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Liu Y, Yu K, Zhang K, Niu M, Chen Q, Liu Y, Wang L, Zhang N, Li W, Zhong X, Li G, Wu S, Zhang J, Liu Y. O-GlcNAcylation promotes topoisomerase IIα catalytic activity in breast cancer chemoresistance. EMBO Rep 2023; 24:e56458. [PMID: 37249035 PMCID: PMC10328065 DOI: 10.15252/embr.202256458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 05/06/2023] [Accepted: 05/12/2023] [Indexed: 05/31/2023] Open
Abstract
DNA topoisomerase IIα (TOP2A) plays a vital role in replication and cell division by catalytically altering DNA topology. It is a prominent target for anticancer drugs, but clinical efficacy is often compromised due to chemoresistance. In this study, we investigate the role of TOP2A O-GlcNAcylation in breast cancer cells and patient tumor tissues. Our results demonstrate that elevated TOP2A, especially its O-GlcNAcylation, promotes breast cancer malignant progression and resistance to adriamycin (Adm). O-GlcNAcylation at Ser1469 enhances TOP2A chromatin DNA binding and catalytic activity, leading to resistance to Adm in breast cancer cells and xenograft models. Mechanistically, O-GlcNAcylation-modulated interactions between TOP2A and cell cycle regulators influence downstream gene expression and contribute to breast cancer drug resistance. These results reveal a previously unrecognized mechanistic role for TOP2A O-GlcNAcylation in breast cancer chemotherapy resistance and provide support for targeting TOP2A O-GlcNAcylation in cancer therapy.
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Affiliation(s)
- Yangzhi Liu
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
| | - Kairan Yu
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
| | - Keren Zhang
- Department of ChemistryCollege of Science, Southern University of Science and TechnologyShenzhenChina
| | - Mingshan Niu
- Blood Diseases Institute, Xuzhou Medical UniversityXuzhouJiangsuChina
| | - Qiushi Chen
- Department of ChemistryThe University of Hong KongHong KongChina
- Laboratory for Synthetic Chemistry and Chemical Biology LimitedHong Kong Science ParkHong KongChina
| | - Yajie Liu
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
| | - Lingyan Wang
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
| | - Nana Zhang
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
| | - Wenli Li
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
| | - Xiaomin Zhong
- Department of OncologyThe Affiliated Huaian No. 1 People's Hospital of Nanjing Medical UniversityHuai'anChina
| | - Guohui Li
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina
| | - Sijin Wu
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina
| | - Jianing Zhang
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
| | - Yubo Liu
- School of Life and Pharmaceutical SciencesDalian University of TechnologyPanjinChina
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2
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Regulation of the mitotic chromosome folding machines. Biochem J 2022; 479:2153-2173. [PMID: 36268993 DOI: 10.1042/bcj20210140] [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: 02/09/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/17/2022]
Abstract
Over the last several years enormous progress has been made in identifying the molecular machines, including condensins and topoisomerases that fold mitotic chromosomes. The discovery that condensins generate chromatin loops through loop extrusion has revolutionized, and energized, the field of chromosome folding. To understand how these machines fold chromosomes with the appropriate dimensions, while disentangling sister chromatids, it needs to be determined how they are regulated and deployed. Here, we outline the current understanding of how these machines and factors are regulated through cell cycle dependent expression, chromatin localization, activation and inactivation through post-translational modifications, and through associations with each other, with other factors and with the chromatin template itself. There are still many open questions about how condensins and topoisomerases are regulated but given the pace of progress in the chromosome folding field, it seems likely that many of these will be answered in the years ahead.
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3
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Identification of crucial hub genes and potential molecular mechanisms in breast cancer by integrated bioinformatics analysis and experimental validation. Comput Biol Med 2022; 149:106036. [DOI: 10.1016/j.compbiomed.2022.106036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 08/14/2022] [Accepted: 08/20/2022] [Indexed: 11/24/2022]
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4
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Zhao F, Chang J, Zhao P, Wang W, Sun X, Ma X, Yin M, Wang Y, Yang Y. Oncogenetic Function and Prognostic Value of DNA Topoisomerase II Alpha in Human Malignances: A Pan-Cancer Analysis. Front Genet 2022; 13:856692. [PMID: 35873470 PMCID: PMC9301266 DOI: 10.3389/fgene.2022.856692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Increasing studies have revealed significant associations between TOP2A with oncogenesis and prognosis of human cancers; however, pan-cancer analysis has not been reported. Here, we explored the potential carcinogenic function and the association with clinical outcomes of TOP2A in 33 different human cancers. The results showed that TOP2A was amplified in 31 investigated cancers; TOP2A expression was significantly associated with metastasis of six different cancers and significantly associated with the survival of patients in ten different cancers; TOP2A-encoded protein was obviously upregulated in five available cancers; phosphorylated TOP2A protein at S1106 was significantly upregulated in all six available cancers. Moreover, TOP2A expression was found to be associated with the cancer-associated immune cell infiltration, including fibroblasts, Tregs, and macrophages. In addition, the Kyoto encyclopedia of genes and genomes (KEGG) pathway and Gene Ontology (GO) enrichment analyses revealed a most significant association between TOP2A with the Wnt signaling pathway and DNA conformation change. This work provides a comprehensive knowledge of TOP2A in different cancers, including carcinogenic function, prognostic values for metastasis, and clinical outcomes.
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Affiliation(s)
- Fulai Zhao
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
| | - Junli Chang
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
| | - Peng Zhao
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
| | - Wenyi Wang
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
| | - Xingyuan Sun
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
| | - Xiaoping Ma
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
| | - Mengchen Yin
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yongjun Wang
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
| | - Yanping Yang
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai, China
- *Correspondence: Yanping Yang,
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5
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McKerrow W, Wang X, Mendez-Dorantes C, Mita P, Cao S, Grivainis M, Ding L, LaCava J, Burns KH, Boeke JD, Fenyö D. LINE-1 expression in cancer correlates with p53 mutation, copy number alteration, and S phase checkpoint. Proc Natl Acad Sci U S A 2022; 119:e2115999119. [PMID: 35169076 PMCID: PMC8872788 DOI: 10.1073/pnas.2115999119] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/14/2022] [Indexed: 12/12/2022] Open
Abstract
Retrotransposons are genomic DNA sequences that copy themselves to new genomic locations via RNA intermediates; LINE-1 is the only active and autonomous retrotransposon in the human genome. The mobility of LINE-1 is largely repressed in somatic tissues but is derepressed in many cancers, where LINE-1 retrotransposition is correlated with p53 mutation and copy number alteration (CNA). In cell lines, inducing LINE-1 expression can cause double-strand breaks (DSBs) and replication stress. Reanalyzing multiomic data from breast, ovarian, endometrial, and colon cancers, we confirmed correlations between LINE-1 expression, p53 mutation status, and CNA. We observed a consistent correlation between LINE-1 expression and the abundance of DNA replication complex components, indicating that LINE-1 may also induce replication stress in human tumors. In endometrial cancer, high-quality phosphoproteomic data allowed us to identify the DSB-induced ATM-MRN-SMC S phase checkpoint pathway as the primary DNA damage response (DDR) pathway associated with LINE-1 expression. Induction of LINE-1 expression in an in vitro model led to increased phosphorylation of MRN complex member RAD50, suggesting that LINE-1 directly activates this pathway.
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Affiliation(s)
- Wilson McKerrow
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY 10016
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016
| | - Xuya Wang
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY 10016
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016
| | - Carlos Mendez-Dorantes
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA 02215
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Paolo Mita
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY 10016
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016
| | - Song Cao
- Department of Medicine and Genetics, Siteman Cancer Center, Washington University in St. Louis, St. Louis, MO 63110
- McDonnell Genome Institute, Washington University in St. Louis, St. Louis, MO 63108
| | - Mark Grivainis
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY 10016
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016
| | - Li Ding
- Department of Medicine and Genetics, Siteman Cancer Center, Washington University in St. Louis, St. Louis, MO 63110
- McDonnell Genome Institute, Washington University in St. Louis, St. Louis, MO 63108
| | - John LaCava
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY 10065
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Kathleen H Burns
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA 02215
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Jef D Boeke
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY 10016;
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016
- Department of Biomedical Engineering, Tandon School of Engineering, Brooklyn, NY11201
| | - David Fenyö
- Institute for Systems Genetics, New York University Grossman School of Medicine, New York, NY 10016;
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016
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UPF1 promotes chemoresistance to oxaliplatin through regulation of TOP2A activity and maintenance of stemness in colorectal cancer. Cell Death Dis 2021; 12:519. [PMID: 34021129 PMCID: PMC8140095 DOI: 10.1038/s41419-021-03798-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 02/04/2023]
Abstract
UPF1 is proved to dysregulate in multiple tumors and influence carcinogenesis. However, the role of UPF1 in oxaliplatin resistance in colorectal cancer (CRC) remains unknown. In our study, UPF1 is upregulated in CRC in mRNA and protein levels and overexpression of UPF1 predicts a poor overall survival (OS) and recurrence-free survival (RFS) in CRC patients and is an independent risk factor for recurrence. UPF1 promotes chemoresistance to oxaliplatin in vitro and in vivo. UPF1-induced oxaliplatin resistance can be associated with interaction between zinc finger of UPF1 and Toprim of TOP2A and increasing phosphorylated TOP2A in a SMG1-dependent manner. Moreover, UPF1 maintains stemness in a TOP2A-dependent manner in CRC. Taken together, UPF1 was overexpressed and predicted a poor prognosis in CRC. UPF1 enhanced chemoresistance to oxaliplatin in CRC, which may result from regulation of TOP2A activity and maintenance of stemness. Our findings could provide a new therapy strategy for chemoresistance to oxaliplatin in CRC patients.
