracellular peptidomics, we identified a novel native peptide PDRL23A (Peptide Derived from RPL23A), that is intimately related to hypoxic stress. We further show that PDRL23A effectively alleviates hypoxia-induced cardiomyocyte injury in vitro, along with improvements in mitochondrial function and redox homeostasis, including ROS accumulation, oxidative phosphorylation, and mitochondrial membrane potential. Strikingly, the in vivo results indicate that, short-term pretreatment with PDRL23A could effectively inhibit I/R-induced cardiomyocyte death, myocardial fibrosis and decreased cardiac function. Interestingly, PDRL23A was found to interact with 60 S ribosomal protein L26 (RPL26), hampering RPL26-governed p53 translation, and resulting in a reduction in the level of p53 protein, which in turn reduced p53-mediated apoptosis under hypoxic conditions. Collectively, a native peptide, PDRL23A, which translationally regulates p53 to protect against myocardial I/R injury, has been identified for the first time. Our findings provide insight into the adaptive mechanisms of hypoxia and present a potential new treatment for myocardial I/R.
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Affiliation(s)
- Anwen Yin
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China
| | - Mengwen Feng
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Li Zhang
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China
| | - Zijie Cheng
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Yun Li
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China.
| | - Lingmei Qian
- Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China; Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
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Ding L, Zhang Z, Zhao C, Chen L, Chen Z, Zhang J, Liu Y, Nie Y, He Y, Liao K, Zhang X. Ribosomal L1 domain-containing protein 1 coordinates with HDM2 to negatively regulate p53 in human colorectal Cancer cells. J Exp Clin Cancer Res 2021; 40:245. [PMID: 34362424 PMCID: PMC8344204 DOI: 10.1186/s13046-021-02057-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 07/31/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ribosomal L1 domain-containing protein 1 (RSL1D1) is a nucleolar protein that is essential in cell proliferation. In the current opinion, RSL1D1 translocates to the nucleoplasm under nucleolar stress and inhibits the E3 ligase activity of HDM2 via direct interaction, thereby leading to stabilization of p53. METHODS Gene knockdown was achieved in HCT116p53+/+, HCT116p53-/-, and HCT-8 human colorectal cancer (CRC) cells by siRNA transfection. A lentiviral expression system was used to establish cell strains overexpressing genes of interest. The mRNA and protein levels in cells were evaluated by qRT-PCR and western blot analyses. Cell proliferation, cell cycle, and cell apoptosis were determined by MTT, PI staining, and Annexin V-FITC/PI double staining assays, respectively. The level of ubiquitinated p53 protein was assessed by IP. The protein-RNA interaction was investigated by RIP. The subcellular localization of proteins of interest was determined by IFA. Protein-protein interaction was investigated by GST-pulldown, BiFC, and co-IP assays. The therapeutic efficacy of RSL1D1 silencing on tumor growth was evaluated in HCT116 tumor-bearing nude mice. RESULTS RSL1D1 distributed throughout the nucleus in human CRC cells. Silencing of RSL1D1 gene induced cell cycle arrest at G1/S and cell apoptosis in a p53-dependent manner. RSL1D1 directly interacted with and recruited p53 to HDM2 to form a ternary RSL1D1/HDM2/p53 protein complex and thereby enhanced p53 ubiquitination and degradation, leading to a decrease in the protein level of p53. Destruction of the ternary complex increased the level of p53 protein. RSL1D1 also indirectly decreased the protein level of p53 by stabilizing HDM2 mRNA. Consequently, the negative regulation of p53 by RSL1D1 facilitated cell proliferation and survival and downregulation of RSL1D1 remarkably inhibited the growth of HCT116p53+/+ tumors in a nude mouse model. CONCLUSION We report, for the first time, that RSL1D1 is a novel negative regulator of p53 in human CRC cells and more importantly, a potential molecular target for anticancer drug development.
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Affiliation(s)
- Li Ding
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Zhiping Zhang
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Chenhong Zhao
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Lei Chen
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Zhiqiang Chen
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Jie Zhang
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Yaxian Liu
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Yesen Nie
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Yanzhi He
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Kai Liao
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Xinyue Zhang
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, Jiangsu, China. .,Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, The Ministry of Agriculture of China, Yangzhou University (26116120), Yangzhou, 225009, Jiangsu, China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, Jiangsu, China.
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Resveratrol Modulation of Apoptosis and Cell Cycle Response to Cisplatin in Head and Neck Cancer Cell Lines. Int J Mol Sci 2021; 22:ijms22126322. [PMID: 34204834 PMCID: PMC8231609 DOI: 10.3390/ijms22126322] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
In head and neck cancers, the effectiveness of cisplatin (CisPt) treatment is limited by its toxicity, especially when higher doses are necessary, and the possible occurrence of cisplatin resistance. This study evaluated the effects of resveratrol (RSV) on the expression of different genes involved in the response of human tumor cells (FaDu, PE/CA-PJ49) to cisplatin therapy. Our results revealed that RSV induced apoptosis amplification in both FaDu and PE/CA-PJ49 cells and modulated the expression of specific genes differently than in normal HaCaT cells. In FaDu cells, combined CisPt + RSV treatment induced an increase in apoptosis, which was associated with an increase in c-MYC and TP53 and a decrease in BCL-2 expression. While CisPt + RSV treatment induced apoptosis in PE/CA-PJ49 cells by inhibition of BCL-2 associated with high levels of MDM-2 and subsequently led to inhibition of TP53 gene expression. Decreased c-MYC expression in PE/CA-PJ49 treated with CisPt + RSV was accompanied by cell cycle blockage in G0/G1 phase. In conclusion, RSV influences tumor cell response to CisPt by inducing apoptosis and modulating gene expression. In addition, in normal HaCaT cells, RSV was able to reduce the harmful effects of CisPt.
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WDR74 modulates melanoma tumorigenesis and metastasis through the RPL5-MDM2-p53 pathway. Oncogene 2020; 39:2741-2755. [PMID: 32005977 DOI: 10.1038/s41388-020-1179-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 01/06/2020] [Accepted: 01/21/2020] [Indexed: 11/08/2022]
Abstract
The key molecules and underlying mechanisms of melanoma metastasis remain poorly understood. Using isobaric tag for relative and absolute quantitation (iTRAQ) proteomic screening, probing of patients' samples, functional verification, and mechanistic validation, we identified the important role of the WD repeat-containing protein 74 (WDR74) in melanoma progression and metastasis. Through gain- and loss-of-function approaches, WDR74 was found to promote cell proliferation, apoptosis resistance, and aggressive behavior in vitro. Moreover, WDR74 contributed to melanoma growth and metastasis in vivo. Mechanistically, WDR74 modulates RPL5 protein levels and consequently regulates MDM2 and insulates the ubiquitination degradation of p53 by MDM2. Our study is the first to reveal the oncogenic role of WDR74 in melanoma progression and the regulatory effect of WDR74 on the RPL5-MDM2-p53 pathway. Collectively, WDR74 can serve as a candidate target for the prevention and treatment of melanoma in the clinic.
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Aguida B, Bouceba T, Créchet JB, Hounguè H, Capo-Chichi C, Nakayama JI, Baouz S, Pelczar H, Woisard A, Jourdan N, Hountondji C. In Vitro Analysis of Protein:Protein Interactions in the Human Cancer-Pertinent rp.eL42-p53-Mdm2 Pathway. Open Biochem J 2019. [DOI: 10.2174/1874091x01913010064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Introduction:
We have recently demonstrated that the eukaryote-specific large subunit ribosomal protein
(rp) eL42 assists catalysis of peptide bond formation at the peptidyl transferase center of 80S
ribosomes in eukaryotic cells. Recently, several ribosomal proteins were shown to have extraribosomal
functions independent of protein biosynthesis. Such functions include regulation of
apoptosis, cell cycle arrest, cell proliferation, neoplastic transformation, cell migration and
invasion, and tumorigenesis through both Mdm2-p53-dependent and p53-independent
mechanisms. Our objective is to demonstrate that overexpression of eL42 in tumor may
incapacitate cell anti-tumor mechanism through interaction with the tumor suppressor protein
p53 and its partner Mdm2.
Methods:
Co-immunoprecipitation technique and the binding assays on Biacore were used to
probe interactions between recombinant eL42, p53 and Mdm2 proteins in a so-called rp-p53-Mdm2 axis.
Results:
We demonstrate that the ribosomal protein eL42, the tumor suppressor protein p53 and the ubiquitin E3 ligase Mdm2 interact with each other in a ternary rp.eL42:p53:Mdm2 complex. Precisely, the interaction between eL42 and p53 is characterized by a strong binding affinity (KD value in the nanomolar range) that is likely to trigger the sequestration of p53 and the inhibition of its tumor suppressor activity. Furthermore, the p53:Mdm2 and eL42:Mdm2 complexes exhibit comparable binding affinities in the micromolar range compatible with Mdm2 being the enzyme which ubiquitinates both the p53 and eL42 substrates. Interestingly, pyridoxal 5'-phosphate (PLP), one of the active forms of vitamin B6, binds to eL42 and significantly inhibits the interaction between eL42 and p53, in accordance with the observation that vitamin B6 is associated with reduced risk of cancer.
Conclusion:
Our study emphasized one more major mechanism of p53 downregulation involving its sequestration by eL42 upon the overexpression of this ribosomal protein. The mechanism described in the present report complemented the well-known p53 downregulation triggered by proteasomal degradation mediated through its ubiquitination by Mdm2.
