1
|
Zhang Y, Pang Y, Zhang K, Song X, Gao J, Zhang S, Deng W. RNA polymerase I subunit RPA43 activates rRNA expression and cell proliferation but inhibits cell migration. Biochim Biophys Acta Gen Subj 2023:130411. [PMID: 37343605 DOI: 10.1016/j.bbagen.2023.130411] [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: 01/30/2023] [Revised: 05/21/2023] [Accepted: 06/13/2023] [Indexed: 06/23/2023]
Abstract
The products synthesized by RNA polymerase I (Pol I) play fundamental roles in several cellular processes, including ribosomal biogenesis, protein synthesis, cell metabolism, and growth. Deregulation of Pol I products can cause various diseases such as ribosomopathies, leukaemia, and solid tumours. However, the detailed mechanism of Pol I-directed transcription remains elusive, and the roles of Pol I subunits in rRNA synthesis and cellular activities still need clarification. In this study, we found that RPA43 expression levels positively correlate with Pol I product accumulation and cell proliferation, indicating that RPA43 activates these processes. Unexpectedly, RPA43 depletion promoted HeLa cell migration, suggesting that RPA43 functions as a negative regulator in cell migration. Mechanistically, RPA43 positively modulates the recruitment of Pol I transcription machinery factors to the rDNA promoter by activating the transcription of the genes encoding Pol I transcription machinery factors. RPA43 inhibits cell migration by dampening the expression of c-JUN and Integrin. Collectively, we found that RPA43 plays opposite roles in cell proliferation and migration except for driving Pol I-dependent transcription. These findings provide novel insights into the regulatory mechanism of Pol I-mediated transcription and cell proliferation and a potential pathway to developing anti-cancer drugs using RPA43 as a target.
Collapse
Affiliation(s)
- Yue Zhang
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Yaoyu Pang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7GE, UK
| | - Kewei Zhang
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Xiaoye Song
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Junwei Gao
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Shuting Zhang
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China
| | - Wensheng Deng
- School of Life Science and Health, Wuhan University of Science and Technology, Wuhan, Hubei province 430065, China.
| |
Collapse
|
2
|
Abstract
In human cells, each rDNA unit consists of the ~13 kb long ribosomal part and ~30 kb long intergenic spacer (IGS). The ribosomal part, transcribed by RNA polymerase I (pol I), includes genes coding for 18S, 5.8S, and 28S RNAs of the ribosomal particles, as well as their four transcribed spacers. Being highly repetitive, intensively transcribed, and abundantly methylated, rDNA is a very fragile site of the genome, with high risk of instability leading to cancer. Multiple small mutations, considerable expansion or contraction of the rDNA locus, and abnormally enhanced pol I transcription are usual symptoms of transformation. Recently it was found that both IGS and the ribosomal part of the locus contain many functional/potentially functional regions producing non-coding RNAs, which participate in the pol I activity regulation, stress reactions, and development of the malignant phenotype. Thus, there are solid reasons to believe that rDNA locus plays crucial role in carcinogenesis. In this review we discuss the data concerning the human rDNA and its closely associated factors as both targets and drivers of the pathways essential for carcinogenesis. We also examine whether variability in the structure of the locus may be blamed for the malignant transformation. Additionally, we consider the prospects of therapy focused on the activity of rDNA.
Collapse
|
3
|
Quinacrine Induces Nucleolar Stress in Treatment-Refractory Ovarian Cancer Cell Lines. Cancers (Basel) 2021; 13:cancers13184645. [PMID: 34572872 PMCID: PMC8466834 DOI: 10.3390/cancers13184645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/03/2021] [Accepted: 09/10/2021] [Indexed: 12/29/2022] Open
Abstract
A considerable subset of gynecologic cancer patients experience disease recurrence or acquired resistance, which contributes to high mortality rates in ovarian cancer (OC). Our prior studies showed that quinacrine (QC), an antimalarial drug, enhanced chemotherapy sensitivity in treatment-refractory OC cells, including artificially generated chemoresistant and high-grade serous OC cells. In this study, we investigated QC-induced transcriptomic changes to uncover its cytotoxic mechanisms of action. Isogenic pairs of OC cells generated to be chemoresistant and their chemosensitive counterparts were treated with QC followed by RNA-seq analysis. Validation of selected expression results and database comparison analyses indicated the ribosomal biogenesis (RBG) pathway is inhibited by QC. RBG is commonly upregulated in cancer cells and is emerging as a drug target. We found that QC attenuates the in vitro and in vivo expression of nucleostemin (NS/GNL3), a nucleolar RBG and DNA repair protein, and the RPA194 catalytic subunit of Pol I that results in RBG inhibition and nucleolar stress. QC promotes the redistribution of fibrillarin in the form of extranuclear foci and nucleolar caps, an indicator of nucleolar stress conditions. In addition, we found that QC-induced downregulation of NS disrupted homologous recombination repair both by reducing NS protein levels and PARylation resulting in reduced RAD51 recruitment to DNA damage. Our data suggest that QC inhibits RBG and this inhibition promotes DNA damage by directly downregulating the NS-RAD51 interaction. Additionally, QC showed strong synergy with PARP inhibitors in OC cells. Overall, we found that QC downregulates the RBG pathway, induces nucleolar stress, supports the increase of DNA damage, and sensitizes cells to PARP inhibition, which supports new therapeutic stratagems for treatment-refractory OC. Our work offers support for targeting RBG in OC and determines NS to be a novel target for QC.
Collapse
|
4
|
Non-Coding RNAs and Splicing Activity in Testicular Germ Cell Tumors. Life (Basel) 2021; 11:life11080736. [PMID: 34440480 PMCID: PMC8399856 DOI: 10.3390/life11080736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/13/2021] [Accepted: 07/22/2021] [Indexed: 01/22/2023] Open
Abstract
Testicular germ cell tumors (TGCTs) are the most common tumors in adolescent and young men. Recently, genome-wide studies have made it possible to progress in understanding the molecular mechanisms underlying the development of tumors. It is becoming increasingly clear that aberrant regulation of RNA metabolism can drive tumorigenesis and influence chemotherapeutic response. Notably, the expression of non-coding RNAs as well as specific splice variants is deeply deregulated in human cancers. Since these cancer-related RNA species are considered promising diagnostic, prognostic and therapeutic targets, understanding their function in cancer development is becoming a major challenge. Here, we summarize how the different expression of RNA species repertoire, including non-coding RNAs and protein-coding splicing variants, impacts on TGCTs’ onset and progression and sustains therapeutic resistance. Finally, the role of transcription-associated R-loop misregulation in the maintenance of genomic stability in TGCTs is also discussed.
Collapse
|
5
|
Ribosomal RNA Transcription Regulation in Breast Cancer. Genes (Basel) 2021; 12:genes12040502. [PMID: 33805424 PMCID: PMC8066022 DOI: 10.3390/genes12040502] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 12/24/2022] Open
Abstract
Ribosome biogenesis is a complex process that is responsible for the formation of ribosomes and ultimately global protein synthesis. The first step in this process is the synthesis of the ribosomal RNA in the nucleolus, transcribed by RNA Polymerase I. Historically, abnormal nucleolar structure is indicative of poor cancer prognoses. In recent years, it has been shown that ribosome biogenesis, and rDNA transcription in particular, is dysregulated in cancer cells. Coupled with advancements in screening technology that allowed for the discovery of novel drugs targeting RNA Polymerase I, this transcriptional machinery is an increasingly viable target for cancer therapies. In this review, we discuss ribosome biogenesis in breast cancer and the different cellular pathways involved. Moreover, we discuss current therapeutics that have been found to affect rDNA transcription and more novel drugs that target rDNA transcription machinery as a promising avenue for breast cancer treatment.
Collapse
|
6
|
Low JY, Sirajuddin P, Moubarek M, Agarwal S, Rege A, Guner G, Liu H, Yang Z, De Marzo AM, Bieberich C, Laiho M. Effective targeting of RNA polymerase I in treatment-resistant prostate cancer. Prostate 2019; 79:1837-1851. [PMID: 31524299 PMCID: PMC7025478 DOI: 10.1002/pros.23909] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/30/2019] [Indexed: 12/28/2022]
Abstract
BACKGROUND Advanced prostate cancers depend on protein synthesis for continued survival and accelerated rates of metabolism for growth. RNA polymerase I (Pol I) is the enzyme responsible for ribosomal RNA (rRNA) transcription and a rate-limiting step for ribosome biogenesis. We have shown using a specific and sensitive RNA probe for the 45S rRNA precursor that rRNA synthesis is increased in prostate adenocarcinoma compared to nonmalignant epithelium. We have introduced a first-in-class Pol I inhibitor, BMH-21, that targets cancer cells of multiple origins, and holds potential for clinical translation. METHODS The effect of BMH-21 was tested in prostate cancer cell lines and in prostate cancer xenograft and mouse genetic models. RESULTS We show that BMH-21 inhibits Pol I transcription in metastatic, castration-resistant, and enzalutamide treatment-resistant prostate cancer cell lines. The genetic abrogation of Pol I effectively blocks the growth of prostate cancer cells. Silencing of p53, a pathway activated downstream of Pol I, does not diminish this effect. We find that BMH-21 significantly inhibited tumor growth and reduced the Ki67 proliferation index in an enzalutamide-resistant xenograft tumor model. A decrease in 45S rRNA synthesis demonstrated on-target activity. Furthermore, the Pol I inhibitor significantly inhibited tumor growth and pathology in an aggressive genetically modified Hoxb13-MYC|Hoxb13-Cre|Ptenfl/fl (BMPC) mouse prostate cancer model. CONCLUSION Taken together, BMH-21 is a novel promising molecule for the treatment of castration-resistant prostate cancer.
