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Si LH, Sun GC, Liu ZW, Gu SY, Yan CH, Xu JY, Jia Y. High expression levels of centromere protein O participates in cell proliferation of human ovarian cancer. J Ovarian Res 2024; 17:126. [PMID: 38890751 PMCID: PMC11184697 DOI: 10.1186/s13048-024-01452-x] [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: 03/13/2024] [Accepted: 06/10/2024] [Indexed: 06/20/2024] Open
Abstract
Ovarian cancer is a common malignant tumor in women, with a high mortality rate ranking first among gynecological tumors. Currently, there is insufficient understanding of the causes, pathogenesis, recurrence and metastasis of ovarian cancer, and early diagnosis and treatment still face great challenges. The sensitivity and specificity of existing ovarian cancer screening methods are still unsatisfactory. Centromere protein O (CENP-O) is a recently discovered structural centromere protein that is involved in cell death and is essential for spindle assembly, chromosome separation, and checkpoint signaling during mitosis. The abnormal high expression of CENP-O was detected in various tumors such as bladder cancer and gastric cancer, and it participates in the regulation of tumor cell proliferation. In this study, we detect the expression abundance of CENP-O mRNA in different ovarian cancer cells ( ES-2, A2780, Caov-3, OVCAR-3 and SK-OV-3). The biological function changes of cell proliferation and apoptosis were detected and the role of CENP-O in ovarian cancer cell proliferation and apoptosis was explored by knocking down the expression of CENP-O gene. The results showed that CENP-O gene was significantly expressed in 5 types of ovarian cancer cell lines. After knocking down the CENP-O gene, the proliferation and cloning ability of ovarian cancer cells decreased, and the apoptosis increased. This study indicates that CENP-O has the potential to be a molecular therapeutic target, and downregulating the expression of CENP-O gene can break the unlimited proliferation ability of cancer cells and promote their apoptosis, providing a foundation and new ideas for subsequent molecular mechanism research and targeted therapy.
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Affiliation(s)
- Li-Hui Si
- Department of Obstetrics and Gynecology, The second Hospital of Jilin University, Changchun, Jilin, China
| | - Guang-Chao Sun
- Department of Neurosurgery, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Zi-Wei Liu
- Department of Obstetrics and Gynecology, The second Hospital of Jilin University, Changchun, Jilin, China
| | - Shi-Yu Gu
- Department of Obstetrics and Gynecology, The second Hospital of Jilin University, Changchun, Jilin, China
| | - Chu-Han Yan
- Department of Obstetrics and Gynecology, The second Hospital of Jilin University, Changchun, Jilin, China
| | - Jin-Yuan Xu
- Department of Obstetrics and Gynecology, The second Hospital of Jilin University, Changchun, Jilin, China
| | - Yan Jia
- Department of Obstetrics and Gynecology, The second Hospital of Jilin University, Changchun, Jilin, China.
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2
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Leeds BK, Kostello KF, Liu YY, Nelson CR, Biggins S, Asbury CL. Mechanical coupling coordinates microtubule growth. eLife 2023; 12:RP89467. [PMID: 38150374 PMCID: PMC10752587 DOI: 10.7554/elife.89467] [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] [Indexed: 12/29/2023] Open
Abstract
During mitosis, kinetochore-attached microtubules form bundles (k-fibers) in which many filaments grow and shorten in near-perfect unison to align and segregate each chromosome. However, individual microtubules grow at intrinsically variable rates, which must be tightly regulated for a k-fiber to behave as a single unit. This exquisite coordination might be achieved biochemically, via selective binding of polymerases and depolymerases, or mechanically, because k-fiber microtubules are coupled through a shared load that influences their growth. Here, we use a novel dual laser trap assay to show that microtubule pairs growing in vitro are coordinated by mechanical coupling. Kinetic analyses show that microtubule growth is interrupted by stochastic, force-dependent pauses and indicate persistent heterogeneity in growth speed during non-pauses. A simple model incorporating both force-dependent pausing and persistent growth speed heterogeneity explains the measured coordination of microtubule pairs without any free fit parameters. Our findings illustrate how microtubule growth may be synchronized during mitosis and provide a basis for modeling k-fiber bundles with three or more microtubules, as found in many eukaryotes.
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Affiliation(s)
- Bonnibelle K Leeds
- Department of Physiology & Biophysics, University of WashingtonSeattleUnited States
| | - Katelyn F Kostello
- Department of Physiology & Biophysics, University of WashingtonSeattleUnited States
| | - Yuna Y Liu
- Department of Physiology & Biophysics, University of WashingtonSeattleUnited States
| | - Christian R Nelson
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Sue Biggins
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Charles L Asbury
- Department of Physiology & Biophysics, University of WashingtonSeattleUnited States
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Leeds BK, Kostello KF, Liu YY, Nelson CR, Biggins S, Asbury CL. Mechanical coupling coordinates microtubule growth. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.29.547092. [PMID: 37905093 PMCID: PMC10614740 DOI: 10.1101/2023.06.29.547092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
During mitosis, kinetochore-attached microtubules form bundles (k-fibers) in which many filaments grow and shorten in near-perfect unison to align and segregate each chromosome. However, individual microtubules grow at intrinsically variable rates, which must be tightly regulated for a k-fiber to behave as a single unit. This exquisite coordination might be achieved biochemically, via selective binding of polymerases and depolymerases, or mechanically, because k-fiber microtubules are coupled through a shared load that influences their growth. Here, we use a novel dual laser trap assay to show that microtubule pairs growing in vitro are coordinated by mechanical coupling. Kinetic analyses show that microtubule growth is interrupted by stochastic, force-dependent pauses and indicate persistent heterogeneity in growth speed during non-pauses. A simple model incorporating both force-dependent pausing and persistent growth speed heterogeneity explains the measured coordination of microtubule pairs without any free fit parameters. Our findings illustrate how microtubule growth may be synchronized during mitosis and provide a basis for modeling k-fiber bundles with three or more microtubules, as found in many eukaryotes.