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Wang W, Kandimalla R, Huang H, Zhu L, Li Y, Gao F, Goel A, Wang X. Molecular subtyping of colorectal cancer: Recent progress, new challenges and emerging opportunities. Semin Cancer Biol 2019; 55:37-52. [PMID: 29775690 PMCID: PMC6240404 DOI: 10.1016/j.semcancer.2018.05.002] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 05/13/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022]
Abstract
Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Similar to many other malignancies, CRC is a heterogeneous disease, making it a clinical challenge for optimization of treatment modalities in reducing the morbidity and mortality associated with this disease. A more precise understanding of the biological properties that distinguish patients with colorectal tumors, especially in terms of their clinical features, is a key requirement towards a more robust, targeted-drug design, and implementation of individualized therapies. In the recent decades, extensive studies have reported distinct CRC subtypes, with a mutation-centered view of tumor heterogeneity. However, more recently, the paradigm has shifted towards transcriptome-based classifications, represented by six independent CRC taxonomies. In 2015, the colorectal cancer subtyping consortium reported the identification of four consensus molecular subtypes (CMSs), providing thus far the most robust classification system for CRC. In this review, we summarize the historical timeline of CRC classification approaches; discuss their salient features and potential limitations that may require further refinement in near future. In other words, in spite of the recent encouraging progress, several major challenges prevent translation of molecular knowledge gleaned from CMSs into the clinic. Herein, we summarize some of these potential challenges and discuss exciting new opportunities currently emerging in related fields. We believe, close collaborations between basic researchers, bioinformaticians and clinicians are imperative for addressing these challenges, and eventually paving the path for CRC subtyping into routine clinical practice as we usher into the era of personalized medicine.
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Affiliation(s)
- Wei Wang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong
| | - Raju Kandimalla
- Center for Gastrointestinal Research, Center for Translational Genomics and Oncology, Baylor Scott & White Research Institute and Charles A Sammons Cancer Center, Baylor Research Institute and Sammons Cancer Center, Baylor University Medical Center, 3410 Worth Street, Suite 610, Dallas, TX 75246, USA
| | - Hao Huang
- College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong
| | - Lina Zhu
- College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong
| | - Ying Li
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong
| | - Feng Gao
- College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong
| | - Ajay Goel
- Center for Gastrointestinal Research, Center for Translational Genomics and Oncology, Baylor Scott & White Research Institute and Charles A Sammons Cancer Center, Baylor Research Institute and Sammons Cancer Center, Baylor University Medical Center, 3410 Worth Street, Suite 610, Dallas, TX 75246, USA.
| | - Xin Wang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong.
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11
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Yang C, Zang W, Ji Y, Li T, Yang Y, Zheng X. Ribosomal protein L6 (RPL6) is recruited to DNA damage sites in a poly(ADP-ribose) polymerase-dependent manner and regulates the DNA damage response. J Biol Chem 2018; 294:2827-2838. [PMID: 30598506 DOI: 10.1074/jbc.ra118.007009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 12/27/2018] [Indexed: 12/21/2022] Open
Abstract
Ribosomal proteins are the building blocks of ribosome biogenesis. Beyond their known participation in ribosome assembly, the ribosome-independent functions of ribosomal proteins are largely unknown. Here, using immunoprecipitation, subcellular fractionation, His-ubiquitin pulldown, and immunofluorescence microscopy assays, along with siRNA-based knockdown approaches, we demonstrate that ribosomal protein L6 (RPL6) directly interacts with histone H2A and is involved in the DNA damage response (DDR). We found that in response to DNA damage, RPL6 is recruited to DNA damage sites in a poly(ADP-ribose) polymerase (PARP)-dependent manner, promoting its interaction with H2A. We also observed that RPL6 depletion attenuates the interaction between mediator of DNA damage checkpoint 1 (MDC1) and H2A histone family member X, phosphorylated (γH2AX), impairs the accumulation of MDC1 at DNA damage sites, and reduces both the recruitment of ring finger protein 168 (RNF168) and H2A Lys-15 ubiquitination (H2AK15ub). These RPL6 depletion-induced events subsequently inhibited the recruitment of the following downstream repair proteins: tumor protein P53-binding protein 1 (TP53BP1) and BRCA1, DNA repair-associated (BRCA1). Moreover, the RPL6 knockdown resulted in defects in the DNA damage-induced G2-M checkpoint, DNA damage repair, and cell survival. In conclusion, our study identifies RPL6 as a critical regulatory factor involved in the DDR. These findings expand our knowledge of the extraribosomal functions of ribosomal proteins in cell physiology and deepen our understanding of the molecular mechanisms underlying DDR regulation.
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Affiliation(s)
- Chuanzhen Yang
- From the State Key Lab of Protein and Plant Gene Research and.,the Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing 100871, China
| | - Weicheng Zang
- From the State Key Lab of Protein and Plant Gene Research and.,the Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yapeng Ji
- From the State Key Lab of Protein and Plant Gene Research and.,the Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing 100871, China
| | - Tingting Li
- From the State Key Lab of Protein and Plant Gene Research and.,the Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yongfeng Yang
- From the State Key Lab of Protein and Plant Gene Research and.,the Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiaofeng Zheng
- From the State Key Lab of Protein and Plant Gene Research and .,the Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing 100871, China
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12
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Ahn JJ, Yong HJ. Antioxidant and inhibition of senescence effects of embelin. BIOMEDICAL DERMATOLOGY 2018. [DOI: 10.1186/s41702-018-0020-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Liu DC, Seimetz J, Lee KY, Kalsotra A, Chung HJ, Lu H, Tsai NP. Mdm2 mediates FMRP- and Gp1 mGluR-dependent protein translation and neural network activity. Hum Mol Genet 2018; 26:3895-3908. [PMID: 29016848 DOI: 10.1093/hmg/ddx276] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 07/11/2017] [Indexed: 01/08/2023] Open
Abstract
Activating Group 1 (Gp1) metabotropic glutamate receptors (mGluRs), including mGluR1 and mGluR5, elicits translation-dependent neural plasticity mechanisms that are crucial to animal behavior and circuit development. Dysregulated Gp1 mGluR signaling has been observed in numerous neurological and psychiatric disorders. However, the molecular pathways underlying Gp1 mGluR-dependent plasticity mechanisms are complex and have been elusive. In this study, we identified a novel mechanism through which Gp1 mGluR mediates protein translation and neural plasticity. Using a multi-electrode array (MEA) recording system, we showed that activating Gp1 mGluR elevates neural network activity, as demonstrated by increased spontaneous spike frequency and burst activity. Importantly, we validated that elevating neural network activity requires protein translation and is dependent on fragile X mental retardation protein (FMRP), the protein that is deficient in the most common inherited form of mental retardation and autism, fragile X syndrome (FXS). In an effort to determine the mechanism by which FMRP mediates protein translation and neural network activity, we demonstrated that a ubiquitin E3 ligase, murine double minute-2 (Mdm2), is required for Gp1 mGluR-induced translation and neural network activity. Our data showed that Mdm2 acts as a translation suppressor, and FMRP is required for its ubiquitination and down-regulation upon Gp1 mGluR activation. These data revealed a novel mechanism by which Gp1 mGluR and FMRP mediate protein translation and neural network activity, potentially through de-repressing Mdm2. Our results also introduce an alternative way for understanding altered protein translation and brain circuit excitability associated with Gp1 mGluR in neurological diseases such as FXS.
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Affiliation(s)
- Dai-Chi Liu
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology.,Neuroscience Program
| | - Joseph Seimetz
- Department of Biochemistry, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Kwan Young Lee
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology
| | - Auinash Kalsotra
- Department of Biochemistry, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Carl R.Woese Institute of Genomic Biology, University of Illinois, Champaign, IL 61801, USA
| | - Hee Jung Chung
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology.,Neuroscience Program.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Hua Lu
- Department of Biochemistry and Molecular Biology.,Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Nien-Pei Tsai
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology.,Neuroscience Program.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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14
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mTOR: An attractive therapeutic target for osteosarcoma? Oncotarget 2018; 7:50805-50813. [PMID: 27177330 PMCID: PMC5226621 DOI: 10.18632/oncotarget.9305] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/05/2016] [Indexed: 02/07/2023] Open
Abstract
Osteosarcoma (OS) is a common primary malignant bone tumor with high morbidity and mortality in children and young adults. How to improve poor prognosis of OS due to resistance to chemotherapy remains a challenge. Recently, growing findings show activation of mammalian target of rapamycin (mTOR), is associated with OS cell growth, proliferation, metastasis. Targeting mTOR may be a promising therapeutic approach for treating OS. This review summarizes the roles of mTOR pathway in OS and present research status of mTOR inhibitors in the context of OS. In addition, we have attempted to discuss how to design a better treatment project for OS by combining mTOR inhibitor with other drugs.
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15
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Lee NK. Preservation effects of geniposidic acid on human keratinocytes (HaCaT) against UVB. BIOMEDICAL DERMATOLOGY 2018. [DOI: 10.1186/s41702-017-0015-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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16
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Ajore R, Raiser D, McConkey M, Jöud M, Boidol B, Mar B, Saksena G, Weinstock DM, Armstrong S, Ellis SR, Ebert BL, Nilsson B. Deletion of ribosomal protein genes is a common vulnerability in human cancer, especially in concert with TP53 mutations. EMBO Mol Med 2017; 9:498-507. [PMID: 28264936 PMCID: PMC5376749 DOI: 10.15252/emmm.201606660] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Heterozygous inactivating mutations in ribosomal protein genes (RPGs) are associated with hematopoietic and developmental abnormalities, activation of p53, and altered risk of cancer in humans and model organisms. Here we performed a large‐scale analysis of cancer genome data to examine the frequency and selective pressure of RPG lesions across human cancers. We found that hemizygous RPG deletions are common, occurring in about 43% of 10,744 cancer specimens and cell lines. Consistent with p53‐dependent negative selection, such lesions are underrepresented in TP53‐intact tumors (P ≪ 10−10), and shRNA‐mediated knockdown of RPGs activated p53 in TP53‐wild‐type cells. In contrast, we did not see negative selection of RPG deletions in TP53‐mutant tumors. RPGs are conserved with respect to homozygous deletions, and shRNA screening data from 174 cell lines demonstrate that further suppression of hemizygously deleted RPGs inhibits cell growth. Our results establish RPG haploinsufficiency as a strikingly common vulnerability of human cancers that associates with TP53 mutations and could be targetable therapeutically.