Collapse
MESH Headings
- Animals
- Benzamides
- Cell Growth Processes/drug effects
- Cell Line, Tumor
- Drug Resistance, Neoplasm
- Enzyme Inhibitors/pharmacology
- Heterocyclic Compounds, 4 or More Rings/pharmacology
- Humans
- Male
- Mice
- Mice, Nude
- Molecular Targeted Therapy
- Nitriles
- PC-3 Cells
- Phenylthiohydantoin/analogs & derivatives
- Phenylthiohydantoin/pharmacology
- Prostatic Neoplasms/drug therapy
- Prostatic Neoplasms/enzymology
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/pathology
- Prostatic Neoplasms, Castration-Resistant/drug therapy
- Prostatic Neoplasms, Castration-Resistant/enzymology
- Prostatic Neoplasms, Castration-Resistant/genetics
- Prostatic Neoplasms, Castration-Resistant/pathology
- RNA Polymerase I/antagonists & inhibitors
- RNA Polymerase I/genetics
- RNA Polymerase I/metabolism
- RNA, Ribosomal/genetics
- Random Allocation
- Transcription, Genetic/drug effects
- Xenograft Model Antitumor Assays
Collapse
Affiliation(s)
- Jin-Yih Low
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Paul Sirajuddin
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Michael Moubarek
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland
| | - Shreya Agarwal
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland
| | - Apurv Rege
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland
| | - Gunes Guner
- Department of Pathology, Urology and Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Hester Liu
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Zhiming Yang
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Angelo M. De Marzo
- Department of Pathology, Urology and Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Charles Bieberich
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland
| | - Marikki Laiho
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| |
Collapse
|
7
|
Pantazi A, Quintanilla A, Hari P, Tarrats N, Parasyraki E, Dix FL, Patel J, Chandra T, Acosta JC, Finch AJ. Inhibition of the 60S ribosome biogenesis GTPase LSG1 causes endoplasmic reticular disruption and cellular senescence. Aging Cell 2019; 18:e12981. [PMID: 31148378 PMCID: PMC6612703 DOI: 10.1111/acel.12981] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 04/06/2019] [Accepted: 04/28/2019] [Indexed: 01/07/2023] Open
Abstract
Cellular senescence is triggered by diverse stimuli and is characterized by long-term growth arrest and secretion of cytokines and chemokines (termed the SASP-senescence-associated secretory phenotype). Senescence can be organismally beneficial as it can prevent the propagation of damaged or mutated clones and stimulate their clearance by immune cells. However, it has recently become clear that senescence also contributes to the pathophysiology of aging through the accumulation of damaged cells within tissues. Here, we describe that inhibition of the reaction catalysed by LSG1, a GTPase involved in the biogenesis of the 60S ribosomal subunit, leads to a robust induction of cellular senescence. Perhaps surprisingly, this was not due to ribosome depletion or translational insufficiency, but rather through perturbation of endoplasmic reticulum homeostasis and a dramatic upregulation of the cholesterol biosynthesis pathway. The underlying transcriptomic signature is shared with several other forms of senescence, and the cholesterol biosynthesis genes contribute to the cell cycle arrest in oncogene-induced senescence. Furthermore, targeting of LSG1 resulted in amplification of the cholesterol/ER signature and restoration of a robust cellular senescence response in transformed cells, suggesting potential therapeutic uses of LSG1 inhibition.
Collapse
Affiliation(s)
- Asimina Pantazi
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Andrea Quintanilla
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Priya Hari
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Nuria Tarrats
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Eleftheria Parasyraki
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Flora L. Dix
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Jaiyogesh Patel
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Tamir Chandra
- MRC Human Genetics Unit, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Juan Carlos Acosta
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| | - Andrew J. Finch
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUK
| |
Collapse
|
8
|
Iarovaia OV, Minina EP, Sheval EV, Onichtchouk D, Dokudovskaya S, Razin SV, Vassetzky YS. Nucleolus: A Central Hub for Nuclear Functions. Trends Cell Biol 2019; 29:647-659. [PMID: 31176528 DOI: 10.1016/j.tcb.2019.04.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/24/2019] [Accepted: 04/26/2019] [Indexed: 12/19/2022]
Abstract
The nucleolus is the largest and most studied nuclear body, but its role in nuclear function is far from being comprehensively understood. Much work on the nucleolus has focused on its role in regulating RNA polymerase I (RNA Pol I) transcription and ribosome biogenesis; however, emerging evidence points to the nucleolus as an organizing hub for many nuclear functions, accomplished via the shuttling of proteins and nucleic acids between the nucleolus and nucleoplasm. Here, we discuss the cellular mechanisms affected by shuttling of nucleolar components, including the 3D organization of the genome, stress response, DNA repair and recombination, transcription regulation, telomere maintenance, and other essential cellular functions.
Collapse
Affiliation(s)
- Olga V Iarovaia
- Institute of Gene Biology of the Russian Academy of Sciences, 119334 Moscow, Russia; LIA 1066 LFR2O French-Russian Joint Cancer Research Laboratory, 94805 Villejuif, France
| | - Elizaveta P Minina
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Eugene V Sheval
- LIA 1066 LFR2O French-Russian Joint Cancer Research Laboratory, 94805 Villejuif, France; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Daria Onichtchouk
- Developmental Biology Unit, Department of Biology I, University of Freiburg, Hauptstrasse 1, D-79104 Freiburg, Germany
| | - Svetlana Dokudovskaya
- LIA 1066 LFR2O French-Russian Joint Cancer Research Laboratory, 94805 Villejuif, France; UMR8126, Université Paris-Sud, CNRS, Institut Gustave Roussy, 94805 Villejuif, France
| | - Sergey V Razin
- Institute of Gene Biology of the Russian Academy of Sciences, 119334 Moscow, Russia; LIA 1066 LFR2O French-Russian Joint Cancer Research Laboratory, 94805 Villejuif, France; Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Yegor S Vassetzky
- LIA 1066 LFR2O French-Russian Joint Cancer Research Laboratory, 94805 Villejuif, France; Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, 119334 Moscow, Russia; UMR8126, Université Paris-Sud, CNRS, Institut Gustave Roussy, 94805 Villejuif, France.
| |
Collapse
|
9
|
Penzo M, Montanaro L, Treré D, Derenzini M. The Ribosome Biogenesis-Cancer Connection. Cells 2019; 8:cells8010055. [PMID: 30650663 PMCID: PMC6356843 DOI: 10.3390/cells8010055] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/08/2019] [Accepted: 01/14/2019] [Indexed: 01/05/2023] Open
Abstract
Multifaceted relations link ribosome biogenesis to cancer. Ribosome biogenesis takes place in the nucleolus. Clarifying the mechanisms involved in this nucleolar function and its relationship with cell proliferation: (1) allowed the understanding of the reasons for the nucleolar changes in cancer cells and their exploitation in tumor pathology, (2) defined the importance of the inhibition of ribosome biogenesis in cancer chemotherapy and (3) focused the attention on alterations of ribosome biogenesis in the pathogenesis of cancer. This review summarizes the research milestones regarding these relevant relationships between ribosome biogenesis and cancer. The structure and function of the nucleolus will also be briefly described.
Collapse
Affiliation(s)
- Marianna Penzo
- Department of Experimental, Diagnostic and Specialty Medicine, Alma Mater Studiorum-University of Bologna, 40138 Bologna, Italy.
- Center for Applied Biomedical Research (CRBA), Alma Mater Studiorum-University of Bologna, 40138 Bologna, Italy.
| | - Lorenzo Montanaro
- Department of Experimental, Diagnostic and Specialty Medicine, Alma Mater Studiorum-University of Bologna, 40138 Bologna, Italy.
- Center for Applied Biomedical Research (CRBA), Alma Mater Studiorum-University of Bologna, 40138 Bologna, Italy.
| | - Davide Treré
- Department of Experimental, Diagnostic and Specialty Medicine, Alma Mater Studiorum-University of Bologna, 40138 Bologna, Italy.
| | | |
Collapse
|
10
|
Nop-7-associated 2 (NSA2) is required for ribosome biogenesis and protein synthesis. Biochem Biophys Res Commun 2018; 505:249-254. [PMID: 30243719 DOI: 10.1016/j.bbrc.2018.09.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 09/07/2018] [Indexed: 12/11/2022]
Abstract
Ribosome biogenesis is a fundamental cellular process and occurs mainly in the nucleolus in eukaryotes. The process is exceptionally complex and highly regulated by numerous ribosomal and non-ribosomal factors. A recent discovery strengthened the link between ribosome biogenesis and malignant transformation. Here, we determined that Nop-7-associated 2 (NSA2) is a nucleolar protein required for ribosome biogenesis. NSA2 knockdown reduced the rate of rRNA synthesis, diminishing the 60S ribosomal subunit. Moreover, we demonstrated that depletion of NSA2 suppressed protein synthesis. To investigate the signaling pathway affected by NSA2, NSA2 was depleted, which triggered the inactivation of the mTOR signaling pathway. Taken together, our findings reveal a novel function of NSA2 and provide insight into the regulation of ribosome biogenesis by NSA2.
Collapse
|
11
|
Marcel V, Nguyen Van Long F, Diaz JJ. 40 Years of Research Put p53 in Translation. Cancers (Basel) 2018; 10:E152. [PMID: 29883412 PMCID: PMC5977125 DOI: 10.3390/cancers10050152] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 12/18/2022] Open
Abstract
Since its discovery in 1979, p53 has shown multiple facets. Initially the tumor suppressor p53 protein was considered as a stress sensor able to maintain the genome integrity by regulating transcription of genes involved in cell cycle arrest, apoptosis and DNA repair. However, it rapidly came into light that p53 regulates gene expression to control a wider range of biological processes allowing rapid cell adaptation to environmental context. Among them, those related to cancer have been extensively documented. In addition to its role as transcription factor, scattered studies reported that p53 regulates miRNA processing, modulates protein activity by direct interaction or exhibits RNA-binding activity, thus suggesting a role of p53 in regulating several layers of gene expression not restricted to transcription. After 40 years of research, it appears more and more clearly that p53 is strongly implicated in translational regulation as well as in the control of the production and activity of the translational machinery. Translation control of specific mRNAs could provide yet unsuspected capabilities to this well-known guardian of the genome.
Collapse
Affiliation(s)
- Virginie Marcel
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France.
| | - Flora Nguyen Van Long
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France.
| | - Jean-Jacques Diaz
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France.
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Kasteri J, Das D, Zhong X, Persaud L, Francis A, Muharam H, Sauane M. Translation Control by p53. Cancers (Basel) 2018; 10:cancers10050133. [PMID: 29734756 PMCID: PMC5977106 DOI: 10.3390/cancers10050133] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 12/11/2022] Open
Abstract
The translation of mRNAs plays a critical role in the regulation of gene expression and therefore, in the regulation of cell proliferation, differentiation and apoptosis. Unrestricted initiation of translation causes malignant transformation and plays a key role in the maintenance and progression of cancers. Translation initiation is regulated by the ternary complex and the eukaryotic initiation factor 4F (eIF4F) complex. The p53 tumor suppressor protein is the most well studied mammalian transcription factor that mediates a variety of anti-proliferative processes. Post-transcriptional mechanisms of gene expression in general and those of translation in particular play a major role in shaping the protein composition of the cell. The p53 protein regulates transcription and controls eIF4F, the ternary complex and the synthesis of ribosomal components, including the down-regulation of rRNA genes. In summary, the induction of p53 regulates protein synthesis and translational control to inhibit cell growth.
