1
|
Zhu M, Li H, Zheng Y, Yang J. Targeting TOP2B as a vulnerability in aging and aging-related diseases. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167044. [PMID: 38296114 DOI: 10.1016/j.bbadis.2024.167044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 12/17/2023] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
The ongoing trend of rapid aging of the global population has unavoidably resulted in an increase in aging-related diseases. There is an immense amount of interest in the scientific community for the identification of molecular targets that may effectively mitigate the process of aging and aging-related diseases. The enzyme Topoisomerase IIβ (TOP2B) plays a crucial role in resolving the topological challenges that occur during DNA-related processes. It is believed that the disruption of TOP2B function contributes to the aging of cells and tissues, as well as the development of age-related diseases. Consequently, targeting TOP2B appears to be a promising approach for interventions aimed at mitigating the effects of aging. This review focuses on recent advancements in the understanding of the role of TOP2B in the processing of aging and aging-related disorders, thus providing a novel avenue for the development of anti-aging strategies.
Collapse
Affiliation(s)
- Man Zhu
- Laboratory of Aging Research, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Hao Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, USA.
| | - Yi Zheng
- Laboratory of Aging Research, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.
| | - Jing Yang
- Laboratory of Aging Research, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.
| |
Collapse
|
2
|
Zhang H, Dong X, Ding X, Liu G, Yang F, Song Q, Sun H, Chen G, Li S, Li Y, Wang M, Guo T, Zhang Z, Li B, Yang L. Bufalin targeting CAMKK2 inhibits the occurrence and development of intrahepatic cholangiocarcinoma through Wnt/β-catenin signal pathway. J Transl Med 2023; 21:900. [PMID: 38082327 PMCID: PMC10714474 DOI: 10.1186/s12967-023-04613-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/10/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Intrahepatic cholangiocarcinoma (ICC) accounts for about 15% of primary liver cancer, and the incidence rate has been rising in recent years. Surgical resection is the best treatment for ICC, but the 5-year survival rate is less than 30%. ICC signature genes are crucial for the early diagnosis of ICC, so it is especially important to find its signature genes and therapeutic drug. Here, we studied that bufalin targeting CAMKK2 promotes mitochondrial dysfunction and inhibits the occurrence and metastasis of intrahepatic cholangiocarcinoma through Wnt/β-catenin signal pathway. METHODS IC50 of bufalin in ICC cells was determined by CCK8 and invasive and migratory abilities were verified by wound healing, cell cloning, transwell and Western blot. IF and IHC verified the expression of CAMKK2 between ICC patients and normal subjects. BLI and pull-down demonstrated the binding ability of bufalin and CAMKK2. Bioinformatics predicted whether CAMKK2 was related to the Wnt/β-catenin pathway. SKL2001, an activator of β-catenin, verified whether bufalin acted through this pathway. In vitro and in vivo experiments verified whether overexpression of CAMKK2 affects the proliferative and migratory effects of ICC. Transmission electron microscopy verified mitochondrial integrity. Associated Ca2+ levels verified the biological effects of ANXA2 on ICC. RESULTS It was found that bufalin inhibited the proliferation and migration of ICC, and CAMKK2 was highly expressed in ICC, and its high expression was positively correlated with poor prognosis.CAMKK2 is a direct target of bufalin, and is associated with the Wnt/β-catenin signaling pathway, which was dose-dependently decreased after bufalin treatment. In vitro and in vivo experiments verified that CAMKK2 overexpression promoted ICC proliferation and migration, and bufalin reversed this effect. CAMKK2 was associated with Ca2+, and changes in Ca2+ content induced changes in the protein content of ANXA2, which was dose-dependently decreasing in cytoplasmic ANXA2 and dose-dependently increasing in mitochondrial ANXA2 after bufalin treatment. In CAMKK2 overexpressing cells, ANXA2 was knocked down, and we found that reversal of CAMKK2 overexpression-induced enhancement of ICC proliferation and migration after siANXA2. CONCLUSIONS Our results suggest that bufalin targeting CAMKK2 promotes mitochondrial dysfunction and inhibits the proliferation and migration of intrahepatic cholangiocarcinoma through Wnt/β-catenin signal pathway. Thus, bufalin, as a drug, may also be used for cancer therapy in ICC in the future.