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Affiliation(s)
- Ram Ajore
- Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - David Raiser
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Marie McConkey
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Magnus Jöud
- Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Bernd Boidol
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Brenton Mar
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | | | - Steven R Ellis
- Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY, USA
| | - Benjamin L Ebert
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA .,Broad Institute, 7 Cambridge Center, Cambridge, MA, USA
| | - Björn Nilsson
- Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden .,Broad Institute, 7 Cambridge Center, Cambridge, MA, USA
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17
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Salimi S, Rezaei M, Mohammadpour-Gharehbagh A, Sajadian M, Sandoughi M. The ID genotype of MDM2 40 bp insertion/deletion polymorphism was associated with lower risk of SLE. Postgrad Med J 2017; 93:758-761. [DOI: 10.1136/postgradmedj-2017-134851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/05/2017] [Accepted: 05/21/2017] [Indexed: 01/30/2023]
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18
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Russo A, Saide A, Smaldone S, Faraonio R, Russo G. Role of uL3 in Multidrug Resistance in p53-Mutated Lung Cancer Cells. Int J Mol Sci 2017; 18:ijms18030547. [PMID: 28273808 PMCID: PMC5372563 DOI: 10.3390/ijms18030547] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 02/21/2017] [Accepted: 03/01/2017] [Indexed: 01/23/2023] Open
Abstract
Cancer is one of the most common causes of death among adults. Chemotherapy is crucial in determining patient survival and quality of life. However, the development of multidrug resistance (MDR) continues to pose a significant challenge in the management of cancer. In this study, we analyzed the role of human ribosomal protein uL3 (formerly rpL3) in multidrug resistance. Our studies revealed that uL3 is a key determinant of multidrug resistance in p53-mutated lung cancer cells by controlling the cell redox status. We established and characterized a multidrug resistant Calu-6 cell line. We found that uL3 down-regulation correlates positively with multidrug resistance. Restoration of the uL3 protein level re-sensitized the resistant cells to the drug by regulating the reactive oxygen species (ROS) levels, glutathione content, glutamate release, and cystine uptake. Chromatin immunoprecipitation experiments and luciferase assays demonstrated that uL3 coordinated the expression of stress-response genes acting as transcriptional repressors of solute carrier family 7 member 11 (xCT) and glutathione S-transferase α1 (GST-α1), independently of Nuclear factor erythroid 2-related factor 2 (Nrf2). Altogether our results describe a new function of uL3 as a regulator of oxidative stress response genes and advance our understanding of the molecular mechanisms underlying multidrug resistance in cancers.
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Affiliation(s)
- Annapina Russo
- Department of Pharmacy, University of Naples "Federico II", Via Domenico Montesano 49, 80131 Naples, Italy.
| | - Assunta Saide
- Department of Pharmacy, University of Naples "Federico II", Via Domenico Montesano 49, 80131 Naples, Italy.
| | - Silvia Smaldone
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Raffaella Faraonio
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples "Federico II", Via Sergio Pansini 5, 80131 Naples, Italy.
| | - Giulia Russo
- Department of Pharmacy, University of Naples "Federico II", Via Domenico Montesano 49, 80131 Naples, Italy.
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19
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Kudryavtseva AV, Lipatova AV, Zaretsky AR, Moskalev AA, Fedorova MS, Rasskazova AS, Shibukhova GA, Snezhkina AV, Kaprin AD, Alekseev BY, Dmitriev AA, Krasnov GS. Important molecular genetic markers of colorectal cancer. Oncotarget 2016; 7:53959-53983. [PMID: 27276710 PMCID: PMC5288236 DOI: 10.18632/oncotarget.9796] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 05/21/2016] [Indexed: 02/06/2023] Open
Abstract
Colorectal cancer (CRC) ranks third in the incidences of cancer morbidity and mortality worldwide. CRC is rather heterogeneous with regard to molecular genetic characteristics and pathogenic pathways. A wide spectrum of biomarkers is used for molecular subtype determination, prognosis, and estimation of sensitivity to different drugs in practice. These biomarkers can include germline and somatic mutations, chromosomal aberrations, genomic abnormalities, gene expression alterations at mRNA or protein level and changes in DNA methylation status. In the present review we discuss the most important and well-studied CRC biomarkers, and their potential clinical significance and current approaches to molecular classification of colorectal tumors.
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Affiliation(s)
- Anna V. Kudryavtseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- National Medical Research Radiological Centre, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Anastasia V. Lipatova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Andrew R. Zaretsky
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexey A. Moskalev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Maria S. Fedorova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- National Medical Research Radiological Centre, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | | | - Galina A. Shibukhova
- National Medical Research Radiological Centre, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | | | - Andrey D. Kaprin
- National Medical Research Radiological Centre, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Boris Y. Alekseev
- National Medical Research Radiological Centre, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Alexey A. Dmitriev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - George S. Krasnov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Orekhovich Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, Moscow, Russia
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20
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Xu X, Xiong X, Sun Y. The role of ribosomal proteins in the regulation of cell proliferation, tumorigenesis, and genomic integrity. SCIENCE CHINA-LIFE SCIENCES 2016; 59:656-72. [DOI: 10.1007/s11427-016-0018-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/06/2016] [Indexed: 01/29/2023]
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21
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Waku T, Nakajima Y, Yokoyama W, Nomura N, Kako K, Kobayashi A, Shimizu T, Fukamizu A. NML-mediated rRNA base methylation links ribosomal subunit formation to cell proliferation in a p53-dependent manner. J Cell Sci 2016; 129:2382-93. [PMID: 27149924 DOI: 10.1242/jcs.183723] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/29/2016] [Indexed: 12/25/2022] Open
Abstract
Ribosomal RNAs (rRNAs) act as scaffolds and ribozymes in ribosomes, and these functions are modulated by post-transcriptional modifications. However, the biological role of base methylation, a well-conserved modification of rRNA, is poorly understood. Here, we demonstrate that a nucleolar factor, nucleomethylin (NML; also known as RRP8), is required for the N(1)-methyladenosine (m(1)A) modification in 28S rRNAs of human and mouse cells. NML also contributes to 60S ribosomal subunit formation. Intriguingly, NML depletion increases 60S ribosomal protein L11 (RPL11) levels in the ribosome-free fraction and protein levels of p53 through an RPL11-MDM2 complex, which activates the p53 pathway. Consequently, the growth of NML-depleted cells is suppressed in a p53-dependent manner. These observations reveal a new biological function of rRNA base methylation, which links ribosomal subunit formation to p53-dependent inhibition of cell proliferation in mammalian cells.
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Affiliation(s)
- Tsuyoshi Waku
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuka Nakajima
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Wataru Yokoyama
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Naoto Nomura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Koichiro Kako
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Akira Kobayashi
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0394, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Akiyoshi Fukamizu
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
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22
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A Zebrafish Model of 5q-Syndrome Using CRISPR/Cas9 Targeting RPS14 Reveals a p53-Independent and p53-Dependent Mechanism of Erythroid Failure. J Genet Genomics 2016; 43:307-18. [DOI: 10.1016/j.jgg.2016.03.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 02/21/2016] [Accepted: 03/06/2016] [Indexed: 11/23/2022]
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23
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Karni-Schmidt O, Lokshin M, Prives C. The Roles of MDM2 and MDMX in Cancer. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2016; 11:617-44. [PMID: 27022975 DOI: 10.1146/annurev-pathol-012414-040349] [Citation(s) in RCA: 200] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
For more than 25 years, MDM2 and its homolog MDMX (also known as MDM4) have been shown to exert oncogenic activity. These two proteins are best understood as negative regulators of the p53 tumor suppressor, although they may have additional p53-independent roles. Understanding the dysregulation of MDM2 and MDMX in human cancers and how they function either together or separately in tumorigenesis may improve methods of diagnosis and for assessing prognosis. Targeting the proteins themselves, or their regulators, may be a promising therapeutic approach to treating some forms of cancer.
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Affiliation(s)
- Orit Karni-Schmidt
- Department of Biological Sciences, Columbia University, New York, NY 10027;
| | - Maria Lokshin
- Department of Biological Sciences, Columbia University, New York, NY 10027;
| | - Carol Prives
- Department of Biological Sciences, Columbia University, New York, NY 10027;
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24
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Goudarzi KM, Lindström MS. Role of ribosomal protein mutations in tumor development (Review). Int J Oncol 2016; 48:1313-24. [PMID: 26892688 PMCID: PMC4777597 DOI: 10.3892/ijo.2016.3387] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/07/2016] [Indexed: 12/16/2022] Open
Abstract
Ribosomes are cellular machines essential for protein synthesis. The biogenesis of ribosomes is a highly complex and energy consuming process that initiates in the nucleolus. Recently, a series of studies applying whole-exome or whole-genome sequencing techniques have led to the discovery of ribosomal protein gene mutations in different cancer types. Mutations in ribosomal protein genes have for example been found in endometrial cancer (RPL22), T-cell acute lymphoblastic leukemia (RPL10, RPL5 and RPL11), chronic lymphocytic leukemia (RPS15), colorectal cancer (RPS20), and glioma (RPL5). Moreover, patients suffering from Diamond-Blackfan anemia, a bone marrow failure syndrome caused by mutant ribosomal proteins are also at higher risk for developing leukemia, or solid tumors. Different experimental models indicate potential mechanisms whereby ribosomal proteins may initiate cancer development. In particular, deregulation of the p53 tumor suppressor network and altered mRNA translation are mechanisms likely to be involved. We envisage that changes in expression and the occurrence of ribosomal protein gene mutations play important roles in cancer development. Ribosome biology constitutes a re-emerging vital area of basic and translational cancer research.