Collapse
Affiliation(s)
- Justina Kasteri
- Department of Biological Sciences, Herbert H. Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
| | - Dibash Das
- Department of Biological Sciences, Herbert H. Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
- Department of Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, Room, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
| | - Xuelin Zhong
- Department of Biological Sciences, Herbert H. Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
- Department of Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, Room, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
| | - Leah Persaud
- Department of Biological Sciences, Herbert H. Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
- Department of Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, Room, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
| | - Ashleigh Francis
- Department of Biological Sciences, Herbert H. Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
| | - Hilal Muharam
- Department of Biological Sciences, Herbert H. Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
| | - Moira Sauane
- Department of Biological Sciences, Herbert H. Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
- Department of Biology, The Graduate Center, City University of New York, 365 Fifth Avenue, Room, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA.
| |
Collapse
|
14
|
Chen TH, Wu YJ, Hou JN, Chiang YH, Cheng CC, Sifiyatun E, Chiu CH, Wang LC, Chen WJ. A novel p53 paralogue mediates antioxidant defense of mosquito cells to survive dengue virus replication. Virology 2018; 519:156-169. [PMID: 29727815 DOI: 10.1016/j.virol.2018.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 03/31/2018] [Accepted: 04/16/2018] [Indexed: 01/22/2023]
Abstract
Mosquito cells allow dengue viruses (DENVs) to undergo replication without causing serious deleterious effects on the cells, leading to advantages for dissemination to other cells. Despite this, increased accumulation of reactive oxygen species (ROS) is usually detected in C6/36 cells with DENV2 infection as shown in mammalian cells. Uniquely, oxidative stress caused by the ROS is alleviated by eliciting antioxidant defense which leads to protection of mosquito cells from the infection. In the present study, a novel p53 paralogue (p53-2) was identified and proved to be regulated in C6/36 cells with DENV2 infection. With a gene-knockdown technique, p53-2 was demonstrated to transcribe catalase which plays a critical role in reducing ROS accumulation and the death rate of infected cells. Ecologically, a higher survival rate of mosquito cells is a prerequisite for prosperous production of viral progeny, allowing infected mosquitoes to remain healthy and active for virus transmission.
Collapse
Affiliation(s)
- Tien-Huang Chen
- Departments of Public Health and Parasitology, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
| | - Yi-Jun Wu
- Graduate Institute of Biomedical Sciences, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
| | - Jiun-Nan Hou
- Graduate Institute of Biomedical Sciences, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
| | - Yi-Hsuan Chiang
- Departments of Public Health and Parasitology, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
| | - Chih-Chieh Cheng
- Graduate Institute of Biomedical Sciences, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
| | - Eny Sifiyatun
- Graduate Institute of Biomedical Sciences, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan; Program in Tropical Medical Science, Gadjah Mada University, Yogyakartan, Indonesia
| | - Cheng-Hsun Chiu
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Kwei-San, Tao-Yuan, Taiwan; Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Kwei-San, Tao-Yuan, Taiwan
| | - Lian-Chen Wang
- Departments of Public Health and Parasitology, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan; Graduate Institute of Biomedical Sciences, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Kwei-San, Tao-Yuan, Taiwan.
| | - Wei-June Chen
- Departments of Public Health and Parasitology, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan; Graduate Institute of Biomedical Sciences, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Kwei-San, Tao-Yuan, Taiwan.
| |
Collapse
|
15
|
Abstract
Ribosome biogenesis is a complex and highly energy-demanding process that requires the concerted action of all three nuclear RNA polymerases (Pol I-III) in eukaryotes. The three largest ribosomal RNAs (rRNAs) originate from a precursor transcript (pre-rRNA) that is encoded by multicopy genes located in the nucleolus. Transcription of these rRNA genes (rDNA) by Pol I is the key regulation step in ribosome production and is tightly controlled by an intricate network of signaling pathways and epigenetic mechanisms. In this article, we give an overview of the composition of the basal Pol I machinery and rDNA chromatin. We discuss rRNA gene regulation in response to environmental signals and developmental cues and focus on perturbations occurring in diseases linked to either excessive or limited rRNA levels. Finally, we discuss the emerging view that rDNA integrity and activity may be involved in the aging process.
Collapse
Affiliation(s)
- Samim Sharifi
- Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University, 07745 Jena, Germany; , .,Leibniz-Institute on Aging-Fritz Lipmann Institute, 07745 Jena, Germany
| | - Holger Bierhoff
- Institute of Biochemistry and Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University, 07745 Jena, Germany; , .,Leibniz-Institute on Aging-Fritz Lipmann Institute, 07745 Jena, Germany
| |
Collapse
|
16
|
Gasch AP, Yu FB, Hose J, Escalante LE, Place M, Bacher R, Kanbar J, Ciobanu D, Sandor L, Grigoriev IV, Kendziorski C, Quake SR, McClean MN. Single-cell RNA sequencing reveals intrinsic and extrinsic regulatory heterogeneity in yeast responding to stress. PLoS Biol 2017; 15:e2004050. [PMID: 29240790 PMCID: PMC5746276 DOI: 10.1371/journal.pbio.2004050] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/28/2017] [Accepted: 11/17/2017] [Indexed: 02/01/2023] Open
Abstract
From bacteria to humans, individual cells within isogenic populations can show significant variation in stress tolerance, but the nature of this heterogeneity is not clear. To investigate this, we used single-cell RNA sequencing to quantify transcript heterogeneity in single Saccharomyces cerevisiae cells treated with and without salt stress to explore population variation and identify cellular covariates that influence the stress-responsive transcriptome. Leveraging the extensive knowledge of yeast transcriptional regulation, we uncovered significant regulatory variation in individual yeast cells, both before and after stress. We also discovered that a subset of cells appears to decouple expression of ribosomal protein genes from the environmental stress response in a manner partly correlated with the cell cycle but unrelated to the yeast ultradian metabolic cycle. Live-cell imaging of cells expressing pairs of fluorescent regulators, including the transcription factor Msn2 with Dot6, Sfp1, or MAP kinase Hog1, revealed both coordinated and decoupled nucleocytoplasmic shuttling. Together with transcriptomic analysis, our results suggest that cells maintain a cellular filter against decoupled bursts of transcription factor activation but mount a stress response upon coordinated regulation, even in a subset of unstressed cells. Genetically identical cells growing in the same environment can vary in their cellular state and behavior. Such heterogeneity may explain why some cells in an isogenic population can survive sudden severe environmental stress whereas other cells succumb. Cell-to-cell variation in gene expression has been linked to variable stress survival, but how and why transcript levels vary across the transcriptome in single cells is only beginning to emerge. Here, we used single-cell RNA sequencing (scRNA-seq) to measure cell-to-cell heterogeneity in the transcriptome of budding yeast (Saccharomyces cerevisiae). We find surprising patterns of variation across known sets of transcription factor targets, indicating that cells vary in their transcriptome profile both before and after stress exposure. scRNA-seq analysis combined with live-cell imaging of transcription factor activation dynamics revealed some cells in which the stress response was coordinately activated and other cells in which the traditional response was decoupled, suggesting unrecognized regulatory nuances that expand our understanding of stress response and survival.
Collapse
Affiliation(s)
- Audrey P. Gasch
- Laboratory of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- * E-mail:
| | - Feiqiao Brian Yu
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - James Hose
- Laboratory of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Leah E. Escalante
- Laboratory of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Mike Place
- Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Rhonda Bacher
- Department of Biostatistics and Medical Informatics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Jad Kanbar
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Doina Ciobanu
- Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Laura Sandor
- Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Igor V. Grigoriev
- Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Christina Kendziorski
- Department of Biostatistics and Medical Informatics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Stephen R. Quake
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
- Chan Zuckerberg Biohub, San Francisco, California, United States of America
| | - Megan N. McClean
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| |
Collapse
|
17
|
Porter JR, Fisher BE, Baranello L, Liu JC, Kambach DM, Nie Z, Koh WS, Luo J, Stommel JM, Levens D, Batchelor E. Global Inhibition with Specific Activation: How p53 and MYC Redistribute the Transcriptome in the DNA Double-Strand Break Response. Mol Cell 2017; 67:1013-1025.e9. [PMID: 28867293 PMCID: PMC5657607 DOI: 10.1016/j.molcel.2017.07.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 06/30/2017] [Accepted: 07/28/2017] [Indexed: 12/24/2022]
Abstract
In response to stresses, cells often halt normal cellular processes, yet stress-specific pathways must bypass such inhibition to generate effective responses. We investigated how cells redistribute global transcriptional activity in response to DNA damage. We show that an oscillatory increase of p53 levels in response to double-strand breaks drives a counter-oscillatory decrease of MYC levels. Using RNA sequencing (RNA-seq) of newly synthesized transcripts, we found that p53-mediated reduction of MYC suppressed general transcription, with the most highly expressed transcripts reduced to a greater extent. In contrast, upregulation of p53 targets was relatively unaffected by MYC suppression. Reducing MYC during the DNA damage response was important for cell-fate regulation, as counteracting MYC repression reduced cell-cycle arrest and elevated apoptosis. Our study shows that global inhibition with specific activation of transcriptional pathways is important for the proper response to DNA damage; this mechanism may be a general principle used in many stress responses.
Collapse
Affiliation(s)
- Joshua R Porter
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Brian E Fisher
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Laura Baranello
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Julia C Liu
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA; National Institute of General Medical Sciences, NIH, Bethesda, MD 20892, USA
| | - Diane M Kambach
- Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Zuqin Nie
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Woo Seuk Koh
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Ji Luo
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Jayne M Stommel
- Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - David Levens
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Eric Batchelor
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
18
|
Abstract
The nucleolus is a distinct compartment of the nucleus responsible for ribosome biogenesis. Mis-regulation of nucleolar functions and of the cellular translation machinery has been associated with disease, in particular with many types of cancer. Indeed, many tumor suppressors (p53, Rb, PTEN, PICT1, BRCA1) and proto-oncogenes (MYC, NPM) play a direct role in the nucleolus, and interact with the RNA polymerase I transcription machinery and the nucleolar stress response. We have identified Dicer and the RNA interference pathway as having an essential role in the nucleolus of quiescent Schizosaccharomyces pombe cells, distinct from pericentromeric silencing, by controlling RNA polymerase I release. We propose that this novel function is evolutionarily conserved and may contribute to the tumorigenic pre-disposition of DICER1 mutations in mammals.
Collapse
Affiliation(s)
- Benjamin Roche
- a Martienssen Lab, Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA
| | - Benoît Arcangioli
- b Genome Dynamics Unit, UMR 3525 CNRS, Institut Pasteur , Paris , France
| | - Rob Martienssen
- a Martienssen Lab, Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA.,c Howard Hughes Medical Institute, Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA
| |
Collapse
|
19
|
Zhang J, Shao J, Zhu L, Zhao R, Xing J, Wang J, Guo X, Tu S, Han B, Yu K. Molecular profiling identifies prognostic markers of stage IA lung adenocarcinoma. Oncotarget 2017; 8:74846-74855. [PMID: 29088828 PMCID: PMC5650383 DOI: 10.18632/oncotarget.20420] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/16/2017] [Indexed: 12/29/2022] Open
Abstract
We previously showed that different pathologic subtypes were associated with different prognostic values in patients with stage IA lung adenocarcinoma (AC). We hypothesize that differential gene expression profiles of different subtypes may be valuable factors for prognosis in stage IA lung adenocarcinoma. We performed microarray gene expression profiling on tumor tissues micro-dissected from patients with acinar and solid predominant subtypes of stage IA lung adenocarcinoma. These patients had undergone a lobectomy and mediastinal lymph node dissection at the Shanghai Chest Hospital, Shanghai, China in 2012. No patient had preoperative treatment. We performed the Gene Set Enrichment Analysis (GSEA) analysis to look for gene expression signatures associated with tumor subtypes. The histologic subtypes of all patients were classified according to the 2015 WHO lung Adenocarcinoma classification. We found that patients with the solid predominant subtype are enriched for genes involved in RNA polymerase activity as well as inactivation of the p53 pathway. Further, we identified a list of genes that may serve as prognostic markers for stage IA lung adenocarcinoma. Validation in the TCGA database shows that these genes are correlated with survival, suggesting that they are novel prognostic factors for stage IA lung adenocarcinoma. In conclusion, we have uncovered novel prognostic factors for stage IA lung adenocarcinoma using gene expression profiling in combination with histopathology subtyping.