Collapse
Affiliation(s)
- Huhu Zhang
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Xiaolei Dong
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Xiaoyan Ding
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Guoxiang Liu
- Department of Clinical Laboratory, Weifang People's Hospital, 151, Guangwen Street, Weifang, 261041, China
| | - Fanghao Yang
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Qinghang Song
- Health Science Center, Qingdao University, Qingdao, 266071, China
| | - Hongxiao Sun
- Heart Center, Women and Children's Hospital, Qingdao University, 6, Tongfu Road, Qingdao, 266034, China
| | - Guang Chen
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Shuang Li
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Ya Li
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Mengjun Wang
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Tingting Guo
- Health Science Center, Qingdao University, Qingdao, 266071, China
| | - Zhe Zhang
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China
| | - Bing Li
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China.
- Department of Hematology, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
| | - Lina Yang
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, 266071, China.
| |
Collapse
|
3
|
Wu QJ, Zhang TN, Chen HH, Yu XF, Lv JL, Liu YY, Liu YS, Zheng G, Zhao JQ, Wei YF, Guo JY, Liu FH, Chang Q, Zhang YX, Liu CG, Zhao YH. The sirtuin family in health and disease. Signal Transduct Target Ther 2022; 7:402. [PMID: 36581622 PMCID: PMC9797940 DOI: 10.1038/s41392-022-01257-8] [Citation(s) in RCA: 123] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/10/2022] [Accepted: 11/18/2022] [Indexed: 12/30/2022] Open
Abstract
Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.
Collapse
Affiliation(s)
- Qi-Jun Wu
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Tie-Ning Zhang
- grid.412467.20000 0004 1806 3501Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Huan-Huan Chen
- grid.412467.20000 0004 1806 3501Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xue-Fei Yu
- grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jia-Le Lv
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yu-Yang Liu
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Ya-Shu Liu
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Gang Zheng
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jun-Qi Zhao
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yi-Fan Wei
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jing-Yi Guo
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Fang-Hua Liu
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Qing Chang
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yi-Xiao Zhang
- grid.412467.20000 0004 1806 3501Department of Urology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Cai-Gang Liu
- grid.412467.20000 0004 1806 3501Department of Cancer, Breast Cancer Center, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yu-Hong Zhao
- grid.412467.20000 0004 1806 3501Liaoning Key Laboratory of Precision Medical Research on Major Chronic Disease, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang, China ,grid.412467.20000 0004 1806 3501Clinical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
| |
Collapse
|
4
|
Bollimpelli VS, Dholaniya PS, Kondapi AK. Topoisomerase IIβ and its role in different biological contexts. Arch Biochem Biophys 2017; 633:78-84. [PMID: 28669856 DOI: 10.1016/j.abb.2017.06.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 06/24/2017] [Accepted: 06/27/2017] [Indexed: 12/27/2022]
Abstract
Topoisomerase IIβ is a type II DNA topoisomerase that was reported to be expressed in all mammalian cells but abundantly expressed in cells that have undergone terminal differentiation to attain a post mitotic state. Enzymatically it catalyzes ATP-dependent topological changes of double stranded DNA, while as a protein it was reported to be associated with several factors in promoting cell growth, migration, DNA repair and transcription regulation. The cellular roles of topoisomerase IIβ are very less understood compared to its counterpart topoisomerase IIα. This review discusses origin of Topoisomerase II beta, its structure, activities reported in vitro and in vivo along with implications in cellular processes namely transcription, DNA repair, neuronal development, aging, HIV-infection and cancer.