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Affiliation(s)
- Kaveh M Goudarzi
- Department of Oncology-Pathology, Karolinska Institutet, Cancer Center Karolinska, CCK R8:05, Karolinska University Hospital in Solna, Stockholm, Sweden
| | - Mikael S Lindström
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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25
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MA LIJIE, LI PEIPEI, WANG RUIXUAN, NAN YANDONG, LIU XUEYING, JIN FAGUANG. Analysis of novel microRNA targets in drug-sensitive and -insensitive small cell lung cancer cell lines. Oncol Rep 2015; 35:1611-21. [DOI: 10.3892/or.2015.4487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 10/26/2015] [Indexed: 11/06/2022] Open
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26
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Giorgi C, Bonora M, Missiroli S, Poletti F, Ramirez FG, Morciano G, Morganti C, Pandolfi PP, Mammano F, Pinton P. Intravital imaging reveals p53-dependent cancer cell death induced by phototherapy via calcium signaling. Oncotarget 2015; 6:1435-45. [PMID: 25544762 PMCID: PMC4359305 DOI: 10.18632/oncotarget.2935] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 12/01/2014] [Indexed: 12/28/2022] Open
Abstract
One challenge in biology is signal transduction monitoring in a physiological context. Intravital imaging techniques are revolutionizing our understanding of tumor and host cell behaviors in the tumor environment. However, these deep tissue imaging techniques have not yet been adopted to investigate the second messenger calcium (Ca2+). In the present study, we established conditions that allow the in vivo detection of Ca2+ signaling in three-dimensional tumor masses in mouse models. By combining intravital imaging and a skinfold chamber technique, we determined the ability of photodynamic cancer therapy to induce an increase in intracellular Ca2+ concentrations and, consequently, an increase in cell death in a p53-dependent pathway.
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Affiliation(s)
- Carlotta Giorgi
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA center, University of Ferrara, Ferrara, Italy
| | - Massimo Bonora
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA center, University of Ferrara, Ferrara, Italy
| | - Sonia Missiroli
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA center, University of Ferrara, Ferrara, Italy
| | - Federica Poletti
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA center, University of Ferrara, Ferrara, Italy
| | - Fabian Galindo Ramirez
- Department of Physics and Astronomy, University of Padua, and Venetian Institute of Molecular Medicine, Padua, Italy.,Instituto de fisiologia, Benemerita Universidad Autónoma de Puebla (BUAP), Puebla, Mexico
| | - Giampaolo Morciano
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA center, University of Ferrara, Ferrara, Italy
| | - Claudia Morganti
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA center, University of Ferrara, Ferrara, Italy
| | - Pier Paolo Pandolfi
- Cancer Genetics Program, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Fabio Mammano
- Department of Physics and Astronomy, University of Padua, and Venetian Institute of Molecular Medicine, Padua, Italy
| | - Paolo Pinton
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology and LTTA center, University of Ferrara, Ferrara, Italy
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27
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Abstract
p53 has been studied intensively as a major tumour suppressor that detects oncogenic events in cancer cells and eliminates them through senescence (a permanent non-proliferative state) or apoptosis. Consistent with this role, p53 activity is compromised in a high proportion of all cancer types, either through mutation of the TP53 gene (encoding p53) or changes in the status of p53 modulators. p53 has additional roles, which may overlap with its tumour-suppressive capacity, in processes including the DNA damage response, metabolism, aging, stem cell differentiation and fertility. Moreover, many mutant p53 proteins, termed 'gain-of-function' (GOF), acquire new activities that help drive cancer aggression. p53 is regulated mainly through protein turnover and operates within a negative-feedback loop with its transcriptional target, MDM2 (murine double minute 2), an E3 ubiquitin ligase which mediates the ubiquitylation and proteasomal degradation of p53. Induction of p53 is achieved largely through uncoupling the p53-MDM2 interaction, leading to elevated p53 levels. Various stress stimuli acting on p53 (such as hyperproliferation and DNA damage) use different, but overlapping, mechanisms to achieve this. Additionally, p53 activity is regulated through critical context-specific or fine-tuning events, mediated primarily through post-translational mechanisms, particularly multi-site phosphorylation and acetylation. In the present review, I broadly examine these events, highlighting their regulatory contributions, their ability to integrate signals from cellular events towards providing most appropriate response to stress conditions and their importance for tumour suppression. These are fascinating aspects of molecular oncology that hold the key to understanding the molecular pathology of cancer and the routes by which it may be tackled therapeutically.
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28
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Zheng J, Lang Y, Zhang Q, Cui D, Sun H, Jiang L, Chen Z, Zhang R, Gao Y, Tian W, Wu W, Tang J, Chen Z. Structure of human MDM2 complexed with RPL11 reveals the molecular basis of p53 activation. Genes Dev 2015. [PMID: 26220995 PMCID: PMC4526736 DOI: 10.1101/gad.261792.115] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Upon ribosomal stress, the central region of MDM2 is bound by ribosomal proteins, particularly ribosomal protein L11 (RPL11), leading to MDM2 inactivation and subsequent p53 activation. Zheng et al. solved the complex structure of human MDM2–RPL11 at 2.4 Å and show that formation of the MDM2–RPL11 complex induces substantial conformational changes in both proteins. The central region of MDM2 is critical for p53 activation and tumor suppression. Upon ribosomal stress, this region is bound by ribosomal proteins, particularly ribosomal protein L11 (RPL11), leading to MDM2 inactivation and subsequent p53 activation. Here, we solved the complex structure of human MDM2–RPL11 at 2.4 Å. MDM2 extensively interacts with RPL11 through an acidic domain and two zinc fingers. Formation of the MDM2–RPL11 complex induces substantial conformational changes in both proteins. RPL11, unable to bind MDM2 mutants, fails to induce the activation of p53 in cells. MDM2 mimics 28S rRNA binding to RPL11. The C4 zinc finger determines RPL11 binding to MDM2 but not its homolog, MDMX. Our results highlight the essential role of the RPL11–MDM2 interaction in p53 activation and tumor suppression and provide a structural basis for potential new anti-tumor drug development.
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Affiliation(s)
- Jiangge Zheng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yue Lang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Qi Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Di Cui
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Haili Sun
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Lun Jiang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Zhenhang Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Rui Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yina Gao
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Wenli Tian
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China
| | - Wei Wu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Jun Tang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
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29
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Esposito D, Crescenzi E, Sagar V, Loreni F, Russo A, Russo G. Human rpL3 plays a crucial role in cell response to nucleolar stress induced by 5-FU and L-OHP. Oncotarget 2015; 5:11737-51. [PMID: 25473889 PMCID: PMC4294388 DOI: 10.18632/oncotarget.2591] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 10/11/2014] [Indexed: 11/25/2022] Open
Abstract
Recent evidence showed that a variety of DNA damaging agents including 5-FU and L-OHP impairs ribosomal biogenesis activating a ribosomal stress pathway. Here, we demonstrate that in lung and colon cancer cell lines devoid of p53, the efficacy of 5-FU and L-OHP chemotherapy depends on rpL3 status. Specifically, we demonstrate that ribosomal stress induced by 5-FU and L-OHP is associated to up-regulation of rpL3 and its accumulation as ribosome-free form. We show that rpL3 participates in the cell response to chemotherapy acting as a critical regulator of cell cycle, apoptosis and DNA repair, by modulating p21 expression. Moreover, we demonstrate that rpL3 is able to control DNA repair also independently from p21 status of cell. It is noteworthy that silencing of rpL3 abolishes the cytotoxic effects of 5-FU and L-OH indicating that the loss of rpL3 makes chemotherapy drugs ineffective. Taking together our results shed light on 5-FU and L-OHP mechanism of action and contribute to more effective clinical use of these drugs in cancer therapy.
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Affiliation(s)
- Davide Esposito
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples 80131, Italy. Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Elvira Crescenzi
- Institute of Experimental Endocrinology and Oncology-CNR, Naples 80131, Italy
| | - Vinay Sagar
- Department of Biology, University of Rome 'Tor Vergata', Rome 00133, Italy
| | - Fabrizio Loreni
- Department of Biology, University of Rome 'Tor Vergata', Rome 00133, Italy
| | - Annapina Russo
- Department of Pharmacy, University of Naples "Federico II", Naples 80131, Italy
| | - Giulia Russo
- Department of Pharmacy, University of Naples "Federico II", Naples 80131, Italy
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30
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Abstract
In this study, Madru et al. determined the structure of the ribosome-bound Rpf2–Rrs1 complex, a complex essential for the assembly of the 5S RNA in ribosomes, and characterized the free and 5S-bound structures. The findings show that Rpf2 and Rrs1 establish a network of protein–protein and protein–RNA interactions with the 5S RNA and specific preribosomes, thus providing novel insight into ribosome biogenesis. In eukaryotes, three of the four ribosomal RNAs (rRNAs)—the 5.8S, 18S, and 25S/28S rRNAs—are processed from a single pre-rRNA transcript and assembled into ribosomes. The fourth rRNA, the 5S rRNA, is transcribed by RNA polymerase III and is assembled into the 5S ribonucleoprotein particle (RNP), containing ribosomal proteins Rpl5/uL18 and Rpl11/uL5, prior to its incorporation into preribosomes. In mammals, the 5S RNP is also a central regulator of the homeostasis of the tumor suppressor p53. The nucleolar localization of the 5S RNP and its assembly into preribosomes are performed by a specialized complex composed of Rpf2 and Rrs1 in yeast or Bxdc1 and hRrs1 in humans. Here we report the structural and functional characterization of the Rpf2–Rrs1 complex alone, in complex with the 5S RNA, and within pre-60S ribosomes. We show that the Rpf2–Rrs1 complex contains a specialized 5S RNA E-loop-binding module, contacts the Rpl5 protein, and also contacts the ribosome assembly factor Rsa4 and the 25S RNA. We propose that the Rpf2–Rrs1 complex establishes a network of interactions that guide the incorporation of the 5S RNP in preribosomes in the initial conformation prior to its rotation to form the central protuberance found in the mature large ribosomal subunit.