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Affiliation(s)
- Bonnibelle K. Leeds
- Physiology & Biophysics Department, University of Washington School of Medicine, Seattle WA, USA
| | - Katelyn F. Kostello
- Physiology & Biophysics Department, University of Washington School of Medicine, Seattle WA, USA
| | - Yuna Y. Liu
- Physiology & Biophysics Department, University of Washington School of Medicine, Seattle WA, USA
| | | | | | - Charles L. Asbury
- Physiology & Biophysics Department, University of Washington School of Medicine, Seattle WA, USA
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Bloomfield M, Cimini D. The fate of extra centrosomes in newly formed tetraploid cells: should I stay, or should I go? Front Cell Dev Biol 2023; 11:1210983. [PMID: 37576603 PMCID: PMC10413984 DOI: 10.3389/fcell.2023.1210983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 07/17/2023] [Indexed: 08/15/2023] Open
Abstract
An increase in centrosome number is commonly observed in cancer cells, but the role centrosome amplification plays along with how and when it occurs during cancer development is unclear. One mechanism for generating cancer cells with extra centrosomes is whole genome doubling (WGD), an event that occurs in over 30% of human cancers and is associated with poor survival. Newly formed tetraploid cells can acquire extra centrosomes during WGD, and a generally accepted model proposes that centrosome amplification in tetraploid cells promotes cancer progression by generating aneuploidy and chromosomal instability. Recent findings, however, indicate that newly formed tetraploid cells in vitro lose their extra centrosomes to prevent multipolar cell divisions. Rather than persistent centrosome amplification, this evidence raises the possibility that it may be advantageous for tetraploid cells to initially restore centrosome number homeostasis and for a fraction of the population to reacquire additional centrosomes in the later stages of cancer evolution. In this review, we explore the different evolutionary paths available to newly formed tetraploid cells, their effects on centrosome and chromosome number distribution in daughter cells, and their probabilities of long-term survival. We then discuss the mechanisms that may alter centrosome and chromosome numbers in tetraploid cells and their relevance to cancer progression following WGD.
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Affiliation(s)
- Mathew Bloomfield
- Department of Biological Sciences and Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, United States
| | - Daniela Cimini
- Department of Biological Sciences and Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, United States
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Shi T, Hu Z, Tian L, Yang Y. Pan-cancer landscape of CENPO and its underlying mechanism in LUAD. Respir Res 2023; 24:113. [PMID: 37061713 PMCID: PMC10105544 DOI: 10.1186/s12931-023-02408-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 03/24/2023] [Indexed: 04/17/2023] Open
Abstract
BACKGROUND Centromere protein O (CENPO) is a newly discovered constitutive centromeric protein, associated with cell death. However, little is known about how CENPO expression is associated with human cancers or immune infiltration. Here, we assessed the function of CENPO in pan-cancer and further verified the results in lung adenocarcinoma (LUAD) through in vitro and in vivo experiments. METHODS Sangerbox and TCGA databases were used to evaluate the CENPO expression level in different human cancer types. A subsequent evaluation of the potential role of CENPO as a diagnostic and prognostic biomarker in pancancer was conducted. The CENPO mutations were analyzed using the cBioPortal database and its function was analyzed using the LinkedOmics and CancerSEA databases. The TIMER2 and TISIDB websites were used to find out how CENPO affects immune infiltration. The expression level of CENPO in LUAD was revealed by TCGA database and immunohistochemical (IHC) staining. Targetscan, miRWalk, miRDB, miRabel, LncBase databases, and Cytoscape tool were used to identify microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that regulate expression and construct ceRNA network. Subsequently, loss-of-function assays were performed to identify the functions of CENPO on the malignant behavior and tumor growth of LUAD in vitro and in vivo experiments. RESULTS In most cancers, CENPO was upregulated and mutated, which predicted a poorer prognosis. Furthermore, infiltration of CENPO and myeloid-derived suppressor cells (MDSC) showed a significant positive correlation, while T-cell NK infiltration showed a significant negative correlation in most cancers. CENPO was expressed at high levels in LUAD and was correlated with p-TNM stage. Furthermore, CENPO knockdown suppressed the malignant phenotypes of LUAD cells, manifested by slower proliferation, cycle in G2, increased apoptosis, decreased migration, and attenuated tumorigenesis. Furthermore, CENPO knockdown decreased CDK1/6, PIK3CA, and inhibited mTOR phosphorylation, suggesting that the mTOR signaling pathway may be involved in CENPO-mediated regulation of LUAD development. CONCLUSIONS In pan-cancer, especially LUAD, CENPO may be a potential biomarker and oncogene. Furthermore, CENPO has been implicated in immune cell infiltration in pan-cancer and represents a potential immunotherapeutic target for tumor therapy.
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Affiliation(s)
- Tongdong Shi
- Department of Infectious Diseases, Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital of Chongqing Medical University, No.288 Tianwen Avenue, Nan'an District, Chongqing, 401336, People's Republic of China
| | - Zaoxiu Hu
- Department of Pathology, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou Road, Xishan District, Kunming, 650118, Yunnan, People's Republic of China
| | - Li Tian
- Department of Infectious Diseases, Key Laboratory of Molecular Biology for Infectious Diseases and Institute for Viral Hepatitis, Chongqing Medical University the Second Affiliated Hospital, 74 Linjiang Road, Chongqing, 400010, People's Republic of China
| | - Yanlong Yang
- Department of Thoracic Surgery, The First Affiliated Hospital of Kunming Medical University, No.295 Xichang Road, Wuhua District, Kunming, 650032, Yunnan, People's Republic of China.