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7
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Chang YW, Hsu CL, Tang CW, Chen XJ, Huang HC, Juan HF. Multiomics Reveals Ectopic ATP Synthase Blockade Induces Cancer Cell Death via a lncRNA-mediated Phospho-signaling Network. Mol Cell Proteomics 2020; 19:1805-1825. [PMID: 32788343 DOI: 10.1074/mcp.ra120.002219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Indexed: 12/24/2022] Open
Abstract
The EGFR tyrosine kinase inhibitor gefitinib is commonly used for lung cancer patients. However, some patients eventually become resistant to gefitinib and develop progressive disease. Here, we indicate that ecto-ATP synthase, which ectopically translocated from mitochondrial inner membrane to plasma membrane, is considered as a potential therapeutic target for drug-resistant cells. Quantitative multi-omics profiling reveals that ecto-ATP synthase inhibitor mediates CK2-dependent phosphorylation of DNA topoisomerase IIα (topo IIα) at serine 1106 and subsequently increases the expression of long noncoding RNA, GAS5. Additionally, we also determine that downstream of GAS5, p53 pathway, is activated by ecto-ATP synthase inhibitor for regulation of programed cell death. Interestingly, GAS5-proteins interactomic profiling elucidates that GAS5 associates with topo IIα and subsequently enhancing the phosphorylation level of topo IIα. Taken together, our findings suggest that ecto-ATP synthase blockade is an effective therapeutic strategy via regulation of CK2/phospho-topo IIα/GAS5 network in gefitinib-resistant lung cancer cells.
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Affiliation(s)
- Yi-Wen Chang
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Chia-Lang Hsu
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan; Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Cheng-Wei Tang
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Xiang-Jun Chen
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Hsuan-Cheng Huang
- Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan.
| | - Hsueh-Fen Juan
- Department of Life Science, Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan; Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.
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Sagredou S, Dalezis P, Nikoleousakos N, Nikolaou M, Voura M, Almpanakis K, Panayiotidis MI, Sarli V, Trafalis DT. 3,6-Disubstituted 1,2,4-Triazolo[3,4- b]Thiadiazoles with Anticancer Activity Targeting Topoisomerase II Alpha. Onco Targets Ther 2020; 13:7369-7386. [PMID: 32801761 PMCID: PMC7395825 DOI: 10.2147/ott.s254856] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 05/30/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Topoisomerase IIα (topIIα) maintains the topology of DNA in order to ensure the proper functioning of numerous DNA processes. Inhibition of topIIα leads to the killing of cancer cells thus constituting such inhibitors as useful tools in cancer therapeutics. Triazolo[3,4-b]thiadiazole derivatives are known for their wide range of pharmacological activities while previous studies have documented their in vitro anticancer activity. The purpose of the current study was to investigate if these chemical compounds can act as topIIα inhibitors in cell-free and cell-based systems. MATERIALS AND METHODS The MTT assay was performed in DLD-1, HT-29, and LoVo cancer cells so as to evaluate the antiproliferative activity of KA25, KA26, and KA39 triazolo[3,4-b]thiadiazole derivatives. The KA39 compound was tested as a potential topIIα inhibitor using the plasmid-based topoisomerase II drug screening kit. The inhibitory effect of the three derivatives on topIIα phosphorylation was studied in HT-29 and LoVo cancer cells according to Human Phospho-TOP2A/Topoisomerase II Alpha Cell-Based Phosphorylation ELISA Kit. Moreover, flow cytometry was utilized in order to explore apoptotic induction and cell cycle growth arrest, upon treatment with KA39, in DLD-1 and HT-29 cells, respectively. In silico studies were also carried out for further investigation. RESULTS All three triazolo[3,4-b]thiadiazole derivatives showed an in vitro antiproliferative effect with the KA39 compound being the most potent one. Our results indicated that KA39 induced both early and late apoptosis as well as cell cycle growth arrest in S phase. In addition, the compound blocked the relaxation of supercoiled DNA while it also inhibited topIIα phosphorylation (upon treatment; P<0.001). CONCLUSION Among the three triazolo[3,4-b]thiadiazole derivatives, KA39 was shown to be the most potent anticancer agent and catalytic inhibitor of topIIα phosphorylation as well.
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Affiliation(s)
- Sofia Sagredou
- Laboratory of Pharmacology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens11527, Greece
| | - Panagiotis Dalezis
- Laboratory of Pharmacology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens11527, Greece
| | - Nikolaos Nikoleousakos
- Laboratory of Pharmacology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens11527, Greece
| | - Michail Nikolaou
- Laboratory of Pharmacology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens11527, Greece
| | - Maria Voura
- Department of Chemistry, Aristotle University of Thessaloniki , Thessaloniki, 54124, Greece
| | | | - Mihalis I Panayiotidis
- Department of Electron Microscopy & Molecular Pathology, The Cyprus Institute of Neurology & Genetics, Nicosia2371, Cyprus
- The Cyprus School of Molecular Medicine, Nicosia1683, Cyprus
| | - Vasiliki Sarli
- Department of Chemistry, Aristotle University of Thessaloniki , Thessaloniki, 54124, Greece
| | - Dimitrios T Trafalis
- Laboratory of Pharmacology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens11527, Greece
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Lotz C, Lamour V. The interplay between DNA topoisomerase 2α post-translational modifications and drug resistance. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2020; 3:149-160. [PMID: 35582608 PMCID: PMC9090595 DOI: 10.20517/cdr.2019.114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/19/2020] [Accepted: 02/05/2020] [Indexed: 01/13/2023]
Abstract
The type 2 DNA topoisomerases (Top2) are conserved enzymes and biomarkers for cell proliferation. The catalytic activities of the human isoform Top2α are essential for the regulation of DNA topology during DNA replication, transcription, and chromosome segregation. Top2α is a prominent target for anti-cancer drugs and is highly regulated by post-translational modifications (PTM). Despite an increasing number of proteomic studies, the extent of PTM in cancer cells and its importance in drug response remains largely uncharacterized. In this review, we highlight the different modifications affecting the human Top2α in healthy and cancer cells, taking advantage of the structure-function information accumulated in the past decades. We also overview the regulation of Top2α by PTM, the level of PTM in cancer cells, and the resistance to therapeutic compounds targeting the Top2 enzyme. Altogether, this review underlines the importance of future studies addressing more systematically the interplay between PTM and Top2 drug resistance.
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Affiliation(s)
- Christophe Lotz
- Integrative Structural Biology Department, IGBMC, Université de Strasbourg, CNRS UMR 7104, INSERM U1258, Illkirch 67404, France
| | - Valérie Lamour
- Integrative Structural Biology Department, IGBMC, Université de Strasbourg, CNRS UMR 7104, INSERM U1258, Illkirch 67404, France
- Hôpitaux Universitaires de Strasbourg, Strasbourg 67000, France
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10
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Borgo C, Ruzzene M. Role of protein kinase CK2 in antitumor drug resistance. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2019; 38:287. [PMID: 31277672 PMCID: PMC6612148 DOI: 10.1186/s13046-019-1292-y] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 06/25/2019] [Indexed: 01/21/2023]
Abstract
Drug resistance represents the major reason of pharmacological treatment failure. It is supported by a broad spectrum of mechanisms, whose molecular bases have been frequently correlated to aberrant protein phosphorylation. CK2 is a constitutively active protein kinase which phosphorylates hundreds of substrates; it is expressed in all cells, but its level is commonly found higher in cancer cells, where it plays anti-apoptotic, pro-migration and pro-proliferation functions. Several evidences support a role for CK2 in processes directly responsible of drug resistance, such as drug efflux and DNA repair; moreover, CK2 intervenes in signaling pathways which are crucial to evade drug response (as PI3K/AKT/PTEN, NF-κB, β-catenin, hedgehog signaling, p53), and controls the activity of chaperone machineries fundamental in resistant cells. Interestingly, a panel of specific and effective inhibitors of CK2 is available, and several examples are known of their efficacy in resistant cells, with synergistic effect when used in combination with conventional drugs, also in vivo. Here we analyze and discuss evidences supporting the hypothesis that CK2 targeting represents a valuable strategy to overcome drug resistance.
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Affiliation(s)
- Christian Borgo
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58b, 35131, Padova, Italy
| | - Maria Ruzzene
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58b, 35131, Padova, Italy.
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11
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Abstract
Drug resistance is a well-known phenomenon that occurs when initially responsive to chemotherapy cancer cells become tolerant and elude further effectiveness of anticancer drugs. Based on their mechanism of action, anticancer drugs can be divided into cytotoxic-based agents and target-based agents. An important role among the therapeutics of the second group is played by drugs targeting topoisomerases, nuclear enzymes critical to DNA function and cell survival. These enzymes are cellular targets of several groups of anticancer agents which generate DNA damage in rapidly proliferating cancer cells. Drugs targeting topoisomerase I are mostly analogs of camtothecin, a natural compound isolated from the bark of a tree growing in China. Drugs targeting topoisomerase II are divided into poisons, such as anthracycline antibiotics, whose action is based on intercalation between DNA bases, and catalytic inhibitors that block topoisomerase II at different stages of the catalytic cycle. Unfortunately, chemotherapy is often limited by the induction of drug resistance. Identifying mechanisms that promote drug resistance is critical for the improvement of patient prognosis. Cancer drug resistance is a complex phenomenon that may be influenced by many factors. Here we discuss various mechanisms by which cancer cells can develop resistance to topoisomerase-directed drugs, which include enhanced drug efflux, mutations in topoisomerase genes, hypophosphorylation of topoisomerase II catalytic domain, activation of NF-κB transcription factor and drug inactivation. All these events may lead to the ineffective induction of cancer cell death. Attempts at circumventing drug resistance through the inhibition of cellular efflux pumps, use of silencing RNAs or inhibition of some important mechanisms, which can allow cancer cells to survive therapy, are also presented.