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31
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Goudarzi KM, Nistér M, Lindström MS. mTOR inhibitors blunt the p53 response to nucleolar stress by regulating RPL11 and MDM2 levels. Cancer Biol Ther 2015; 15:1499-514. [PMID: 25482947 DOI: 10.4161/15384047.2014.955743] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a master regulator of cell growth through its ability to stimulate ribosome biogenesis and mRNA translation. In contrast, the p53 tumor suppressor negatively controls cell growth and is activated by a wide range of insults to the cell. The mTOR and p53 signaling pathways are connected by a number of different mechanisms. Chemotherapeutics that inhibit ribosome biogenesis often induce nucleolar stress and activation of p53. Here we have investigated how the p53 response to nucleolar stress is affected by simultaneous mTOR inhibition in osteosarcoma and glioma cell lines. We found that inhibitors of the mTOR pathway including rapamycin, wortmannin, and caffeine blunted the p53 response to nucleolar stress induced by actinomycin D. Synthetic inhibitors of mTOR (temsirolimus, LY294.002 and PP242) also impaired actinomycin D triggered p53 stabilization and induction of p21. Ribosomal protein (RPL11) is known to be required for p53 protein stabilization following nucleolar stress. Treatment of cells with mTOR inhibitors may lead to reduced synthesis of RPL11 and thereby destabilize p53. We found that rapamycin mimicked the effect of RPL11 depletion in terms of blunting the p53 response to nucleolar stress. However, the extent to which the levels of p53 and RPL11 were reduced by rapamycin varied between cell lines. Additional mechanisms whereby rapamycin blunts the p53 response to nucleolar stress are likely to be involved. Indeed, rapamycin increased the levels of endogenous MDM2 despite inhibition of its phosphorylation at Ser-166. Our findings may have implications for the design of combinatorial cancer treatments with mTOR pathway inhibitors.
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Key Words
- 5-FU, 5-fluorouracil
- Act D, actinomycin D
- BrdU, bromodeoxyuridine
- CHX, cycloheximide
- DMSO, dimethylsulphoxide
- DOX, doxorubicin
- EGCG, epigallocatechin-3-gallate
- FACS, fluorescence-activated cell sorting
- MPA, mycophenolic acid
- MTT, (3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide)
- PI, propidium iodide
- actinomycin D
- caffeine
- glioma
- mTOR
- mTOR, mechanistic target of rapamycin
- nutlin-3
- p21
- p53
- rapamycin
- ribosomal protein L11
- ribosome biogenesis
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Affiliation(s)
- Kaveh M Goudarzi
- a Department of Oncology-Pathology; Karolinska Institutet; Cancer Center Karolinska ; Karolinska University Hospital ; Stockholm , Sweden
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32
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Zheng J, Lang Y, Zhang Q, Cui D, Sun H, Jiang L, Chen Z, Zhang R, Gao Y, Tian W, Wu W, Tang J, Chen Z. Structure of human MDM2 complexed with RPL11 reveals the molecular basis of p53 activation. Genes Dev 2015. [PMID: 26220995 DOI: 10.1101/gad.261792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
The central region of MDM2 is critical for p53 activation and tumor suppression. Upon ribosomal stress, this region is bound by ribosomal proteins, particularly ribosomal protein L11 (RPL11), leading to MDM2 inactivation and subsequent p53 activation. Here, we solved the complex structure of human MDM2-RPL11 at 2.4 Å. MDM2 extensively interacts with RPL11 through an acidic domain and two zinc fingers. Formation of the MDM2-RPL11 complex induces substantial conformational changes in both proteins. RPL11, unable to bind MDM2 mutants, fails to induce the activation of p53 in cells. MDM2 mimics 28S rRNA binding to RPL11. The C4 zinc finger determines RPL11 binding to MDM2 but not its homolog, MDMX. Our results highlight the essential role of the RPL11-MDM2 interaction in p53 activation and tumor suppression and provide a structural basis for potential new anti-tumor drug development.
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Affiliation(s)
- Jiangge Zheng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yue Lang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Qi Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Di Cui
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Haili Sun
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Lun Jiang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Zhenhang Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Rui Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yina Gao
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Wenli Tian
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China
| | - Wei Wu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Jun Tang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
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33
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Datta D, Anbarasu K, Rajabather S, Priya RS, Desai P, Mahalingam S. Nucleolar GTP-binding Protein-1 (NGP-1) Promotes G1 to S Phase Transition by Activating Cyclin-dependent Kinase Inhibitor p21 Cip1/Waf1. J Biol Chem 2015. [PMID: 26203195 DOI: 10.1074/jbc.m115.637280] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nucleolar GTP-binding protein (NGP-1) is overexpressed in various cancers and proliferating cells, but the functional significance remains unknown. In this study, we show that NGP-1 promotes G1 to S phase transition of cells by enhancing CDK inhibitor p21(Cip-1/Waf1) expression through p53. In addition, our results suggest that activation of the cyclin D1-CDK4 complex by NGP-1 via maintaining the stoichiometry between cyclin D1-CDK4 complex and p21 resulted in hyperphosphorylation of retinoblastoma protein at serine 780 (p-RB(Ser-780)) followed by the up-regulation of E2F1 target genes required to promote G1 to S phase transition. Furthermore, our data suggest that ribosomal protein RPL23A interacts with NGP-1 and abolishes NGP-1-induced p53 activity by enhancing Mdm2-mediated p53 polyubiquitination. Finally, reduction of p-RB(Ser-780) levels and E2F1 target gene expression upon ectopic expression of RPL23a resulted in arrest at the G1 phase of the cell cycle. Collectively, this investigation provides evidence that NGP-1 promotes cell cycle progression through the activation of the p53/p21(Cip-1/Waf1) pathway.
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Affiliation(s)
- Debduti Datta
- From the Laboratory of Molecular Virology and Cell Biology, National Cancer Tissue Biobank, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology-Madras, Chennai 600 036, India
| | - Kumaraswamy Anbarasu
- From the Laboratory of Molecular Virology and Cell Biology, National Cancer Tissue Biobank, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology-Madras, Chennai 600 036, India
| | - Suryaraja Rajabather
- From the Laboratory of Molecular Virology and Cell Biology, National Cancer Tissue Biobank, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology-Madras, Chennai 600 036, India
| | - Rangasamy Sneha Priya
- From the Laboratory of Molecular Virology and Cell Biology, National Cancer Tissue Biobank, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology-Madras, Chennai 600 036, India
| | - Pavitra Desai
- From the Laboratory of Molecular Virology and Cell Biology, National Cancer Tissue Biobank, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology-Madras, Chennai 600 036, India
| | - Sundarasamy Mahalingam
- From the Laboratory of Molecular Virology and Cell Biology, National Cancer Tissue Biobank, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology-Madras, Chennai 600 036, India
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34
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Meng X, Carlson NR, Dong J, Zhang Y. Oncogenic c-Myc-induced lymphomagenesis is inhibited non-redundantly by the p19Arf-Mdm2-p53 and RP-Mdm2-p53 pathways. Oncogene 2015; 34:5709-17. [PMID: 25823025 DOI: 10.1038/onc.2015.39] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 11/24/2014] [Accepted: 01/14/2015] [Indexed: 01/01/2023]
Abstract
The multifaceted oncogene c-Myc plays important roles in the development and progression of human cancer. Recent in vitro and in vivo studies have shown that the p19Arf-Mdm2-p53 and the ribosomal protein (RP)-Mdm2-p53 pathways are both essential in preventing oncogenic c-Myc-induced tumorigenesis. Disruption of each pathway individually by p19Arf deletion or by Mdm2(C305F) mutation, which disrupts RP-Mdm2 binding, accelerates Eμ-myc transgene-induced pre-B/B-cell lymphoma in mice at seemingly similar paces with median survival around 10 and 11 weeks, respectively, compared to 20 weeks for Eμ-myc transgenic mice. Because p19Arf can inhibit ribosomal biogenesis through its interaction with nucleophosmin (NPM/B23), RNA helicase DDX5 and RNA polymerase I transcription termination factor (TTF-I), it has been speculated that the p19Arf-Mdm2-p53 and the RP-Mdm2-p53 pathways might be a single p19Arf-RP-Mdm2-p53 pathway, in which p19Arf activates p53 by inhibiting RP biosynthesis; thus, p19Arf deletion or Mdm2(C305F) mutation would result in similar consequences. Here, we generated mice with concurrent p19Arf deletion and Mdm2(C305F) mutation and investigated the compound mice for tumorigenesis in the absence and the presence of oncogenic c-Myc overexpression. In the absence of Eμ-myc transgene, the Mdm2(C305F) mutation did not elicit spontaneous tumors in mice, nor did it accelerate spontaneous tumors in mice with p19Arf deletion. In the presence of Eμ-myc transgene, however, Mdm2(C305F) mutation significantly accelerated p19Arf deletion-induced lymphomagenesis and promoted rapid metastasis. We found that when p19Arf-Mdm2-p53 and RP-Mdm2-p53 pathways are independently disrupted, oncogenic c-Myc-induced p53 stabilization and activation is only partially attenuated. When both pathways are concurrently disrupted, however, c-Myc-induced p53 stabilization and activation are essentially obliterated. Thus, the p19Arf-Mdm2-p53 and the RP-Mdm2-p53 are non-redundant pathways possessing similar capabilities to activate p53 upon c-Myc overexpression.