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Intra-tumor heterogeneity, turnover rate and karyotype space shape susceptibility to missegregation-induced extinction. PLoS Comput Biol 2023; 19:e1010815. [PMID: 36689467 PMCID: PMC9917311 DOI: 10.1371/journal.pcbi.1010815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/10/2023] [Accepted: 12/12/2022] [Indexed: 01/24/2023] Open
Abstract
The phenotypic efficacy of somatic copy number alterations (SCNAs) stems from their incidence per base pair of the genome, which is orders of magnitudes greater than that of point mutations. One mitotic event stands out in its potential to significantly change a cell's SCNA burden-a chromosome missegregation. A stochastic model of chromosome mis-segregations has been previously developed to describe the evolution of SCNAs of a single chromosome type. Building upon this work, we derive a general deterministic framework for modeling missegregations of multiple chromosome types. The framework offers flexibility to model intra-tumor heterogeneity in the SCNAs of all chromosomes, as well as in missegregation- and turnover rates. The model can be used to test how selection acts upon coexisting karyotypes over hundreds of generations. We use the model to calculate missegregation-induced population extinction (MIE) curves, that separate viable from non-viable populations as a function of their turnover- and missegregation rates. Turnover- and missegregation rates estimated from scRNA-seq data are then compared to theoretical predictions. We find convergence of theoretical and empirical results in both the location of MIE curves and the necessary conditions for MIE. When a dependency of missegregation rate on karyotype is introduced, karyotypes associated with low missegregation rates act as a stabilizing refuge, rendering MIE impossible unless turnover rates are exceedingly high. Intra-tumor heterogeneity, including heterogeneity in missegregation rates, increases as tumors progress, rendering MIE unlikely.
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Dong Q, Li F. Cell cycle control of kinetochore assembly. Nucleus 2022; 13:208-220. [PMID: 36037227 PMCID: PMC9427032 DOI: 10.1080/19491034.2022.2115246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The kinetochore is a large proteinaceous structure assembled on the centromeres of chromosomes. The complex machinery links chromosomes to the mitotic spindle and is essential for accurate chromosome segregation during cell division. The kinetochore is composed of two submodules: the inner and outer kinetochore. The inner kinetochore is assembled on centromeric chromatin and persists with centromeres throughout the cell cycle. The outer kinetochore attaches microtubules to the inner kinetochore, and assembles only during mitosis. The review focuses on recent advances in our understanding of the mechanisms governing the proper assembly of the outer kinetochore during mitosis and highlights open questions for future investigation.
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Affiliation(s)
- Qianhua Dong
- Department of Biology, New York University, New York, NY, USA
| | - Fei Li
- Department of Biology, New York University, New York, NY, USA
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8
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Kucharski TJ, Hards R, Vandal SE, Abad MA, Jeyaprakash AA, Kaye E, al-Rawi A, Ly T, Godek KM, Gerber SA, Compton DA. Small changes in phospho-occupancy at the kinetochore-microtubule interface drive mitotic fidelity. J Cell Biol 2022; 221:213364. [PMID: 35878017 PMCID: PMC9351707 DOI: 10.1083/jcb.202107107] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 04/19/2022] [Accepted: 07/05/2022] [Indexed: 01/24/2023] Open
Abstract
Kinetochore protein phosphorylation promotes the correction of erroneous microtubule attachments to ensure faithful chromosome segregation during cell division. Determining how phosphorylation executes error correction requires an understanding of whether kinetochore substrates are completely (i.e., all-or-none) or only fractionally phosphorylated. Using quantitative mass spectrometry (MS), we measured phospho-occupancy on the conserved kinetochore protein Hec1 (NDC80) that directly binds microtubules. None of the positions measured exceeded ∼50% phospho-occupancy, and the cumulative phospho-occupancy changed by only ∼20% in response to changes in microtubule attachment status. The narrow dynamic range of phospho-occupancy is maintained, in part, by the ongoing phosphatase activity. Further, both Cdk1-Cyclin B1 and Aurora kinases phosphorylate Hec1 to enhance error correction in response to different types of microtubule attachment errors. The low inherent phospho-occupancy promotes microtubule attachment to kinetochores while the high sensitivity of kinetochore-microtubule attachments to small changes in phospho-occupancy drives error correction and ensures high mitotic fidelity.
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Affiliation(s)
- Thomas J. Kucharski
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Rufus Hards
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Sarah E. Vandal
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Maria Alba Abad
- Wellcome Centre For Cell Biology, University of Edinburgh, Edinburgh, UK
| | | | - Edward Kaye
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Aymen al-Rawi
- Wellcome Centre For Cell Biology, University of Edinburgh, Edinburgh, UK
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Tony Ly
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Kristina M. Godek
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH
| | - Scott A. Gerber
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Duane A. Compton
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH
- Correspondence to Duane A. Compton:
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Rosas-Salvans M, Sutanto R, Suresh P, Dumont S. The Astrin-SKAP complex reduces friction at the kinetochore-microtubule interface. Curr Biol 2022; 32:2621-2631.e3. [PMID: 35580605 PMCID: PMC9295892 DOI: 10.1016/j.cub.2022.04.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/17/2022] [Accepted: 04/21/2022] [Indexed: 10/18/2022]
Abstract
The kinetochore links chromosomes to spindle microtubules to drive chromosome segregation at cell division. While we know nearly all mammalian kinetochore proteins, how these give rise to the strong yet dynamic microtubule attachments required for function remains poorly understood. Here, we focus on the Astrin-SKAP complex, which localizes to bioriented kinetochores and is essential for chromosome segregation but whose mechanical role is unclear. Live imaging reveals that SKAP depletion dampens the movement and decreases the coordination of metaphase sister kinetochores and increases the tension between them. Using laser ablation to isolate kinetochores bound to polymerizing versus depolymerizing microtubules, we show that without SKAP, kinetochores move slower on both polymerizing and depolymerizing microtubules and that more force is needed to rescue microtubules to polymerize. Thus, in contrast to the previously described kinetochore proteins that increase the grip on microtubules under force, Astrin-SKAP reduces the grip, increasing attachment dynamics and force responsiveness and reducing friction. Together, our findings suggest a model where the Astrin-SKAP complex effectively "lubricates" correct, bioriented attachments to help preserve them.