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Affiliation(s)
- Karol Wtorek
- Department of Biomolecular Chemistry, Medical University of Łódź, Poland
| | - Angelika Długosz
- Department of Biomolecular Chemistry, Medical University of Łódź, Poland
| | - Anna Janecka
- Department of Biomolecular Chemistry, Medical University of Łódź, Poland
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12
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Shen S, Kong J, Qiu Y, Yang X, Wang W, Yan L. Identification of core genes and outcomes in hepatocellular carcinoma by bioinformatics analysis. J Cell Biochem 2018; 120:10069-10081. [PMID: 30525236 DOI: 10.1002/jcb.28290] [Citation(s) in RCA: 205] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/24/2018] [Indexed: 02/05/2023]
Abstract
Hepatocellular carcinoma (HCC) is the most common malignant liver disease in the world. However, the mechanistic relationships among various genes and signaling pathways are still largely unclear. In this study, we aimed to elucidate potential core candidate genes and pathways in HCC. The expression profiles GSE14520, GSE25097, GSE29721, and GSE62232, which cover 606 tumor and 550 nontumour samples, were downloaded from the Gene Expression Omnibus (GEO) database. Furthermore, HCC RNA-seq datasets were also downloaded from the Cancer Genome Atlas (TCGA) database. The differentially expressed genes (DEGs) were filtered using R software, and we performed gene ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analysis using the online databases DAVID 6.8 and KOBAS 3.0. Furthermore, the protein-protein interaction (PPI) network complex of these DEGs was constructed by Cytoscape software, the molecular complex detection (MCODE) plug-in and the online database STRING. First, a total of 173 DEGs (41 upregulated and 132 downregulated) were identified that were aberrantly expressed in both the GEO and TCGA datasets. Second, GO analysis revealed that most of the DEGs were significantly enriched in extracellular exosomes, cytosol, extracellular region, and extracellular space. Signaling pathway analysis indicated that the DEGs had common pathways in metabolism-related pathways, cell cycle, and biological oxidations. Third, 146 nodes were identified from the DEG PPI network complex, and two important modules with a high degree were detected using the MCODE plug-in. In addition, 10 core genes were identified, TOP2A, NDC80, FOXM1, HMMR, KNTC1, PTTG1, FEN1, RFC4, SMC4, and PRC1. Finally, Kaplan-Meier analysis of overall survival and correlation analysis were applied to these genes. The abovementioned findings indicate that the identified core genes and pathways in this bioinformatics analysis could significantly enrich our understanding of the development and recurrence of HCC; furthermore, these candidate genes and pathways could be therapeutic targets for HCC treatment.
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Affiliation(s)
- Shu Shen
- Department of Liver Surgery & Liver Transplantation Center, West China Hospital of Sichuan University, Chengdu, China
| | - Junjie Kong
- Department of Liver Surgery & Liver Transplantation Center, West China Hospital of Sichuan University, Chengdu, China
| | - Yiwen Qiu
- Department of Liver Surgery & Liver Transplantation Center, West China Hospital of Sichuan University, Chengdu, China
| | - Xianwei Yang
- Department of Liver Surgery & Liver Transplantation Center, West China Hospital of Sichuan University, Chengdu, China
| | - Wentao Wang
- Department of Liver Surgery & Liver Transplantation Center, West China Hospital of Sichuan University, Chengdu, China
| | - Lvnan Yan
- Department of Liver Surgery & Liver Transplantation Center, West China Hospital of Sichuan University, Chengdu, China
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13
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Huang CT, Hsieh CH, Oyang YJ, Huang HC, Juan HF. A Large-Scale Gene Expression Intensity-Based Similarity Metric for Drug Repositioning. iScience 2018; 7:40-52. [PMID: 30267685 PMCID: PMC6135902 DOI: 10.1016/j.isci.2018.08.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 07/10/2018] [Accepted: 08/19/2018] [Indexed: 01/04/2023] Open
Abstract
Biological systems often respond to a specific environmental or genetic perturbation without pervasive gene expression changes. Such robustness to perturbations, however, is not reflected on the current computational strategies that utilize gene expression similarity metrics for drug discovery and repositioning. Here we propose a new expression-intensity-based similarity metric that consistently achieved better performance than other state-of-the-art similarity metrics with respect to the gold-standard clustering of drugs with known mechanisms of action. The new metric directly emphasizes the genes exhibiting the greatest changes in expression in response to a perturbation. Using the new framework to systematically compare 3,332 chemical and 3,934 genetic perturbations across 10 cell types representing diverse cellular signatures, we identified thousands of recurrent and cell type-specific connections. We also experimentally validated two drugs identified by the analysis as potential topoisomerase inhibitors. The new framework is a valuable resource for hypothesis generation, functional testing, and drug repositioning. Intensity-based similarity metric surpasses other standard metrics in drug clustering This metric was applied to compare thousands of compounds for drug repurposing Two drugs are experimentally confirmed as potential topoisomerase inhibitors
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Affiliation(s)
- Chen-Tsung Huang
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 10617, Taiwan
| | - Chiao-Hui Hsieh
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Yen-Jen Oyang
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 10617, Taiwan
| | - Hsuan-Cheng Huang
- Institute of Biomedical Informatics, Center for Systems and Synthetic Biology, National Yang-Ming University, Taipei 11221, Taiwan.
| | - Hsueh-Fen Juan
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 10617, Taiwan; Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan; Department of Life Science, National Taiwan University, Taipei 10617, Taiwan.
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14
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Piskadlo E, Oliveira RA. A Topology-Centric View on Mitotic Chromosome Architecture. Int J Mol Sci 2017; 18:E2751. [PMID: 29258269 PMCID: PMC5751350 DOI: 10.3390/ijms18122751] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 02/04/2023] Open
Abstract
Mitotic chromosomes are long-known structures, but their internal organization and the exact process by which they are assembled are still a great mystery in biology. Topoisomerase II is crucial for various aspects of mitotic chromosome organization. The unique ability of this enzyme to untangle topologically intertwined DNA molecules (catenations) is of utmost importance for the resolution of sister chromatid intertwines. Although still controversial, topoisomerase II has also been proposed to directly contribute to chromosome compaction, possibly by promoting chromosome self-entanglements. These two functions raise a strong directionality issue towards topoisomerase II reactions that are able to disentangle sister DNA molecules (in trans) while compacting the same DNA molecule (in cis). Here, we review the current knowledge on topoisomerase II role specifically during mitosis, and the mechanisms that directly or indirectly regulate its activity to ensure faithful chromosome segregation. In particular, we discuss how the activity or directionality of this enzyme could be regulated by the SMC (structural maintenance of chromosomes) complexes, predominantly cohesin and condensin, throughout mitosis.
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Affiliation(s)
- Ewa Piskadlo
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
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15
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Kozuki T, Chikamori K, Surleac MD, Micluta MA, Petrescu AJ, Norris EJ, Elson P, Hoeltge GA, Grabowski DR, Porter ACG, Ganapathi RN, Ganapathi MK. Roles of the C-terminal domains of topoisomerase IIα and topoisomerase IIβ in regulation of the decatenation checkpoint. Nucleic Acids Res 2017; 45:5995-6010. [PMID: 28472494 PMCID: PMC5449615 DOI: 10.1093/nar/gkx325] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 04/14/2017] [Indexed: 12/13/2022] Open
Abstract
Topoisomerase (topo) IIα and IIβ maintain genome stability and are targets for anti-tumor drugs. In this study, we demonstrate that the decatenation checkpoint is regulated, not only by topo IIα, as previously reported, but also by topo IIβ. The decatenation checkpoint is most efficient when both isoforms are present. Regulation of this checkpoint and sensitivity to topo II-targeted drugs is influenced by the C-terminal domain (CTD) of the topo II isoforms and by a conserved non-catalytic tyrosine, Y640 in topo IIα and Y656 in topo IIβ. Deletion of most of the CTD of topo IIα, while preserving the nuclear localization signal (NLS), enhances the decatenation checkpoint and sensitivity to topo II-targeted drugs. In contrast, deletion of most of the CTD of topo IIβ, while preserving the NLS, and mutation of Y640 in topo IIα and Y656 in topo IIβ inhibits these activities. Structural studies suggest that the differential impact of the CTD on topo IIα and topo IIβ function may be due to differences in CTD charge distribution and differential alignment of the CTD with reference to transport DNA. Together these results suggest that topo IIα and topo IIβ cooperate to maintain genome stability, which may be distinctly modulated by their CTDs.
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Affiliation(s)
- Toshiyuki Kozuki
- Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Kenichi Chikamori
- Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Marius D Surleac
- Department of Bioinformatics, Institute of Biochemistry of the Romanian Academy, Bucharest, Romania
| | - Marius A Micluta
- Department of Bioinformatics, Institute of Biochemistry of the Romanian Academy, Bucharest, Romania
| | - Andrei J Petrescu
- Department of Bioinformatics, Institute of Biochemistry of the Romanian Academy, Bucharest, Romania
| | - Eric J Norris
- Department of Cancer Pharmacology, Levine Cancer Institute, Carolinas HealthCare System, 1021 Morehead Medical Drive, Charlotte, NC 28204, USA
| | - Paul Elson
- Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Gerald A Hoeltge
- Clinical Pathology, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Dale R Grabowski
- Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Andrew C G Porter
- Imperial College Faculty of Medicine, Hammersmith Hospital, London W10 ONN, UK
| | - Ram N Ganapathi
- Department of Cancer Pharmacology, Levine Cancer Institute, Carolinas HealthCare System, 1021 Morehead Medical Drive, Charlotte, NC 28204, USA
| | - Mahrukh K Ganapathi
- Department of Cancer Pharmacology, Levine Cancer Institute, Carolinas HealthCare System, 1021 Morehead Medical Drive, Charlotte, NC 28204, USA
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Mdm2 selectively suppresses DNA damage arising from inhibition of topoisomerase II independent of p53. Oncogene 2017; 36:6085-6096. [PMID: 28692049 DOI: 10.1038/onc.2017.229] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/10/2017] [Accepted: 05/25/2017] [Indexed: 12/20/2022]
Abstract
Mdm2 is often overexpressed in tumors that retain wild-type TP53 but may affect therapeutic response independently of p53. Herein is shown that tumor cells with MDM2 amplification are selectively resistant to treatment with topoisomerase II poisons but not other DNA damaging agents. Tumor cells that overexpress Mdm2 have reduced DNA double-strand breaks in response to doxorubicin or etoposide. This latter result is not due to altered drug uptake. The selective attenuation of DNA damage in response to these agents is dependent on both Mdm2 levels and an intact ubiquitin ligase function. These findings reveal a novel, p53-independent activity of Mdm2 and have important implications for the choice of chemotherapeutic agents in the treatment of Mdm2-overexpressing tumors.