Collapse
Affiliation(s)
- Jie Zhang
- Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Pathology, Shanghai, China
| | - Jinchen Shao
- Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Pathology, Shanghai, China
| | - Lei Zhu
- Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Pathology, Shanghai, China
| | - Ruiying Zhao
- Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Pathology, Shanghai, China
| | - Jie Xing
- Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Pathology, Shanghai, China
| | - Jun Wang
- Tumor Initiation & Maintenance Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla
| | - Xiaohui Guo
- Bioinformatics Core, Sanford Burnham Prebys Medical Discovery Institute, La Jolla
| | - Shichun Tu
- Allele Biotechnology & Pharmaceuticals, Inc., Nancy Ridge Drive, San Diego, USA
| | - Baohui Han
- Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Pulmonary Medicine, Shanghai, China
| | - Keke Yu
- Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Pathology, Shanghai, China.,Shanghai Chest Hospital, Shanghai JiaoTong University, Department of Biobank, Shanghai, China
| |
Collapse
|
20
|
Fischer M. Census and evaluation of p53 target genes. Oncogene 2017; 36:3943-3956. [PMID: 28288132 PMCID: PMC5511239 DOI: 10.1038/onc.2016.502] [Citation(s) in RCA: 592] [Impact Index Per Article: 84.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/23/2016] [Accepted: 11/29/2016] [Indexed: 12/17/2022]
Abstract
The tumor suppressor p53 functions primarily as a transcription factor. Mutation of the TP53 gene alters its response pathway, and is central to the development of many cancers. The discovery of a large number of p53 target genes, which confer p53's tumor suppressor function, has led to increasingly complex models of p53 function. Recent meta-analysis approaches, however, are simplifying our understanding of how p53 functions as a transcription factor. In the survey presented here, a total set of 3661 direct p53 target genes is identified that comprise 3509 potential targets from 13 high-throughput studies, and 346 target genes from individual gene analyses. Comparison of the p53 target genes reported in individual studies with those identified in 13 high-throughput studies reveals limited consistency. Here, p53 target genes have been evaluated based on the meta-analysis data, and the results show that high-confidence p53 target genes are involved in multiple cellular responses, including cell cycle arrest, DNA repair, apoptosis, metabolism, autophagy, mRNA translation and feedback mechanisms. However, many p53 target genes are identified only in a small number of studies and have a higher likelihood of being false positives. While numerous mechanisms have been proposed for mediating gene regulation in response to p53, recent advances in our understanding of p53 function show that p53 itself is solely an activator of transcription, and gene downregulation by p53 is indirect and requires p21. Taking into account the function of p53 as an activator of transcription, recent results point to an unsophisticated means of regulation.
Collapse
Affiliation(s)
- M Fischer
- Molecular Oncology, Medical School, University of Leipzig, Leipzig, Germany
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
21
|
Regulatory module involving FGF13, miR-504, and p53 regulates ribosomal biogenesis and supports cancer cell survival. Proc Natl Acad Sci U S A 2016; 114:E496-E505. [PMID: 27994142 DOI: 10.1073/pnas.1614876114] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The microRNA miR-504 targets TP53 mRNA encoding the p53 tumor suppressor. miR-504 resides within the fibroblast growth factor 13 (FGF13) gene, which is overexpressed in various cancers. We report that the FGF13 locus, comprising FGF13 and miR-504, is transcriptionally repressed by p53, defining an additional negative feedback loop in the p53 network. Furthermore, we show that FGF13 1A is a nucleolar protein that represses ribosomal RNA transcription and attenuates protein synthesis. Importantly, in cancer cells expressing high levels of FGF13, the depletion of FGF13 elicits increased proteostasis stress, associated with the accumulation of reactive oxygen species and apoptosis. Notably, stepwise neoplastic transformation is accompanied by a gradual increase in FGF13 expression and increased dependence on FGF13 for survival ("nononcogene addiction"). Moreover, FGF13 overexpression enables cells to cope more effectively with the stress elicited by oncogenic Ras protein. We propose that, in cells in which activated oncogenes drive excessive protein synthesis, FGF13 may favor survival by maintaining translation rates at a level compatible with the protein quality-control capacity of the cell. Thus, FGF13 may serve as an enabler, allowing cancer cells to evade proteostasis stress triggered by oncogene activation.
Collapse
|
22
|
He X, Li Y, Dai MS, Sun XX. Ribosomal protein L4 is a novel regulator of the MDM2-p53 loop. Oncotarget 2016; 7:16217-26. [PMID: 26908445 PMCID: PMC4941309 DOI: 10.18632/oncotarget.7479] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/09/2016] [Indexed: 12/29/2022] Open
Abstract
A number of ribosomal proteins (RPs) have been shown to play a critical role in coordinating ribosome biogenesis with cell growth and proliferation by suppressing MDM2 to induce p53 activation. While how the MDM2-p53 pathway is regulated by multiple RPs is unclear, it remains to be interesting to identify additional RPs that can regulate this pathway. Here we report that ribosomal protein L4 (RPL4) directly interacts with MDM2 at the central acidic domain and suppresses MDM2-mediated p53 ubiquitination and degradation, leading to p53 stabilization and activation. Interestingly, overexpression of RPL4 promotes the binding of MDM2 to RPL5 and RPL11 and forms a complex with RPL5, RPL11 and MDM2 in cells. Conversely, knockdown of RPL4 also induces p53 levels and p53-dependent cell cycle arrest. This p53-dependent effect requires both RPL5 and RPL11, suggesting that depletion of RPL4 triggers ribosomal stress. Together, our results reveal that balanced levels of RPL4 are critical for normal cell growth and proliferation via regulating the MDM2-p53 loop.
Collapse
Affiliation(s)
- Xia He
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
- Department of Radiation Oncology, Jiangsu Cancer Hospital, Nanjing, China
| | - Yuhuang Li
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - Mu-Shui Dai
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - Xiao-Xin Sun
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
23
|
Shi Z, Barna M. Translating the genome in time and space: specialized ribosomes, RNA regulons, and RNA-binding proteins. Annu Rev Cell Dev Biol 2015; 31:31-54. [PMID: 26443190 DOI: 10.1146/annurev-cellbio-100814-125346] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A central question in cell and developmental biology is how the information encoded in the genome is differentially interpreted to generate a diverse array of cell types. A growing body of research on posttranscriptional gene regulation is revealing that both global protein synthesis rates and the translation of specific mRNAs are highly specialized in different cell types. How this exquisite translational regulation is achieved is the focus of this review. Two levels of regulation are discussed: the translation machinery and cis-acting elements within mRNAs. Recent evidence shows that the ribosome itself directs how the genome is translated in time and space and reveals surprising functional specificity in individual components of the core translation machinery. We are also just beginning to appreciate the rich regulatory information embedded in the untranslated regions of mRNAs, which direct the selective translation of transcripts. These hidden RNA regulons may interface with a myriad of RNA-binding proteins and specialized translation machinery to provide an additional layer of regulation to how transcripts are spatiotemporally expressed. Understanding this largely unexplored world of translational codes hardwired in the core translation machinery is an exciting new research frontier fundamental to our understanding of gene regulation, organismal development, and evolution.
Collapse
Affiliation(s)
- Zhen Shi
- Department of Developmental Biology and Department of Genetics, Stanford University, Stanford, California 94305;
| | - Maria Barna
- Department of Developmental Biology and Department of Genetics, Stanford University, Stanford, California 94305;
| |
Collapse
|
24
|
Yu F, Bracken CP, Pillman KA, Lawrence DM, Goodall GJ, Callen DF, Neilsen PM. p53 Represses the Oncogenic Sno-MiR-28 Derived from a SnoRNA. PLoS One 2015; 10:e0129190. [PMID: 26061048 PMCID: PMC4465335 DOI: 10.1371/journal.pone.0129190] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/07/2015] [Indexed: 12/19/2022] Open
Abstract
p53 is a master tumour repressor that participates in vast regulatory networks, including feedback loops involving microRNAs (miRNAs) that regulate p53 and that themselves are direct p53 transcriptional targets. We show here that a group of polycistronic miRNA-like non-coding RNAs derived from small nucleolar RNAs (sno-miRNAs) are transcriptionally repressed by p53 through their host gene, SNHG1. The most abundant of these, sno-miR-28, directly targets the p53-stabilizing gene, TAF9B. Collectively, p53, SNHG1, sno-miR-28 and TAF9B form a regulatory loop which affects p53 stability and downstream p53-regulated pathways. In addition, SNHG1, SNORD28 and sno-miR-28 are all significantly upregulated in breast tumours and the overexpression of sno-miR-28 promotes breast epithelial cell proliferation. This research has broadened our knowledge of the crosstalk between small non-coding RNA pathways and roles of sno-miRNAs in p53 regulation.
Collapse
Affiliation(s)
- Feng Yu
- Centre for Personalized Cancer Medicine, University of Adelaide, Adelaide, SA, Australia
- Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
- Centre for Cancer Biology, SA Pathology, Adelaide, SA, Australia
| | - Cameron P. Bracken
- Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
- Centre for Cancer Biology, SA Pathology, Adelaide, SA, Australia
- * E-mail:
| | - Katherine A. Pillman
- ACRF Cancer Genomics Facility, Centre for Cancer Biology, SA Pathology, Adelaide, Australia
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - David M. Lawrence
- ACRF Cancer Genomics Facility, Centre for Cancer Biology, SA Pathology, Adelaide, Australia
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Gregory J. Goodall
- Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
- Centre for Cancer Biology, SA Pathology, Adelaide, SA, Australia
| | - David F. Callen
- Centre for Personalized Cancer Medicine, University of Adelaide, Adelaide, SA, Australia
- Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Paul M. Neilsen
- Centre for Personalized Cancer Medicine, University of Adelaide, Adelaide, SA, Australia
- Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
- Swinburne University of Technology, Kuching, Sarawak, Malaysia
| |
Collapse
|
25
|
Ho YH, Gasch AP. Exploiting the yeast stress-activated signaling network to inform on stress biology and disease signaling. Curr Genet 2015; 61:503-11. [PMID: 25957506 DOI: 10.1007/s00294-015-0491-0] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 12/24/2022]
Abstract
Healthy cells utilize intricate systems to monitor their environment and mount robust responses in the event of cellular stress. Whether stress arises from external insults or defects due to mutation and disease, cells must be able to respond precisely to mount the appropriate defenses. Multi-faceted stress responses are generally coupled with arrest of growth and cell-cycle progression, which both limits the transmission of damaged materials and serves to reallocate limited cellular resources toward defense. Therefore, stress defense versus rapid growth represent competing interests in the cell. How eukaryotic cells set the balance between defense versus proliferation, and in particular knowledge of the regulatory networks that control this decision, are poorly understood. In this perspective, we expand upon our recent work inferring the stress-activated signaling network in budding yeast, which captures pathways controlling stress defense and regulators of growth and cell-cycle progression. We highlight similarities between the yeast and mammalian stress responses and explore how stress-activated signaling networks in yeast can inform on signaling defects in human cancers.