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Affiliation(s)
- Miquel Rosas-Salvans
- Department of Bioengineering & Therapeutic Sciences, UCSF, 600 16th Street, San Francisco, CA 94158, USA.
| | - Renaldo Sutanto
- Department of Bioengineering & Therapeutic Sciences, UCSF, 600 16th Street, San Francisco, CA 94158, USA
| | - Pooja Suresh
- Department of Bioengineering & Therapeutic Sciences, UCSF, 600 16th Street, San Francisco, CA 94158, USA; Biophysics Graduate Program, UCSF, 600 16th Street, San Francisco, CA 94158, USA
| | - Sophie Dumont
- Department of Bioengineering & Therapeutic Sciences, UCSF, 600 16th Street, San Francisco, CA 94158, USA; Biophysics Graduate Program, UCSF, 600 16th Street, San Francisco, CA 94158, USA; Department of Biochemistry & Biophysics, UCSF, 600 16th Street, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, 499 Illinois Street, San Francisco, CA 94158, USA.
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10
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Iemura K, Yoshizaki Y, Kuniyasu K, Tanaka K. Attenuated Chromosome Oscillation as a Cause of Chromosomal Instability in Cancer Cells. Cancers (Basel) 2021; 13:cancers13184531. [PMID: 34572757 PMCID: PMC8470601 DOI: 10.3390/cancers13184531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Chromosomal instability (CIN), a condition in which chromosome missegregation occurs at high rates, is widely seen in cancer cells. Causes of CIN in cancer cells are not fully understood. A recent report suggests that chromosome oscillation, an iterative chromosome motion typically seen in metaphase around the spindle equator, is attenuated in cancer cells, and is associated with CIN. Chromosome oscillation promotes the correction of erroneous kinetochore-microtubule attachments through phosphorylation of Hec1, a kinetochore protein that binds to microtubules, by Aurora A kinase residing on the spindle. In this review, we focused on this unappreciated link between chromosome oscillation and CIN. Abstract Chromosomal instability (CIN) is commonly seen in cancer cells, and related to tumor progression and poor prognosis. Among the causes of CIN, insufficient correction of erroneous kinetochore (KT)-microtubule (MT) attachments plays pivotal roles in various situations. In this review, we focused on the previously unappreciated role of chromosome oscillation in the correction of erroneous KT-MT attachments, and its relevance to the etiology of CIN. First, we provided an overview of the error correction mechanisms for KT-MT attachments, especially the role of Aurora kinases in error correction by phosphorylating Hec1, which connects MT to KT. Next, we explained chromosome oscillation and its underlying mechanisms. Then we introduced how chromosome oscillation is involved in the error correction of KT-MT attachments, based on recent findings. Chromosome oscillation has been shown to promote Hec1 phosphorylation by Aurora A which localizes to the spindle. Finally, we discussed the link between attenuated chromosome oscillation and CIN in cancer cells. This link underscores the role of chromosome dynamics in mitotic fidelity, and the mutual relationship between defective chromosome dynamics and CIN in cancer cells that can be a target for cancer therapy.
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11
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Iemura K, Natsume T, Maehara K, Kanemaki MT, Tanaka K. Chromosome oscillation promotes Aurora A-dependent Hec1 phosphorylation and mitotic fidelity. J Cell Biol 2021; 220:212099. [PMID: 33988677 PMCID: PMC8129796 DOI: 10.1083/jcb.202006116] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 03/10/2021] [Accepted: 04/21/2021] [Indexed: 12/30/2022] Open
Abstract
Most cancer cells show chromosomal instability, a condition where chromosome missegregation occurs frequently. We found that chromosome oscillation, an iterative chromosome motion during metaphase, is attenuated in cancer cell lines. We also found that metaphase phosphorylation of Hec1 at serine 55, which is mainly dependent on Aurora A on the spindle, is reduced in cancer cell lines. The Aurora A-dependent Hec1-S55 phosphorylation level was regulated by the chromosome oscillation amplitude and vice versa: Hec1-S55 and -S69 phosphorylation by Aurora A is required for efficient chromosome oscillation. Furthermore, enhancement of chromosome oscillation reduced the number of erroneous kinetochore-microtubule attachments and chromosome missegregation, whereas inhibition of Aurora A during metaphase increased such errors. We propose that Aurora A-mediated metaphase Hec1-S55 phosphorylation through chromosome oscillation, together with Hec1-S69 phosphorylation, ensures mitotic fidelity by eliminating erroneous kinetochore-microtubule attachments. Attenuated chromosome oscillation and the resulting reduced Hec1-S55 phosphorylation may be a cause of CIN in cancer cell lines.