Collapse
Affiliation(s)
- V Satish Bollimpelli
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Pankaj S Dholaniya
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Anand K Kondapi
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
| |
Collapse
|
5
|
Kenig S, Faoro V, Bourkoula E, Podergajs N, Ius T, Vindigni M, Skrap M, Lah T, Cesselli D, Storici P, Vindigni A. Topoisomerase IIβ mediates the resistance of glioblastoma stem cells to replication stress-inducing drugs. Cancer Cell Int 2016; 16:58. [PMID: 27462186 PMCID: PMC4960855 DOI: 10.1186/s12935-016-0339-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 07/18/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Glioblastoma stem cells (GSC) have been extensively recognized as a plausible cause of glioblastoma resistance to therapy and recurrence resulting in high glioblastoma mortality. Abnormalities in the DNA repair pathways might be responsible for the inability of the currently used chemotherapeutics to eliminate the (GSC) subpopulation. METHODS In this work, we compared the expression of sixty DNA repair related genes between primary glioblastoma cell cultures and the glioblastoma enriched stem cell primary cultures. MTT test was used to analyze the effect of selected drugs and immunofluorescence to evaluate the load of DNA damage. RESULTS We found several differentially expressed genes and we identified topoisomerase IIβ (Top2β) as the gene with highest up-regulation in GSC. Also among the tested cell lines the expression of Top2β was the highest in NCH421k cells, a well-characterized glioblastoma cell line with all the stemness characteristics. On the other hand, Top2β expression markedly decreased upon the induction of differentiation by all trans-retinoic acid. Depletion of Top2β increased the sensitivity of NCH421k cells to replication stress inducing drugs, such as cisplatin, methyl-methanesulfonate, hydrogen peroxide, and temozolomide. Consistently, we found an increased load of DNA damage and increased Chk1 activation upon Top2β depletion in NCH421k cells. CONCLUSION We suggest that Top2β may represent a new target for gene therapy in glioblastoma. In addition, the other genes that we found to be up-regulated in GSC versus glioblastoma primary cells should be further investigated as glioblastoma theranostics.
Collapse
Affiliation(s)
- Saša Kenig
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste, Strada Statale 14-km 163, 5, Basovizza, 34149 Trieste, Italy
| | - Valentina Faoro
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste, Strada Statale 14-km 163, 5, Basovizza, 34149 Trieste, Italy
| | - Evgenia Bourkoula
- Department of Medical and Biological Sciences, University of Udine, Piazzale Kolbe 4, 33100 Udine, Italy
| | - Neža Podergajs
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Tamara Ius
- Neurosurgery Unit, Department of Neurosciences, Santa Maria della Misericordia University Hospital, Piazzale Santa Maria della Misericordia, 15, Udine, Italy
| | - Marco Vindigni
- Neurosurgery Unit, Department of Neurosciences, Santa Maria della Misericordia University Hospital, Piazzale Santa Maria della Misericordia, 15, Udine, Italy
| | - Miran Skrap
- Neurosurgery Unit, Department of Neurosciences, Santa Maria della Misericordia University Hospital, Piazzale Santa Maria della Misericordia, 15, Udine, Italy
| | - Tamara Lah
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia ; Faculty of Chemistry and Chemical Engineering, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Daniela Cesselli
- Department of Medical and Biological Sciences, University of Udine, Piazzale Kolbe 4, 33100 Udine, Italy
| | - Paola Storici
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste, Strada Statale 14-km 163, 5, Basovizza, 34149 Trieste, Italy
| | - Alessandro Vindigni
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste, Strada Statale 14-km 163, 5, Basovizza, 34149 Trieste, Italy ; Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO USA
| |
Collapse
|
6
|
Ray S, Panova T, Miller G, Volkov A, Porter ACG, Russell J, Panov KI, Zomerdijk JCBM. Topoisomerase IIα promotes activation of RNA polymerase I transcription by facilitating pre-initiation complex formation. Nat Commun 2013; 4:1598. [PMID: 23511463 PMCID: PMC3615473 DOI: 10.1038/ncomms2599] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 02/09/2013] [Indexed: 11/15/2022] Open
Abstract
