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Maehama T, Nishio M, Otani J, Mak TW, Suzuki A. Nucleolar stress: Molecular mechanisms and related human diseases. Cancer Sci 2023; 114:2078-2086. [PMID: 36762786 PMCID: PMC10154868 DOI: 10.1111/cas.15755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/29/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
Ribosome biogenesis in the nucleolus is an important process that consumes 80% of a cell's intracellular energy supply. Disruption of this process results in nucleolar stress, triggering the activation of molecular systems that respond to this stress to maintain homeostasis. Although nucleolar stress was originally thought to be caused solely by abnormalities of ribosomal RNA (rRNA) and ribosomal proteins (RPs), an accumulating body of more current evidence suggests that many other factors, including the DNA damage response and oncogenic stress, are also involved in nucleolar stress response signaling. Cells reacting to nucleolar stress undergo cell cycle arrest or programmed death, mainly driven by activation of the tumor suppressor p53. This observation has nominated nucleolar stress as a promising target for cancer therapy. However, paradoxically, some RP mutations have also been implicated in cancer initiation and progression, necessitating caution. In this article, we summarize recent findings on the molecular mechanisms of nucleolar stress and the human ribosomal diseases and cancers that arise in its wake.
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Affiliation(s)
- Tomohiko Maehama
- Division of Molecular and Cellular Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Miki Nishio
- Division of Molecular and Cellular Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Junji Otani
- Division of Molecular and Cellular Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tak Wah Mak
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada.,Departments of Immunology and Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Department of Pathology, LKS Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong
| | - Akira Suzuki
- Division of Molecular and Cellular Biology, Kobe University Graduate School of Medicine, Kobe, Japan
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2
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Ishihara Y, Nakamura K, Nakagawa S, Okamoto Y, Yamamoto M, Furukawa T, Kawahara K. Nucleolar Stress Response via Ribosomal Protein L11 Regulates Topoisomerase Inhibitor Sensitivity of P53-Intact Cancers. Int J Mol Sci 2022; 23:ijms232415986. [PMID: 36555627 PMCID: PMC9784028 DOI: 10.3390/ijms232415986] [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: 10/28/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Nucleolar stress response is caused by perturbations in ribosome biogenesis, induced by the inhibition of ribosomal RNA processing and synthesis, as well as ribosome assembly. This response induces p53 stabilization and activation via ribosomal protein L11 (RPL11), suppressing tumor progression. However, anticancer agents that kill cells via this mechanism, and their relationship with the therapeutic efficiency of these agents, remain largely unknown. Here, we sought to investigate whether topoisomerase inhibitors can induce nucleolar stress response as they reportedly block ribosomal RNA transcription. Using rhabdomyosarcoma and rhabdoid tumor cell lines that are sensitive to the nucleolar stress response, we evaluated whether nucleolar stress response is associated with sensitivity to topoisomerase inhibitors ellipticine, doxorubicin, etoposide, topotecan, and anthracyclines. Cell proliferation assay indicated that small interfering RNA-mediated RPL11 depletion resulted in decreased sensitivity to topoisomerase inhibitors. Furthermore, the expression of p53 and its downstream target proteins via western blotting showed the suppression of p53 pathway activation upon RPL11 knockdown. These results suggest that the sensitivity of cancer cells to topoisomerase inhibitors is regulated by RPL11-mediated nucleolar stress responses. Thus, RPL11 expression may contribute to the prediction of the therapeutic efficacy of topoisomerase inhibitors and increase their therapeutic effect of topoisomerase inhibitors.
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Affiliation(s)
- Yuka Ishihara
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8520, Japan
| | - Kiyoshiro Nakamura
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8520, Japan
| | - Shunsuke Nakagawa
- Department of Pediatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8520, Japan
| | - Yasuhiro Okamoto
- Department of Pediatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8520, Japan
| | - Masatatsu Yamamoto
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8520, Japan
| | - Tatsuhiko Furukawa
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8520, Japan
| | - Kohichi Kawahara
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8520, Japan
- Correspondence: ; Tel.: +81-99-275-5490
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3
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Wu M, Lu L, Chen S, Li Y, Zhang Q, Fu S, Deng X. Natural products inducing nucleolar stress: implications in cancer therapy. Anticancer Drugs 2022; 33:e21-e27. [PMID: 34561998 DOI: 10.1097/cad.0000000000001146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The nucleolus is the site of ribosome biogenesis and is found to play an important role in stress sensing. For over 100 years, the increase in the size and number of nucleoli has been considered as a marker of aggressive tumors. Despite this, the contribution of the nucleolus and the biologic processes mediated by it to cancer pathogenesis has been largely overlooked. This state has been changed over the recent decades with the demonstration that the nucleolus controls numerous cellular functions associated with cancer development. Induction of nucleolar stress has recently been regarded as being superior to conventional cytotoxic/cytostatic strategy in that it is more selective to neoplastic cells while sparing normal cells. Natural products represent an excellent source of bioactive molecules and some of them have been found to be able to induce nucleolar stress. The demonstration of these nucleolar stress-inducing natural products has paved the way for a new therapeutic approach to more delicate tumor cell-killing. This review provides a contemporary summary of the role of the nucleolus as a novel promising target for cancer therapy, with particular emphasis on natural products as an exciting new class of anti-cancer drugs with nucleolar stress-inducing properties.
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Affiliation(s)
- Mi Wu
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University
- Department of Pathophysiology, Hunan Normal University School of Medicine, Changsha
| | - Lu Lu
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University
- Department of Pathophysiology, Hunan Normal University School of Medicine, Changsha
| | - Sisi Chen
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University
- Department of Pathophysiology, Hunan Normal University School of Medicine, Changsha
| | - Ying Li
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University
- Department of Pathophysiology, Hunan Normal University School of Medicine, Changsha
| | - Qiuting Zhang
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University
- Department of Pathophysiology, Hunan Normal University School of Medicine, Changsha
| | - Shujun Fu
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University
- Department of Pathophysiology, Hunan Normal University School of Medicine, Changsha
| | - Xiyun Deng
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University
- Department of Pathophysiology, Hunan Normal University School of Medicine, Changsha
- Department of Pathophysiology, Jishou University School of Medicine, Jishou, Hunan, China
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4
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Kudo M, Anam MB, Istiaq A, Ahmad SAI, Ito N, Ohta K. Ribosome Incorporation Induces EMT-like Phenomenon with Cell Cycle Arrest in Human Breast Cancer Cell. Cells Tissues Organs 2021; 211:212-221. [PMID: 33640894 DOI: 10.1159/000513908] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 12/18/2020] [Indexed: 01/10/2023] Open
Abstract
Although ribosomes are generally known to be a translational machinery, some ribosomal proteins also have accessory functions involving early development and differentiation. Previously, we reported that ribosome incorporation into human dermal fibroblasts generated embryoid body-like cell clusters, altered cellular fate, and differentiated into cells of all 3 germ layers. However, the molecular phenomena induced by ribosome incorporation in the cell remained unknown. Here, we demonstrate that ribosome incorporation into human breast cancer cell MCF7 leads to ribosome-induced cell clusters (RICs) formation accompanying with epithelial-mesenchymal transition (EMT)-like gene expression. Following ribosome incorporation, MCF7 cells cease proliferation, which is caused by inhibition of cell cycle transition from G0 to G1 phase. Further, MCF7 RICs show induced expression of EMT markers, TGF-β1 and Snail along with autophagy markers and tumor suppressor gene p53. These findings indicate that the incorporation of ribosome into cancer cells induces an EMT-like phenomenon and changes the cancer cell characteristics.
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Affiliation(s)
- Mikiko Kudo
- Department of Stem Cell Biology, Faculty of Arts and Science, Kyushu University, Fukuoka, Japan.,Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Mohammad Badrul Anam
- Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Arif Istiaq
- Department of Stem Cell Biology, Faculty of Arts and Science, Kyushu University, Fukuoka, Japan.,Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.,HIGO Program, Kumamoto University, Kumamoto, Japan
| | - Shah Adil Ishtiyaq Ahmad
- Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.,Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, Bangladesh
| | - Naofumi Ito
- Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kunimasa Ohta
- Department of Stem Cell Biology, Faculty of Arts and Science, Kyushu University, Fukuoka, Japan, .,Department of Developmental Neurobiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan,
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5
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Jangid A, Malik MZ, Ramaswamy R, Singh RKB. Transition and identification of pathological states in p53 dynamics for therapeutic intervention. Sci Rep 2021; 11:2349. [PMID: 33504910 PMCID: PMC7840995 DOI: 10.1038/s41598-021-82054-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 01/11/2021] [Indexed: 01/30/2023] Open
Abstract
We study a minimal model of the stress-driven p53 regulatory network that includes competition between active and mutant forms of the tumor-suppressor gene p53. Depending on the nature and level of the external stress signal, four distinct dynamical states of p53 are observed. These states can be distinguished by different dynamical properties which associate to active, apoptotic, pre-malignant and cancer states. Transitions between any two states, active, apoptotic, and cancer, are found to be unidirectional and irreversible if the stress signal is either oscillatory or constant. When the signal decays exponentially, the apoptotic state vanishes, and for low stress the pre-malignant state is bounded by two critical points, allowing the system to transition reversibly from the active to the pre-malignant state. For significantly large stress, the range of the pre-malignant state expands, and the system moves to irreversible cancerous state, which is a stable attractor. This suggests that identification of the pre-malignant state may be important both for therapeutic intervention as well as for drug delivery.