Collapse
Affiliation(s)
- Yi-Hsuan Ho
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Audrey P Gasch
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| |
Collapse
|
26
|
Marcel V, Catez F, Diaz JJ. p53, a translational regulator: contribution to its tumour-suppressor activity. Oncogene 2015; 34:5513-23. [DOI: 10.1038/onc.2015.25] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/08/2015] [Accepted: 01/12/2015] [Indexed: 12/14/2022]
|
27
|
Grewal SS. Why should cancer biologists care about tRNAs? tRNA synthesis, mRNA translation and the control of growth. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:898-907. [PMID: 25497380 DOI: 10.1016/j.bbagrm.2014.12.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/01/2014] [Accepted: 12/04/2014] [Indexed: 10/24/2022]
Abstract
Transfer RNAs (tRNAs) are essential for mRNA translation. They are transcribed in the nucleus by RNA polymerase III and undergo many modifications before contributing to cytoplasmic protein synthesis. In this review I highlight our understanding of how tRNA biology may be linked to the regulation of mRNA translation, growth and tumorigenesis. First, I review how oncogenes and tumour suppressor signalling pathways, such as the PI3 kinase/TORC1, Ras/ERK, Myc, p53 and Rb pathways, regulate Pol III and tRNA synthesis. In several cases, this regulation contributes to cell, tissue and body growth, and has implications for our understanding of tumorigenesis. Second, I highlight some recent work, particularly in model organisms such as yeast and Drosophila, that shows how alterations in tRNA synthesis may be not only necessary, but also sufficient to drive changes in mRNA translation and growth. These effects may arise due to both absolute increases in total tRNA levels, but also changes in the relative levels of tRNAs in the overall pool. Finally, I review some recent studies that have revealed how tRNA modifications (amino acid acylation, base modifications, subcellular shuttling, and cleavage) can be regulated by growth and stress cues to selectively influence mRNA translation. Together these studies emphasize the importance of the regulation of tRNA synthesis and modification as critical control points in protein synthesis and growth. This article is part of a Special Issue entitled: Translation and Cancer.
Collapse
Affiliation(s)
- Savraj S Grewal
- Department of Biochemistry and Molecular Biology, Clark H. Smith Brain Tumour Centre, Southern Alberta Cancer Research Institute, University of Calgary, HRIC, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada.
| |
Collapse
|
28
|
Lopez-Camacho C, van Wijnen AJ, Lian JB, Stein JL, Stein GS. CBFβ and the leukemogenic fusion protein CBFβ-SMMHC associate with mitotic chromosomes to epigenetically regulate ribosomal genes. J Cell Biochem 2014; 115:2155-64. [PMID: 25079347 PMCID: PMC4199869 DOI: 10.1002/jcb.24892] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 07/25/2014] [Indexed: 01/01/2023]
Abstract
Mitotic bookmarking is an epigenetic control mechanism that sustains gene expression in progeny cells; it is often found in genes related to the maintenance of cellular phenotype and growth control. RUNX transcription factors regulate a broad spectrum of RNA Polymerase (Pol II) transcribed genes important for lineage commitment but also regulate RNA Polymerase I (Pol I) driven ribosomal gene expression, thus coordinating control of cellular identity and proliferation. In this study, using fluorescence microscopy and biochemical approaches we show that the principal RUNX co-factor, CBFβ, associates with nucleolar organizing regions (NORs) during mitosis to negatively regulate RUNX-dependent ribosomal gene expression. Of clinical relevance, we establish for the first time that the leukemogenic fusion protein CBFβ-SMMHC (smooth muscle myosin heavy chain) also associates with ribosomal genes in interphase chromatin and mitotic chromosomes to promote and epigenetically sustain regulation of ribosomal genes through RUNX factor interactions. Our results demonstrate that CBFβ contributes to the transcriptional regulation of ribosomal gene expression and provide further understanding of the epigenetic role of CBFβ-SMMHC in proliferation and maintenance of the leukemic phenotype.
Collapse
Affiliation(s)
- Cesar Lopez-Camacho
- Department of Biochemistry and Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT 05405 USA
| | - Andre J. van Wijnen
- Departments of Orthopedic Surgery and Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Jane B. Lian
- Department of Biochemistry and Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT 05405 USA
| | - Janet L. Stein
- Department of Biochemistry and Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT 05405 USA
| | - Gary S. Stein
- Department of Biochemistry and Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT 05405 USA
| |
Collapse
|
29
|
Woods SJ, Hannan KM, Pearson RB, Hannan RD. The nucleolus as a fundamental regulator of the p53 response and a new target for cancer therapy. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:821-9. [PMID: 25464032 DOI: 10.1016/j.bbagrm.2014.10.007] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 10/30/2014] [Accepted: 10/31/2014] [Indexed: 01/10/2023]
Abstract
BACKGROUND Recent studies have highlighted the fundamental role that key oncogenes such as MYC, RAS and PI3K occupy in driving RNA Polymerase I transcription in the nucleolus. In addition to maintaining essential levels of protein synthesis, hyperactivated ribosome biogenesis and nucleolar function plays a central role in suppressing p53 activation in response to oncogenic stress. Consequently, disruption of ribosome biogenesis by agents such as the small molecule inhibitor of RNA Polymerase I transcription, CX-5461, has shown unexpected, potent, and selective effects in killing tumour cells via disruption of nucleolar function leading to activation of p53, independent of DNA damage. SCOPE OF REVIEW This review will explore the mechanism of DNA damage-independent activation of p53 via the nucleolar surveillance pathway and how this can be utilised to design novel cancer therapies. MAJOR CONCLUSION AND GENERAL SIGNIFICANCE Non-genotoxic targeting of nucleolar function may provide a new paradigm for treatment of a broad range of oncogene-driven malignancies with improved therapeutic windows. This article is part of a Special Issue entitled: Translation and Cancer.
Collapse
Affiliation(s)
- Simone J Woods
- Division of Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia
| | - Katherine M Hannan
- Division of Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Richard B Pearson
- Division of Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria 3052, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3052, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3168, Australia.
| | - Ross D Hannan
- Division of Research, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria 3052, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3052, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3168, Australia; School of Biomedical Sciences, University of Queensland, Queensland 4072, Australia.
| |
Collapse
|
30
|
Peltonen K, Colis L, Liu H, Jäämaa S, Zhang Z, Af Hällström T, Moore HM, Sirajuddin P, Laiho M. Small molecule BMH-compounds that inhibit RNA polymerase I and cause nucleolar stress. Mol Cancer Ther 2014; 13:2537-46. [PMID: 25277384 DOI: 10.1158/1535-7163.mct-14-0256] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Activation of the p53 pathway has been considered a therapeutic strategy to target cancers. We have previously identified several p53-activating small molecules in a cell-based screen. Two of the compounds activated p53 by causing DNA damage, but this modality was absent in the other four. We recently showed that one of these, BMH-21, inhibits RNA polymerase I (Pol I) transcription, causes the degradation of Pol I catalytic subunit RPA194, and has potent anticancer activity. We show here that three remaining compounds in this screen, BMH-9, BMH-22, and BMH-23, cause reorganization of nucleolar marker proteins consistent with segregation of the nucleolus, a hallmark of Pol I transcription stress. Further, the compounds destabilize RPA194 in a proteasome-dependent manner and inhibit nascent rRNA synthesis and expression of the 45S rRNA precursor. BMH-9- and BMH-22-mediated nucleolar stress was detected in ex vivo-cultured human prostate tissues indicating good tissue bioactivity. Testing of closely related analogues showed that their activities were chemically constrained. Viability screen for BMH-9, BMH-22, and BMH-23 in the NCI60 cancer cell lines showed potent anticancer activity across many tumor types. Finally, we show that the Pol I transcription stress by BMH-9, BMH-22, and BMH-23 is independent of p53 function. These results highlight the dominant impact of Pol I transcription stress on p53 pathway activation and bring forward chemically novel lead molecules for Pol I inhibition, and, potentially, cancer targeting.
Collapse
Affiliation(s)
- Karita Peltonen
- Center for Drug Research, University of Helsinki, Helsinki, Finland
| | - Laureen Colis
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Hester Liu
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sari Jäämaa
- Center for Drug Research, University of Helsinki, Helsinki, Finland
| | - Zhewei Zhang
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Taija Af Hällström
- Institute for Molecular Medicine Finland FIMM, University of Helsinki, Helsinki, Finland
| | - Henna M Moore
- Center for Drug Research, University of Helsinki, Helsinki, Finland
| | - Paul Sirajuddin
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Marikki Laiho
- Center for Drug Research, University of Helsinki, Helsinki, Finland. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland. Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| |
Collapse
|
31
|
Wang W, Nag S, Zhang X, Wang MH, Wang H, Zhou J, Zhang R. Ribosomal proteins and human diseases: pathogenesis, molecular mechanisms, and therapeutic implications. Med Res Rev 2014; 35:225-85. [PMID: 25164622 DOI: 10.1002/med.21327] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ribosomes are essential components of the protein synthesis machinery. The process of ribosome biogenesis is well organized and tightly regulated. Recent studies have shown that ribosomal proteins (RPs) have extraribosomal functions that are involved in cell proliferation, differentiation, apoptosis, DNA repair, and other cellular processes. The dysfunction of RPs has been linked to the development and progression of hematological, metabolic, and cardiovascular diseases and cancer. Perturbation of ribosome biogenesis results in ribosomal stress, which triggers activation of the p53 signaling pathway through RPs-MDM2 interactions, resulting in p53-dependent cell cycle arrest and apoptosis. RPs also regulate cellular functions through p53-independent mechanisms. We herein review the recent advances in several forefronts of RP research, including the understanding of their biological features and roles in regulating cellular functions, maintaining cell homeostasis, and their involvement in the pathogenesis of human diseases. We also highlight the translational potential of this research for the identification of molecular biomarkers, and in the discovery and development of novel treatments for human diseases.