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17
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Chen YTS, Wu J, Modrich P, Hsieh TS. The C-terminal 20 Amino Acids of Drosophila Topoisomerase 2 Are Required for Binding to a BRCA1 C Terminus (BRCT) Domain-containing Protein, Mus101, and Fidelity of DNA Segregation. J Biol Chem 2016; 291:13216-28. [PMID: 27129233 DOI: 10.1074/jbc.m116.721357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic topoisomerase 2 (Top2) and one of its interacting partners, topoisomerase IIβ binding protein 1 (TopBP1) are two proteins performing essential cellular functions. We mapped the interacting domains of these two proteins using co-immunoprecipitation and pulldown experiments with truncated or mutant Drosophila Top2 with various Ser-to-Ala substitutions. We discovered that the last 20 amino acids of Top2 represent the key region for binding with Mus101 (the Drosophila homolog of TopBP1) and that phosphorylation of Ser-1428 and Ser-1443 is important for Top2 to interact with the N terminus of Mus101, which contains the BRCT1/2 domains. The interaction between Mus101 and the Top2 C-terminal regulatory domain is phosphorylation-dependent because treatment with phosphatase abolishes their association in pulldown assays. The binding affinity of N-terminal Mus101 with a synthetic phosphorylated peptide spanning the last 25 amino acids of Top2 (with Ser(P)-1428 and Ser(P)-1443) was determined by surface plasmon resonance with a Kd of 0.57 μm In an in vitro decatenation assay, Mus101 can specifically reduce the decatenation activity of Top2, and dephosphorylation of Top2 attenuates this response. Next, we endeavored to establish a cellular system for testing the biological function of Top2-Mus101 interaction. Top2-silenced S2 cells rescued by Top2Δ20, Top2 with 20 amino acids truncated from the C terminus, developed abnormally high chromosome numbers, which implies that Top2-Mus101 interaction is important for maintaining the fidelity of chromosome segregation during mitosis.
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Affiliation(s)
| | | | | | - Tao-Shih Hsieh
- From the Department of Biochemistry and the Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710 and
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18
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Long-term exposure to irinotecan reduces cell migration in glioma cells. J Neurooncol 2016; 127:455-62. [DOI: 10.1007/s11060-016-2058-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 01/22/2016] [Indexed: 10/22/2022]
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19
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Topoisomerase 2 Alpha Cooperates with Androgen Receptor to Contribute to Prostate Cancer Progression. PLoS One 2015; 10:e0142327. [PMID: 26560244 PMCID: PMC4641711 DOI: 10.1371/journal.pone.0142327] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/19/2015] [Indexed: 11/25/2022] Open
Abstract
Overexpression of TOP2A is associated with risk of systemic progression in prostate cancer patients, and higher levels of TOP2A were found in hormone-resistant cases. To elucidate the mechanism by which high levels of TOP2A contribute to tumor progression we generated TOP2A overexpressing prostate cancer cell lines. We show that TOP2A promotes tumor aggressiveness by inducing chromosomal rearrangements of genes that contribute to a more invasive phenotype. Anti-androgen treatment alone was ineffective in killing TOP2A overexpressing cells due to activation of an androgen receptor network. TOP2A poisons killed tumor cells more efficiently early in the progression course, while at later stages they provided greater benefit when combined with anti-androgen therapy. Mechanistically, we find that TOP2A enhances androgen signaling by facilitating transcription of androgen responsive genes, thereby promoting tumor cell growth. These studies revealed a relationship between TOP2A and androgen receptor signaling pathway that contributes to prostate cancer progression and confers sensitivity to treatments.
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20
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Quantitative interactome analysis reveals a chemoresistant edgotype. Nat Commun 2015; 6:7928. [PMID: 26235782 PMCID: PMC4532879 DOI: 10.1038/ncomms8928] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 06/25/2015] [Indexed: 02/07/2023] Open
Abstract
Chemoresistance is a common mode of therapy failure for many cancers. Tumours develop resistance to chemotherapeutics through a variety of mechanisms, with proteins serving pivotal roles. Changes in protein conformations and interactions affect the cellular response to environmental conditions contributing to the development of new phenotypes. The ability to understand how protein interaction networks adapt to yield new function or alter phenotype is limited by the inability to determine structural and protein interaction changes on a proteomic scale. Here, chemical crosslinking and mass spectrometry were employed to quantify changes in protein structures and interactions in multidrug-resistant human carcinoma cells. Quantitative analysis of the largest crosslinking-derived, protein interaction network comprising 1,391 crosslinked peptides allows for ‘edgotype' analysis in a cell model of chemoresistance. We detect consistent changes to protein interactions and structures, including those involving cytokeratins, topoisomerase-2-alpha, and post-translationally modified histones, which correlate with a chemoresistant phenotype. Changes in protein–protein interactions result in changes to cellular phenotype. Here the authors use crosslinking mass spectrometry to derive a quantitative protein interaction network in drug-sensitive and -resistant HeLa cells, and uncover a chemoresistant ‘edgotype'.
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21
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Chen T, Sun Y, Ji P, Kopetz S, Zhang W. Topoisomerase IIα in chromosome instability and personalized cancer therapy. Oncogene 2014; 34:4019-31. [PMID: 25328138 PMCID: PMC4404185 DOI: 10.1038/onc.2014.332] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/08/2014] [Accepted: 09/08/2014] [Indexed: 12/29/2022]
Abstract
Genome instability is a hallmark of cancer cells. Chromosome instability (CIN), which is often mutually exclusive from hypermutation genotypes, represents a distinct subtype of genome instability. Hypermutations in cancer cells are due to defects in DNA repair genes, but the cause of CIN is still elusive. However, because of the extensive chromosomal abnormalities associated with CIN, its cause is likely a defect in a network of genes that regulate mitotic checkpoints and chromosomal organization and segregation. Emerging evidence has shown that the chromosomal decatenation checkpoint, which is critical for chromatin untangling and packing during genetic material duplication, is defective in cancer cells with CIN. The decatenation checkpoint is known to be regulated by a family of enzymes called topoisomerases. Among them, the gene encoding topoisomerase IIα (TOP2A) is commonly altered at both gene copy number and gene expression level in cancer cells. Thus, abnormal alterations of TOP2A, its interacting proteins, and its modifications may play a critical role in CIN in human cancers. Clinically, a large arsenal of topoisomerase inhibitors have been used to suppress DNA replication in cancer. However, they often lead to the secondary development of leukemia because of their effect on the chromosomal decatenation checkpoint. Therefore, topoisomerase drugs must be used judiciously and administered on an individual basis. In this review, we highlight the biological function of TOP2A in chromosome segregation and the mechanisms that regulate this enzyme's expression and activity. We also review the roles of TOP2A and related proteins in human cancers, and raise a perspective for how to target TOP2A in personalized cancer therapy.
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Affiliation(s)
- T Chen
- 1] Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA [2] Department of Endoscopy Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Y Sun
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - P Ji
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - S Kopetz
- Department of Gastrointestinal Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - W Zhang
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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22
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Farr CJ, Antoniou-Kourounioti M, Mimmack ML, Volkov A, Porter ACG. The α isoform of topoisomerase II is required for hypercompaction of mitotic chromosomes in human cells. Nucleic Acids Res 2014; 42:4414-26. [PMID: 24476913 PMCID: PMC3985649 DOI: 10.1093/nar/gku076] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
As proliferating cells transit from interphase into M-phase, chromatin undergoes extensive reorganization, and topoisomerase (topo) IIα, the major isoform of this enzyme present in cycling vertebrate cells, plays a key role in this process. In this study, a human cell line conditional null mutant for topo IIα and a derivative expressing an auxin-inducible degron (AID)-tagged version of the protein have been used to distinguish real mitotic chromosome functions of topo IIα from its more general role in DNA metabolism and to investigate whether topo IIβ makes any contribution to mitotic chromosome formation. We show that topo IIβ does contribute, with endogenous levels being sufficient for the initial stages of axial shortening. However, a significant effect of topo IIα depletion, seen with or without the co-depletion of topo IIβ, is the failure of chromosomes to hypercompact when delayed in M-phase. This requires much higher levels of topo II protein and is impaired by drugs or mutations that affect enzyme activity. A prolonged delay at the G2/M border results in hyperefficient axial shortening, a process that is topo IIα-dependent. Rapid depletion of topo IIα has allowed us to show that its function during late G2 and M-phase is truly required for shaping mitotic chromosomes.