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Affiliation(s)
- Amit Jangid
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Md Zubbair Malik
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Ram Ramaswamy
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, 110016, India.
| | - R K Brojen Singh
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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6
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Micol-Ponce R, Sarmiento-Mañús R, Fontcuberta-Cervera S, Cabezas-Fuster A, de Bures A, Sáez-Vásquez J, Ponce MR. SMALL ORGAN4 Is a Ribosome Biogenesis Factor Involved in 5.8S Ribosomal RNA Maturation. PLANT PHYSIOLOGY 2020; 184:2022-2039. [PMID: 32913045 PMCID: PMC7723108 DOI: 10.1104/pp.19.01540] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 08/27/2020] [Indexed: 05/09/2023]
Abstract
Ribosome biogenesis is crucial for cellular metabolism and has important implications for disease and aging. Human (Homo sapiens) glioma tumor-suppressor candidate region gene2 (GLTSCR2) and yeast (Saccharomyces cerevisiae) Nucleolar protein53 (Nop53) are orthologous proteins with demonstrated roles as ribosome biogenesis factors; knockdown of GLTSCR2 impairs maturation of 18S and 5.8S ribosomal RNAs (rRNAs), and Nop53 is required for maturation of 5.8S and 25S rRNAs. Here, we characterized SMALL ORGAN4 (SMO4), the most likely ortholog of human GLTSCR2 and yeast Nop53 in Arabidopsis (Arabidopsis thaliana). Loss of function of SMO4 results in a mild morphological phenotype; however, we found that smo4 mutants exhibit strong cytological and molecular phenotypes: nucleolar hypertrophy and disorganization, overaccumulation of 5.8S and 18S rRNA precursors, and an imbalanced 40S:60S ribosome subunit ratio. Like yeast Nop53 and human GLTSCR2, Arabidopsis SMO4 participates in 5.8S rRNA maturation. In yeast, Nop53 cooperates with mRNA transport4 (Mtr4) for 5.8S rRNA maturation. In Arabidopsis, we found that SMO4 plays similar roles in the 5.8S rRNA maturation pathway than those described for MTR4. However, SMO4 seems not to participate in the degradation of by-products derived from the 5'-external transcribed spacer (ETS) of 45S pre-rRNA, as MTR4 does.
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Affiliation(s)
- Rosa Micol-Ponce
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Alicante, Spain
| | - Raquel Sarmiento-Mañús
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Alicante, Spain
| | - Sara Fontcuberta-Cervera
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Alicante, Spain
| | - Adrián Cabezas-Fuster
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Alicante, Spain
| | - Anne de Bures
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, 66860 Perpignan, France
- Universite Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, 66860 Perpignan, France
| | - Julio Sáez-Vásquez
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, 66860 Perpignan, France
- Universite Perpignan Via Domitia, Laboratoire Génome et Développement des Plantes, Unité Mixte de Recherche 5096, 66860 Perpignan, France
| | - María Rosa Ponce
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Alicante, Spain
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7
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Park YJ, Kim TS, Kim EH, Kim HD, Kim J. Ribosomal protein S3 is a novel negative regulator of non-homologous end joining repair of DNA double-strand breaks. FASEB J 2020; 34:8102-8113. [PMID: 32297663 DOI: 10.1096/fj.201903245r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/16/2020] [Accepted: 03/31/2020] [Indexed: 11/11/2022]
Abstract
DNA double-strand breaks (DSBs) are one of the most serious types of DNA damage. However, multiple repair pathways are present in cells to ensure rapid and appropriate repair of DSBs. Pathway selection depends on several factors including cell type, cell cycle phase, and damage severity. Ribosomal protein S3 (rpS3), a component of the 40S small ribosomal subunit, is a multi-functional protein primarily involved in protein synthesis. rpS3 is also involved in the mediation of various extra-ribosomal pathways, including DNA damage processing and the stress response. Here, we report that rpS3 is a novel negative regulator of non-homologous end joining (NHEJ)-mediated repair of DSBs. We found that rpS3 interacts with the Ku heterodimers of the DNA-dependent protein kinase (DNA-PK) complex and slows down NHEJ ligation reactions, ultimately triggering p53-dependent cell death following treatment with high-dose ionizing radiation. After DSB formation, DNA-PK phosphorylates rpS3, which consequently reduces the binding of rpS3 to the Ku complex. We hypothesized that rpS3 may play a role in DSB repair by repressing NHEJ, while inducing other repair pathways, and by initiating DSB-induced cell death in response to severe DNA damage.
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Affiliation(s)
- Yong Jun Park
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Tae-Sung Kim
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Eun-Ho Kim
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, Republic of Korea
| | | | - Joon Kim
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, Republic of Korea.,HAEL Lab, Korea University, Seoul, Korea
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8
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Hu W, Liang YX, Luo JM, Gu XW, Chen ZC, Fu T, Zhu YY, Lin S, Diao HL, Jia B, Yang ZM. Nucleolar stress regulation of endometrial receptivity in mouse models and human cell lines. Cell Death Dis 2019; 10:831. [PMID: 31685803 PMCID: PMC6828743 DOI: 10.1038/s41419-019-2071-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/20/2019] [Accepted: 10/16/2019] [Indexed: 12/17/2022]
Abstract
Embryo implantation is essential to the successful establishment of pregnancy. A previous study has demonstrated that actinomycin D (ActD) could initiate the activation of mouse delayed implantation. However, the mechanism underlying this activation remains to be elucidated. A low dose of ActD is an inducer of nucleolar stress. This study was to examine whether nucleolar stress is involved in embryo implantation. We showed that nucleolar stress occurred when delayed implantation was activated by ActD in mice. ActD treatment also stimulated the Lif-STAT3 pathway. During early pregnancy, nucleolar stress was detected in the luminal epithelial cells during the receptive phase. Blastocyst-derived lactate could induce nucleolar stress in cultured luminal epithelial cells. The inhibition of nucleophosmin1 (NPM1), which was a marker of nucleolar stress, compromised uterine receptivity and decreased the implantation rates in pregnant mice. To translate these mouse data into humans, we examined nucleolar stress in human endometrium. Our data demonstrated that ActD-induced nucleolar stress had positive effects on the embryo attachment by upregulating IL32 expression in non-receptive epithelial cells rather than receptive epithelial cells. Our data should be the first to demonstrate that nucleolar stress is present during early pregnancy and is able to induce embryo implantation in both mice and humans.
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Affiliation(s)
- Wei Hu
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China
| | - Yu-Xiang Liang
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China.,Laboratory Animal Center, Shanxi Key Laboratory of Experimental Animal Science and Animal Model of Human Disease, Shanxi Medical University, 030001, Taiyuan, China.,Shanxi Key Laboratory of Birth Defect and Cell Regeneration, Shanxi Medical University, 030001, Taiyuan, China
| | - Jia-Mei Luo
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China
| | - Xiao-Wei Gu
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China
| | - Zi-Cong Chen
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China
| | - Tao Fu
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China
| | - Yu-Yuan Zhu
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China
| | - Shuai Lin
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China
| | - Hong-Lu Diao
- Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine, 442000, Shiyan, China
| | - Bo Jia
- Jiangxi Provincial Institute of Occupational Medicine, 330006, Nanchang, China
| | - Zeng-Ming Yang
- College of Veterinary Medicine, South China Agricultural University, 510642, Guangzhou, China.
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9
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Matos-Perdomo E, Machín F. Nucleolar and Ribosomal DNA Structure under Stress: Yeast Lessons for Aging and Cancer. Cells 2019; 8:cells8080779. [PMID: 31357498 PMCID: PMC6721496 DOI: 10.3390/cells8080779] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/15/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023] Open
Abstract
Once thought a mere ribosome factory, the nucleolus has been viewed in recent years as an extremely sensitive gauge of diverse cellular stresses. Emerging concepts in nucleolar biology include the nucleolar stress response (NSR), whereby a series of cell insults have a special impact on the nucleolus. These insults include, among others, ultra-violet radiation (UV), nutrient deprivation, hypoxia and thermal stress. While these stresses might influence nucleolar biology directly or indirectly, other perturbances whose origin resides in the nucleolar biology also trigger nucleolar and systemic stress responses. Among the latter, we find mutations in nucleolar and ribosomal proteins, ribosomal RNA (rRNA) processing inhibitors and ribosomal DNA (rDNA) transcription inhibition. The p53 protein also mediates NSR, leading ultimately to cell cycle arrest, apoptosis, senescence or differentiation. Hence, NSR is gaining importance in cancer biology. The nucleolar size and ribosome biogenesis, and how they connect with the Target of Rapamycin (TOR) signalling pathway, are also becoming important in the biology of aging and cancer. Simple model organisms like the budding yeast Saccharomyces cerevisiae, easy to manipulate genetically, are useful in order to study nucleolar and rDNA structure and their relationship with stress. In this review, we summarize the most important findings related to this topic.
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Affiliation(s)
- Emiliano Matos-Perdomo
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
- Escuela de Doctorado y Estudios de Postgrado, Universidad de La Laguna, 38200 Tenerife, Spain
| | - Félix Machín
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain.
- Instituto de Tecnologías Biomédicas, Universidad de La Laguna, 38200 Tenerife, Spain.
- Facultad de Ciencias de la Salud, Universidad Fernando Pessoa Canarias, 35450 Santa María de Guía, Gran Canaria, Spain.
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10
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Pfister AS. Emerging Role of the Nucleolar Stress Response in Autophagy. Front Cell Neurosci 2019; 13:156. [PMID: 31114481 PMCID: PMC6503120 DOI: 10.3389/fncel.2019.00156] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/08/2019] [Indexed: 12/12/2022] Open
Abstract
Autophagy represents a conserved self-digestion program, which allows regulated degradation of cellular material. Autophagy is activated by cellular stress, serum starvation and nutrient deprivation. Several autophagic pathways have been uncovered, which either non-selectively or selectively target the cellular cargo for lysosomal degradation. Autophagy engages the coordinated action of various key regulators involved in the steps of autophagosome formation, cargo targeting and lysosomal fusion. While non-selective (macro)autophagy is required for removal of bulk material or recycling of nutrients, selective autophagy mediates specific targeting of damaged organelles or protein aggregates. By proper action of the autophagic machinery, cellular homeostasis is maintained. In contrast, failure of this fundamental process is accompanied by severe pathophysiological conditions. Hallmarks of neuropathological disorders are for instance accumulated, mis-folded protein aggregates and damaged mitochondria. The nucleolus has been recognized as central hub in the cellular stress response. It represents a sub-nuclear organelle essential for ribosome biogenesis and also functions as stress sensor by mediating cell cycle arrest or apoptosis. Thus, proper nucleolar function is mandatory for cell growth and survival. Here, I highlight the emerging role of nucleolar factors in the regulation of autophagy. Moreover, I discuss the nucleolar stress response as a novel signaling pathway in the context of autophagy, health and disease.