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Affiliation(s)
- Kenji Iemura
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan
| | - Toyoaki Natsume
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka, Japan.,Department of Genetics, The Graduate University for Advanced Studies, Mishima, Shizuoka, Japan
| | - Kayoko Maehara
- Department of Nutrition, Graduate School of Health Sciences, Kio University, Kitakatsuragi, Nara, Japan
| | - Masato T Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka, Japan.,Department of Genetics, The Graduate University for Advanced Studies, Mishima, Shizuoka, Japan
| | - Kozo Tanaka
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan
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12
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Renda F, Khodjakov A. Role of spatial patterns and kinetochore architecture in spindle morphogenesis. Semin Cell Dev Biol 2021; 117:75-85. [PMID: 33836948 PMCID: PMC8762378 DOI: 10.1016/j.semcdb.2021.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 12/30/2022]
Abstract
Mitotic spindle is a self-assembling macromolecular machine responsible for the faithful segregation of chromosomes during cell division. Assembly of the spindle is believed to be governed by the 'Search & Capture' (S&C) principle in which dynamic microtubules explore space in search of kinetochores while the latter capture microtubules and thus connect chromosomes to the spindle. Due to the stochastic nature of the encounters between kinetochores and microtubules, the time required for incorporating all chromosomes into the spindle is profoundly affected by geometric constraints, such as the size and shape of kinetochores as well as their distribution in space at the onset of spindle assembly. In recent years, several molecular mechanisms that control these parameters have been discovered. It is now clear that stochastic S&C takes place in structured space, where components are optimally distributed and oriented to minimize steric hindrances. Nucleation of numerous non-centrosomal microtubules near kinetochores accelerates capture, while changes in the kinetochore architecture at various stages of spindle assembly promote proper connection of sister kinetochores to the opposite spindle poles. Here we discuss how the concerted action of multiple facilitating mechanisms ensure that the spindle assembles rapidly yet with a minimal number of errors.
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Affiliation(s)
- Fioranna Renda
- Biggs Laboratory, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12237, United States.
| | - Alexey Khodjakov
- Biggs Laboratory, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12237, United States; Rensselaer Polytechnic Institute, Troy, NY 12180, United States.
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13
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Cui YJ, Liu C, Ma CC, Ji YT, Yao YL, Tang LQ, Zhang CM, Wu JD, Liu ZP. SAR Investigation and Discovery of Water-Soluble 1-Methyl-1,4-dihydroindeno[1,2- c]pyrazoles as Potent Tubulin Polymerization Inhibitors. J Med Chem 2020; 63:14840-14866. [PMID: 33201714 DOI: 10.1021/acs.jmedchem.0c01345] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Taking the previously discovered 1-methyl-1,4-dihydroindeno[1,2c]pyrazol derivative LL01 as a lead, systematic structural modifications were made at the phenolic 6- and 7-positions and the aniline at the 3-position of the indenopyrazole core to investigate the SARs and to improve water solubility. Among the designed indenopyrazoles ID01-ID33, a series of potent MTAs were identified. As the hydrochloride salt(s), ID09 and ID33 showed excellent aqueous solubility and favorable Log P value and displayed noteworthily low nanomolar potency against a variety of tumor cells, including those taxol-resistant ones. They inhibited tubulin polymerization, disrupted cellular microtubule networks by targeting the colchicine site, and promoted HepG2 cell cycle arrest and cell apoptosis. In the HepG2 xenograft mouse model, ID09 and ID33 effectively inhibited tumor growth at an oral dose of 25 mg/kg. At an intravenous (iv) injection dose of 10 mg/kg every other day, ID09 suppressed tumor growth by 68% without obvious toxicity.
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Affiliation(s)
- Ying-Jie Cui
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
| | - Chao Liu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
| | - Chen-Chen Ma
- Central Laboratory, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan 250012, P. R. China
| | - Ya-Ting Ji
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
| | - Yi-Li Yao
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
| | - Long-Qian Tang
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
| | - Cheng-Mei Zhang
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
| | - Jing-De Wu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
| | - Zhao-Peng Liu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, P. R. China
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14
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Kinetochore-microtubule coupling mechanisms mediated by the Ska1 complex and Cdt1. Essays Biochem 2020; 64:337-347. [PMID: 32844209 DOI: 10.1042/ebc20190075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 11/17/2022]
Abstract
The faithful segregation of duplicated sister chromatids rely on the remarkable ability of kinetochores to sustain stable load bearing attachments with the dynamic plus ends of kinetochore-microtubules (kMTs). The outer layer of the kinetochore recruits several motor and non-motor microtubule-associated proteins (MAPs) that help the kinetochores establish and maintain a load bearing dynamic attachment with kMTs. The primary kMT-binding protein, the Ndc80 complex (Ndc80c), which is highly conserved among diverse organisms from yeast to humans, performs this essential function with assistance from other MAPs. These MAPs are not an integral part of the kinetochore, but they localize to the kinetochore periodically throughout mitosis and regulate the strength of the kinetochore microtubule attachments. Here, we attempt to summarize the recent advances that have been made toward furthering our understanding of this co-operation between the Ndc80c and these MAPs, focusing on the spindle and kinetochore-associated 1 (Ska1) complex (Ska1c) and Cdc10-dependent transcript 1 (Cdt1) in humans.
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15
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Long AF, Suresh P, Dumont S. Individual kinetochore-fibers locally dissipate force to maintain robust mammalian spindle structure. J Cell Biol 2020; 219:e201911090. [PMID: 32435797 PMCID: PMC7401803 DOI: 10.1083/jcb.201911090] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/16/2020] [Accepted: 04/27/2020] [Indexed: 01/16/2023] Open
Abstract
At cell division, the mammalian kinetochore binds many spindle microtubules that make up the kinetochore-fiber. To segregate chromosomes, the kinetochore-fiber must be dynamic and generate and respond to force. Yet, how it remodels under force remains poorly understood. Kinetochore-fibers cannot be reconstituted in vitro, and exerting controlled forces in vivo remains challenging. Here, we use microneedles to pull on mammalian kinetochore-fibers and probe how sustained force regulates their dynamics and structure. We show that force lengthens kinetochore-fibers by persistently favoring plus-end polymerization, not by increasing polymerization rate. We demonstrate that force suppresses depolymerization at both plus and minus ends, rather than sliding microtubules within the kinetochore-fiber. Finally, we observe that kinetochore-fibers break but do not detach from kinetochores or poles. Together, this work suggests an engineering principle for spindle structural homeostasis: different physical mechanisms of local force dissipation by the k-fiber limit force transmission to preserve robust spindle structure. These findings may inform how other dynamic, force-generating cellular machines achieve mechanical robustness.