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Affiliation(s)
- Christine J Farr
- Department of Genetics, University of Cambridge, Downing St, Cambridge CB2 3EH, UK and Centre for Haematology, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Rd, London W12 0NN, UK
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Bhosle J, Kiakos K, Porter ACG, Wu J, Makris A, Hartley JA, Hochhauser D. Treatment with gefitinib or lapatinib induces drug resistance through downregulation of topoisomerase IIα expression. Mol Cancer Ther 2013; 12:2897-908. [PMID: 24092808 DOI: 10.1158/1535-7163.mct-12-1049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The EGF receptor (EGFR) is therapeutically targeted by antibodies and small molecules in solid tumors including lung, colorectal, and breast cancer. However, chemotherapy remains important, and efforts to improve efficacy through combination with targeted agents is challenging. This study examined the effects of short and long durations of exposure to the EGFR- and HER2-targeted tyrosine kinase inhibitors (TKI) gefitinib and lapatinib, on induction of cell death and DNA damage by topoisomerase IIα (Topo IIα) poisons, in the SK-Br-3 HER2-amplified breast cancer cell line. Short exposure to either gefitinib or lapatinib for 1 hour did not affect the induction of apoptosis by the Topo IIα poisons doxorubicin, etoposide, and m-AMSA. In contrast, cells treated for 48 hours were resistant to all three drugs. Short exposure (1 hour) to TKI did not alter the number of DNA single- or double-strand breaks (DSB) induced, whereas longer exposure (48 hours) reduced the number of DNA DSBs and the formation of γ-H2AX foci. Both gefitinib and lapatinib reduced the expression and activity of Topo IIα at 48 hours. Studies using a cell line with inducible downregulation of Topo IIα showed that expression of Topo IIα, and not Topo IIβ, determined the number of DNA strand breaks induced by these chemotherapeutic agents. These results indicate that prolonged exposure to TKIs targeting EGFR and HER2 induce resistance to doxorubicin, etoposide, and m-AMSA through downregulation of Topo IIα. This may explain why their addition to chemotherapy regimens have not increased efficacy.
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Affiliation(s)
- Jaishree Bhosle
- Corresponding Author: Daniel Hochhauser, UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street, London WC1E 6BT, UK.
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Wartlick F, Bopp A, Henninger C, Fritz G. DNA damage response (DDR) induced by topoisomerase II poisons requires nuclear function of the small GTPase Rac. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3093-3103. [DOI: 10.1016/j.bbamcr.2013.08.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 08/14/2013] [Accepted: 08/23/2013] [Indexed: 01/12/2023]
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Ganapathi RN, Ganapathi MK. Mechanisms regulating resistance to inhibitors of topoisomerase II. Front Pharmacol 2013; 4:89. [PMID: 23914174 PMCID: PMC3729981 DOI: 10.3389/fphar.2013.00089] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 06/24/2013] [Indexed: 11/13/2022] Open
Abstract
Inhibitors of topoisomerase II (topo II) are clinically effective in the management of hematological malignancies and solid tumors. The efficacy of anti-tumor drugs targeting topo II is often limited by resistance and studies with in vitro cell culture models have provided several insights on potential mechanisms. Multidrug transporters that are involved in the efflux and consequently reduced cytotoxicity of diverse anti-tumor agents suggest that they play an important role in resistance to clinically active drugs. However, in clinical trials, modulating the multidrug-resistant phenotype with agents that inhibit the efflux pump has not had an impact. Since reduced drug accumulation per se is insufficient to explain tumor cell resistance to topo II inhibitors several studies have focused on characterizing mechanisms that impact on DNA damage mediated by drugs that target the enzyme. Mammalian topo IIα and topo IIβ isozymes exhibit similar catalytic, but different biologic, activities. Whereas topo IIα is associated with cell division, topo IIβ is involved in differentiation. In addition to site specific mutations that can affect drug-induced topo II-mediated DNA damage, post-translation modification of topo II primarily by phosphorylation can potentially affect enzyme-mediated DNA damage and the downstream cytotoxic response of drugs targeting topo II. Signaling pathways that can affect phosphorylation and changes in intracellular calcium levels/calcium dependent signaling that can regulate site-specific phosphorylation of topoisomerase have an impact on downstream cytotoxic effects of topo II inhibitors. Overall, tumor cell resistance to inhibitors of topo II is a complex process that is orchestrated not only by cellular pharmacokinetics but more importantly by enzymatic alterations that govern the intrinsic drug sensitivity.
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Affiliation(s)
- Ram N Ganapathi
- Levine Cancer Institute, Carolinas HealthCare System Charlotte, NC, USA
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26
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Hernández S, Venegas M, Brahm J, Villanueva RA. The viral transactivator HBx protein exhibits a high potential for regulation via phosphorylation through an evolutionarily conserved mechanism. Infect Agent Cancer 2012; 7:27. [PMID: 23079056 PMCID: PMC3533737 DOI: 10.1186/1750-9378-7-27] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 09/20/2012] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED BACKGROUND Hepatitis B virus (HBV) encodes an oncogenic factor, HBx, which is a multifunctional protein that can induce dysfunctional regulation of signaling pathways, transcription, and cell cycle progression, among other processes, through interactions with target host factors. The subcellular localization of HBx is both cytoplasmic and nuclear. This dynamic distribution of HBx could be essential to the multiple roles of the protein at different stages during HBV infection. Transactivational functions of HBx may be exerted both in the nucleus, via interaction with host DNA-binding proteins, and in the cytoplasm, via signaling pathways. Although there have been many studies describing different pathways altered by HBx, and its innumerable binding partners, the molecular mechanism that regulates its different roles has been difficult to elucidate. METHODS In the current study, we took a bioinformatics approach to investigate whether the viral protein HBx might be regulated via phosphorylation by an evolutionarily conserved mechanism. RESULTS We found that the phylogenetically conserved residues Ser25 and Ser41 (both within the negative regulatory domain), and Thr81 (in the transactivation domain) are predicted to be phosphorylated. By molecular 3D modeling of HBx, we further show these residues are all predicted to be exposed on the surface of the protein, making them easily accesible to these types of modifications. Furthermore, we have also identified Yin Yang sites that might have the potential to be phosphorylated and O-β-GlcNAc interplay at the same residues. CONCLUSIONS Thus, we propose that the different roles of HBx displayed in different subcellular locations might be regulated by an evolutionarily conserved mechanism of posttranslational modification, via phosphorylation.
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Affiliation(s)
- Sergio Hernández
- Laboratorio de Virus Hepatitis, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Avda. República 217, 3er piso, Santiago 8370146, Chile
| | - Mauricio Venegas
- Sección de Gastroenterología, Departamento de Medicina, Hospital Clínico Universidad de Chile, Avda. Santos Dumont 999, Independencia, Santiago 8340457, Chile
| | - Javier Brahm
- Sección de Gastroenterología, Departamento de Medicina, Hospital Clínico Universidad de Chile, Avda. Santos Dumont 999, Independencia, Santiago 8340457, Chile
| | - Rodrigo A Villanueva
- Laboratorio de Virus Hepatitis, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Avda. República 217, 3er piso, Santiago 8370146, Chile
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Abdallah QM, Phillips RM, Johansson F, Helleday T, Cosentino L, Abdel-Rahman H, Etzad J, Wheelhouse RT, Kiakos K, Bingham JP, Hartley JA, Patterson LH, Pors K. Minor structural modifications to alchemix influence mechanism of action and pharmacological activity. Biochem Pharmacol 2012; 83:1514-22. [DOI: 10.1016/j.bcp.2012.02.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 02/21/2012] [Indexed: 10/28/2022]
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28
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Gardner L, Malik R, Shimizu Y, Mullins N, ElShamy WM. Geminin overexpression prevents the completion of topoisomerase IIα chromosome decatenation, leading to aneuploidy in human mammary epithelial cells. Breast Cancer Res 2011; 13:R53. [PMID: 21595939 PMCID: PMC3218940 DOI: 10.1186/bcr2884] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 04/16/2011] [Accepted: 05/19/2011] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION The nuclear enzyme topoisomerase IIα (TopoIIα) is able to cleave DNA in a reversible manner, making it a valuable target for agents such as etoposide that trap the enzyme in a covalent bond with the 5' DNA end to which it cleaves. This prevents DNA religation and triggers cell death in cancer cells. However, development of resistance to these agents limits their therapeutic use. In this study, we examined the therapeutic targeting of geminin for improving the therapeutic potential of TopoIIα agents. METHODS Human mammary epithelial (HME) cells and several breast cancer cell lines were used in this study. Geminin, TopoIIα and cell division cycle 7 (Cdc7) silencing were done using specific small interfering RNA. Transit or stable inducible overexpression of these proteins and casein kinase Iε (CKIε) were also used, as well as several pharmacological inhibitors that target TopoIIα, Cdc7 or CKIε. We manipulated HME cells that expressed H2B-GFP, or did not, to detect chromosome bridges. Immunoprecipitation and direct Western blot analysis were used to detect interactions between these proteins and their total expression, respectively, whereas interactions on chromosomal arms were detected using a trapped in agarose DNA immunostaining assay. TopoIIα phosphorylation by Cdc7 or CKIε was done using an in vitro kinase assay. The TopoGen decatenation kit was used to measure TopoIIα decatenation activity. Finally, a comet assay and metaphase chromosome spread were used to detect chromosome breakage and changes in chromosome condensation or numbers, respectively. RESULTS We found that geminin and TopoIIα interact primarily in G2/M/early G1 cells on chromosomes, that geminin recruits TopoIIα to chromosomal decatenation sites or vice versa and that geminin silencing in HME cells triggers the formation of chromosome bridges by suppressing TopoIIα access to chromosomal arms. CKIε kinase phosphorylates and positively regulates TopoIIα chromosome localization and function. CKIε kinase overexpression or Cdc7 kinase silencing, which we show phosphorylates TopoIIα in vitro, restored DNA decatenation and chromosome segregation in geminin-silenced cells before triggering cell death. In vivo, at normal concentration, geminin recruits the deSUMOylating sentrin-specific proteases SENP1 and SENP2 enzymes to deSUMOylate chromosome-bound TopoIIα and promote its release from chromosomes following completion of DNA decatenation. In cells overexpressing geminin, premature departure of TopoIIα from chromosomes is thought to be due to the fact that geminin recruits more of these deSUMOylating enzymes, or recruits them earlier, to bound TopoIIα. This triggers premature release of TopoIIα from chromosomes, which we propose induces aneuploidy in HME cells, since chromosome breakage generated through this mechanism were not sensed and/or repaired and the cell cycle was not arrested. Expression of mitosis-inducing proteins such as cyclin A and cell division kinase 1 was also increased in these cells because of the overexpression of geminin. CONCLUSIONS TopoIIα recruitment and its chromosome decatenation function require a normal level of geminin. Geminin silencing induces a cytokinetic checkpoint in which Cdc7 phosphorylates TopoIIα and inhibits its chromosomal recruitment and decatenation and/or segregation function. Geminin overexpression prematurely deSUMOylates TopoIIα, triggering its premature departure from chromosomes and leading to chromosomal abnormalities and the formation of aneuploid, drug-resistant cancer cells. On the basis of our findings, we propose that therapeutic targeting of geminin is essential for improving the therapeutic potential of TopoIIα agents.