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Affiliation(s)
- Astrid S Pfister
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, Ulm University, Ulm, Germany
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11
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Lu L, Yi H, Chen C, Yan S, Yao H, He G, Li G, Jiang Y, Deng T, Deng X. Nucleolar stress: is there a reverse version? J Cancer 2018; 9:3723-3727. [PMID: 30405843 PMCID: PMC6216007 DOI: 10.7150/jca.27660] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/04/2018] [Indexed: 12/20/2022] Open
Abstract
The nucleolus is a dynamic structure that has roles in various physiological and pathophysiological processes. Perturbations on many aspects of the nucleolar functions are thought to cause “nucleolar stress”, which occurs in response to a variety of chemotherapeutic drugs. The main characteristic changes of nucleolar stress include: 1) reduction of the size and volume of the nucleolus; 2) inhibition of RNA Pol I-mediated rRNA synthesis; and 3) nucleoplasmic translocation of nucleolar stress-related proteins. In studying the apoptosis-inducing effect of the natural compound lovastatin (LV) on breast cancer stem cells, we unexpectedly uncovered a novel form of nucleolar stress, which we call “reverse nucleolar stress”. In our system, the canonical nucleolus stress inducer doxorubicin caused nucleoplasmic translocation of the nucleolar protein NPM and complete abolishment of Nolc1, an NPM-interacting protein and an activator of rRNA transcription. In contrast, the reverse nucleolar stress induced by LV is manifested as a more localized perinucleolar distribution of NPM and an increase in the protein level of Nolc1. Furthermore, translocation of the ribosomal protein RPL3 from the cytoplasm to the nucleolus and increased AgNOR staining were observed. These changes characterize a novel pattern of nucleolar stress doubtlessly distinguishable from the canonical one. The functional consequences of reverse nucleolar stress are not clear at present but may presumably be related to cell death or even normalization of the stressed cell. The discovery of reverse nucleolar stress opens up a new area of research in molecular and cellular biology and might have important implications in cancer therapy.
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Affiliation(s)
- Lu Lu
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China.,Departments of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan 410013, China
| | - Huimei Yi
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China.,Departments of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan 410013, China
| | - Chao Chen
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China.,Departments of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan 410013, China
| | - Shichao Yan
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China.,Departments of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan 410013, China
| | - Hui Yao
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China.,Departments of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan 410013, China
| | - Guangchun He
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China.,Departments of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan 410013, China
| | - Guifei Li
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China
| | - Yiqun Jiang
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China
| | - Tuo Deng
- Diabetes Research Center and Center for Bioenergetics, Houston Methodist Research Institute, Houston, Texas 77030, USA.,Department of Medicine, Weill Cornell Medical College at Cornell University, New York, New York 10021, USA
| | - Xiyun Deng
- Key Laboratory of Translational Cancer Stem Cell Research, Hunan Normal University, Changsha, Hunan 410013, China.,Departments of Pathology and Pathophysiology, Hunan Normal University School of Medicine, Changsha, Hunan 410013, China
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12
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Abstract
The nucleolus is a prominent subnuclear compartment, where ribosome biosynthesis takes place. Recently, the nucleolus has gained attention for its novel role in the regulation of cellular stress. Nucleolar stress is emerging as a new concept, which is characterized by diverse cellular insult-induced abnormalities in nucleolar structure and function, ultimately leading to activation of p53 or other stress signaling pathways and alterations in cell behavior. Despite a number of comprehensive reviews on this concept, straightforward and clear-cut way criteria for a nucleolar stress state, regarding the factors that elicit this state, the morphological and functional alterations as well as the rationale for p53 activation are still missing. Based on literature of the past two decades, we herein summarize the evolution of the concept and provide hallmarks of nucleolar stress. Along with updated information and thorough discussion of existing confusions in the field, we pay particular attention to the current understanding of the sensing mechanisms, i.e., how stress is integrated by p53. In addition, we propose our own emphasis regarding the role of nucleolar protein NPM1 in the hallmarks of nucleolar stress and sensing mechanisms. Finally, the links of nucleolar stress to human diseases are briefly and selectively introduced.
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Affiliation(s)
- Kai Yang
- Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China.,Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Shanghai Institute of Traumatology and Orthopedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
| | - Jie Yang
- Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China
| | - Jing Yi
- Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China
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13
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Kamijo Y, Kawahara K, Yoshinaga T, Kurata H, Arima K, Furukawa T. A novel isolation method for cancer prognostic factors via the p53 pathway by a combination of in vitro and in silico analyses. Oncoscience 2018; 5:88-98. [PMID: 29854877 PMCID: PMC5978436 DOI: 10.18632/oncoscience.411] [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: 03/12/2018] [Accepted: 04/21/2018] [Indexed: 12/02/2022] Open
Abstract
Identifying new therapeutic target genes affecting the survival of patients with cancer is crucial for the development of new cancer therapies. Here, we developed a novel technology combining in vitro short hairpin RNA (shRNA) library screening and in silico analysis of the tumor transcriptome to identify prognostic factors via the p53 tumor-suppressor pathway. For initial screening, we screened 5,000 genes through selection of shRNAs in p53 wild-type tumor cells that altered sensitivity to the p53 activator actinomycin D (ActD) to identify p53 regulatory genes; shRNAs targeting 322 genes were obtained. Among these 322 genes, seven were prognostic factor candidates whose high expression increased ActD sensitivity while prolonging the survival period in patients with the p53 wild-type genotype. Conversely, we identified 33 genes as prognostic factor candidates among ActD-resistant genes related to a shortened survival period only in p53 wild-type tumors. These 40 genes had biological functions such as apoptosis, drug response, cell cycle checkpoint, and cell proliferation. The 40 genes selected by this method contained many known genes related to the p53 pathway and prognosis in patients with cancer. In summary, we developed an efficient screening method to identify p53-dependent prognostic factors with in vitro experimental data and database analysis.
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Affiliation(s)
- Yohey Kamijo
- Department of Molecular Oncology, Graduate School Medical and Dental Sciences, Kagoshima University, Kagoshima 890- 8544, Japan
- Department of Chemistry and Bioscience, Faculty of Science, Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kohichi Kawahara
- Department of Molecular Oncology, Graduate School Medical and Dental Sciences, Kagoshima University, Kagoshima 890- 8544, Japan
| | - Takuma Yoshinaga
- Division of Clinical Application, Nanpuh Hospital, Kagoshima 892-8512, Japan
| | - Hiroyuki Kurata
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Fukuoka 820-8502, Japan
| | - Kazunari Arima
- Department of Chemistry and Bioscience, Faculty of Science, Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Tatsuhiko Furukawa
- Department of Molecular Oncology, Graduate School Medical and Dental Sciences, Kagoshima University, Kagoshima 890- 8544, Japan
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14
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Chen H, Han L, Tsai H, Wang Z, Wu Y, Duo Y, Cao W, Chen L, Tan Z, Xu N, Huang X, Zhuang J, Huang L. PICT-1 is a key nucleolar sensor in DNA damage response signaling that regulates apoptosis through the RPL11-MDM2-p53 pathway. Oncotarget 2018; 7:83241-83257. [PMID: 27829214 PMCID: PMC5347766 DOI: 10.18632/oncotarget.13082] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/19/2016] [Indexed: 12/12/2022] Open
Abstract
PICT-1 is an essential ribosome biogenesis factor whose loss induces p53 accumulation and apoptosis. Here, we show that DNA damage changes PICT-1 localization and decreases PICT-1 protein levels via the proteasome pathway. Two important phosphatidylinositol 3-kinase-like kinases (PIKKs), ataxia-telangiectasia mutated (ATM) and the Ku70 subunit of DNA-dependent protein kinase (DNA-PK), co-localize and interact with PICT-1 in the nucleolus. Computational prediction of phosphorylation sites and detection using an anti-phospho-substrate antibody suggest that PICT-1 might be a substrate of PIKKs. PICT-1 S233 and T289 were identified as the key phosphorylation sites in this pathway, as mutating both to alanine abolished UVB-induced increase of PICT-1 phosporylation. Inhibition of PIKKs or ATM (with wortmannin and KU55933, respectively) prevented the agglomeration and degradation of PICT-1, suggesting that ATM is a key regulator of PICT-1. PICT-1(S233A, T289A) demonstrated marked resistance to DNA damage-induced agglomeration and loss of PICT-1. Phosphomimetic PICT-1 (S233D, T289D) showed a different nuclear distribution and was more rapidly degraded after DNA damage than wild-type PICT-1. Furthermore, both phosphorylation and degradation of PICT-1 released RPL11 from the nucleolus to the nucleoplasm, increased binding of RPL11 to MDM2, and promoted p53 accumulation and apoptosis in an ATM-dependent manner after DNA damage. These data indicate that PICT-1 is a major nucleolar sensor of the DNA damage repair response and an important upstream regulator of p53 via the RPL11-MDM2-p53 pathway.
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Affiliation(s)
- Hongbo Chen
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China.,Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Liqiao Han
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China.,The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Hsiangi Tsai
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhiwei Wang
- Department of Laboratory Medicine, The Fourth Affiliated Hospital of Guangzhou Medical University, Guangzhou 511447, China
| | - Yanping Wu
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yanhong Duo
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Wei Cao
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lijun Chen
- Technology Center of Guangxi Entry-Exit Inspection and Quarantine Bureau, Nanning 530021, China
| | - Zhirong Tan
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Ning Xu
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Xianzhang Huang
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Junhua Zhuang
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China
| | - Laiqiang Huang
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
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15
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Pfister AS, Kühl M. Of Wnts and Ribosomes. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 153:131-155. [PMID: 29389514 DOI: 10.1016/bs.pmbts.2017.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Wnt proteins are secreted glycoproteins that activate different intracellular signal transduction pathways. They regulate cell proliferation and are required for proper embryonic development. Misregulation of Wnt signaling can result in various diseases including cancer. In most circumstances, cell growth is essential for cell division and thus cell proliferation. Therefore, several reports have highlighted the key role of Wnt proteins for cell growth. Ribosomes represent the cellular protein synthesis machinery and cells need to be equipped with an appropriate number of ribosomes to allow cell growth. Recent findings suggest a role for Wnt proteins in regulating ribosome biogenesis and we here summarize these findings representing a previously unknown function of Wnt proteins. Understanding this role of Wnt signaling might open new avenues to slow down proliferation by drugs for instance in cancer therapy.