Collapse
Affiliation(s)
- Wei Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas, 79106; Cancer Biology Center, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas, 79106
| | | | | | | | | | | | | |
Collapse
|
32
|
Su L, Zheng H, Li Z, Qiu J, Chen S, Liu J, Ou TM, Tan JH, Gu LQ, Huang ZS, Li D. Mechanistic studies on the anticancer activity of 2,4-disubstituted quinazoline derivative. Biochim Biophys Acta Gen Subj 2014; 1840:3123-30. [PMID: 25018006 DOI: 10.1016/j.bbagen.2014.07.004] [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] [Received: 04/16/2014] [Revised: 06/23/2014] [Accepted: 07/02/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND Accelerated proliferation of solid tumor and hematologic cancer cells is related to accelerated transcription of ribosomal DNA by the RNA polymerase I to produce elevated level of ribosomal RNA. Therefore, down-regulation of RNA polymerase I transcription in cancer cells is an important anticancer therapeutic strategy. METHODS A variety of methods were used, including cloning, expression and purification of protein, electrophoretic mobility shift assay (EMSA), circular dichroic (CD) spectroscopy, CD-melting, isothermal titration calorimetry (ITC), chromatin immunoprecipitation (Ch-IP), RNA interference, RT-PCR, Western blot, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell assay. RESULTS Our results showed that 2,4-disubstituted quinazoline derivative Sysu12d could down-regulate c-myc through stabilization of c-myc promoter G-quadruplex, resulting in down-regulation of nucleolin expression. Sysu12d could also disrupt nucleolin/G-quadruplex complex. Both of the above contributed to the down-regulation of ribosomal RNA synthesis, followed by activation of p53 and then cancer cell apoptosis. CONCLUSIONS These mechanistic studies set up the basis for further development of Sysu12d as a new type of lead compound for cancer treatment. GENERAL SIGNIFICANCE 2,4-Disubstituted quinazoline derivatives may have multi-functional effect for cancer treatment.
Collapse
Affiliation(s)
- Lijuan Su
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Huaqin Zheng
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Zeng Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Jun Qiu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Siqi Chen
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Jinggong Liu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Tian-Miao Ou
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Jia-Heng Tan
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Lian-Quan Gu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Zhi-Shu Huang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China
| | - Ding Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, 132 Waihuan East Road, Guangzhou 510006, PR China.
| |
Collapse
|
33
|
Neben CL, Idoni B, Salva JE, Tuzon CT, Rice JC, Krakow D, Merrill AE. Bent bone dysplasia syndrome reveals nucleolar activity for FGFR2 in ribosomal DNA transcription. Hum Mol Genet 2014; 23:5659-71. [PMID: 24908667 DOI: 10.1093/hmg/ddu282] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Fibroblast growth factor receptor 2 (FGFR2) promotes osteoprogenitor proliferation and differentiation during bone development, yet how the receptor elicits these distinct cellular responses remains unclear. Analysis of the FGFR2-skeletal disorder bent bone dysplasia syndrome (BBDS) demonstrates that FGFR2, in addition to its canonical signaling activities at the plasma membrane, regulates bone formation from within the nucleolus. Previously, we showed that the unique FGFR2 mutations that cause BBDS reduce receptor levels at the plasma membrane and diminish responsiveness to extracellular FGF2. In this study, we find that these mutations, despite reducing canonical signaling, enhance nucleolar occupancy of FGFR2 at the ribosomal DNA (rDNA) promoter. Nucleolar FGFR2 activates rDNA transcription via interactions with FGF2 and UBF1 by de-repressing RUNX2. An increase in the nucleolar activity of FGFR2 in BBDS elevates levels of ribosomal RNA in the developing bone, consequently promoting osteoprogenitor cell proliferation and decreasing differentiation. Identifying FGFR2 as a transcriptional regulator of rDNA in bone unexpectedly reveals a nucleolar route for FGF signaling that allows for independent regulation of osteoprogenitor cell proliferation and differentiation.
Collapse
Affiliation(s)
- Cynthia L Neben
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Brian Idoni
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and
| | - Joanna E Salva
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Creighton T Tuzon
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Judd C Rice
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Deborah Krakow
- Departments of Orthopaedic Surgery, Human Genetics, Pediatrics and Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Amy E Merrill
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA,
| |
Collapse
|
34
|
Dichamp I, Séité P, Agius G, Barbarin A, Beby-Defaux A. Human papillomavirus 16 oncoprotein E7 stimulates UBF1-mediated rDNA gene transcription, inhibiting a p53-independent activity of p14ARF. PLoS One 2014; 9:e96136. [PMID: 24798431 PMCID: PMC4010441 DOI: 10.1371/journal.pone.0096136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 04/03/2014] [Indexed: 11/18/2022] Open
Abstract
High-risk human papillomavirus oncoproteins E6 and E7 play a major role in HPV-related cancers. One of the main functions of E7 is the degradation of pRb, while E6 promotes the degradation of p53, inactivating the p14ARF-p53 pathway. pRb and p14ARF can repress ribosomal DNA (rDNA) transcription in part by targeting the Upstream Binding Factor 1 (UBF1), a key factor in the activation of RNA polymerase I machinery. We showed, through ectopic expression and siRNA silencing of p14ARF and/or E7, that E7 stimulates UBF1-mediated rDNA gene transcription, partly because of increased levels of phosphorylated UBF1, preventing the inhibitory function of p14ARF. Unexpectedly, activation of rDNA gene transcription was higher in cells co-expressing p14ARF and E7, compared to cells expressing E7 alone. We did not find a difference in P-UBF1 levels that could explain this data. However, p14ARF expression induced E7 to accumulate into the nucleolus, where rDNA transcription takes place, providing an opportunity for E7 to interact with nucleolar proteins involved in this process. GST-pull down and co-immunoprecipitation assays showed interactions between p14ARF, UBF1 and E7, although p14ARF and E7 are not able to directly interact. Co-expression of a pRb-binding-deficient mutant (E7C24G) and p14ARF resulted in EC24G nucleolar accumulation, but not in a significant higher activation of rDNA transcription, suggesting that the inactivation of pRb is involved in this phenomenon. Thus, p14ARF fails to prevent E7-mediated UBF1 phosphorylation, but could facilitate nucleolar pRb inactivation by targeting E7 to the nucleolus. While others have reported that p19ARF, the mouse homologue of p14ARF, inhibits some functions of E7, we showed that E7 inhibits a p53-independent function of p14ARF. These results point to a mutually functional interaction between p14ARF and E7 that might partly explain why the sustained p14ARF expression observed in most cervical pre-malignant lesions and malignancies may be ineffective.
Collapse
Affiliation(s)
- Isabelle Dichamp
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
| | - Paule Séité
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
| | - Gérard Agius
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
| | - Alice Barbarin
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
| | - Agnès Beby-Defaux
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
- * E-mail:
| |
Collapse
|
35
|
Abstract
Long known as the center of ribosome synthesis, the nucleolus is connected to cell cycle regulation in more subtle ways. One is a surveillance system that reacts promptly when rRNA synthesis or processing is impaired, halting cell cycle progression. Conversely, the nucleolus also acts as a first-responder to growth-related stress signals. Here we review emerging concepts on how these "infraribosomal" links between the nucleolus and cell cycle progression operate in both forward and reverse gears. We offer perspectives on how new cancer therapeutic designs that target this infraribosomal mode of cell growth control may shape future clinical progress.
Collapse
Affiliation(s)
- Robert Y L Tsai
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA; and
| | - Thoru Pederson
- Program in Cell and Developmental Dynamics, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| |
Collapse
|
36
|
Vlatković N, Boyd MT, Rubbi CP. Nucleolar control of p53: a cellular Achilles' heel and a target for cancer therapy. Cell Mol Life Sci 2014; 71:771-91. [PMID: 23685903 PMCID: PMC11113510 DOI: 10.1007/s00018-013-1361-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 04/07/2013] [Accepted: 04/30/2013] [Indexed: 02/07/2023]
Abstract
Nucleoli perform a crucial cell function, ribosome biogenesis, and of critical relevance to the subject of this review, they are also extremely sensitive to cellular stresses, which can cause loss of function and/or associated structural disruption. In recent years, we have learned that cells take advantage of this stress sensitivity of nucleoli, using them as stress sensors. One major protein regulated by this role of nucleoli is the tumor suppressor p53, which is activated in response to diverse cellular injuries in order to exert its onco-protective effects. Here we discuss a model of nucleolar regulation of p53, which proposes that key steps in the promotion of p53 degradation by the ubiquitin ligase MDM2 occur in nucleoli, thus providing an explanation for the observed link between nucleolar disruption and p53 stability. We review current evidence for this compartmentalization in p53 homeostasis and highlight current limitations of the model. Interestingly, a number of current chemotherapeutic agents capable of inducing a p53 response are likely to do so by targeting nucleolar functions and these compounds may serve to inform further improved therapeutic targeting of nucleoli.
Collapse
Affiliation(s)
- Nikolina Vlatković
- Cancer Research Centre, University of Liverpool, 200 London Rd, Liverpool, L3 9TA UK
| | - Mark T. Boyd
- Cancer Research Centre, University of Liverpool, 200 London Rd, Liverpool, L3 9TA UK
| | - Carlos P. Rubbi
- Cancer Research Centre, University of Liverpool, 200 London Rd, Liverpool, L3 9TA UK
| |
Collapse
|
37
|
Peltonen K, Colis L, Liu H, Trivedi R, Moubarek MS, Moore HM, Bai B, Rudek MA, Bieberich CJ, Laiho M. A targeting modality for destruction of RNA polymerase I that possesses anticancer activity. Cancer Cell 2014; 25:77-90. [PMID: 24434211 PMCID: PMC3930145 DOI: 10.1016/j.ccr.2013.12.009] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/03/2013] [Accepted: 12/16/2013] [Indexed: 01/07/2023]
Abstract
We define the activity and mechanisms of action of a small molecule lead compound for cancer targeting. We show that the compound, BMH-21, has wide and potent antitumorigenic activity across NCI60 cancer cell lines and represses tumor growth in vivo. BMH-21 binds GC-rich sequences, which are present at a high frequency in ribosomal DNA genes, and potently and rapidly represses RNA polymerase I (Pol I) transcription. Strikingly, we find that BMH-21 causes proteasome-dependent destruction of RPA194, the large catalytic subunit protein of Pol I holocomplex, and this correlates with cancer cell killing. Our results show that Pol I activity is under proteasome-mediated control, which reveals an unexpected therapeutic opportunity.