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Affiliation(s)
- Lauren Gardner
- Cancer Institute, Department of Biochemistry, University of Mississippi Medical Center, Jackson, 39216, USA
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Use of the hollow fiber assay for the evaluation of DNA damaging agents. J Pharmacol Toxicol Methods 2011; 64:226-32. [PMID: 21569858 DOI: 10.1016/j.vascn.2011.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 03/22/2011] [Accepted: 04/19/2011] [Indexed: 12/26/2022]
Abstract
INTRODUCTION The preclinical development and clinical progression of potential anticancer agents are highly time and resource-intensive. Traditionally, promising compounds in vitro undergo further screening in xenograft models, a long process that uses large numbers of animals. In order to hasten compound progression, the hollow fiber assay (HFA) was developed by the US National Cancer Institute as an additional filtering step in drug development, bridging the gap between in vitro and xenograft compound screening. The HFA demonstrates a good correlation in terms of clinical predictivity, and has significant reduction and refinement benefits for animal usage. In addition, the assay enables the study of basic pharmacological properties of compounds under investigation. The HFA has been mainly used as a rapid in vivo cytotoxicity screen, but has also been shown to be amenable to study drug/target interactions in vivo. One of the challenges of the HFA is the small sample sizes obtained, which can limit sensitivity. METHODS Here we specifically focus on the detection of DNA double-strand breaks, monitoring the effects of standard and novel anti-cancer agents on human lung, colon and breast cancer cell lines using immunoblotting and flow cytometry techniques for γ-H2A.X. This presented a further challenge due to the low abundance of the target event. RESULTS We found a good correlation between techniques in terms of rate of detection and sensitivity confirming the ability to use the HFA for detection of these specific drug-target interactions. DISCUSSION The results demonstrate good sensitivity and predictability for drug behavior in an assay where cell number is limited. In contrast to conventional xenograft studies, this short-term assay also enables analysis of pharmacodynamic endpoints in tumor cells in vivo. Importantly, there is a significant impact on reduction and refinement of the use of animals in incorporating this assay into the drug development process.
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Grozav AG, Willard BB, Kozuki T, Chikamori K, Micluta MA, Petrescu AJ, Kinter M, Ganapathi R, Ganapathi MK. Tyrosine 656 in topoisomerase IIβ is important for the catalytic activity of the enzyme: Identification based on artifactual +80-Da modification at this site. Proteomics 2011; 11:829-42. [PMID: 21280220 DOI: 10.1002/pmic.201000194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 09/01/2010] [Accepted: 11/25/2010] [Indexed: 12/11/2022]
Abstract
Topoisomerase (topo) II catalyzes topological changes in DNA. Although both human isozymes, topo IIα and β are phosphorylated, site-specific phosphorylation of topo IIβ is poorly characterized. Using LC-MS/MS analysis of topo IIβ, cleaved with trypsin, Arg C or cyanogen bromide (CNBr) plus trypsin, we detected four +80-Da modified sites: tyr656, ser1395, thr1426 and ser1545. Phosphorylation at ser1395, thr1426 and ser1545 was established based on neutral loss of H(3) PO(4) (-98 Da) in the CID spectra and on differences in 2-D-phosphopeptide maps of (32) P-labeled wild-type (WT) and S1395A or T1426A/S1545A mutant topo IIβ. However, phosphorylation at tyr656 could not be verified by 2-D-phosphopeptide mapping of (32) P-labeled WT and Y656F mutant protein or by Western blotting with phosphotyrosine-specific antibodies. Since the +80-Da modification on tyr656 was observed exclusively during cleavage with CNBr and trypsin, this modification likely represented bromination, which occurred during CNBr cleavage. Re-evaluation of the CID spectra identified +78/+80-Da fragment ions in CID spectra of two peptides containing tyr656 and tyr711, confirming bromination. Interestingly, mutation of only tyr656, but not ser1395, thr1326 or ser1545, decreased topo IIβ activity, suggesting a functional role for tyr656. These results, while identifying an important tyrosine in topo IIβ, underscore the importance of careful interpretation of modifications having the same nominal mass.
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Affiliation(s)
- Adrian G Grozav
- Clinical Pharmacology Program, Taussig Cancer Institute, Cleveland, OH, USA
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Targeting PKC delta-mediated topoisomerase II beta overexpression subverts the differentiation block in a retinoic acid-resistant APL cell line. Leukemia 2010; 24:729-39. [PMID: 20200558 DOI: 10.1038/leu.2010.27] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Retinoic acid (RA) relieves the maturation block in t(15:17) acute promyelocytic leukemia (APL), leading to granulocytic differentiation. However, RA treatment alone invariably results in RA resistance, both in vivo and in vitro. RA-resistant cell lines have been shown to serve as useful models for elucidation of mechanisms of resistance. Previously, we identified topoisomerase II beta (TOP2B) as a novel mediator of RA-resistance in APL cell lines. In this study, we show that both TOP2B protein stability and activity are regulated by a member of the protein kinase C (PRKC) family, PRKC delta (PRKCD). Co-treatment with a pharmacologic inhibitor of PRKCD and RA resulted in the induction of an RA responsive reporter construct, as well as the endogenous RA target genes, CEBPE, CYP26A1 and RIG-I. Furthermore, the co-treatment overcame the differentiation block in RA-resistant cells, as assessed by morphological analysis, restoration of promyelocytic leukemia nuclear bodies, induction of CD11c cell surface expression and an increase in nitro-blue-tetrazolium reduction. Cumulatively, our data suggest a model whereby inhibition of PRKCD decreases TOP2B protein levels, leading to a loss of TOP2B-mediated repressive effects on RA-induced transcription and granulocytic differentiation.
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Grozav AG, Chikamori K, Kozuki T, Grabowski DR, Bukowski RM, Willard B, Kinter M, Andersen AH, Ganapathi R, Ganapathi MK. Casein kinase I delta/epsilon phosphorylates topoisomerase IIalpha at serine-1106 and modulates DNA cleavage activity. Nucleic Acids Res 2008; 37:382-92. [PMID: 19043076 PMCID: PMC2632902 DOI: 10.1093/nar/gkn934] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We previously reported that phosphorylation of topoisomerase (topo) IIα at serine-1106 (Ser-1106) regulates enzyme activity and sensitivity to topo II-targeted drugs. In this study we demonstrate that phosphorylation of Ser-1106, which is flanked by acidic amino acids, is regulated in vivo by casein kinase (CK) Iδ and/or CKIɛ, but not by CKII. The CKI inhibitors, CKI-7 and IC261, reduced Ser-1106 phosphorylation and decreased formation of etoposide-stabilized topo II–DNA cleavable complex. In contrast, the CKII inhibitor, 5,6-dichlorobenzimidazole riboside, did not affect etoposide-stabilized topo II–DNA cleavable complex formation. Since, IC261 specifically targets the Ca2+-regulated isozymes, CKIδ and CKIɛ, we examined the effect of down-regulating these enzymes on Ser-1106 phosphorylation. Down-regulation of these isozymes with targeted si-RNAs led to hypophosphorylation of the Ser-1106 containing peptide. However, si-RNA-mediated down-regulation of CKIIα and α′ did not alter Ser-1106 phosphorylation. Furthermore, reduced phosphorylation of Ser-1106, observed in HRR25 (CKIδ/ɛ homologous gene)-deleted Saccharomyces cerevisiae cells transformed with human topo IIα, was enhanced following expression of human CKIɛ. Down-regulation of CKIδ and CKIɛ also led to reduced formation of etoposide stabilized topo II–DNA cleavable complex. These results provide strong support for an essential role of CKIδ/ɛ in phosphorylating Ser-1106 in human topo IIα and in regulating enzyme function.
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Affiliation(s)
- Adrian G Grozav
- Clinical Pharmacology Program, Taussig Cancer Institute, Cleveland, OH 44195, USA
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Shinagawa H, Miki Y, Yoshida K. BRCA1-mediated ubiquitination inhibits topoisomerase II alpha activity in response to oxidative stress. Antioxid Redox Signal 2008; 10:939-49. [PMID: 18162055 DOI: 10.1089/ars.2007.1851] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Topoisomerase IIalpha is known to be critically involved in both cell proliferation and cell death. The mechanisms responsible for stress-dependent topoisomerase IIalpha alterations, however, remain unclear. This study focused on the behavior of topoisomerase IIalpha in response to oxidative stress induced by hydrogen peroxide (H(2)O(2)). The catalytic activity of topoisomerase IIalpha in MOLT-4 cells treated with H(2)O(2) decreased in parallel with the alteration of topoisomerase IIalpha expression. The ubiquitination of topoisomerase IIalpha was dependent on oxidative stress. BRCA1, a tumor-suppressor gene, appeared to be involved in these alterations in topoisomerase IIalpha. Furthermore, the retinoblastoma protein (pRb) was required for the ubiquitination of topoisomerase IIalpha by BRCA1. We conclude that the functions of topoisomerase IIalpha are regulated by ubiquitination on exposure to oxidative stress.