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Affiliation(s)
- Astrid S Pfister
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany.
| | - Michael Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
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16
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Krishnamoorthy A, Witkowski A, Ryan RO. Nutlin-3a Nanodisks Induce p53 Stabilization and Apoptosis in a Subset of Cultured Glioblastoma Cells. JOURNAL OF NANOMEDICINE & NANOTECHNOLOGY 2017; 8:454. [PMID: 28966869 PMCID: PMC5619870 DOI: 10.4172/2157-7439.1000454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nanodisks (ND) are ternary complexes of phospholipid, one or more hydrophobic bioactive agents and an apolipoprotein scaffold. These nanoscale assemblies are organized as a disk-shaped lipid bilayer whose perimeter is stabilized by an apolipoprotein scaffold. Solubilization of hydrophobic bioactive agents is achieved by their integration into the ND lipid milieu. When the cis-imidazoline, nutlin-3a, was incubated with phosphatidylcholine and apolipoprotein A-I, it was conferred with aqueous solubility as judged by spectroscopic analysis. Nondenaturing polyacrylamide gel electrophoresis yielded evidence of a homogeneous population of ND particles ~9 nm in diameter. Gel filtration chromatography experiments revealed the association of nutlin-3a with ND is reversible. Biological activity of nutlin-3a ND was examined in three distinct glioblastoma cell lines, U87MG, SF763 and SF767. Incubation of U87MG cells with nutlin-3a ND induced concentration-dependent cell growth arrest and apoptosis. SF763 cells demonstrated modest cell growth arrest only at high concentrations of nutlin-3a ND and no apoptosis. SF767 cells were unaffected by nutlin-3a ND. Immunoblot analysis revealed nutlin-3a ND induced time-dependent stabilization of the master tumor suppressor, p53, and up regulation of the E3 ubiquitin ligase, murine double minute 2 in U87MG cells, but not the other glioma cell lines. The nanoscale size of the formulation particles, their facile assembly and nutlin-3a solubilization capability suggest ND represent a potentially useful vehicle for in vivo administration of this anti-tumor agent.
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Affiliation(s)
- A Krishnamoorthy
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - A Witkowski
- Children’s Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland CA, USA
| | - RO Ryan
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA, USA
- Children’s Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland CA, USA
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA
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17
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Takafuji T, Kayama K, Sugimoto N, Fujita M. GRWD1, a new player among oncogenesis-related ribosomal/nucleolar proteins. Cell Cycle 2017; 16:1397-1403. [PMID: 28722511 DOI: 10.1080/15384101.2017.1338987] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Increasing attention has been paid to certain ribosomal or ribosome biosynthesis-related proteins involved in oncogenesis. Members of one group are classified as "tumor suppressive factors" represented by RPL5 and RPL11; loss of their functions leads to cancer predisposition. RPL5 and RPL11 prevent tumorigenesis by binding to and inhibiting the MDM2 ubiquitin ligase and thereby up-regulating p53. Many other candidate tumor suppressive ribosomal/nucleolar proteins have been suggested. However, it remains to be experimentally clarified whether many of these factors can actually prevent tumorigenesis and if so, how they do so. Conversely, some ribosomal/nucleolar proteins promote tumorigenesis. For example, PICT1 binds to and anchors RPL11 in nucleoli, down-regulating p53 and promoting tumorigenesis. GRWD1 was recently identified as another such factor. When overexpressed, GRWD1 suppresses p53 and transforms normal human cells, probably by binding to RPL11 and sequestrating it from MDM2. However, other pathways may also be involved.
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Affiliation(s)
- Takuya Takafuji
- a Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences , Kyushu University , Higashi-ku, Fukuoka , Japan
| | - Kota Kayama
- a Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences , Kyushu University , Higashi-ku, Fukuoka , Japan
| | - Nozomi Sugimoto
- a Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences , Kyushu University , Higashi-ku, Fukuoka , Japan
| | - Masatoshi Fujita
- a Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences , Kyushu University , Higashi-ku, Fukuoka , Japan
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18
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Rothblum LI, Rothblum K, Chang E. PAF53 is essential in mammalian cells: CRISPR/Cas9 fails to eliminate PAF53 expression. Gene 2016; 612:55-60. [PMID: 28042089 DOI: 10.1016/j.gene.2016.12.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/16/2016] [Accepted: 12/23/2016] [Indexed: 10/20/2022]
Abstract
When mammalian cells are nutrient and/or growth factor deprived, exposed to inhibitors of protein synthesis, stressed by heat shock or grown to confluence, rDNA transcription is essentially shut off. Various mechanisms are available to accomplish this downshift in ribosome biogenesis. Muramatsu's laboratory (Hanada et al., 1996) first demonstrated that mammalian PAF53 was essential for specific rDNA transcription and that PAF53 levels were regulated in response to growth factors. While S. cerevisae A49, the homologue of vertebrate PAF53, is not essential for viability (Liljelund et al., 1992), deletion of yA49 results in colonies that grow at 6% of the wild type rate at 25°C. Experiments described by Wang et al. (2015) identified PAF53 as a gene "essential for optimal proliferation". However, they did not discriminate genes essential for viability. Hence, in order to resolve this question, we designed a series of experiments to determine if PAF53 was essential for cell survival. We set out to delete the gene product from mammalian cells using CRISPR/CAS9 technology. Human 293 cells were transfected with lentiCRISPR v2 carrying genes for various sgRNA that targeted PAF53. In some experiments, the cells were cotransfected in parallel with plasmids encoding FLAG-tagged mouse PAF53. After treating the transfected cells with puromycin (to select for the lentiCRISPR backbone), cells were cloned and analyzed by western blots for PAF53 expression. Genomic DNA was amplified across the "CRISPRd" exon, cloned and sequenced to identify mutated PAF53 genes. We obtained cell lines in which the endogenous PAF53 gene was "knocked out" only when we rescued with FLAG-PAF53. DNA sequencing demonstrated that in the absence of ectopic PAF53 expression, cells demonstrated unique means of surviving; including recombination or the utilization of alternative reading frames. We never observed a clone in which one PAF53 gene is expressed, unless there was also ectopic expression In the absence of ectopic gene expression, the gene products of both endogenous genes were expressed, irrespective of whether they were partially mutant proteins or not.
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Affiliation(s)
- Lawrence I Rothblum
- Depoartment of Cell Biology, The University of Oklahoma College of Medicine, Oklahoma City, OK 73104, United States.
| | - Katrina Rothblum
- Depoartment of Cell Biology, The University of Oklahoma College of Medicine, Oklahoma City, OK 73104, United States
| | - Eugenie Chang
- Depoartment of Cell Biology, The University of Oklahoma College of Medicine, Oklahoma City, OK 73104, United States
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19
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Scott DD, Oeffinger M. Nucleolin and nucleophosmin: nucleolar proteins with multiple functions in DNA repair. Biochem Cell Biol 2016; 94:419-432. [PMID: 27673355 DOI: 10.1139/bcb-2016-0068] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The nucleolus represents a highly multifunctional intranuclear organelle in which, in addition to the canonical ribosome assembly, numerous processes such as transcription, DNA repair and replication, the cell cycle, and apoptosis are coordinated. The nucleolus is further a key hub in the sensing of cellular stress and undergoes major structural and compositional changes in response to cellular perturbations. Numerous nucleolar proteins have been identified that, upon sensing nucleolar stress, deploy additional, non-ribosomal roles in the regulation of varied cell processes including cell cycle arrest, arrest of DNA replication, induction of DNA repair, and apoptosis, among others. The highly abundant proteins nucleophosmin (NPM1) and nucleolin (NCL) are two such factors that transit to the nucleoplasm in response to stress, and participate directly in the repair of numerous different DNA damages. This review discusses the contributions made by NCL and (or) NPM1 to the different DNA repair pathways employed by mammalian cells to repair DNA insults, and examines the implications of such activities for the regulation, pathogenesis, and therapeutic targeting of NPM1 and NCL.
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Affiliation(s)
- Daniel D Scott
- a Laboratory of RNP Biochemistry, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC H2W 1R7, Canada
- b Division of Experimental Medicine, Faculty of Medicine, McGill University, Montréal, QC H3A 2A3, Canada
| | - Marlene Oeffinger
- a Laboratory of RNP Biochemistry, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC H2W 1R7, Canada
- b Division of Experimental Medicine, Faculty of Medicine, McGill University, Montréal, QC H3A 2A3, Canada
- c Département de biochimie et médecine moléculaire, Faculté de Médecine, Université de Montréal, QC H3T 1J4, Canada
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20
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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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21
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Jackson RA, Wu JS, Chen ES. C1D family proteins in coordinating RNA processing, chromosome condensation and DNA damage response. Cell Div 2016; 11:2. [PMID: 27030795 PMCID: PMC4812661 DOI: 10.1186/s13008-016-0014-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 02/22/2016] [Indexed: 12/02/2022] Open
Abstract
Research on the involvement of C1D and its yeast homologues Rrp47 (S. cerevisiae) and Cti1 (S. pombe) in DNA damage repair and RNA processing has remained mutually exclusive, with most studies predominantly concentrating on Rrp47. This review will look to reconcile the functions of these proteins in their involvement with the RNA exosome, in the regulation of chromatin architecture, and in the repair of DNA double-strand breaks, focusing on non-homologous end joining and homologous recombination. We propose that C1D is situated in a central position to maintain genomic stability at highly transcribed gene loci by coordinating these processes through the timely recruitment of relevant regulatory factors. In the event that the damage is beyond repair, C1D induces apoptosis in a p53-dependent manner.