Collapse
Affiliation(s)
- Karita Peltonen
- Molecular Cancer Biology Program and Centre for Drug Research, University of Helsinki, Helsinki 00014, Finland
| | - Laureen Colis
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Hester Liu
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Rishi Trivedi
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Michael S Moubarek
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Henna M Moore
- Molecular Cancer Biology Program and Centre for Drug Research, University of Helsinki, Helsinki 00014, Finland
| | - Baoyan Bai
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Michelle A Rudek
- Department of Oncology and The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Charles J Bieberich
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Marikki Laiho
- Molecular Cancer Biology Program and Centre for Drug Research, University of Helsinki, Helsinki 00014, Finland; Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA; Department of Oncology and The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA.
| |
Collapse
|
38
|
Floutsakou I, Agrawal S, Nguyen TT, Seoighe C, Ganley ARD, McStay B. The shared genomic architecture of human nucleolar organizer regions. Genome Res 2013; 23:2003-12. [PMID: 23990606 PMCID: PMC3847771 DOI: 10.1101/gr.157941.113] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The short arms of the five acrocentric human chromosomes harbor sequences that direct the assembly and function of the nucleolus, one of the key functional domains of the nucleus, yet they are absent from the current human genome assembly. Here we describe the genomic architecture of these human nucleolar organizers. Sequences distal and proximal to ribosomal gene arrays are conserved among the acrocentric chromosomes, suggesting they are sites of frequent recombination. Although previously believed to be heterochromatic, characterization of these two flanking regions reveals that they share a complex genomic architecture similar to other euchromatic regions of the genome, but they have distinct genomic characteristics. Proximal sequences are almost entirely segmentally duplicated, similar to the regions bordering centromeres. In contrast, the distal sequence is predominantly unique to the acrocentric short arms and is dominated by a very large inverted repeat. We show that the distal element is localized to the periphery of the nucleolus, where it appears to anchor the ribosomal gene repeats. This, combined with its complex chromatin structure and transcriptional activity, suggests that this region is involved in nucleolar organization. Our results provide a platform for investigating the role of NORs in nucleolar formation and function, and open the door for determining the role of these regions in the well-known empirical association of nucleoli with pathology.
Collapse
Affiliation(s)
- Ioanna Floutsakou
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland, Galway, Galway, Ireland
| | | | | | | | | | | |
Collapse
|
39
|
Hein N, Hannan KM, George AJ, Sanij E, Hannan RD. The nucleolus: an emerging target for cancer therapy. Trends Mol Med 2013; 19:643-54. [PMID: 23953479 DOI: 10.1016/j.molmed.2013.07.005] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 07/10/2013] [Accepted: 07/15/2013] [Indexed: 02/07/2023]
Abstract
For over 100 years, pathologists have utilised an increase in size and number of nucleoli, the subnuclear site of ribosome synthesis, as a marker of aggressive tumours. Despite this, the contribution of the nucleolus and ribosomal RNA synthesis to cancer has been largely overlooked. This concept has recently changed with the demonstration that the nucleolus indirectly controls numerous other cellular functions, in particular, the cellular activity of the critical tumour suppressor protein, p53. Moreover, selective inhibition of ribosomal gene transcription in the nucleolus has been shown to be an effective therapeutic strategy to promote cancer-specific activation of p53. This article reviews the largely untapped potential of the nucleolus and ribosomal gene transcription as exciting new targets for cancer therapy.
Collapse
Affiliation(s)
- Nadine Hein
- Division of Cancer Research, Peter MacCallum Cancer Centre, East Melbourne, 3002, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, 3010, Victoria, Australia
| | | | | | | | | |
Collapse
|
40
|
Freire-Picos MA, Landeira-Ameijeiras V, Mayán MD. Stalled RNAP-II molecules bound to non-coding rDNA spacers are required for normal nucleolus architecture. Yeast 2013; 30:267-77. [PMID: 23703787 DOI: 10.1002/yea.2961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/16/2013] [Accepted: 05/19/2013] [Indexed: 11/10/2022] Open
Abstract
The correct distribution of nuclear domains is critical for the maintenance of normal cellular processes such as transcription and replication, which are regulated depending on their location and surroundings. The most well-characterized nuclear domain, the nucleolus, is essential for cell survival and metabolism. Alterations in nucleolar structure affect nuclear dynamics; however, how the nucleolus and the rest of the nuclear domains are interconnected is largely unknown. In this report, we demonstrate that RNAP-II is vital for the maintenance of the typical crescent-shaped structure of the nucleolar rDNA repeats and rRNA transcription. When stalled RNAP-II molecules are not bound to the chromatin, the nucleolus loses its typical crescent-shaped structure. However, the RNAP-II interaction with Seh1p, or cryptic transcription by RNAP-II, is not critical for morphological changes.
Collapse
Affiliation(s)
- M A Freire-Picos
- MRC Clinical Sciences Centre, Imperial College, London, W12 0NN, UK
| | | | | |
Collapse
|
41
|
Bywater MJ, Pearson RB, McArthur GA, Hannan RD. Dysregulation of the basal RNA polymerase transcription apparatus in cancer. Nat Rev Cancer 2013; 13:299-314. [PMID: 23612459 DOI: 10.1038/nrc3496] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mutations that directly affect transcription by RNA polymerases rank among the most central mediators of malignant transformation, but the frequency of new anticancer drugs that selectively target defective transcription apparatus entering the clinic has been limited. This is because targeting the large protein-protein and protein-DNA interfaces that control both generic and selective aspects of RNA polymerase transcription has proved extremely difficult. However, recent technological advances have led to a 'quantum leap' in our comprehension of the structure and function of the core RNA polymerase components, how they are dysregulated in a broad range of cancers and how they may be targeted for 'transcription therapy'.
Collapse
Affiliation(s)
- Megan J Bywater
- Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne 8006, Victoria, Australia
| | | | | | | |
Collapse
|
42
|
Andrews WJ, Panova T, Normand C, Gadal O, Tikhonova IG, Panov KI. Old drug, new target: ellipticines selectively inhibit RNA polymerase I transcription. J Biol Chem 2013; 288:4567-82. [PMID: 23293027 DOI: 10.1074/jbc.m112.411611] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Transcription by RNA polymerase I (Pol-I) is the main driving force behind ribosome biogenesis, a fundamental cellular process that requires the coordinated transcription of all three nuclear polymerases. Increased Pol-I transcription and the concurrent increase in ribosome biogenesis has been linked to the high rates of proliferation in cancers. The ellipticine family contains a number of potent anticancer therapeutic agents, some having progressed to stage I and II clinical trials; however, the mechanism by which many of the compounds work remains unclear. It has long been thought that inhibition of Top2 is the main reason behind the drugs antiproliferative effects. Here we report that a number of the ellipticines, including 9-hydroxyellipticine, are potent and specific inhibitors of Pol-I transcription, with IC(50) in vitro and in cells in the nanomolar range. Essentially, the drugs did not affect Pol-II and Pol-III transcription, demonstrating a high selectivity. We have shown that Pol-I inhibition occurs by a p53-, ATM/ATR-, and Top2-independent mechanism. We discovered that the drug influences the assembly and stability of preinitiation complexes by targeting the interaction between promoter recognition factor SL1 and the rRNA promoter. Our findings will have an impact on the design and development of novel therapeutic agents specifically targeting ribosome biogenesis.
Collapse
Affiliation(s)
- William J Andrews
- School of Biological Sciences, The Queen’s University Belfast, Belfast BT9 7BL, United Kingdom
| | | | | | | | | | | |
Collapse
|
43
|
Ray S, Panova T, Miller G, Volkov A, Porter ACG, Russell J, Panov KI, Zomerdijk JCBM. Topoisomerase IIα promotes activation of RNA polymerase I transcription by facilitating pre-initiation complex formation. Nat Commun 2013; 4:1598. [PMID: 23511463 PMCID: PMC3615473 DOI: 10.1038/ncomms2599] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 02/09/2013] [Indexed: 11/15/2022] Open
Abstract
Type II DNA topoisomerases catalyse DNA double-strand cleavage, passage and re-ligation to effect topological changes. There is considerable interest in elucidating topoisomerase II roles, particularly as these proteins are targets for anti-cancer drugs. Here we uncover a role for topoisomerase IIα in RNA polymerase I-directed ribosomal RNA gene transcription, which drives cell growth and proliferation and is upregulated in cancer cells. Our data suggest that topoisomerase IIα is a component of the initiation-competent RNA polymerase Iβ complex and interacts directly with RNA polymerase I-associated transcription factor RRN3, which targets the polymerase to promoter-bound SL1 in pre-initiation complex formation. In cells, activation of rDNA transcription is reduced by inhibition or depletion of topoisomerase II, and this is accompanied by reduced transient double-strand DNA cleavage in the rDNA-promoter region and reduced pre-initiation complex formation. We propose that topoisomerase IIα functions in RNA polymerase I transcription to produce topological changes at the rDNA promoter that facilitate efficient de novo pre-initiation complex formation.
Collapse
Affiliation(s)
- Swagat Ray
- School of Biological Sciences and the Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Tatiana Panova
- School of Biological Sciences and the Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast BT9 7BL, UK
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gail Miller
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Arsen Volkov
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, Du Cane Road, London W12 0NN, UK
| | - Andrew C. G. Porter
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, Du Cane Road, London W12 0NN, UK
| | - Jackie Russell
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Konstantin I. Panov
- School of Biological Sciences and the Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast BT9 7BL, UK
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- These authors contributed equally to this work
| | - Joost C. B. M. Zomerdijk
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- These authors contributed equally to this work
| |
Collapse
|
44
|
Clarke C, Henry M, Doolan P, Kelly S, Aherne S, Sanchez N, Kelly P, Kinsella P, Breen L, Madden SF, Zhang L, Leonard M, Clynes M, Meleady P, Barron N. Integrated miRNA, mRNA and protein expression analysis reveals the role of post-transcriptional regulation in controlling CHO cell growth rate. BMC Genomics 2012; 13:656. [PMID: 23170974 PMCID: PMC3544584 DOI: 10.1186/1471-2164-13-656] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 11/09/2012] [Indexed: 12/20/2022] Open
Abstract
Background To study the role of microRNA (miRNA) in the regulation of Chinese hamster ovary (CHO) cell growth, qPCR, microarray and quantitative LC-MS/MS analysis were utilised for simultaneous expression profiling of miRNA, mRNA and protein. The sample set under investigation consisted of clones with variable cellular growth rates derived from the same population. In addition to providing a systems level perspective on cell growth, the integration of multiple profiling datasets can facilitate the identification of non-seed miRNA targets, complement computational prediction tools and reduce false positive and false negative rates. Results 51 miRNAs were associated with increased growth rate (35 miRNAs upregulated and 16 miRNAs downregulated). Gene ontology (GO) analysis of genes (n=432) and proteins (n=285) found to be differentially expressed (DE) identified biological processes driving proliferation including mRNA processing and translation. To investigate the influence of miRNA on these processes we combined the proteomic and transcriptomic data into two groups. The first set contained candidates where evidence of translational repression was observed (n=158). The second group was a mixture of proteins and mRNAs where evidence of translational repression was less clear (n=515). The TargetScan algorithm was utilised to predict potential targets within these two groups for anti-correlated DE miRNAs. Conclusions The evidence presented in this study indicates that biological processes such as mRNA processing and protein synthesis are correlated with growth rate in CHO cells. Through the integration of expression data from multiple levels of the biological system a number of proteins central to these processes including several hnRNPs and components of the ribosome were found to be post-transcriptionally regulated. We utilised the expression data in conjunction with in-silico tools to identify potential miRNA-mediated regulation of mRNA/proteins involved in CHO cell growth rate. These data have allowed us to prioritise candidates for cell engineering and/or biomarkers relevant to industrial cell culture. We also expect the knowledge gained from this study to be applicable to other fields investigating the role of miRNAs in mammalian cell growth.