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Affiliation(s)
- X Meng
- Department of Radiation Oncology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Hospital and Institute of Hepatobiliary Surgery, Chinese PLA General Hospital, Beijing, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, China
| | - N R Carlson
- Department of Radiation Oncology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - J Dong
- Hospital and Institute of Hepatobiliary Surgery, Chinese PLA General Hospital, Beijing, China.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, China
| | - Y Zhang
- Department of Radiation Oncology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, China.,Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, USA
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35
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Kim TH, Leslie P, Zhang Y. Ribosomal proteins as unrevealed caretakers for cellular stress and genomic instability. Oncotarget 2015; 5:860-71. [PMID: 24658219 PMCID: PMC4011588 DOI: 10.18632/oncotarget.1784] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Ribosomal proteins (RPs) have gained much attention for their extraribosomal functions particularly with respect to p53 regulation. To date, about fourteen RPs have shown to bind to MDM2 and regulate p53. Upon binding to MDM2, the RPs suppress MDM2 E3 ubiquitin ligase activity resulting in the stabilization and activation of p53. Of the RPs that bind to MDM2, RPL5 and RPL11 are the most studied and RPL11 appears to have the most significant role in p53 regulation. Considering that more than 17% of RP species have been shown to interact with MDM2, one of the questions remains unresolved is why so many RPs bind MDM2 and modulate p53. Genes encoding RPs are widely dispersed on different chromosomes in both mice and humans. As components of ribosome, RP expression is tightly regulated to meet the appropriate stoichiometric ratio between RPs and rRNAs. Once genomic instability (e.g. aneuploidy) occurs, transcriptional and translational changes due to change of DNA copy number can result in an imbalance in the expression of RPs including those that bind to MDM2. Such an imbalance in RP expression could lead to failure to assemble functional ribosomes resulting in ribosomal stress. We propose that RPs have evolved ability to regulate MDM2 in response to genomic instability as an additional layer of p53 regulation. Full understanding of the biological roles of RPs could potentially establish RPs as a novel class of therapeutic targets in human diseases such as cancer.
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Affiliation(s)
- Tae-Hyung Kim
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC, USA
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36
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Chen CS, Ho DR, Chen FY, Chen CR, Ke YD, Su JGJ. AKT mediates actinomycin D-induced p53 expression. Oncotarget 2015; 5:693-703. [PMID: 24525337 PMCID: PMC3996664 DOI: 10.18632/oncotarget.1328] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
At high cytotoxic concentrations, actinomycin D (ActD) blocks transcription, decreasing levels of MDM2 and thus causing p53 stabilization. At low cytostatic concentrations, ActD causes ribosomal stress, which decreases MDM2 activity, resulting in p53 stabilization and activation. ActD can thus be used for p53-based cyclotherapy. We analyzed pathways mediating ActD-induced p53 expression. Inhibitors (LY294002, wortmannin, and deguelin) of phosphatidylinositol 3-kinases (PI3K) and AKT, but not inhibitors of MEK1/2, JNK, and p38-MAPK abolished the ActD-induced p53 expression in diverse cell types. RNA interference further supported these results. When AKT was downregulated by small hairpin RNA-AKTs, ActD-induced p53 expression was significantly decreased. ActD caused AKT phosphorylation at Ser473, indicating full activation of AKT. The potential for cancer therapy is discussed.
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Affiliation(s)
- Chih-Shou Chen
- Division of Urology, Department of Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan, ROC
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37
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Gismondi A, Caldarola S, Lisi G, Juli G, Chellini L, Iadevaia V, Proud CG, Loreni F. Ribosomal stress activates eEF2K-eEF2 pathway causing translation elongation inhibition and recruitment of terminal oligopyrimidine (TOP) mRNAs on polysomes. Nucleic Acids Res 2014; 42:12668-80. [PMID: 25332393 PMCID: PMC4227798 DOI: 10.1093/nar/gku996] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 09/30/2014] [Accepted: 10/06/2014] [Indexed: 11/14/2022] Open
Abstract
The synthesis of adequate amounts of ribosomes is an essential task for the cell. It is therefore not surprising that regulatory circuits exist to organize the synthesis of ribosomal components. It has been shown that defect in ribosome biogenesis (ribosomal stress) induces apoptosis or cell cycle arrest through activation of the tumor suppressor p53. This mechanism is thought to be implicated in the pathophysiology of a group of genetic diseases such as Diamond Blackfan Anemia which are called ribosomopathies. We have identified an additional response to ribosomal stress that includes the activation of eukaryotic translation elongation factor 2 kinase with a consequent inhibition of translation elongation. This leads to a translational reprogramming in the cell that involves the structurally defined group of messengers called terminal oligopyrimidine (TOP) mRNAs which encode ribosomal proteins and translation factors. In fact, while general protein synthesis is decreased by the impairment of elongation, TOP mRNAs are recruited on polysomes causing a relative increase in the synthesis of TOP mRNA-encoded proteins compared to other proteins. Therefore, in response to ribosomal stress, there is a change in the translation pattern of the cell which may help restore a sufficient level of ribosomes.
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Affiliation(s)
- Angelo Gismondi
- Department of Biology, University Tor Vergata, Roma, 00133, Italy
| | - Sara Caldarola
- Department of Biology, University Tor Vergata, Roma, 00133, Italy
| | - Gaia Lisi
- Department of Biology, University Tor Vergata, Roma, 00133, Italy
| | - Giada Juli
- Department of Biology, University Tor Vergata, Roma, 00133, Italy
| | - Lidia Chellini
- Department of Biology, University Tor Vergata, Roma, 00133, Italy
| | - Valentina Iadevaia
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | | | - Fabrizio Loreni
- Department of Biology, University Tor Vergata, Roma, 00133, Italy
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Maruyama Y, Miyazaki T, Ikeda K, Okumura T, Sato W, Horie-Inoue K, Okamoto K, Takeda S, Inoue S. Short hairpin RNA library-based functional screening identified ribosomal protein L31 that modulates prostate cancer cell growth via p53 pathway. PLoS One 2014; 9:e108743. [PMID: 25285958 PMCID: PMC4186824 DOI: 10.1371/journal.pone.0108743] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/25/2014] [Indexed: 11/22/2022] Open
Abstract
Androgen receptor is a primary transcription factor involved in the proliferation of prostate cancer cells. Thus, hormone therapy using antiandrogens, such as bicalutamide, is a first-line treatment for the disease. Although hormone therapy initially reduces the tumor burden, many patients eventually relapse, developing tumors with acquired endocrine resistance. Elucidation of the molecular mechanisms underlying endocrine resistance is therefore a fundamental issue for the understanding and development of alternative therapeutics for advanced prostate cancer. In the present study, we performed short hairpin RNA (shRNA)-mediated functional screening to identify genes involved in bicalutamide-mediated effects on LNCaP prostate cancer cells. Among such candidate genes selected by screening using volcano plot analysis, ribosomal protein L31 (RPL31) was found to be essential for cell proliferation and cell-cycle progression in bicalutamide-resistant LNCaP (BicR) cells, based on small interfering RNA (siRNA)-mediated knockdown experiments. Of note, RPL31 mRNA is more abundantly expressed in BicR cells than in parental LNCaP cells, and clinical data from ONCOMINE and The Cancer Genome Altas showed that RPL31 is overexpressed in prostate carcinomas compared with benign prostate tissues. Intriguingly, protein levels of the tumor suppressor p53 and its targets, p21 and MDM2, were increased in LNCaP and BicR cells treated with RPL31 siRNA. We observed decreased degradation of p53 protein after RPL31 knockdown. Moreover, the suppression of growth and cell cycle upon RPL31 knockdown was partially recovered with p53 siRNA treatment. These results suggest that RPL31 is involved in bicalutamide-resistant growth of prostate cancer cells. The shRNA-mediated functional screen in this study provides new insight into the molecular mechanisms and therapeutic targets of advanced prostate cancer.
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Affiliation(s)
- Yojiro Maruyama
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
- Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo, Japan
| | - Toshiaki Miyazaki
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Kazuhiro Ikeda
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Toshiyuki Okumura
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Wataru Sato
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Kuniko Horie-Inoue
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Koji Okamoto
- Division of Cancer Differentiation, National Cancer Center Research Institute, Tokyo, Japan
| | - Satoru Takeda
- Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo, Japan
| | - Satoshi Inoue
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
- Departments of Geriatric Medicine and Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- * E-mail:
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Abdel Hamid TM, El Gammal MM, Eibead GT, Saber MM, Abol Elazm OM. Clinical impact of SNP of P53 genes pathway on the adult AML patients. ACTA ACUST UNITED AC 2014; 20:328-35. [PMID: 25232917 DOI: 10.1179/1607845414y.0000000200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
INTRODUCTION Acute myeloid leukemia (AML) is a highly heterogeneous disease, with biologically and prognostically different subtypes. AIM To study the impact of p53, p21, and mdm2 gene polymorphisms on the clinical outcome in adult AML patients treated at the National Cancer Institute (NCI) - Cairo University. METHODS Forty-eight adult AML patients presented to the Medical Oncology Department, NCI, from April 2010 till November 2011. Clinical data and bone marrow samples were obtained. Molecular genetic analysis involving P53, MDM2, and P21 single-nucleotide gene polymorphisms was done using polymerase chain reaction-restriction fragment length polymorphism coupled analysis. RESULTS The mean age was 35.7 years. After a median follow-up period of 12 months, 28 patients (58.4%) achieved complete remission (CR) and the overall survival (OS) was 8.7 months. Patients with homozygous Arg/arg at codon 72 of P53 had a better median OS months than Arg/Pro and Pro/Pro (13.4 vs. 8.4 vs. 1.5 months, respectively; P = 0.045). P53/p21 combination had a better median OS and disease-free survival (DFS) of 12.1 and 13.7 months for wild type cases (GG + Ser/ser) and 20.3 and 20.7 months for patients with either variant genes (GC + Ser/arg) compared with 1.1 and 1.9 months for patients with both variant genes (CC + arg/arg), (P = 0.037 and 0.004). The presence of wild genotype of either P21 or MDM2 may abolish the effect of P53 homozygous variant genotype on the OS. Neither p21nor mdm2 polymorphism alone showed an impact on OS or DFS. CR was not affected by any of the three gene polymorphisms. CONCLUSION The p53 pathway gene polymorphisms may affect the OS of adult AML patients.