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Affiliation(s)
- Rebecca A Jackson
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597 Singapore
| | - Jocelyn Shumei Wu
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597 Singapore
| | - Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597 Singapore ; National University Health System (NUHS), Singapore, 119228 Singapore ; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 119228 Singapore
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22
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Ma L, Zhao W, Zheng Q, Chen T, Qi J, Li G, Tong T. Ribosomal L1 domain and lysine-rich region are essential for CSIG/ RSL1D1 to regulate proliferation and senescence. Biochem Biophys Res Commun 2015; 469:593-8. [PMID: 26686419 DOI: 10.1016/j.bbrc.2015.12.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 12/01/2015] [Indexed: 12/14/2022]
Abstract
The expression change of cellular senescence-associated genes is underlying the genetic foundation of cellular senescence. Using a suppressive subtractive hybridization system, we identified CSIG (cellular senescence-inhibited gene protein; RSL1D1) as a novel senescence-associated gene. CSIG is implicated in various process including cell cycle regulation, apoptosis, and tumor metastasis. We previously showed that CSIG plays an important role in regulating cell proliferation and cellular senescence progression through inhibiting PTEN, however, which domain or region of CSIG contributes to this function? To clarify this question, we investigated the functional importance of ribosomal L1 domain and lysine (Lys) -rich region of CSIG. The data showed that expression of CSIG potently reduced PTEN expression, increased cell proliferation rates, and reduced the senescent phenotype (lower SA-β-gal activity). By contrast, neither the expression of CSIG N- terminal (NT) fragment containing the ribosomal L1 domain nor C-terminal (CT) fragment containing Lys-rich region could significantly altered the levels of PTEN; instead of promoting cell proliferation and delaying cellular senescence, expression of CSIG-NT or CSIG-CT inhibited cell proliferation and accelerated cell senescence (increased SA-β-gal activity) compared to either CSIG over-expressing or control (empty vector transfected) cells. The further immunofluorescence analysis showed that CSIG-CT and CSIG-NT truncated proteins exhibited different subcellular distribution with that of wild-type CSIG. Conclusively, both ribosomal L1 domain and Lys-rich region of CSIG are critical for CSIG to act as a regulator of cell proliferation and cellular senescence.
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Affiliation(s)
- Liwei Ma
- Research Center on Aging, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, 38 Xueyuan Road, Beijing 100191, PR China
| | - Wenting Zhao
- Research Center on Aging, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, 38 Xueyuan Road, Beijing 100191, PR China
| | - Quanhui Zheng
- Research Center on Aging, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, 38 Xueyuan Road, Beijing 100191, PR China
| | - Tianda Chen
- Research Center on Aging, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, 38 Xueyuan Road, Beijing 100191, PR China
| | - Ji Qi
- Research Center on Aging, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, 38 Xueyuan Road, Beijing 100191, PR China
| | - Guodong Li
- Research Center on Aging, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, 38 Xueyuan Road, Beijing 100191, PR China
| | - Tanjun Tong
- Research Center on Aging, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, 38 Xueyuan Road, Beijing 100191, PR China.
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23
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Watanabe-Susaki K, Takada H, Enomoto K, Miwata K, Ishimine H, Intoh A, Ohtaka M, Nakanishi M, Sugino H, Asashima M, Kurisaki A. Biosynthesis of ribosomal RNA in nucleoli regulates pluripotency and differentiation ability of pluripotent stem cells. Stem Cells 2015; 32:3099-111. [PMID: 25187421 DOI: 10.1002/stem.1825] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 07/23/2014] [Indexed: 01/28/2023]
Abstract
Pluripotent stem cells have been shown to have unique nuclear properties, for example, hyperdynamic chromatin and large, condensed nucleoli. However, the contribution of the latter unique nucleolar character to pluripotency has not been well understood. Here, we show that fibrillarin (FBL), a critical methyltransferase for ribosomal RNA (rRNA) processing in nucleoli, is one of the proteins highly expressed in pluripotent embryonic stem (ES) cells. Stable expression of FBL in ES cells prolonged the pluripotent state of mouse ES cells cultured in the absence of leukemia inhibitory factor (LIF). Analyses using deletion mutants and a point mutant revealed that the methyltransferase activity of FBL regulates stem cell pluripotency. Knockdown of this gene led to significant delays in rRNA processing, growth inhibition, and apoptosis in mouse ES cells. Interestingly, both partial knockdown of FBL and treatment with actinomycin D, an inhibitor of rRNA synthesis, induced the expression of differentiation markers in the presence of LIF and promoted stem cell differentiation into neuronal lineages. Moreover, we identified p53 signaling as the regulatory pathway for pluripotency and differentiation of ES cells. These results suggest that proper activity of rRNA production in nucleoli is a novel factor for the regulation of pluripotency and differentiation ability of ES cells.
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Affiliation(s)
- Kanako Watanabe-Susaki
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki, Japan
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24
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Zhang XR, Qin Z, Zhang X, Hu Y. Arabidopsis SMALL ORGAN 4, a homolog of yeast NOP53, regulates cell proliferation rate during organ growth. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:810-818. [PMID: 26310197 DOI: 10.1111/jipb.12424] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 08/23/2015] [Indexed: 06/04/2023]
Abstract
Cell proliferation is a fundamental event essential for plant organogenesis and contributes greatly to the final organ size. Although the control of cell proliferation in plants has been extensively studied, how the plant sets the cell number required for a single organ is largely elusive. Here, we describe the Arabidopsis SMALL ORGAN 4 (SMO4) that functions in the regulation of cell proliferation rate and thus final organ size. The smo4 mutant exhibits a reduced size of organs due to the decreased cell number, and further analysis reveals that such phenotype results from a retardation of the cell cycle progression during organ development. SMO4 encodes a homolog of NUCLEOLAR PROTEIN 53 (NOP53) in Saccharomyces cerevisiae and is expressed primarily in tissues undergoing cell proliferation. Nevertheless, further complementation tests show that SMO4 could not rescue the lethal defect of NOP53 mutant of S. cerevisiae. These results define SMO4 as an important regulator of cell proliferation during organ growth and suggest that SMO4 might have been evolutionarily divergent from NOP53.
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Affiliation(s)
- Xiao-Ran Zhang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
| | - Zhixiang Qin
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
| | - Xiao Zhang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100093, China
| | - Yuxin Hu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- National Center for Plant Gene Research, Beijing, 100093, China
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25
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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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26
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O'Sullivan JM, Pai DA, Cridge AG, Engelke DR, Ganley ARD. The nucleolus: a raft adrift in the nuclear sea or the keystone in nuclear structure? Biomol Concepts 2015; 4:277-86. [PMID: 25436580 DOI: 10.1515/bmc-2012-0043] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 12/21/2012] [Indexed: 11/15/2022] Open
Abstract
The nucleolus is a prominent nuclear structure that is the site of ribosomal RNA (rRNA) transcription, and hence ribosome biogenesis. Cellular demand for ribosomes, and hence rRNA, is tightly linked to cell growth and the rRNA makes up the majority of all the RNA within a cell. To fulfill the cellular demand for rRNA, the ribosomal RNA (rDNA) genes are amplified to high copy number and transcribed at very high rates. As such, understanding the rDNA has profound consequences for our comprehension of genome and transcriptional organization in cells. In this review, we address the question of whether the nucleolus is a raft adrift the sea of nuclear DNA, or actively contributes to genome organization. We present evidence supporting the idea that the nucleolus, and the rDNA contained therein, play more roles in the biology of the cell than simply ribosome biogenesis. We propose that the nucleolus and the rDNA are central factors in the spatial organization of the genome, and that rapid alterations in nucleolar structure in response to changing conditions manifest themselves in altered genomic structures that have functional consequences. Finally, we discuss some predictions that result from the nucleolus having a central role in nuclear organization.
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27
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Pfister AS, Keil M, Kühl M. The Wnt Target Protein Peter Pan Defines a Novel p53-independent Nucleolar Stress-Response Pathway. J Biol Chem 2015; 290:10905-18. [PMID: 25759387 PMCID: PMC4409253 DOI: 10.1074/jbc.m114.634246] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Indexed: 12/27/2022] Open
Abstract
Proper ribosome formation is a prerequisite for cell growth and proliferation. Failure of this process results in nucleolar stress and p53-mediated apoptosis. The Wnt target Peter Pan (PPAN) is required for 45 S rRNA maturation. So far, the role of PPAN in nucleolar stress response has remained elusive. We demonstrate that PPAN localizes to mitochondria in addition to its nucleolar localization and inhibits the mitochondrial apoptosis pathway in a p53-independent manner. Loss of PPAN induces BAX stabilization, depolarization of mitochondria, and release of cytochrome c, demonstrating its important role as an anti-apoptotic factor. Staurosporine-induced nucleolar stress and apoptosis disrupt nucleolar PPAN localization and induce its accumulation in the cytoplasm. This is accompanied by phosphorylation and subsequent cleavage of PPAN by caspases. Moreover, we show that PPAN is a novel interaction partner of the anti-apoptotic protein nucleophosmin (NPM). PPAN depletion induces NPM and upstream-binding factor (UBF) degradation, which is independent of caspases. In summary, we provide evidence for a novel nucleolar stress-response pathway involving PPAN, NPM, and BAX to guarantee cell survival in a p53-independent manner.
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Affiliation(s)
- Astrid S. Pfister
- From the Institute for Biochemistry and Molecular Biology, Ulm University, 89081 Ulm, Germany
| | - Marina Keil
- From the Institute for Biochemistry and Molecular Biology, Ulm University, 89081 Ulm, Germany
| | - Michael Kühl
- From the Institute for Biochemistry and Molecular Biology, Ulm University, 89081 Ulm, Germany, To whom correspondence should be addressed: Institute for Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany. Tel.: 49-731-500-23283; Fax: 49-731-500-23277; E-mail:
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28
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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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Proteomic characterization of the nucleolar linker histone H1 interaction network. J Mol Biol 2015; 427:2056-71. [PMID: 25584861 DOI: 10.1016/j.jmb.2015.01.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 12/03/2014] [Accepted: 01/05/2015] [Indexed: 01/25/2023]
Abstract
To investigate the relationship between linker histone H1 and protein-protein interactions in the nucleolus, we used biochemical and proteomics approaches to characterize nucleoli purified from cultured human and mouse cells. Mass spectrometry identified 175 proteins in human T cell nucleolar extracts that bound to Sepharose-immobilized H1 in vitro. Gene ontology analysis found significant enrichment for H1 binding proteins with functions related to nucleolar chromatin structure and RNA polymerase I transcription regulation, rRNA processing, and mRNA splicing. Consistent with the affinity binding results, H1 existed in large (400 to >650kDa) macromolecular complexes in human T cell nucleolar extracts. To complement the biochemical experiments, we investigated the effects of in vivo H1 depletion on protein content and structural integrity of the nucleolus using the H1 triple isoform knockout (H1ΔTKO) mouse embryonic stem cell (mESC) model system. Proteomic profiling of purified wild-type mESC nucleoli identified a total of 613 proteins, only ~60% of which were detected in the H1 mutant nucleoli. Within the affected group, spectral counting analysis quantitated 135 specific nucleolar proteins whose levels were significantly altered in H1ΔTKO mESC. Importantly, the functions of the affected proteins in mESC closely overlapped with those of the human T cell nucleolar H1 binding proteins. Immunofluorescence microscopy of intact H1ΔTKO mESC demonstrated both a loss of nucleolar RNA content and altered nucleolar morphology resulting from in vivo H1 depletion. We conclude that H1 organizes and maintains an extensive protein-protein interaction network in the nucleolus required for nucleolar structure and integrity.