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Affiliation(s)
- Alexandra F. Long
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA
- Department of Bioengineering and Therapeutic Science, University of California, San Francisco, San Francisco, CA
| | - Pooja Suresh
- Biophysics Graduate Program, University of California, San Francisco, San Francisco, CA
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA
- Department of Bioengineering and Therapeutic Science, University of California, San Francisco, San Francisco, CA
| | - Sophie Dumont
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA
- Biophysics Graduate Program, University of California, San Francisco, San Francisco, CA
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA
- Department of Bioengineering and Therapeutic Science, University of California, San Francisco, San Francisco, CA
- Chan Zuckerberg Biohub, San Francisco, CA
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16
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Barroso-Vilares M, Macedo JC, Reis M, Warren JD, Compton D, Logarinho E. Small-molecule inhibition of aging-associated chromosomal instability delays cellular senescence. EMBO Rep 2020; 21:e49248. [PMID: 32134180 PMCID: PMC7202060 DOI: 10.15252/embr.201949248] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/05/2020] [Accepted: 02/13/2020] [Indexed: 12/18/2022] Open
Abstract
Chromosomal instability (CIN) refers to the rate at which cells are unable to properly segregate whole chromosomes, leading to aneuploidy. Besides its prevalence in cancer cells and postulated implications in promoting tumorigenesis, studies in aneuploidy‐prone mouse models uncovered an unanticipated link between CIN and aging. Using young to old‐aged human dermal fibroblasts, we observed a dysfunction of the mitotic machinery arising with age that mildly perturbs chromosome segregation fidelity and contributes to the generation of fully senescent cells. Here, we investigated mitotic mechanisms that contribute to age‐associated CIN. We found that elderly cells have an increased number of stable kinetochore–microtubule (k‐MT) attachments and decreased efficiency in the correction of improper k‐MT interactions. Chromosome mis‐segregation rates in old‐aged cells decreased upon both genetic and small‐molecule enhancement of MT‐depolymerizing kinesin‐13 activity. Notably, restored chromosome segregation accuracy inhibited the phenotypes of cellular senescence. Therefore, we provide mechanistic insight into age‐associated CIN and disclose a strategy for the use of a small‐molecule to inhibit age‐associated CIN and to delay the cellular hallmarks of aging.
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Affiliation(s)
- Monika Barroso-Vilares
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Aging and Aneuploidy Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Programa doutoral em Biologia Molecular e Celular, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Joana C Macedo
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Aging and Aneuploidy Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Marta Reis
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Aging and Aneuploidy Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Jessica D Warren
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Duane Compton
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Elsa Logarinho
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Aging and Aneuploidy Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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17
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Girão H, Maiato H. Measurement of Microtubule Half-Life and Poleward Flux in the Mitotic Spindle by Photoactivation of Fluorescent Tubulin. Methods Mol Biol 2020; 2101:235-246. [PMID: 31879908 DOI: 10.1007/978-1-0716-0219-5_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The study of microtubule dynamics is of utmost importance for the understanding of the mechanisms underlying mitotic fidelity. During mitosis, the microtubular cytoskeleton reorganizes to assemble a mitotic spindle necessary for chromosome segregation. Several methods, such as controlled exposure to cold, high pressure, high calcium concentration, or microtubule depolymerizing drugs, have been widely used to evaluate the dynamic properties of specific spindle microtubule populations. However, while these methods offer a qualitative approach that is sufficient to discern differences among specific spindle microtubule populations, they fall short in providing a robust quantitative picture that is sensitive enough to highlight minor differences, for example when comparing spindle microtubule dynamics in different genetic backgrounds. In this chapter we describe a detailed methodology to measure spindle microtubule dynamics using photoactivation of fluorescently tagged tubulin in living cells. This methodology allows the quantitative discrimination of the turnover of specific microtubule populations (e.g., kinetochore vs. non-kinetochore microtubules), as well as determination of microtubule poleward flux rates. These two conspicuous features of metazoan spindles must be tightly regulated to allow, on the one hand, efficient error correction, and on the other hand the satisfaction of the spindle assembly checkpoint that controls mitotic fidelity.
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Affiliation(s)
- Hugo Girão
- Chromosome Instability & Dynamics Laboratory, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Helder Maiato
- Chromosome Instability & Dynamics Laboratory, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal. .,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal. .,Experimental Biology Unit, Faculdade de Medicina, Cell Division Group, Department of Biomedicine, Universidade do Porto, Porto, Portugal.
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18
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Barbosa J, Martins T, Bange T, Tao L, Conde C, Sunkel C. Polo regulates Spindly to prevent premature stabilization of kinetochore-microtubule attachments. EMBO J 2019; 39:e100789. [PMID: 31849090 DOI: 10.15252/embj.2018100789] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 12/13/2022] Open
Abstract
Accurate chromosome segregation in mitosis requires sister kinetochores to bind to microtubules from opposite spindle poles. The stability of kinetochore-microtubule attachments is fine-tuned to prevent or correct erroneous attachments while preserving amphitelic interactions. Polo kinase has been implicated in both stabilizing and destabilizing kinetochore-microtubule attachments. However, the mechanism underlying Polo-destabilizing activity remains elusive. Here, resorting to an RNAi screen in Drosophila for suppressors of a constitutively active Polo mutant, we identified a strong genetic interaction between Polo and the Rod-ZW10-Zwilch (RZZ) complex, whose kinetochore accumulation has been shown to antagonize microtubule stability. We find that Polo phosphorylates Spindly and impairs its ability to bind to Zwilch. This precludes dynein-mediated removal of the RZZ from kinetochores and consequently delays the formation of stable end-on attachments. We propose that high Polo-kinase activity following mitotic entry directs the RZZ complex to minimize premature stabilization of erroneous attachments, whereas a decrease in active Polo in later mitotic stages allows the formation of stable amphitelic spindle attachments. Our findings demonstrate that Polo tightly regulates the RZZ-Spindly-dynein module during mitosis to ensure the fidelity of chromosome segregation.