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Affiliation(s)
- Hirokuni Shinagawa
- Department of Molecular Genetics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
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Li H, Wang Y, Liu X. Plk1-dependent phosphorylation regulates functions of DNA topoisomerase IIalpha in cell cycle progression. J Biol Chem 2008; 283:6209-21. [PMID: 18171681 DOI: 10.1074/jbc.m709007200] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plk1 (Polo-like kinase 1) has been documented as a critical regulator of many mitotic events. However, increasing evidence supports the notion that Plk1 might also have functions outside of mitosis. Using biochemical fractionation and RNA interference approaches, we found that Plk1 was required for both G(1)/S and G(2)/M phases and that DNA topoisomerase IIalpha (topoIIalpha) was a potential target for Plk1 in both interphase and mitosis. Plk1 phosphorylates Ser(1337) and Ser(1524) of topoIIalpha. Overexpression of an unphosphorylatable topoIIalpha mutant led to S phase arrest, suggesting that Plk1-associated phosphorylation first occurs in S phase. Moreover, overexpression of the unphosphorylatable topoIIalpha mutant activated the ATM/R-dependent DNA damage checkpoint, probably due to reduced catalytic activity of topoIIalpha, and resulted in accumulation of catenated DNA. Finally, we showed that wild type topoIIalpha, but not the unphosphorylatable mutant, was able to rescue topoIIalpha depletion-induced defects in sister chromatid segregation, indicating that Plk1-associated phosphorylation is essential for the functions of topoIIalpha in mitosis.
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Affiliation(s)
- Hongchang Li
- Department of Biochemistry and the Cancer Center, Purdue University, 175 S. University Street, West Lafayette, IN 47907, USA
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Wang L, Sun J, Li YQ, Chen ZS, Akiyama SI, Xian LJ. Reversal effect of BM-cyclin 1 on multidrug resistance in C-A120 cells. Anticancer Drugs 2007; 18:1015-21. [PMID: 17704651 DOI: 10.1097/cad.0b013e328223f14d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In this study, multidrug-resistant human epidermoid C-A120 cells and the sensitive parental KB cells were used as experimental models. BM-cyclin 1, a traditional antimycoplasma drug, was tested to explore the reversal effect of multidrug resistance and its mechanisms in these cell lines. The MTT analysis showed that BM-cyclin 1 could reverse multidrug resistance effectively in C-A120 cells; the sensitivity of C-A120 cells to adriamycin, etoposide and cisplatin was enhanced by 6.0, 8.2 and 1.7 times, respectively. Immunoblotting analysis and reverse transcription-polymerase chain reaction were used to study the BM-cyclin 1-induced changes in topoisomerase IIalpha. The results showed that the expression of topoisomerase IIalpha in treated C-A120 cells increased significantly. Topoisomerase II catalytic activity increased by 30% compared with the untreated cells, as measured by decatenation of kinetopolast DNA. Immunoblotting analysis also indicated the transcription factor levels of specificity: those of protein 1 (Sp1) and nuclear factor-YA increased after treatment with BM-cyclin 1, whereas the mRNA and protein expression of multidrug resistance protein 2 was significantly downregulated. These results demonstrated that BM-cyclin 1 could effectively reverse the multidrug resistance of C-A120 cells by increasing the expression of topoisomerase IIalpha and by suppressing the expression of multidrug resistance protein 2, strongly suggesting that BM-cyclin 1 is a potential multidrug resistance reversal agent.
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Affiliation(s)
- Lin Wang
- State Key Laboratory of Oncology in Southern China
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Parissenti AM, Hembruff SL, Villeneuve DJ, Veitch Z, Guo B, Eng J. Gene expression profiles as biomarkers for the prediction of chemotherapy drug response in human tumour cells. Anticancer Drugs 2007; 18:499-523. [PMID: 17414620 DOI: 10.1097/cad.0b013e3280262427] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Genome profiling approaches such as cDNA microarray analysis and quantitative reverse transcription polymerase chain reaction are playing ever-increasing roles in the classification of human cancers and in the discovery of biomarkers for the prediction of prognosis in cancer patients. Increasing research efforts are also being directed at identifying set of genes whose expression can be correlated with response to specific drugs or drug combinations. Such genes hold the prospect of tailoring chemotherapy regimens to the individual patient, based on tumour or host gene expression profiles. This review outlines recent advances and challenges in using genome profiling for the identification of tumour or host genes whose expression correlates with response to chemotherapy drugs both in vitro and in clinical studies. Genetic predictors of response to a variety of anticancer agents are discussed, including the anthracyclines, taxanes, topoisomerase I and II inhibitors, nucleoside analogs, alkylating agents, and vinca alkaloids.
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Affiliation(s)
- Amadeo M Parissenti
- Tumour Biology Research Program, Sudbury Regional Hospital, Department of Biology, Laurentian University, Sudbury, Ottawa, Ontario, Canada.
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Pors K, Shnyder SD, Teesdale-Spittle PH, Hartley JA, Zloh M, Searcey M, Patterson LH. Synthesis of DNA-directed pyrrolidinyl and piperidinyl confined alkylating chloroalkylaminoanthraquinones: potential for development of tumor-selective N-oxides. J Med Chem 2007; 49:7013-23. [PMID: 17125254 DOI: 10.1021/jm0608154] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel series of 1,4-disubstituted chloroethylaminoanthraquinones, containing alkylating chloroethylamino functionalities as part of a rigid piperidinyl or pyrrolidinyl ring-system, have been prepared. The target compounds were prepared by ipso-displacement of halides of various anthraquinone chromophores by either hydroxylated or chlorinated piperidinyl- or pyrrolidinyl-alkylamino side chains. The chloroethylaminoanthraquinones were shown to alkylate guanine residues of linearized pBR322 (1-20 microM), and two symmetrically 1,4-disubstituted anthraquinones (compounds 14 and 15) were shown to interstrand cross-link DNA in the low nM range. Several 1,4-disubstituted chloroethylaminoanthraquinones were potently cytotoxic (IC50 values: <or=40 nM) in human ovarian cancer A2780 cells. Two agents (compounds 18 and 19) exhibited mean GI50 values of 96 nM and 182 nM, respectively, in the NCI human tumor cell line panel. Derivatization of the potent DNA cross-linking agent 15 to an N-oxide resulted in loss of the DNA unwinding, DNA interstrand cross-linking and cytotoxic activity of the parent molecule.
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Affiliation(s)
- Klaus Pors
- Institute of Cancer Therapeutics, University of Bradford, West Yorkshire, BD7 1DP, United Kingdom
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Mirski SEL, Sparks KE, Friedrich B, Köhler M, Mo YY, Beck WT, Cole SPC. Topoisomerase II binds importin alpha isoforms and exportin/CRM1 but does not shuttle between the nucleus and cytoplasm in proliferating cells. Exp Cell Res 2007; 313:627-37. [PMID: 17182034 DOI: 10.1016/j.yexcr.2006.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 10/12/2006] [Accepted: 11/07/2006] [Indexed: 01/11/2023]
Abstract
Resistance to anticancer drugs that target DNA topoisomerase II (topo II) isoforms alpha and/or beta is associated with decreased nuclear and increased cytoplasmic topo IIalpha. Earlier studies have confirmed that functional nuclear localization and export signal sequences (NLS and NES) are present in both isoforms. In this study, we show that topo II alpha and beta bind and are imported into the nucleus by importin alpha1, alpha3, and alpha5 in conjunction with importin beta. Topo IIalpha also binds exportin/CRM1 in vitro. However, wild-type topo IIalpha has only been observed in the cytoplasm of cells that are entering plateau phase growth. This suggests that topo IIalpha may shuttle between the nucleus and the cytoplasm with the equilibrium towards the nucleus in proliferating cells but towards the cytoplasm in plateau phase cells. The CRM1 inhibitor Leptomycin B increases the nuclear localization of GFP-tagged topo IIalpha with a mutant NLS, suggesting that its export is being inhibited. However, homokaryon shuttling experiments indicate that fluorescence-tagged wild-type topo II alpha and beta proteins do not shuttle in proliferating Cos-1 or HeLa cells. We conclude that topo II alpha and beta nuclear export is inhibited in proliferating cells so that these proteins do not shuttle.
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Affiliation(s)
- Shelagh E L Mirski
- Division of Cancer Biology and Genetics, Cancer Research Institute, Queen's University, Kingston, ON, Canada K7L 3N6
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Gilroy KL, Leontiou C, Padget K, Lakey JH, Austin CA. mAMSA resistant human topoisomerase IIbeta mutation G465D has reduced ATP hydrolysis activity. Nucleic Acids Res 2006; 34:1597-607. [PMID: 16549872 PMCID: PMC1405819 DOI: 10.1093/nar/gkl057] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Type II Human DNA Topoisomerases (topos II) play an essential role in DNA replication and transcription and are important targets for cancer chemotherapeutic drugs. Topoisomerase II causes transient double-strand breaks in DNA, forming a gate through which another double helix is passed, and acts as a DNA dependent ATPase. Mutations in topoII have been linked to atypical multi-drug resistance. Both human Topoisomerase II isoforms, α and β, are targeted by amsacrine. We have used a forced molecular evolution approach to identify mutations conferring resistance to acridines. Here we report mutation βG465D, which was selected with mAMSA and DACA and is cross-resistant to etoposide, ellipticine and doxorubicin. Resistance to mAMSA appears to decrease over time indicating a previously unreported resistance mechanism. G465D lies within the B′ domain in the region that contacts the cleaved gate helix. There is a 3-fold decrease in ATP affinity and ATP hydrolysis and an altered requirement for magnesium in decatenation assays. The decatenation rate is decreased for the mutated G465D protein. And we report for the first time the use of fluorescence anisotropy with intact human topoisomerase II.