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30
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Tao Z, Wang H, Xia Q, Li K, Li K, Jiang X, Xu G, Wang G, Ying Z. Nucleolar stress and impaired stress granule formation contribute to C9orf72 RAN translation-induced cytotoxicity. Hum Mol Genet 2015; 24:2426-41. [PMID: 25575510 DOI: 10.1093/hmg/ddv005] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/06/2015] [Indexed: 12/14/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are the two common neurodegenerative diseases that have been associated with the GGGGCC·GGCCCC repeat RNA expansion in a noncoding region of C9orf72. It has been previously reported that unconventional repeat-associated non-ATG (RAN) translation of GGGGCC·GGCCCC repeats produces five types of dipeptide-repeat proteins (referred to as RAN proteins): poly-glycine-alanine (GA), poly-glycine-proline (GP), poly-glycine-arginine (GR), poly-proline-arginine (PR) and poly-proline-alanine (PA). Although protein aggregates of RAN proteins have been found in patients, it is unclear whether RAN protein aggregation induces neurotoxicity. In the present study, we aimed to understand the biological properties of all five types of RAN proteins. Surprisingly, our results showed that none of these RAN proteins was aggregate-prone in our cellular model and that the turnover of these RAN proteins was not affected by the ubiquitin-proteasome system or autophagy. Moreover, poly-GR and poly-PR, but not poly-GA, poly-GP or poly-PA, localized to the nucleolus and induced the translocation of the key nucleolar component nucleophosmin, leading to nucleolar stress and cell death. This poly-GR- and poly-PR-mediated defect in nucleolar function was associated with the suppression of ribosomal RNA synthesis and the impairment of stress granule formation. Taken together, the results of the present study suggest a simple model of the molecular mechanisms underlying RAN translation-mediated cytotoxicity in C9orf72-linked ALS/FTD in which nucleolar stress, but not protein aggregation, is the primary contributor to C9orf72-linked neurodegeneration.
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Affiliation(s)
- Zhouteng Tao
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences
| | - Hongfeng Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences
| | - Qin Xia
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences
| | - Ke Li
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences
| | - Kai Li
- Department of Pharmacology, College of Pharmaceutical Sciences
| | - Xiaogang Jiang
- Department of Pharmacology, College of Pharmaceutical Sciences
| | - Guoqiang Xu
- Laboratory of Chemical Biology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences
| | - Guanghui Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230027, China
| | - Zheng Ying
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215021, China and
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31
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Thorenoor N, Slaby O. Small nucleolar RNAs functioning and potential roles in cancer. Tumour Biol 2014; 36:41-53. [DOI: 10.1007/s13277-014-2818-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 11/04/2014] [Indexed: 11/27/2022] Open
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32
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Stępiński D. Functional ultrastructure of the plant nucleolus. PROTOPLASMA 2014; 251:1285-306. [PMID: 24756369 PMCID: PMC4209244 DOI: 10.1007/s00709-014-0648-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 04/08/2014] [Indexed: 05/23/2023]
Abstract
Nucleoli are nuclear domains present in almost all eukaryotic cells. They not only specialize in the production of ribosomal subunits but also play roles in many fundamental cellular activities. Concerning ribosome biosynthesis, particular stages of this process, i.e., ribosomal DNA transcription, primary RNA transcript processing, and ribosome assembly proceed in precisely defined nucleolar subdomains. Although eukaryotic nucleoli are conservative in respect of their main function, clear morphological differences between these structures can be noticed between individual kingdoms. In most cases, a plant nucleolus shows well-ordered structure in which four main ultrastructural components can be distinguished: fibrillar centers, dense fibrillar component, granular component, and nucleolar vacuoles. Nucleolar chromatin is an additional crucial structural component of this organelle. Nucleolonema, although it is not always an unequivocally distinguished nucleolar domain, has often been described as a well-grounded morphological element, especially of plant nucleoli. The ratios and morphology of particular subcompartments of a nucleolus can change depending on its metabolic activity which in turn is correlated with the physiological state of a cell, cell type, cell cycle phase, as well as with environmental influence. Precise attribution of functions to particular nucleolar subregions in the process of ribosome biosynthesis is now possible using various approaches. The presented description of plant nucleolar morphology summarizes previous knowledge regarding the function of nucleoli as well as of their particular subdomains not only in the course of ribosome biosynthesis.
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Affiliation(s)
- Dariusz Stępiński
- Department of Cytophysiology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland,
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Ghosh M, Ryan RO. Curcumin homing to the nucleolus: mechanism for initiation of an apoptotic program. J Nutr Biochem 2014; 25:1117-1123. [PMID: 25172633 DOI: 10.1016/j.jnutbio.2014.06.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/07/2014] [Accepted: 06/12/2014] [Indexed: 11/15/2022]
Abstract
Curcumin is a plant-derived polyphenol that displays antitumor properties. Incubation of cultured SF-767 glioma cells with curcumin gave rise to intense intranuclear foci of curcumin fluorescence. In vitro studies revealed that nuclear homing by curcumin is not a result of DNA/chromatin binding. On the other hand, curcumin fluorescence colocalized with nucleophosmin, a nucleolus marker protein. To determine the temporal relationship between curcumin-induced apoptosis and nucleolar homing, confocal live cell imaging was performed. The data show that curcumin localization to the nucleolus occurs prior to cell surface exposure of phosphatidylserine. In studies of the mechanism of curcumin-induced apoptosis in SF-767 cells, its effect on the subcellular location of p14(ARF) was determined. Whereas p14(ARF) was confined to the nucleolus in untreated cells, 2 h following incubation with curcumin, it displayed a diffuse nuclear distribution. Given the role of nuclear p14(ARF) in binding the E3 ubiquitin ligase, mouse double minute 2 homolog (MDM2), the effect of curcumin treatment on cellular levels of the tumor suppressor protein, p53, was examined. Between 2 and 4 h following curcumin treatment, p53 levels increased with maximum levels reached by 8 h. Thus, curcumin homing to the nucleolus induces redistribution of p14(ARF) to the nucleoplasm where interaction with MDM2 leads to stabilization of p53, with subsequent initiation of apoptosis.
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Affiliation(s)
- Mistuni Ghosh
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland CA 94609, USA
| | - Robert O Ryan
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland CA 94609, USA.
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34
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Mahboubi H, Stochaj U. Nucleoli and Stress Granules: Connecting Distant Relatives. Traffic 2014; 15:1179-93. [DOI: 10.1111/tra.12191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 06/30/2014] [Accepted: 06/30/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Hicham Mahboubi
- Department of Physiology; McGill University; 3655 Promenade Sir William Osler Montreal Quebec H3G 1Y6 Canada
| | - Ursula Stochaj
- Department of Physiology; McGill University; 3655 Promenade Sir William Osler Montreal Quebec H3G 1Y6 Canada
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35
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Saito K, Iizuka Y, Ohta S, Takahashi S, Nakamura K, Saya H, Yoshida K, Kawakami Y, Toda M. Functional analysis of a novel glioma antigen, EFTUD1. Neuro Oncol 2014; 16:1618-29. [PMID: 25015090 DOI: 10.1093/neuonc/nou132] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A cDNA library made from 2 glioma cell lines, U87MG and T98G, was screened by serological identification of antigens by recombinant cDNA expression (SEREX) using serum from a glioblastoma patient. Elongation factor Tu GTP binding domain containing protein 1 (EFTUD1), which is required for ribosome biogenesis, was identified. A cancer microarray database showed overexpression of EFTUD1 in gliomas, suggesting that EFTUD1 is a candidate molecular target for gliomas. METHODS EFTUD1 expression in glioma cell lines and glioma tissue was assessed by Western blot, quantitative PCR, and immunohistochemistry. The effect on ribosome biogenesis, cell growth, cell cycle, and induction of apoptosis and autophagy in glioma cells during the downregulation of EFTUD1 was investigated. To reveal the role of autophagy, the autophagy-blocker, chloroquine (CQ), was used in glioma cells downregulating EFTUD1. The effect of combining CQ with EFTUD1 inhibition in glioma cells was analyzed. RESULTS EFTUD1 expression in glioma cell lines and tissue was higher than in normal brain tissue. Downregulating EFTUD1 induced G1 cell-cycle arrest and apoptosis, leading to reduced glioma cell proliferation. The mechanism underlying this antitumor effect was impaired ribosome biogenesis via EFTUD1 inhibition. Additionally, protective autophagy was induced by glioma cells as an adaptive response to EFTUD1 inhibition. The antitumor effect induced by the combined treatment was significantly higher than that of either EFTUD1 inhibition or CQ alone. CONCLUSION These results suggest that EFTUD1 represents a novel therapeutic target and that the combination of EFTUD1 inhibition with autophagy blockade may be effective in the treatment of gliomas.
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Affiliation(s)
- Katsuya Saito
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Yukihiko Iizuka
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Shigeki Ohta
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Satoshi Takahashi
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Kenta Nakamura
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Hideyuki Saya
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Kazunari Yoshida
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Yutaka Kawakami
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
| | - Masahiro Toda
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan (K.S., S.T., K.Y., M.T.); Neuro-immunology Research Group, Keio University School of Medicine, Tokyo, Japan (Y.I., S.O., M.T.); Department of Physiology, Keio University School of Medicine, Tokyo, Japan (S.O.); Division of Cellular Signaling, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (K.N., Y.K.); Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan (H.S.)