Type II DNA topoisomerases catalyse DNA double-strand cleavage, passage and re-ligation to effect topological changes. There is considerable interest in elucidating topoisomerase II roles, particularly as these proteins are targets for anti-cancer drugs. Here we uncover a role for topoisomerase IIα in RNA polymerase I-directed ribosomal RNA gene transcription, which drives cell growth and proliferation and is upregulated in cancer cells. Our data suggest that topoisomerase IIα is a component of the initiation-competent RNA polymerase Iβ complex and interacts directly with RNA polymerase I-associated transcription factor RRN3, which targets the polymerase to promoter-bound SL1 in pre-initiation complex formation. In cells, activation of rDNA transcription is reduced by inhibition or depletion of topoisomerase II, and this is accompanied by reduced transient double-strand DNA cleavage in the rDNA-promoter region and reduced pre-initiation complex formation. We propose that topoisomerase IIα functions in RNA polymerase I transcription to produce topological changes at the rDNA promoter that facilitate efficient de novo pre-initiation complex formation. Topoisomerases facilitate the progress of elongating polymerases during transcription. Zomerdijk and colleagues now demonstrate an additional role for this enzyme; their data suggest that Top2 can cleave DNA inducing topological changes at the ribosomal DNA promoter, which assists de novo assembly of the RNA polymerase I pre-initiation complex.
Collapse
Affiliation(s)
- Swagat Ray
- School of Biological Sciences and the Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Gupta KP, Swain U, Rao KS, Kondapi AK. Topoisomerase IIβ regulates base excision repair capacity of neurons. Mech Ageing Dev 2012; 133:203-13. [PMID: 22433436 DOI: 10.1016/j.mad.2012.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 02/28/2012] [Accepted: 03/07/2012] [Indexed: 12/18/2022]
Abstract
Topoisomerase IIβ (TopoIIβ), an enzyme involved in DNA rearrangements, is predominantly present in brain and its levels are shown to decrease with age. This study characterizes the function of TopoIIβ in regulating BER (base excision repair) activity. TopoIIβ deficient granule neurons (CGNT⁻) show greater sensitivity to N-ethyl N-nitroso urea (ENU)-mediated DNA damage. The cell-free extracts of TopoIIβ knockdown cells (ECGNT⁻) show a significant decrease in G-U BER activity during ENU-treatment as well as during recovery, suggesting that TopoIIβ promotes G-U BER activity. Since G-U BER activity is not affected in the presence of ICRF-193, catalytic inhibitor of TopoIIβ, the activity of enzyme per se may not be participating in BER activity. Further characterization of the activities of BER enzymes present in ECGNT⁻ shows that uracil DNA-glycosylase (UDG) and ligase (LIG) activities decrease significantly in both ENU treatment and recovery. Supplementation of TopoIIβ to ECGNT⁻ does not restore ligation activity and ICRF-193 does not influence the LIG activity. These results suggest a role, at least an indirect one, of TopoIIβ in the repair of ENU-mediated strand breaks via BER pathway including the activities of UDG and LIG.
Collapse
Affiliation(s)
- K Preeti Gupta
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, Andhra Pradesh, India
| | | | | | | |
Collapse
|
8
|
Selective silencing of DNA topoisomerase IIβ in human mesenchymal stem cells by siRNAs (small interfering RNAs). CELL BIOLOGY INTERNATIONAL REPORTS 2011; 18:e00010. [PMID: 23119146 PMCID: PMC3475440 DOI: 10.1042/cbr20110003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 03/22/2011] [Indexed: 01/16/2023]
Abstract
hMSCs (human mesenchymal stem cells) express two isoforms of DNA topo II (topoisomerase II). Although both isoforms have the same catalytic activity, they are specialized for different functions in the cell: while topo IIα is essential for chromosome segregation in mitotic cells, topo IIβ is involved in more specific cellular functions. A number of inhibitors are available that inhibit the catalytic activity of both topo II isoforms. However, in order to investigate the isoform-specific inhibition of these two enzymes, it is necessary to use other techniques such as siRNA (small interfering RNA) interference to selectively silence either one of the isoforms individually. Depending on the lipid charge densities and protein varieties of the cell membrane, previous studies have demonstrated that transfection efficiencies of siRNAs to hMSCs are very low. In the study reported here, we demonstrate the use of Lipofectamine RNAiMAX as an efficient transfection reagent to introduce siRNAs into human mesenchymal stem cells with significantly great efficiency to silence topo IIβ selectively. A high level of transfection efficiency (80%) was achieved by using unlabelled topo IIβ-specific siRNA oligos. Specifically, it was confirmed repeatedly that green labelled siRNAs interfere with the transfection of siRNAs. The reagent induced minimal cytotoxicity (3.5–4.5%), and cell viability of the transfected hMSCs decreased 20–30% compared with untreated cells, depending on the concentration of the reagent.