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Affiliation(s)
- Kathryn L Gilroy
- The Institute for Cell and Molecular Biosciences, The University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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Braun AH, Stark K, Dirsch O, Hilger RA, Seeber S, Vanhoefer U. The epidermal growth factor receptor tyrosine kinase inhibitor gefitinib sensitizes colon cancer cells to irinotecan. Anticancer Drugs 2005; 16:1099-108. [PMID: 16222152 DOI: 10.1097/00001813-200511000-00009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Epidermal growth factor receptor (EGFR) overactivity plays a significant role in colon cancer biology and has been associated with poor clinical prognosis. Early clinical trials reported efficacy of receptor-targeted compounds, including modulation of clinical irinotecan resistance. We investigated the effects of the EGFR tyrosine kinase inhibitor gefitinib on cellular determinants of irinotecan resistance in human colon cancer cells. At non-cytotoxic concentrations, gefitinib sensitized colon cancer cells to SN-38, the active metabolite of irinotecan. Gefitinib increased the SN-38-mediated induction of protein-linked DNA single-strand breaks in a dose-dependent manner, with no alteration of topoisomerase (Topo) I protein expression or enzymatic activity. Whereas Topo IIbeta protein expression was not affected by gefitinib, significant time- and concentration-dependent downregulation of Topo IIalpha protein and inhibition of its enzymatic function were observed, corresponding to a G1 phase cell cycle arrest. Gefitinib significantly inhibited EGFR-associated signaling molecules, including phospho-mitogen-activated protein kinase or protein kinase C, which may account for decreases in proliferation or topoisomerase activity, respectively. Although a dose-dependent decrease of the BCRP/MXR/ABCP half-transporter was observed under gefitinib, cellular pharmacokinetics revealed no significant differences in accumulation or retention of the active SN-38 lactone using reverse-phase HPLC analysis. This study delineates mechanisms that may contribute to the synergism observed between irinotecan and EGFR inhibitors.
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Affiliation(s)
- Ada Henrike Braun
- Department of Internal Medicine (Cancer Research), West German Cancer Center, Essen, Germany.
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Gray MD, Mann M, Nitiss JL, Hendershot LM. Activation of the unfolded protein response is necessary and sufficient for reducing topoisomerase IIalpha protein levels and decreasing sensitivity to topoisomerase-targeted drugs. Mol Pharmacol 2005; 68:1699-707. [PMID: 16141312 DOI: 10.1124/mol.105.014753] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A wide range of chemotherapeutic agents has been identified that are active against solid tumors. However, resistance remains an important obstacle to the development of curative regimens. Whereas much attention has been paid to acquired drug resistance, a variety of physiological pathways also have been described that reduce the sensitivity of previously untreated tumors to cytotoxic antitumor agents. Treatment of cells with pharmacological agents that alter the environment of the endoplasmic reticulum (ER) and activate the unfolded protein response (UPR) can render cells resistant to topoisomerase II poisons. We describe experiments showing that activation of the mammalian ER stress response is both necessary and sufficient to decrease topoisomerase IIalpha protein levels and to render cells resistant to etoposide, a topoisomerase II-targeting drug. This is not caused by the elevated levels of BiP that are a hallmark of this response, because a cell line that has been engineered to overexpress BiP does not show increased resistance to etoposide. The UPR was shown to be required for altered drug sensitivity, because the BiP-overexpressing cell line, which is unable to activate the UPR, did not show decreased topoisomerase II levels or increased resistance to etoposide in response to stress conditions. The transient overexpression of an unfolded protein activated the UPR and led to the concomitant loss of topoisomerase IIalpha protein from the cells, demonstrating that UPR activation is sufficient for the changes in topoisomerase II levels that had been observed previously with pharmacological induction of the UPR.
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Affiliation(s)
- Miranda D Gray
- Department of Molecular Pharmacology, St. Jude Children's Research Hospital, 332 N. Lauderdale, Memphis, Tennessee 38105, USA
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Sengupta T, Mukherjee M, Das R, Das A, Majumder HK. Characterization of the DNA-binding domain and identification of the active site residue in the 'Gyr A' half of Leishmania donovani topoisomerase II. Nucleic Acids Res 2005; 33:2364-73. [PMID: 15860773 PMCID: PMC1087781 DOI: 10.1093/nar/gki527] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
DNA topoisomerase II is a multidomain homodimeric enzyme that changes DNA topology by coupling ATP hydrolysis to the transport of one DNA helix through a transient double-stranded break in another. To investigate the biochemical properties of the individual domains of Leishmania donovani topoisomerase II, four truncation mutants were generated. Deletion of 178 aminoacids from the C-terminus (core and LdΔC1058) had no apparent effect on the DNA-binding or cleavage activities of the enzymes. However, when 429 aminoacids from the N-terminus and 451 aminoacids from the C-terminus were removed (LdΔNΔC), the enzyme was no longer active. Moreover, the removal of 429 aminoacids from the N-terminus (LdΔNΔC, core and LdΔN429) render the mutant proteins incapable of performing ATP hydrolysis. The mutant proteins show cleavage activities at wide range of KCl concentrations (25–350 mM). In addition, the mutant proteins, excepting LdΔNΔC, can also act on kDNA and linearize the minicircles. Surprisingly, the mutant proteins fail to show the formation of the enhanced cleavable complex in the presence of etoposide. Our findings suggest that the conformation required for interaction with the drug is absent in the mutant proteins. Here, we have also identified Tyr775 through direct sequencing of the DNA linked peptide as the catalytic residue implicated in DNA-breakage and rejoining. Taken together, our results demonstrate that topoisomerase II are functionally and mechanistically conserved enzymes and the variations in activity seem to reflect functional optimization for its physiological role during parasite genome replication.
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Affiliation(s)
| | | | | | - Aditi Das
- Sealy Center for Molecular Sciences, University of TexasMedical Branch, Galveston, USA
| | - Hemanta K. Majumder
- To whom correspondence should be addressed. Tel: +91 33 2412 3207; Fax: +91 33 2473 5197;
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Martincic D, Hande KR. Topoisomerase II inhibitors. CANCER CHEMOTHERAPY AND BIOLOGICAL RESPONSE MODIFIERS 2005; 22:101-21. [PMID: 16110609 DOI: 10.1016/s0921-4410(04)22005-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Danko Martincic
- Vanderbilt/Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232, USA
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Carpenter AJ, Porter ACG. Construction, characterization, and complementation of a conditional-lethal DNA topoisomerase IIalpha mutant human cell line. Mol Biol Cell 2004; 15:5700-11. [PMID: 15456904 PMCID: PMC532048 DOI: 10.1091/mbc.e04-08-0732] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
DNA Topoisomerase IIalpha (topoIIalpha) is a DNA decatenating enzyme, abundant constituent of mammalian mitotic chromosomes, and target of numerous antitumor drugs, but its exact role in chromosome structure and dynamics is unclear. In a powerful new approach to this important problem, with significant advantages over the use of topoII inhibitors or RNA interference, we have generated and characterized a human cell line (HTETOP) in which >99.5% topoIIalpha expression can be silenced in all cells by the addition of tetracycline. TopoIIalpha-depleted HTETOP cells enter mitosis and undergo chromosome condensation, albeit with delayed kinetics, but normal anaphases and cytokineses are completely prevented, and all cells die, some becoming polyploid in the process. Cells can be rescued by expression of topoIIalpha fused to green fluorescent protein (GFP), even when certain phosphorylation sites have been mutated, but not when the catalytic residue Y805 is mutated. Thus, in addition to validating GFP-tagged topoIIalpha as an indicator for endogenous topoIIalpha dynamics, our analyses provide new evidence that topoIIalpha plays a largely redundant role in chromosome condensation, but an essential catalytic role in chromosome segregation that cannot be complemented by topoIIbeta and does not require phosphorylation at serine residues 1106, 1247, 1354, or 1393.
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Affiliation(s)
- Adam J Carpenter
- Gene Targeting Group, Medical Research Council Clinical Sciences Centre, Imperial College Faculty of Medicine, Hammersmith Hospital Campus, London W12 ONN, United Kingdom
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Kim SJ, Kim JH, Kim YG, Lim HS, Oh JW. Protein kinase C-related kinase 2 regulates hepatitis C virus RNA polymerase function by phosphorylation. J Biol Chem 2004; 279:50031-41. [PMID: 15364941 DOI: 10.1074/jbc.m408617200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The hepatitis C virus (HCV) NS5B protein is the viral RNA-dependent RNA polymerase required for replication of the HCV RNA genome. We have identified a peptide that most closely resembles a short region of the protein kinase C-related kinase 2 (PRK2) by screening of a random 12-mer peptide library displayed on the surface of the M13 bacteriophage with NS5B proteins immobilized on microwell plates. Competitive phage enzyme-linked immunosorbent assay with a synthetic peptide showed that the phage clone displaying this peptide could bind HCV RNA polymerase with a high affinity. Coimmunoprecipitation and colocalization studies demonstrated in vivo interaction of NS5B with PRK2. In vitro kinase assays demonstrated that PRK2 specifically phosphorylates NS5B by interaction with the N-terminal finger domain of NS5B (amino acids 1-187). Consistent with the in vitro NS5B-phosphorylating activity of PRK2, we detected the phosphorylated form of NS5B by metabolic cell labeling. Furthermore, HCV NS5B immunoprecipitated from HCV subgenomic replicon cells was specifically recognized by an antiphosphoserine antibody. Knock-down of the endogenous PRK2 expression using a PRK2-specific small interfering RNA inhibited HCV RNA replication. In contrast, PRK2 overexpression, which was accompanied by an increase of in the level of its active form, dramatically enhanced HCV RNA replication. Altogether, our results indicate that HCV RNA replication is regulated by NS5B phosphorylation by PRK2.
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Affiliation(s)
- Seong-Jun Kim
- Department of Biotechnology, Yonsei University, Seoul 120-749, Korea
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Affiliation(s)
- R Pieters
- University Medical Center Rotterdam, Sophia Childrens Hospital, Pediatric Oncology/Hematology, Rotterdam, The Netherlands.
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