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Wang W, Nag S, Zhang X, Wang MH, Wang H, Zhou J, Zhang R. Ribosomal proteins and human diseases: pathogenesis, molecular mechanisms, and therapeutic implications. Med Res Rev 2014; 35:225-85. [PMID: 25164622 DOI: 10.1002/med.21327] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ribosomes are essential components of the protein synthesis machinery. The process of ribosome biogenesis is well organized and tightly regulated. Recent studies have shown that ribosomal proteins (RPs) have extraribosomal functions that are involved in cell proliferation, differentiation, apoptosis, DNA repair, and other cellular processes. The dysfunction of RPs has been linked to the development and progression of hematological, metabolic, and cardiovascular diseases and cancer. Perturbation of ribosome biogenesis results in ribosomal stress, which triggers activation of the p53 signaling pathway through RPs-MDM2 interactions, resulting in p53-dependent cell cycle arrest and apoptosis. RPs also regulate cellular functions through p53-independent mechanisms. We herein review the recent advances in several forefronts of RP research, including the understanding of their biological features and roles in regulating cellular functions, maintaining cell homeostasis, and their involvement in the pathogenesis of human diseases. We also highlight the translational potential of this research for the identification of molecular biomarkers, and in the discovery and development of novel treatments for human diseases.
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Affiliation(s)
- Wei Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas, 79106; Cancer Biology Center, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas, 79106
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Diesch J, Hannan RD, Sanij E. Perturbations at the ribosomal genes loci are at the centre of cellular dysfunction and human disease. Cell Biosci 2014; 4:43. [PMID: 25949792 PMCID: PMC4422213 DOI: 10.1186/2045-3701-4-43] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 07/27/2014] [Indexed: 01/05/2023] Open
Abstract
Ribosomal RNA (rRNA) gene (rDNA) transcription by RNA Polymerase I (Pol I) drives cell growth and underlies nucleolar structure and function, indirectly coordinating many fundamental cellular processes. The importance of keeping rDNA transcription under tight control is reflected by the fact that deranged Pol I transcription is a feature of cancer and other human disorders. In this review, we discuss multiple aspects of rDNA function including the relationship between Pol I transcription and proliferative capacity, the role of Pol I transcription in mediating nucleolar structure and integrity, and rDNA/nucleolar interactions with the genome and their influence on heterochromatin and global genome stability. Furthermore, we discuss how perturbations in the structure of the rDNA loci might contribute to human disease, in some cases independent of effects on ribosome biogenesis.
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Affiliation(s)
- Jeannine Diesch
- Growth Control Laboratory, Research Division, Peter MacCallum Cancer Centre, St. Andrews Place, East Melbourne, Victoria 3002, Australia ; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Ross D Hannan
- Growth Control Laboratory, Research Division, Peter MacCallum Cancer Centre, St. Andrews Place, East Melbourne, Victoria 3002, Australia ; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria 3010, Australia ; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia ; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia ; Division of Cancer Medicine, Peter MacCallum Cancer Centre, St. Andrews Place, East Melbourne, Victoria 3002, Australia ; School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Elaine Sanij
- Growth Control Laboratory, Research Division, Peter MacCallum Cancer Centre, St. Andrews Place, East Melbourne, Victoria 3002, Australia ; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria 3010, Australia ; Department of Pathology, University of Melbourne, Parkville, Victoria 3010, Australia
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42
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Sierecki E, Giles N, Polinkovsky M, Moustaqil M, Alexandrov K, Gambin Y. A cell-free approach to accelerate the study of protein-protein interactions in vitro. Interface Focus 2014; 3:20130018. [PMID: 24511386 DOI: 10.1098/rsfs.2013.0018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Protein-protein interactions are highly desirable targets in drug discovery, yet only a fraction of drugs act as binding inhibitors. Here, we review the different technologies used to find and validate protein-protein interactions. We then discuss how the novel combination of cell-free protein expression, AlphaScreen and single-molecule fluorescence spectroscopy can be used to rapidly map protein interaction networks, determine the architecture of protein complexes, and find new targets for drug discovery.
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Affiliation(s)
- E Sierecki
- Institute for Molecular Bioscience , University of Queensland , Saint Lucia, Queensland , Australia
| | - N Giles
- Institute for Molecular Bioscience , University of Queensland , Saint Lucia, Queensland , Australia
| | - M Polinkovsky
- Institute for Molecular Bioscience , University of Queensland , Saint Lucia, Queensland , Australia
| | - M Moustaqil
- Institute for Molecular Bioscience , University of Queensland , Saint Lucia, Queensland , Australia
| | - K Alexandrov
- Institute for Molecular Bioscience , University of Queensland , Saint Lucia, Queensland , Australia
| | - Y Gambin
- Institute for Molecular Bioscience , University of Queensland , Saint Lucia, Queensland , Australia
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43
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Havel JJ, Li Z, Cheng D, Peng J, Fu H. Nuclear PRAS40 couples the Akt/mTORC1 signaling axis to the RPL11-HDM2-p53 nucleolar stress response pathway. Oncogene 2014; 34:1487-98. [PMID: 24704832 PMCID: PMC4216640 DOI: 10.1038/onc.2014.91] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 02/26/2014] [Accepted: 03/01/2014] [Indexed: 12/27/2022]
Abstract
The Ribosomal Protein (RP)-HDM2-p53 pathway has been shown to play key roles in oncogene-induced apoptosis and senescence, but the mechanism regulating this pathway remains elusive. The Proline-Rich Akt Substrate of 40 kDA (PRAS40) has recently been identified as a binding partner and inhibitor of the mechanistic Target of Rapamycin Complex 1 (mTORC1). Although other inhibitors of mTORC1 are known tumor suppressors, PRAS40 promotes cell survival and tumorigenesis. Here we demonstrate that Akt- and mTORC1-mediated phosphorylation of PRAS40 at T246 and S221, respectively, promotes nuclear-specific association of PRAS40 with Ribosomal Protein L11 (RPL11). Importantly, silencing of PRAS40 induces upregulation of p53 in a manner dependent upon RPL11. This effect is rescued by wild type PRAS40, but not by the RPL11 binding-null PRAS40 T246A mutant. We find that PRAS40 negatively regulates the RPL11-HDM2-p53 nucleolar stress response pathway and suppresses induction of p53-mediated cellular senescence. This work identifies nuclear PRAS40 as a dual-input signaling checkpoint that links cell growth and proliferation to inhibition of cellular senescence. These findings may help to explain the pro-tumorigenic effect of PRAS40 and identify the PRAS40-RPL11 complex as a promising target for p53-restorative anti-cancer drug discovery.
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Affiliation(s)
- J J Havel
- 1] Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA [2] Graduate Program in Molecular and Systems Pharmacology, Emory University, Atlanta, GA, USA
| | - Z Li
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - D Cheng
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - J Peng
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - H Fu
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
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Zhao Y, Yu H, Hu W. The regulation of MDM2 oncogene and its impact on human cancers. Acta Biochim Biophys Sin (Shanghai) 2014; 46:180-9. [PMID: 24389645 DOI: 10.1093/abbs/gmt147] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Tumor suppressor p53 plays a central role in preventing tumor formation. The levels and activity of p53 is under tight regulation to ensure its proper function. Murine double minute 2 (MDM2), a p53 target gene, is an E3 ubiquitin ligase. MDM2 is a key negative regulator of p53 protein, and forms an auto-regulatory feedback loop with p53. MDM2 is an oncogene with both p53-dependent and p53-independent oncogenic activities, and often has increased expression levels in a variety of human cancers. MDM2 is highly regulated; the levels and function of MDM2 are regulated at the transcriptional, translational and post-translational levels. This review provides an overview of the regulation of MDM2. Dysregulation of MDM2 impacts significantly upon the p53 functions, and in turn the tumorigenesis. Considering the key role that MDM2 plays in human cancers, a better understanding of the regulation of MDM2 will help us to develop novel and more effective cancer therapeutic strategies to target MDM2 and activate p53 in cells.