Collapse
Key Words
- DMEM, Dulbecco's modified Eagle's medium
- DNA topoisomerase IIβ
- GFP, green fluorescent protein
- HEK, human embryonic kidney
- LDH, lactate dehydrogenase
- MSC, mesenchymal stem cell
- MSC-FBS, MSC-qualified fetal bovine serum
- PE, phycoerythrin
- RNAi, RNA interference
- RNAiMAX
- hMSC, human mesenchymal stem cell
- human mesenchymal stem cell
- siRNA transfection
- siRNA, small interfering RNA
- topo II, topoisomerase II
Collapse
|
9
|
Shain KH, Dalton WS. Environmental-mediated drug resistance: a target for multiple myeloma therapy. Expert Rev Hematol 2011; 2:649-62. [PMID: 21082957 DOI: 10.1586/ehm.09.55] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Multiple myeloma is an incurable malignancy of mature clonal B cells. The refractory nature of this disease has long been attributed to the acquisition of drug resistance. Traditionally, mechanisms of drug resistance have been defined by genetic, acquired changes in the expression or function of specific genes products. However, over the past 10 years a large body of evidence has emerged demonstrating that in addition to mechanisms of drug resistance intrinsic to the cancer cell, there exist dynamic, de novo mechanisms coordinated by the tumor microenvironment resulting in a environmental-mediated drug resistance (EM-DR). Within this review we will provide an overview of some of these mechanisms of drug resistance and how they contribute to minimal residual disease and subsequent treatment failure. By understanding mechanisms of EM-DR, therapeutic targets can be identified and interventions designed to reduce minimal residual disease and improve clinical outcomes.
Collapse
Affiliation(s)
- Kenneth H Shain
- Departments of Experimental Therapeutics and Oncologic Sciences, H. Lee Moffitt Cancer Center and Research Institute, University of South Florida, 12902 Magnolia Drive, Tampa, FL 33612, USA.
| | | |
Collapse
|
10
|
Bower JJ, Karaca GF, Zhou Y, Simpson DA, Cordeiro-Stone M, Kaufmann WK. Topoisomerase IIalpha maintains genomic stability through decatenation G(2) checkpoint signaling. Oncogene 2010; 29:4787-99. [PMID: 20562910 PMCID: PMC2928865 DOI: 10.1038/onc.2010.232] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Topoisomerase IIalpha (topoIIalpha) is an essential mammalian enzyme that topologically modifies DNA and is required for chromosome segregation during mitosis. Previous research suggests that inhibition of topoII decatenatory activity triggers a G(2) checkpoint response, which delays mitotic entry because of insufficient decatenation of daughter chromatids. Here we examine the effects of both topoIIalpha and topoIIbeta on decatenatory activity in cell extracts, DNA damage and decatenation G(2) checkpoint function, and the frequencies of p16(INK4A) allele loss and gain. In diploid human fibroblast lines, depletion of topoIIalpha by small-interfering RNA was associated with severely reduced decatenatory activity, delayed progression from G(2) into mitosis and insensitivity to G(2) arrest induced by the topoII catalytic inhibitor ICRF-193. Furthermore, interphase nuclei of topoIIalpha-depleted cells showed increased frequencies of losses and gains of the tumor suppressor genetic locus p16(INK4A). This study shows that the topoIIalpha protein is required for decatenation G(2) checkpoint function, and inactivation of decatenation and the decatenation G(2) checkpoint leads to abnormal chromosome segregation and genomic instability.