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Affiliation(s)
- João Barbosa
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
| | - Torcato Martins
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Tanja Bange
- MPI für molekulare Physiologie, Dortmund, Germany
| | - Li Tao
- Department of Biology, University of Hawaii, Hilo, HI, USA
| | - Carlos Conde
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
| | - Claudio Sunkel
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal.,ICBAS-Instituto de Ciência Biomédica de Abel Salazar, Universidade do Porto, Porto, Portugal
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19
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Cao Y, Xiong J, Li Z, Zhang G, Tu Y, Wang L, Jie Z. CENPO expression regulates gastric cancer cell proliferation and is associated with poor patient prognosis. Mol Med Rep 2019; 20:3661-3670. [PMID: 31485675 PMCID: PMC6755171 DOI: 10.3892/mmr.2019.10624] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 07/17/2019] [Indexed: 01/01/2023] Open
Abstract
Gastric cancer (GC) is one of the most common malignancies worldwide; however, understanding of its development and carcinogenesis is currently limited. Centromere protein O (CENPO), is a newly discovered constitutive centromeric protein, associated with cell death. The expression of CENPO in human cancers, including GC, is currently unknown. The aim of the present study was to investigate the clinical association between CENPO and GC, and to elucidate the potential mechanisms of CENPO in the process of GC progression. The results demonstrated that CENPO was expressed at high levels in GC and was correlated with p-TNM stage. In addition, CENPO was observed to be a marker of poor prognosis in patients with GC. Knockdown of CENPO contributed to GC cell growth inhibition and apoptosis induction. In addition, downregulation of CENPO expression suppressed GC cell growth in vivo. Furthermore, CENPO knockdown decreased ataxia telangiectasia mutated (ATM), cyclin D1 and c-Jun expression, indicating that the ATM signaling pathway may be involved in CENPO-mediated regulation of GC cell growth. In conclusion, increased CENPO expression may be associated with the aggressive tumor biology of GC and CENPO may present a novel therapeutic target and prognostic biomarker for patients with GC.
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Affiliation(s)
- Yi Cao
- Department of Gastrointestinal Surgery, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Jianbo Xiong
- Department of Gastrointestinal Surgery, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Zhengrong Li
- Department of Gastrointestinal Surgery, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Guoyang Zhang
- Department of Gastrointestinal Surgery, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Yi Tu
- Department of Pathology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Lizhen Wang
- Department of Pathology, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Zhigang Jie
- Department of Gastrointestinal Surgery, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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20
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Amin MA, Agarwal S, Varma D. Mapping the kinetochore MAP functions required for stabilizing microtubule attachments to chromosomes during metaphase. Cytoskeleton (Hoboken) 2019; 76:398-412. [PMID: 31454167 DOI: 10.1002/cm.21559] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 08/07/2019] [Accepted: 08/22/2019] [Indexed: 12/24/2022]
Abstract
In mitosis, faithful chromosome segregation is orchestrated by the dynamic interactions between the spindle microtubules (MTs) emanating from the opposite poles and the kinetochores of the chromosomes. However, the precise mechanism that coordinates the coupling of the kinetochore components to dynamic MTs has been a long-standing question. Microtubule-associated proteins (MAPs) regulate MT nucleation and dynamics, MT-mediated transport and MT cross-linking in cells. During mitosis, MAPs play an essential role not only in determining spindle length, position, and orientation but also in facilitating robust kinetochore-microtubule (kMT) attachments by linking the kinetochores to spindle MTs efficiently. The stability of MTs imparted by the MAPs is critical to ensure accurate chromosome segregation. This review primarily focuses on the specific function of nonmotor kinetochore MAPs, their recruitment to kinetochores and their MT-binding properties. We also attempt to synthesize and strengthen our understanding of how these MAPs work in coordination with the kinetochore-bound Ndc80 complex (the key component at the MT-binding interface in metaphase and anaphase) to establish stable kMT attachments and control accurate chromosome segregation during mitosis.
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Affiliation(s)
- Mohammed A Amin
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Shivangi Agarwal
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Dileep Varma
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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21
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The mammalian kinetochore-microtubule interface: robust mechanics and computation with many microtubules. Curr Opin Cell Biol 2019; 60:60-67. [PMID: 31132675 DOI: 10.1016/j.ceb.2019.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 12/31/2022]
Abstract
The kinetochore drives chromosome segregation at cell division. It acts as a physical link between chromosomes and dynamic microtubules, and as a signaling hub detecting and processing microtubule attachments to control anaphase onset. The mammalian kinetochore is a large macromolecular machine that forms a dynamic interface with the many microtubules that it binds. While we know most of the kinetochore's component parts, how they work together to give rise to its robust functions remains poorly understood. Here we highlight recent findings that shed light on this question, driven by an expanding physical and molecular toolkit. We present emerging principles that underlie the kinetochore's robust microtubule grip, such as redundancy, specialization, and dynamicity, and present signal processing principles that connect this microtubule grip to robust computation. Throughout, we identify open questions, and define simple engineering concepts that provide insight into kinetochore function.