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Avitabile D, Genovese L, Ponti D, Ranieri D, Raffa S, Calogero A, Torrisi MR. Nucleolar localization and circadian regulation of Per2S, a novel splicing variant of the Period 2 gene. Cell Mol Life Sci 2014; 71:2547-59. [PMID: 24202686 PMCID: PMC11113094 DOI: 10.1007/s00018-013-1503-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 09/26/2013] [Accepted: 10/17/2013] [Indexed: 12/14/2022]
Abstract
In this work, we show for the first time that a second splicing variant of the core clock gene Period 2 (Per2), Per2S, is expressed at both the mRNA and protein levels in human keratinocytes and that it localizes in the nucleoli. Moreover, we show that a reversible perturbation of the nucleolar structure acts as a resetting stimulus for the cellular clock. Per2S expression and periodic oscillation upon dexamethasone treatment were assessed by qRT-PCR using specific primers. Western blot (WB) analysis using an antibody against the recombinant human PER2 (abRc) displayed an intense band at a molecular weight of ~55 kDa, close to the predicted size of Per2S, and a weaker band at the expected size of Per2 (~140 kDa). The antibody raised against PER2 pS662 (abS662), an epitope absent in PER2S, detected only the higher band. Immunolocalization studies with abRc revealed a peculiar nucleolar signal colocalizing with the nucleolar marker nucleophosmin, whereas with abS662 the signal was predominantly diffuse all over the nucleus and partially colocalized with abRc in the nucleolus. The analysis of cell fractions by WB confirmed the enrichment of PER2S and the presence of PER2 in the nucleolar compartment. Finally, a pulse (1 h) of actinomycin D (0.01 μg/ml) induced reversible nucleolar disruption, PER2S de-localization and circadian synchronization of clock and Per2S genes. Our work represents the first evidence that the Per2S splicing isoform is a clock component expressed in human cells localizing in the nucleolus. These results suggest a critical role for the nucleolus in the process of circadian synchronization in human keratinocytes.
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Affiliation(s)
- Daniele Avitabile
- Department of Clinical and Molecular Medicine, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University of Rome, Via di Grottarossa 1035, 00189, Rome, Italy,
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Okamura K, Takayama K, Kawahara K, Harada T, Nishio M, Otsubo K, Ijichi K, Kohno M, Iwama E, Fujii A, Ota K, Koga T, Okamoto T, Suzuki A, Nakanishi Y. PICT1 expression is a poor prognostic factor in non-small cell lung cancer. Oncoscience 2014; 1:375-82. [PMID: 25594032 PMCID: PMC4278310 DOI: 10.18632/oncoscience.43] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 05/25/2014] [Indexed: 02/07/2023] Open
Abstract
PICT1 is a key regulator of the MDM2–TP53 pathway. High mRNA expression levels of PICT1 are associated with poor prognosis in several cancers with wild-type TP53. In this study, we identified the PICT1 protein expression profile in non-small cell lung cancer (NSCLC) with wild-type TP53 in the nucleolus and cytoplasm, and revealed the relationship between PICT1 expression and patient clinicopathological factors. PICT1 expression in the tumor cells of 96 NSCLC patients with wild-type TP53 was evaluated by immunohistochemistry. Forty-three of 96 (44.8%) NSCLC samples were positive for nucleolar PICT1, while 40/96 (41.7%) NSCLC samples were positive for cytoplasmic PICT1. There was no correlation between nucleolar PICT1 expression and clinicopathological factors. However, cytoplasmic PICT1 expression was significantly correlated with sex, smoking history, differentiation, lymphatic invasion and pathological stage. In multivariate analysis, lymphatic invasion was significantly associated with cytoplasmic PICT1 expression (hazard ratio: 5.02, P = 0.026). We scrutinized PICT1 expression in samples of NSCLC with wild-type TP53, and showed a correlation between cytoplasmic PICT1 expression and several clinicopathological factors in these patients. Our results indicate that cytoplasmic PICT1 expression is a poor prognostic factor and is associated with tumor progression via lymphatic invasion in these patients.
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Affiliation(s)
- Kyoko Okamura
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Koichi Takayama
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Kohichi Kawahara
- Department of Molecular Oncology, Graduate School of Medical and Dental Science, Kagoshima University, Japan. ; Division of Cancer Genetics, Medical Institute of Bioregulation, Kyushu University, Japan
| | - Taishi Harada
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Miki Nishio
- Division of Cancer Genetics, Medical Institute of Bioregulation, Kyushu University, Japan
| | - Kohei Otsubo
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan. ; Division of Cancer Genetics, Medical Institute of Bioregulation, Kyushu University, Japan
| | - Kayo Ijichi
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan. ; Division of Pathophysiological and Experimental Pathology, Department of Pathology, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Mikihiro Kohno
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Eiji Iwama
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan. ; Faculty of Medical Sciences, Department of Comprehensive Clinical Oncology, Kyushu University, Japan
| | - Akiko Fujii
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Keiichi Ota
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Takaomi Koga
- Division of Pathophysiological and Experimental Pathology, Department of Pathology, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Tatsuro Okamoto
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Japan
| | - Akira Suzuki
- Division of Cancer Genetics, Medical Institute of Bioregulation, Kyushu University, Japan
| | - Yoichi Nakanishi
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Japan
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Nosrati N, Kapoor NR, Kumar V. Combinatorial action of transcription factors orchestrates cell cycle-dependent expression of the ribosomal protein genes and ribosome biogenesis. FEBS J 2014; 281:2339-52. [DOI: 10.1111/febs.12786] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 03/01/2014] [Accepted: 03/17/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Nagisa Nosrati
- Virology Group; International Centre for Genetic Engineering and Biotechnology; New Delhi India
| | - Neetu R. Kapoor
- Virology Group; International Centre for Genetic Engineering and Biotechnology; New Delhi India
| | - Vijay Kumar
- Virology Group; International Centre for Genetic Engineering and Biotechnology; New Delhi India
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Jin YQ, An GS, Ni JH, Li SY, Jia HT. ATM-dependent E2F1 accumulation in the nucleolus is an indicator of ribosomal stress in early response to DNA damage. Cell Cycle 2014; 13:1627-38. [PMID: 24675884 DOI: 10.4161/cc.28605] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The nucleolus plays a major role in ribosome biogenesis. Most genotoxic agents disrupt nucleolar structure and function, which results in the stabilization/activation of p53, inducing cell cycle arrest or apoptosis. Likewise, transcription factor E2F1 as a DNA damage responsive protein also plays roles in cell cycle arrest, DNA repair, or apoptosis in response to DNA damage through transcriptional response and protein-protein interaction. Furthermore, E2F1 is known to be involved in regulating rRNA transcription. However, how E2F1 displays in coordinating DNA damage and nucleolar stress is unclear. In this study, we demonstrate that ATM-dependent E2F1 accumulation in the nucleolus is a characteristic feature of nucleolar stress in early response to DNA damage. We found that at the early stage of DNA damage, E2F1 accumulation in the nucleolus was an ATM-dependent and a common event in p53-suficient and -deficient cells. Increased nucleolar E2F1 was sequestered by the nucleolar protein p14ARF, which repressed E2F1-dependent rRNA transcription initiation, and was coupled with S phase. Our data indicate that early accumulation of E2F1 in the nucleolus is an indicator for nucleolar stress and a component of ATM pathway, which presumably buffers elevation of E2F1 in the nucleoplasm and coordinates the diversifying mechanisms of E2F1 acts in cell cycle progression and apoptosis in early response to DNA damage.
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Affiliation(s)
- Ya-Qiong Jin
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Beijing, PR China
| | - Guo-Shun An
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Beijing, PR China
| | - Ju-Hua Ni
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Beijing, PR China
| | - Shu-Yan Li
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Beijing, PR China
| | - Hong-Ti Jia
- Department of Biochemistry and Molecular Biology; Peking University Health Science Center; Beijing, PR China; Department of Biochemistry and Molecular Biology; Capital Medical University; Beijing, PR China
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40
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Targeting RNA polymerase I to treat MYC-driven cancer. Oncogene 2014; 34:403-12. [PMID: 24608428 DOI: 10.1038/onc.2014.13] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/08/2014] [Accepted: 01/08/2014] [Indexed: 02/06/2023]
Abstract
The MYC oncoprotein and transcription factor is dysregulated in a majority of human cancers and is considered a major driver of the malignant phenotype. As such, developing drugs for effective inhibition of MYC in a manner selective to malignancies is a 'holy grail' of transcription factor-based cancer therapy. Recent advances in elucidating MYC biology in both normal cells and pathological settings were anticipated to bring inhibition of tumorigenic MYC function closer to the clinic. However, while the extensive array of cellular pathways that MYC impacts present numerous fulcrum points on which to leverage MYC's therapeutic potential, identifying the critical target(s) for MYC-specific cancer therapy has been difficult to achieve. Somewhat unexpectedly, MYC's fundamental role in regulating the 'housekeeping' process of ribosome biogenesis, one of the most ubiquitously required and conserved cell functions, may provide the Achilles' heel for therapeutically targeting MYC-driven tumors.