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Affiliation(s)
- Yuhan Zhao
- Rutgers Cancer Institute of New Jersey, Rutgers the State University of New Jersey, New Brunswick, NJ 08903, USA
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45
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Wang L, Liu Z, Jing P, Shao L, Chen L, He X, Gong W. Effects of murine double minute 2 polymorphisms on the risk and survival of osteosarcoma: a systemic review and meta-analysis. Tumour Biol 2014; 35:1649-52. [PMID: 24122202 DOI: 10.1007/s13277-013-1227-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 09/16/2013] [Indexed: 01/24/2023] Open
Abstract
Murine double minute 2 (MDM2) plays an important role in the carcinogenesis of many cancers including osteosarcoma. We performed a systemic review and meta-analysis to assess the effects of MDM2 polymorphisms on osteosarcoma risk and survival of patients with osteosarcoma. PubMed, Web of Science, and Wanfang databases were searched for eligible studies on the associations of MDM2 polymorphisms with osteosarcoma risk and survival of patients with osteosarcoma. Pooled odds ratio (OR) or hazard ratio (HR) with 95 % confidence intervals (95 % CIs) was used to assess the effects of MDM2 polymorphisms on osteosarcoma risk and survival of patients with osteosarcoma. Overall, MDM2 rs2279744 polymorphism was associated with a risk of osteosarcoma (allele model, OR = 1.60, 95 % CI 1.23-2.07, P < 0.001; codominant model, OR = 2.47, 95 % CI 1.46-4.19, P = 0.001; recessive model, OR = 2.13, 95 % CI 1.32-3.46, P = 0.002; dominant model, OR = 1.61, 95 % CI 1.12-2.33, P = 0.01). MDM2 rs1690916 polymorphism was also associated with a risk of osteosarcoma (OR = 0.60, 95 % CI 0.46-0.77, P < 0.001). However, MDM2 rs2279744 polymorphism was not associated with the overall survival of patients with osteosarcoma (codominant model, HR = 1.01, 95 % CI 0.53-1.91, P = 0.98; recessive model, HR = 1.07, 95 % CI 0.54-2.11, P = 0.85; dominant model, HR = 1.04, 95 % CI 0.65-1.66, P = 0.87). The meta-analysis suggests that MDM2 polymorphisms have some effects on the risk of osteosarcoma but have no effect on the survival of patients with osteosarcoma. Future studies are needed to further assess the effects of MDM2 polymorphisms on the risk and survival of osteosarcoma.
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46
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Quin JE, Devlin JR, Cameron D, Hannan KM, Pearson RB, Hannan RD. Targeting the nucleolus for cancer intervention. Biochim Biophys Acta Mol Basis Dis 2014; 1842:802-16. [PMID: 24389329 DOI: 10.1016/j.bbadis.2013.12.009] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 12/17/2013] [Indexed: 12/17/2022]
Abstract
The contribution of the nucleolus to cancer is well established with respect to its traditional role in facilitating ribosome biogenesis and proliferative capacity. More contemporary studies however, infer that nucleoli contribute a much broader role in malignant transformation. Specifically, extra-ribosomal functions of the nucleolus position it as a central integrator of cellular proliferation and stress signaling, and are emerging as important mechanisms for modulating how oncogenes and tumor suppressors operate in normal and malignant cells. The dependence of certain tumor cells to co-opt nucleolar processes to maintain their cancer phenotypes has now clearly been demonstrated by the application of small molecule inhibitors of RNA Polymerase I to block ribosomal DNA transcription and disrupt nucleolar function (Bywater et al., 2012 [1]). These drugs, which selectively kill tumor cells in vivo while sparing normal cells, have now progressed to clinical trials. It is likely that we have only just begun to scratch the surface of the potential of the nucleolus as a new target for cancer therapy, with "suppression of nucleolar stress" representing an emerging "hallmark" of cancer. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.
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Affiliation(s)
- Jaclyn E Quin
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Jennifer R Devlin
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Donald Cameron
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Kate M Hannan
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Richard B Pearson
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Ross D Hannan
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia; School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.
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Bai D, Zhang J, Xiao W, Zheng X. Regulation of the HDM2-p53 pathway by ribosomal protein L6 in response to ribosomal stress. Nucleic Acids Res 2013; 42:1799-811. [PMID: 24174547 PMCID: PMC3919599 DOI: 10.1093/nar/gkt971] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The HDM2-p53 loop is crucial for monitoring p53 level and human pathologies. Therefore, identification of novel molecules involved in this regulatory loop is necessary for understanding the dynamic regulation of p53 and treatment of human diseases. Here, we characterized that the ribosomal protein L6 binds to and suppresses the E3 ubiquitin ligase activity of HDM2, and subsequently attenuates HDM2-mediated p53 polyubiquitination and degradation. The enhanced p53 activity further slows down cell cycle progression and leads to cell growth inhibition. Conversely, the level of p53 is dramatically decreased upon the depletion of RPL6, indicating that RPL6 is essential for p53 stabilization. We also found that RPL6 translocalizes from the nucleolus to nucleoplasm under ribosomal stress, which facilitates its binding with HDM2. The interaction of RPL6 and HDM2 drives HDM2-mediated RPL6 polyubiquitination and proteasomal degradation. Longer treatment of actinomycin D increases RPL6 ubiquitination and destabilizes RPL6, and thereby putatively attenuates p53 response until the level of L6 subsides. Therefore, RPL6 and HDM2 form an autoregulatory feedback loop to monitor the level of p53 in response to ribosomal stress. Together, our study identifies the crucial function of RPL6 in regulating HDM2-p53 pathway, which highlights the importance of RPL6 in human genetic diseases and cancers.
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Affiliation(s)
- Dongmei Bai
- State Key Lab of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China and Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Beijing 100871, China
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Chillemi G, Davidovich P, D'Abramo M, Mametnabiev T, Garabadzhiu AV, Desideri A, Melino G. Molecular dynamics of the full-length p53 monomer. Cell Cycle 2013; 12:3098-108. [PMID: 23974096 DOI: 10.4161/cc.26162] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The p53 protein is frequently mutated in a very large proportion of human tumors, where it seems to acquire gain-of-function activity that facilitates tumor onset and progression. A possible mechanism is the ability of mutant p53 proteins to physically interact with other proteins, including members of the same family, namely p63 and p73, inactivating their function. Assuming that this interaction might occurs at the level of the monomer, to investigate the molecular basis for this interaction, here, we sample the structural flexibility of the wild-type p53 monomeric protein. The results show a strong stability up to 850 ns in the DNA binding domain, with major flexibility in the N-terminal transactivations domains (TAD1 and TAD2) as well as in the C-terminal region (tetramerization domain). Several stable hydrogen bonds have been detected between N-terminal or C-terminal and DNA binding domain, and also between N-terminal and C-terminal. Essential dynamics analysis highlights strongly correlated movements involving TAD1 and the proline-rich region in the N-terminal domain, the tetramerization region in the C-terminal domain; Lys120 in the DNA binding region. The herein presented model is a starting point for further investigation of the whole protein tetramer as well as of its mutants.
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McCubrey JA, Demidenko ZN. Recent discoveries in the cycling, growing and aging of the p53 field. Aging (Albany NY) 2013; 4:887-93. [PMID: 23425920 PMCID: PMC3615156 DOI: 10.18632/aging.100529] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The P53 gene and it product p53 protein is the most studied tumor suppressor, which was considered as oncogene for two decades until 1990. More than 60 thousand papers on the topic of p53 has been abstracted in Pubmed. What yet could be discovered about its role in cell death, growth arrest and apoptosis, as well as a mediator of the therapeutic effect of anticancer drugs. Still during recent few years even more amazing discoveries have been done. Here we review such topics as suppression of epigenetic silencing of a large number of non-coding RNAs, role of p53 in suppression of the senescence phenotype, inhibition of oncogenic metabolism, protection of normal cells from chemotherapy and even tumor suppression without apoptosis and cell cycle arrest.
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Affiliation(s)
- James A McCubrey
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, NC 27858, USA.
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Wang Z, Inuzuka H, Zhong J, Fukushima H, Wan L, Liu P, Wei W. DNA damage-induced activation of ATM promotes β-TRCP-mediated Mdm2 ubiquitination and destruction. Oncotarget 2013; 3:1026-35. [PMID: 22976441 PMCID: PMC3660052 DOI: 10.18632/oncotarget.640] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Mdm2 oncoprotein promotes p53 ubiquitination and destruction. Yet, exact molecular mechanisms of Mdm2 destruction itself, under DNA damaging conditions, remain unclear. Recently, we identified SCFβ-TRCP as a novel E3 ligase that targets Mdm2 for ubiquitination and destruction in a Casein Kinase Iδ (CKIδ)-dependent manner. However, it remains elusive how the β-TRCP/CKIδ/Mdm2 signaling axis is regulated by DNA damage signals to govern p53 activity. Consistent with previous studies, we found that inactivation of the Ataxia Telangiectasia Mutated (ATM) kinase, in turn, impaired DNA damage-induced Mdm2 destruction. Although phosphorylation of Mdm2 at Ser395 (an ATM phosphorylation site) facilitated Mdm2 interaction with β-TRCP, Ser395A-Mdm2 was degraded non-distinguishably from WT-Mdm2 by SCFβ-TRCP upon DNA damaging treatments. This indicates that in addition to phosphorylating Mdm2 at Ser395, ATM may govern Mdm2 stability through other unknown mechanisms. We further demonstrated that DNA damage-induced activation of ATM directly phosphorylated CKIδ at two well-conserved S/TQ sites, which promotes CKIδ nuclear localization to increase CKIδ-mediated phosphorylation of Mdm2, thereby facilitating subsequent Mdm2 ubiquitination by SCFβ-TRCP. Our studies provide a molecular mechanism of how ATM could govern DNA damage-induced destruction of Mdm2 in part by phosphorylating both Mdm2 and CKIδ to modulate SCFβ-TRCP–mediated Mdm2 ubiquitination. Given the pivotal role of Mdm2 in the negative regulation of p53, this work will also provide a rationale for developing CKIδ or ATM agonists as anti-cancer agents.
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Affiliation(s)
- Zhiwei Wang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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