Collapse
Affiliation(s)
- J J Bower
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | | | | | | | | |
Collapse
|
11
|
Hazlehurst LA. Detection of DNA damage induced by topoisomerase II inhibitors, gamma radiation and crosslinking agents using the comet assay. Methods Mol Biol 2009; 523:169-76. [PMID: 19381939 DOI: 10.1007/978-1-59745-190-1_12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The comet assay is a simple gel electrophoresis method for visualizing and quantifying DNA damage. The comet assay is sensitive and reproducible and can be used to detect single-strand DNA breaks, double-strand DNA breaks, protein-associated DNA strand breaks and DNA crosslinks. The comet assay uses fluorescent DNA-binding dyes to detect both damaged DNA that resides in the tail region and undamaged DNA that is retained in the head region following gel electrophoresis. This assay is a single cell-based assay and thus is highly adaptable for measuring DNA damage in clinical samples. Furthermore, unlike other assays the detection of DNA damage is not dependent on the random incorporation of radiolabeled nucleotides. Again this can be problematic with clinical samples as proliferation rates are often slow and culturing of primary patient specimens for 48 h required to randomly label DNA is often not possible. In this chapter we will outline the comet assay for the detection of DNA damage induced by topoisomerase II inhibitors, cross-linking agents and gamma radiation.
Collapse
Affiliation(s)
- Lori A Hazlehurst
- Department of Interdisciplinary Oncology, Experimental Therapeutics and Drug Discovery Programs, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| |
Collapse
|
12
|
Abstract
Eukaryotic type II topoisomerases (Topo II) are implicated in a wide range of cellular processes. Cells in which Topo II protein has been specifically depleted or mutated provide powerful systems for analysing the normal in vivo functions of Topo II proteins and for assessing their roles in various chemotherapy regimens. Summarised here are the ways in which Topo II has been depleted or mutated in animal cells and the type of information gleaned. The cell lines generated are tabulated and represent a useful resource for further in vivo studies of Topo II function, one that we expect to grow in size and utility in the coming years.
Collapse
Affiliation(s)
- Andrew C G Porter
- Department of Haematology, Imperial College Faculty of Medicine, London, UK
| |
Collapse
|
13
|
Mandraju RK, Kannapiran P, Kondapi AK. Distinct roles of Topoisomerase II isoforms: DNA damage accelerating α, double strand break repair promoting β. Arch Biochem Biophys 2008; 470:27-34. [DOI: 10.1016/j.abb.2007.10.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 10/26/2007] [Accepted: 10/28/2007] [Indexed: 10/22/2022]
|
14
|
Martins RP, Krawetz SA. Decondensing the protamine domain for transcription. Proc Natl Acad Sci U S A 2007; 104:8340-5. [PMID: 17483471 PMCID: PMC1895951 DOI: 10.1073/pnas.0700076104] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Potentiation is the transition from higher-order, transcriptionally silent chromatin to a less condensed state requisite to accommodating the molecular elements required for transcription. To examine the underlying mechanism of potentiation an approximately 13.7-kb mouse protamine domain of increased nuclease sensitivity flanked by 5' and 3' nuclear matrix attachment regions was defined. The potentiated DNase I-sensitive region is formed at the pachytene spermatocyte stage with the recruitment to the nuclear matrix of a large approximately 9.6-kb region just upstream of the domain. Attachment is then specified in the transcribing round spermatid, recapitulating the organization of the human cluster. In comparison to other modifiers that have no effect, i.e., histone methylation, HP1, and SATB1, topoisomerase engages nuclear matrix binding as minor marks of histone acetylation appear. Reorganization is marked by specific sites of topoisomerase II activity that are initially detected in leptotene-zygotene spermatocytes just preceding the formation of the DNase I-sensitive domain. This has provided a likely model of the events initiating potentiation, i.e., the opening of a chromatin domain.