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Antoniali G, Lirussi L, Poletto M, Tell G. Emerging roles of the nucleolus in regulating the DNA damage response: the noncanonical DNA repair enzyme APE1/Ref-1 as a paradigmatical example. Antioxid Redox Signal 2014; 20:621-39. [PMID: 23879289 PMCID: PMC3901381 DOI: 10.1089/ars.2013.5491] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 07/22/2013] [Indexed: 12/25/2022]
Abstract
SIGNIFICANCE An emerging concept in DNA repair mechanisms is the evidence that some key enzymes, besides their role in the maintenance of genome stability, display also unexpected noncanonical functions associated with RNA metabolism in specific subcellular districts (e.g., nucleoli). During the evolution of these key enzymes, the acquisition of unfolded domains significantly amplified the possibility to interact with different partners and substrates, possibly explaining their phylogenetic gain of functions. RECENT ADVANCES After nucleolar stress or DNA damage, many DNA repair proteins can freely relocalize from nucleoli to the nucleoplasm. This process may represent a surveillance mechanism to monitor the synthesis and correct assembly of ribosomal units affecting cell cycle progression or inducing p53-mediated apoptosis or senescence. CRITICAL ISSUES A paradigm for this kind of regulation is represented by some enzymes of the DNA base excision repair (BER) pathway, such as apurinic/apyrimidinic endonuclease 1 (APE1). In this review, the role of the nucleolus and the noncanonical functions of the APE1 protein are discussed in light of their possible implications in human pathologies. FUTURE DIRECTIONS A productive cross-talk between DNA repair enzymes and proteins involved in RNA metabolism seems reasonable as the nucleolus is emerging as a dynamic functional hub that coordinates cell growth arrest and DNA repair mechanisms. These findings will drive further analyses on other BER proteins and might imply that nucleic acid processing enzymes are more versatile than originally thought having evolved DNA-targeted functions after a previous life in the early RNA world.
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Affiliation(s)
- Giulia Antoniali
- Department of Medical and Biological Sciences, University of Udine , Udine, Italy
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Tissue specific roles for the ribosome biogenesis factor Wdr43 in zebrafish development. PLoS Genet 2014; 10:e1004074. [PMID: 24497835 PMCID: PMC3907300 DOI: 10.1371/journal.pgen.1004074] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 11/15/2013] [Indexed: 01/23/2023] Open
Abstract
During vertebrate craniofacial development, neural crest cells (NCCs) contribute to most of the craniofacial pharyngeal skeleton. Defects in NCC specification, migration and differentiation resulting in malformations in the craniofacial complex are associated with human craniofacial disorders including Treacher-Collins Syndrome, caused by mutations in TCOF1. It has been hypothesized that perturbed ribosome biogenesis and resulting p53 mediated neuroepithelial apoptosis results in NCC hypoplasia in mouse Tcof1 mutants. However, the underlying mechanisms linking ribosome biogenesis and NCC development remain poorly understood. Here we report a new zebrafish mutant, fantome (fan), which harbors a point mutation and predicted premature stop codon in zebrafish wdr43, the ortholog to yeast UTP5. Although wdr43 mRNA is widely expressed during early zebrafish development, and its deficiency triggers early neural, eye, heart and pharyngeal arch defects, later defects appear fairly restricted to NCC derived craniofacial cartilages. Here we show that the C-terminus of Wdr43, which is absent in fan mutant protein, is both necessary and sufficient to mediate its nucleolar localization and protein interactions in metazoans. We demonstrate that Wdr43 functions in ribosome biogenesis, and that defects observed in fan mutants are mediated by a p53 dependent pathway. Finally, we show that proper localization of a variety of nucleolar proteins, including TCOF1, is dependent on that of WDR43. Together, our findings provide new insight into roles for Wdr43 in development, ribosome biogenesis, and also ribosomopathy-induced craniofacial phenotypes including Treacher-Collins Syndrome.
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Fierro-Monti I, Echeverria P, Racle J, Hernandez C, Picard D, Quadroni M. Dynamic impacts of the inhibition of the molecular chaperone Hsp90 on the T-cell proteome have implications for anti-cancer therapy. PLoS One 2013; 8:e80425. [PMID: 24312219 PMCID: PMC3842317 DOI: 10.1371/journal.pone.0080425] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 10/02/2013] [Indexed: 11/19/2022] Open
Abstract
The molecular chaperone Hsp90-dependent proteome represents a complex protein network of critical biological and medical relevance. Known to associate with proteins with a broad variety of functions termed clients, Hsp90 maintains key essential and oncogenic signalling pathways. Consequently, Hsp90 inhibitors are being tested as anti-cancer drugs. Using an integrated systematic approach to analyse the effects of Hsp90 inhibition in T-cells, we quantified differential changes in the Hsp90-dependent proteome, Hsp90 interactome, and a selection of the transcriptome. Kinetic behaviours in the Hsp90-dependent proteome were assessed using a novel pulse-chase strategy (Fierro-Monti et al., accompanying article), detecting effects on both protein stability and synthesis. Global and specific dynamic impacts, including proteostatic responses, are due to direct inhibition of Hsp90 as well as indirect effects. As a result, a decrease was detected in most proteins that changed their levels, including known Hsp90 clients. Most likely, consequences of the role of Hsp90 in gene expression determined a global reduction in net de novo protein synthesis. This decrease appeared to be greater in magnitude than a concomitantly observed global increase in protein decay rates. Several novel putative Hsp90 clients were validated, and interestingly, protein families with critical functions, particularly the Hsp90 family and cofactors themselves as well as protein kinases, displayed strongly increased decay rates due to Hsp90 inhibitor treatment. Remarkably, an upsurge in survival pathways, involving molecular chaperones and several oncoproteins, and decreased levels of some tumour suppressors, have implications for anti-cancer therapy with Hsp90 inhibitors. The diversity of global effects may represent a paradigm of mechanisms that are operating to shield cells from proteotoxic stress, by promoting pro-survival and anti-proliferative functions. Data are available via ProteomeXchange with identifier PXD000537.
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Affiliation(s)
- Ivo Fierro-Monti
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Pablo Echeverria
- Département de Biologie Cellulaire, Université de Genève, Genève, Switzerland
| | - Julien Racle
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Vital-IT Group, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Celine Hernandez
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- Vital-IT Group, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Didier Picard
- Département de Biologie Cellulaire, Université de Genève, Genève, Switzerland
| | - Manfredo Quadroni
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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Thapa M, Bommakanti A, Shamsuzzaman M, Gregory B, Samsel L, Zengel JM, Lindahl L. Repressed synthesis of ribosomal proteins generates protein-specific cell cycle and morphological phenotypes. Mol Biol Cell 2013; 24:3620-33. [PMID: 24109599 PMCID: PMC3842990 DOI: 10.1091/mbc.e13-02-0097] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Cell stress caused by repression of 54 individual ribosomal genes in Saccharomyces cerevisiae is analyzed. Cell cycle progression and cell morphology responses are specific to the protein whose synthesis is repressed but bud site selection is not. Proteins that generate G2/M and G1 phenotypes map to separate areas of the ribosomal particle. The biogenesis of ribosomes is coordinated with cell growth and proliferation. Distortion of the coordinated synthesis of ribosomal components affects not only ribosome formation, but also cell fate. However, the connection between ribosome biogenesis and cell fate is not well understood. To establish a model system for inquiries into these processes, we systematically analyzed cell cycle progression, cell morphology, and bud site selection after repression of 54 individual ribosomal protein (r-protein) genes in Saccharomyces cerevisiae. We found that repression of nine 60S r-protein genes results in arrest in the G2/M phase, whereas repression of nine other 60S and 22 40S r-protein genes causes arrest in the G1 phase. Furthermore, bud morphology changes after repression of some r-protein genes. For example, very elongated buds form after repression of seven 60S r-protein genes. These genes overlap with, but are not identical to, those causing the G2/M cell cycle phenotype. Finally, repression of most r-protein genes results in changed sites of bud formation. Strikingly, the r-proteins whose repression generates similar effects on cell cycle progression cluster in the ribosome physical structure, suggesting that different topological areas of the precursor and/or mature ribosome are mechanistically connected to separate aspects of the cell cycle.
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Affiliation(s)
- Mamata Thapa
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250 Flow Cytometry Core Facility, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
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Makarova JA, Ivanova SM, Tonevitsky AG, Grigoriev AI. New functions of small nucleolar RNAs. BIOCHEMISTRY (MOSCOW) 2013; 78:638-50. [DOI: 10.1134/s0006297913060096] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Marin-Vicente C, Lyutvinskiy Y, Romans Fuertes P, Zubarev RA, Visa N. The Effects of 5-Fluorouracil on the Proteome of Colon Cancer Cells. J Proteome Res 2013; 12:1969-79. [DOI: 10.1021/pr400052p] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Consuelo Marin-Vicente
- Department of Molecular Biosciences,
The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Department of Medical Biochemistry
and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Yaroslav Lyutvinskiy
- Department of Medical Biochemistry
and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Patricia Romans Fuertes
- Department of Molecular Biosciences,
The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Roman A. Zubarev
- Department of Medical Biochemistry
and Biophysics, Karolinska Institutet, Stockholm, Sweden
- SciLifeLab, Stockholm, Sweden
| | - Neus Visa
- Department of Molecular Biosciences,
The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Serum non-coding RNAs as biomarkers for osteoarthritis progression after ACL injury. Osteoarthritis Cartilage 2012; 20:1631-7. [PMID: 22944527 PMCID: PMC3478481 DOI: 10.1016/j.joca.2012.08.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 08/09/2012] [Accepted: 08/22/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The aim of this study was to examine serum non-coding RNAs as potential biomarkers for cartilage damage associated with anterior cruciate ligament (ACL) injury. METHODS Serum was obtained from 80 patients 1 year after surgery for ACL injury and 60 normal donors without overt skeletal injury. Total serum RNA was isolated, small non-coding RNAs profiled by TaqMan array MicroRNA (miRNA) analysis and individual small RNA assays performed by quantitative TaqMan RT-PCR (qPCR). Semi-quantitative magnetic resonance imaging (MRI) analysis was performed using Whole Organ Magnetic Resonance Knee Score (WORMS) scoring for analysis of cartilage damage. RESULTS Initial TaqMan array miRNA profiling showed an increased serum concentration of a small nucleolar RNA (snoRNA), U48, in five patients with cartilage damage compared with that in five patients without cartilage damage and six normal donors. Independent qPCR analysis of snoRNAs in serum from all patients and normal donors showed a strong association between the serum level of another snoRNA, U38, and cartilage damage in ACL injury patients and together with snoRNA, U48, clear distinction between ACL injury patients and normal donors. CONCLUSION SnoRNAs U38 and U48 are significantly elevated in the serum of patients developing cartilage damage at 1 year after ACL injury. Serum levels of U38 have the potential to facilitate early diagnosis of patients with cartilage damage after ACL injury. This study suggests serum non-coding RNAs may serve as novel noninvasive biomarkers for the detection and assessment of cartilage damage after ACL injury.
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