Collapse
Affiliation(s)
- Colin Clarke
- National Institute for Cellular Biotechnology, Dublin City University, Dublin 9, Ireland.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
The oncoprotein MDM2 is both the transcriptional target and the predominant antagonist of the tumor suppressor p53. MDM2 inhibits the functions of p53 via a negative feedback loop that can be circumvented by several ribosomal proteins in response to nucleolar or ribosomal stress. Stress conditions in the nucleolus can be triggered by a variety of extracellular and intracellular insults that impair ribosomal biogenesis and function, such as chemicals, nutrient deprivation, DNA damaging agents, or genetic alterations. The past decade has witnessed a tremendous progress in understanding this previously underinvestigated ribosomal stress-MDM2-p53 pathway. Here, we review the recent progress in understanding this unique signaling pathway, discuss its biological and pathological significance, and share with readers our insight into the research in this field.
Collapse
Affiliation(s)
- Xiang Zhou
- Department of Biochemistry & Molecular Biology and Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA, USA
| | | | | | | |
Collapse
|
46
|
Holmberg Olausson K, Nistér M, Lindström MS. p53 -Dependent and -Independent Nucleolar Stress Responses. Cells 2012; 1:774-98. [PMID: 24710530 PMCID: PMC3901145 DOI: 10.3390/cells1040774] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 09/28/2012] [Accepted: 10/01/2012] [Indexed: 12/27/2022] Open
Abstract
The nucleolus has emerged as a cellular stress sensor and key regulator of p53-dependent and -independent stress responses. A variety of abnormal metabolic conditions, cytotoxic compounds, and physical insults induce alterations in nucleolar structure and function, a situation known as nucleolar or ribosomal stress. Ribosomal proteins, including RPL11 and RPL5, become increasingly bound to the p53 regulatory protein MDM2 following nucleolar stress. Ribosomal protein binding to MDM2 blocks its E3 ligase function leading to stabilization and activation of p53. In this review we focus on a number of novel regulators of the RPL5/RPL11-MDM2-p53 complex including PICT1 (GLTSCR2), MYBBP1A, PML and NEDD8. p53-independent pathways mediating the nucleolar stress response are also emerging and in particular the negative control that RPL11 exerts on Myc oncoprotein is of importance, given the role of Myc as a master regulator of ribosome biogenesis. We also briefly discuss the potential of chemotherapeutic drugs that specifically target RNA polymerase I to induce nucleolar stress.
Collapse
Affiliation(s)
- Karl Holmberg Olausson
- Department of Oncology-Pathology, Karolinska Institutet, Cancer Center Karolinska R8:05, Karolinska University Hospital in Solna, SE-17176, Stockholm, Sweden.
| | - Monica Nistér
- Department of Oncology-Pathology, Karolinska Institutet, Cancer Center Karolinska R8:05, Karolinska University Hospital in Solna, SE-17176, Stockholm, Sweden.
| | - Mikael S Lindström
- Department of Oncology-Pathology, Karolinska Institutet, Cancer Center Karolinska R8:05, Karolinska University Hospital in Solna, SE-17176, Stockholm, Sweden.
| |
Collapse
|
47
|
Haddach M, Schwaebe MK, Michaux J, Nagasawa J, O'Brien SE, Whitten JP, Pierre F, Kerdoncuff P, Darjania L, Stansfield R, Drygin D, Anderes K, Proffitt C, Bliesath J, Siddiqui-Jain A, Omori M, Huser N, Rice WG, Ryckman DM. Discovery of CX-5461, the First Direct and Selective Inhibitor of RNA Polymerase I, for Cancer Therapeutics. ACS Med Chem Lett 2012; 3:602-6. [PMID: 24900516 DOI: 10.1021/ml300110s] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 05/08/2012] [Indexed: 01/15/2023] Open
Abstract
Accelerated proliferation of solid tumor and hematologic cancer cells is linked to accelerated transcription of rDNA by the RNA polymerase I (Pol I) enzyme to produce elevated levels of rRNA (rRNA). Indeed, upregulation of Pol I, frequently caused by mutational alterations among tumor suppressors and oncogenes, is required for maintenance of the cancer phenotype and forms the basis for seeking selective inhibitors of Pol I as anticancer therapeutics. 2-(4-Methyl-[1,4]diazepan-1-yl)-5-oxo-5H-7-thia-1,11b-diaza-benzo[c]fluorene-6-carboxylic acid (5-methyl-pyrazin-2-ylmethyl)-amide (CX-5461, 7c) has been identified as the first potent, selective, and orally bioavailable inhibitor of RNA Pol I transcription with in vivo activity in tumor growth efficacy models. The preclinical data support the development of CX-5461 as an anticancer drug with potential for activity in several types of cancer.
Collapse
Affiliation(s)
- Mustapha Haddach
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Michael K. Schwaebe
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Jerome Michaux
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Johnny Nagasawa
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Sean E. O'Brien
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Jeffrey P. Whitten
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Fabrice Pierre
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Pauline Kerdoncuff
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Levan Darjania
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Ryan Stansfield
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Denis Drygin
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Kenna Anderes
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Chris Proffitt
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Josh Bliesath
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Adam Siddiqui-Jain
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - May Omori
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - Nanni Huser
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - William G. Rice
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| | - David M. Ryckman
- Cylene Pharmaceuticals, 5820
Nancy Ridge Drive, Suite 200, San Diego, California 92121, United
States
| |
Collapse
|
48
|
Zhang X, Wang W, Wang H, Wang MH, Xu W, Zhang R. Identification of ribosomal protein S25 (RPS25)-MDM2-p53 regulatory feedback loop. Oncogene 2012; 32:2782-91. [PMID: 22777350 DOI: 10.1038/onc.2012.289] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
There is an increasing interest in determining the role of ribosomal proteins (RPs) in the regulation of MDM2-p53 pathway in coordinating cellular response to stress. Herein, we report a novel regulatory role of ribosomal protein S25 (RPS25) in MDM2-mediated p53 degradation and a feedback regulation of S25 by p53. We demonstrated that S25 interacted with MDM2 and inhibited its E3 ligase activity, resulting in the reduction of MDM2-mediated p53 ubiquitination and the stabilization and activation of p53. S25, MDM2 and p53 formed a ternary complex following ribosomal stress. The nucleolar localization and MDM2-binding domains of S25 were critical for its role in MDM2-mediated p53 regulation. Knockdown of S25 by siRNA attenuated the induction and activation of p53 following ribosomal stress. S25 stabilized and cooperated with MDMX to regulate MDM2 E3 ligase activity. Furthermore, S25 was identified to be a transcriptional target of p53; p53 directly bound to S25 promoter and suppressed S25 expression. Our results suggest that there is a S25-MDM2-p53 regulatory feedback loop, which may have an important role in cancer development and progression.
Collapse
Affiliation(s)
- X Zhang
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, School of Pharmacy, Amarillo, TX 79106, USA
| | | | | | | | | | | |
Collapse
|
49
|
Ali SA, Dobson JR, Lian JB, Stein JL, van Wijnen AJ, Zaidi SK, Stein GS. A RUNX2-HDAC1 co-repressor complex regulates rRNA gene expression by modulating UBF acetylation. J Cell Sci 2012; 125:2732-9. [PMID: 22393235 DOI: 10.1242/jcs.100909] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The osteogenic and oncogenic transcription factor RUNX2 downregulates the RNA polymerase I (RNA Pol I)-mediated transcription of rRNAs and changes histone modifications associated with the rDNA repeat. However, the mechanisms by which RUNX2 suppresses rRNA transcription are not well understood. RUNX2 cofactors such as histone deacetylases (HDACs) play a key role in chromatin remodeling and regulation of gene transcription. Here, we show that RUNX2 recruits HDAC1 to the rDNA repeats in osseous cells. This recruitment alters the histone modifications associated with active rRNA-encoding genes and causes deacetylation of the protein upstream binding factor (UBF, also known as UBTF). Downregulation of RUNX2 expression reduces the localization of HDAC1 to the nucleolar periphery and also decreases the association between HDAC1 and UBF. Functionally, depletion of HDAC1 relieves the RUNX2-mediated repression of rRNA-encoding genes and concomitantly increases cell proliferation and global protein synthesis in osseous cells. Our findings collectively identify a RUNX2-HDAC1-dependent mechanism for the regulation of rRNA-encoding genes and suggest that there is plasticity to RUNX2-mediated epigenetic control, which is mediated through selective mitotic exclusion of co-regulatory factors.
Collapse
Affiliation(s)
- Syed A Ali
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Castle CD, Cassimere EK, Denicourt C. LAS1L interacts with the mammalian Rix1 complex to regulate ribosome biogenesis. Mol Biol Cell 2012; 23:716-28. [PMID: 22190735 PMCID: PMC3279398 DOI: 10.1091/mbc.e11-06-0530] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 11/14/2011] [Accepted: 12/13/2011] [Indexed: 01/02/2023] Open
Abstract
The coordination of RNA polymerase I transcription with pre-rRNA processing, preribosomal particle assembly, and nuclear export is a finely tuned process requiring the concerted actions of a number of accessory factors. However, the exact functions of some of these proteins and how they assemble in subcomplexes remain poorly defined. LAS1L was first described as a nucleolar protein required for maturation of the 60S preribosomal subunit. In this paper, we demonstrate that LAS1L interacts with PELP1, TEX10, and WDR18, the mammalian homologues of the budding yeast Rix1 complex, along with NOL9 and SENP3, to form a novel nucleolar complex that cofractionates with the 60S preribosomal subunit. Depletion of LAS1L-associated proteins results in a p53-dependent G1 arrest and leads to defects in processing of the pre-rRNA internal transcribed spacer 2 region. We further show that the nucleolar localization of this complex requires active RNA polymerase I transcription and the small ubiquitin-like modifier-specific protease SENP3. Taken together, our data identify a novel mammalian complex required for 60S ribosomal subunit synthesis, providing further insight into the intricate, yet poorly described, process of ribosome biogenesis in higher eukaryotes.
Collapse
Affiliation(s)
- Christopher D. Castle
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030
| | - Erica K. Cassimere
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030
| | - Catherine Denicourt
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030
| |
Collapse
|