Collapse
Affiliation(s)
| | - Stephen A. Krawetz
- *Center for Molecular Medicine and Genetics and
- Department of Obstetrics and Gynecology, School of Medicine and Institute for Scientific Computing, Wayne State University, Detroit, MI 48201
- To whom correspondence should be addressed at:
253 C. S. Mott Center, 275 East Hancock Avenue, Detroit, MI 48201. E-mail:
| |
Collapse
|
15
|
Juillerat A, Juillerat-Jeanneret L. S-alkylthiolation of O6-methylguanine-DNA-methyltransferase (MGMT) to sensitize cancer cells to anticancer therapy. Expert Opin Ther Targets 2007; 11:349-61. [PMID: 17298293 DOI: 10.1517/14728222.11.3.349] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
O6-methylguanine DNA methyltransferase/O6-alkylguanine DNA alkyltransferase (MGMT/AGT) removes alkyl adducts from the O6-position of guanine in DNA. Expression of MGMT in human cancers has been associated with resistance to therapies using alkylating agents. MGMT promoter methylation regulates its expression and response to alkylating agents. A combination of O6-benzylguanine-based inhibitors of MGMT with alkylating agents improved the efficacy. However, this is associated with enhanced cytotoxicity and the induction of GC to AT transition mutations presumably also in progenitor/stem cells. A few recent studies have described analogs of O6-benzylguanine targeting defined pathways of cancer cells that can be used to improve the selectivity of O6-benzylguanine-based inhibitors for cancer cells. Therefore, MGMT inhibitor targeting represents a reliable strategy for improving cancer therapy with alkylating agents.
Collapse
Affiliation(s)
- Alexandre Juillerat
- Institute of Chemical Sciences and Engineering, Swiss Institute of Technology of Lausanne (EPFL), Lausanne, Switzerland
| | | |
Collapse
|
16
|
Pourpak A, Landowski TH, Dorr RT. Ethonafide-Induced Cytotoxicity Is Mediated by Topoisomerase II Inhibition in Prostate Cancer Cells. J Pharmacol Exp Ther 2007; 321:1109-17. [PMID: 17351106 DOI: 10.1124/jpet.106.117457] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ethonafide is an anthracene-containing derivative of amonafide that belongs to the azonafide series of anticancer agents. The lack of cross-resistance in multidrug-resistant cancer cell lines and the absence of a quinone and hydroquinone moiety make ethonafide a potentially less cardiotoxic replacement for existing anthracene-containing anticancer agents. For this study, we investigated the anticancer activity and mechanism of ethonafide in human prostate cancer cell lines. Ethonafide was cytotoxic against three human prostate cancer cell lines at nanomolar concentrations. Ethonafide was found to be better tolerated and more effective at inhibiting tumor growth compared with mitoxantrone in a human xenograft tumor regression mouse model. Mechanistically, we found that ethonafide inhibited topoisomerase II activity by stabilizing the enzyme-DNA complex, involving both topoisomerase IIalpha and -beta. In addition, ethonafide induced a potent G(2) cell cycle arrest in the DU 145 human prostate cancer cell line. By creating stable cell lines with decreased expression of topoisomerase IIalpha or -beta, we found that a decrease in topoisomerase IIalpha protein expression renders the cell line resistant to ethonafide. The decrease in sensitivity to ethonafide was associated with a decrease in DNA damage and an increase in DNA repair as measured by the neutral comet assay. These data demonstrate that ethonafide is a topoisomerase II poison and that it is topoisomerase IIalpha-specific in the DU 145 human prostate cancer cell line.
Collapse
Affiliation(s)
- Alan Pourpak
- Department of Pharmacology, Arizona Cancer Center, The University of Arizona, Tucson, AZ 85724, USA
| | | | | |
Collapse
|