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22
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Ilan Y. Randomness in microtubule dynamics: an error that requires correction or an inherent plasticity required for normal cellular function? Cell Biol Int 2019; 43:739-748. [DOI: 10.1002/cbin.11157] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 04/28/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Yaron Ilan
- Department of MedicineHadassah‐Hebrew University Medical CenterJerusalem IL91120 Israel
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23
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Malaby HLH, Dumas ME, Ohi R, Stumpff J. Kinesin-binding protein ensures accurate chromosome segregation by buffering KIF18A and KIF15. J Cell Biol 2019; 218:1218-1234. [PMID: 30709852 PMCID: PMC6446846 DOI: 10.1083/jcb.201806195] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 11/09/2018] [Accepted: 01/08/2019] [Indexed: 12/22/2022] Open
Abstract
Kinesin-binding protein (KBP) is identified as a regulator of the kinesins KIF18A and KIF15 during mitosis. KBP buffers the activity of these motors to control chromosome alignment and spindle integrity in metaphase and prevent lagging chromosomes in anaphase. Mitotic kinesins must be regulated to ensure a precise balance of spindle forces and accurate segregation of chromosomes into daughter cells. Here, we demonstrate that kinesin-binding protein (KBP) reduces the activity of KIF18A and KIF15 during metaphase. Overexpression of KBP disrupts the movement and alignment of mitotic chromosomes and decreases spindle length, a combination of phenotypes observed in cells deficient for KIF18A and KIF15, respectively. We show through gliding filament and microtubule co-pelleting assays that KBP directly inhibits KIF18A and KIF15 motor activity by preventing microtubule binding. Consistent with these effects, the mitotic localizations of KIF18A and KIF15 are altered by overexpression of KBP. Cells depleted of KBP exhibit lagging chromosomes in anaphase, an effect that is recapitulated by KIF15 and KIF18A overexpression. Based on these data, we propose a model in which KBP acts as a protein buffer in mitosis, protecting cells from excessive KIF18A and KIF15 activity to promote accurate chromosome segregation.
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Affiliation(s)
- Heidi L H Malaby
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT
| | - Megan E Dumas
- Department of Cell and Developmental Biology, Vanderbilt University Medical School, Nashville, TN
| | - Ryoma Ohi
- The Life Sciences Institute, University of Michigan Medical School, Ann Arbor, MI .,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI
| | - Jason Stumpff
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT
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24
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Menyhárt O, Nagy Á, Győrffy B. Determining consistent prognostic biomarkers of overall survival and vascular invasion in hepatocellular carcinoma. ROYAL SOCIETY OPEN SCIENCE 2018; 5:181006. [PMID: 30662724 PMCID: PMC6304123 DOI: 10.1098/rsos.181006] [Citation(s) in RCA: 293] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 11/08/2018] [Indexed: 05/03/2023]
Abstract
Background: Potential prognostic biomarker candidates for hepatocellular carcinoma (HCC) are abundant, but their generalizability is unexplored. We cross-validated markers of overall survival (OS) and vascular invasion in independent datasets. Methods: The literature search yielded 318 genes related to survival and 52 related to vascular invasion. Validation was performed in three datasets (RNA-seq, n = 371; Affymetrix arrays, n = 91; Illumina gene chips, n = 135) by uni- and multivariate Cox regression and Mann-Whitney U-test, separately for Asian and Caucasian patients. Results: One hundred and eighty biomarkers remained significant in Asian and 128 in Caucasian subjects at p < 0.05. After multiple testing correction BIRC5 (p = 1.9 × 10-10), CDC20 (p = 2.5 × 10-9) and PLK1 (p = 3 × 10-9) endured as best performing genes in Asian patients; however, none remained significant in the Caucasian cohort. In a multivariate analysis, significance was reached by stage (p = 0.0018) and expression of CENPH (p = 0.0038) and CDK4 (p = 0.038). KIF18A was the only gene predicting vascular invasion in the Affymetrix and Illumina cohorts (p = 0.003 and p = 0.025, respectively). Conclusion: Overall, about half of biomarker candidates failed to retain prognostic value and none were better than stage predicting OS. Impact: Our results help to eliminate biomarkers with limited capability to predict OS and/or vascular invasion.
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Affiliation(s)
- Otília Menyhárt
- 2nd Department of Pediatrics, Semmelweis University, H-1094 Budapest, Hungary
- MTA TTK Lendület Cancer Biomarker Research Group, Institute of Enzymology, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Ádám Nagy
- 2nd Department of Pediatrics, Semmelweis University, H-1094 Budapest, Hungary
- MTA TTK Lendület Cancer Biomarker Research Group, Institute of Enzymology, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Balázs Győrffy
- 2nd Department of Pediatrics, Semmelweis University, H-1094 Budapest, Hungary
- MTA TTK Lendület Cancer Biomarker Research Group, Institute of Enzymology, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
- Author for correspondence: Balázs Győrffy e-mail:
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25
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Dumitru AMG, Rusin SF, Clark AEM, Kettenbach AN, Compton DA. Cyclin A/Cdk1 modulates Plk1 activity in prometaphase to regulate kinetochore-microtubule attachment stability. eLife 2017; 6:e29303. [PMID: 29154753 PMCID: PMC5706962 DOI: 10.7554/elife.29303] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 11/10/2017] [Indexed: 12/24/2022] Open
Abstract
The fidelity of chromosome segregation in mitosis is safeguarded by the precise regulation of kinetochore microtubule (k-MT) attachment stability. Previously, we demonstrated that Cyclin A/Cdk1 destabilizes k-MT attachments to promote faithful chromosome segregation. Here, we use quantitative phosphoproteomics to identify 156 Cyclin A/Cdk1 substrates in prometaphase. One Cyclin A/Cdk1 substrate is myosin phosphatase targeting subunit 1 (MYPT1), and we show that MYPT1 localization to kinetochores depends on Cyclin A/Cdk1 activity and that MYPT1 destabilizes k-MT attachments by negatively regulating Plk1 at kinetochores. Thus, Cyclin A/Cdk1 phosphorylation primes MYPT1 for Plk1 binding. Interestingly, priming of PBIP1 by Plk1 itself (self-priming) increased in MYPT1-depleted cells showing that MYPT1 provides a molecular link between the processes of Cdk1-dependent priming and self-priming of Plk1 substrates. These data demonstrate cross-regulation between Cyclin A/Cdk1-dependent and Plk1-dependent phosphorylation of substrates during mitosis to ensure efficient correction of k-MT attachment errors necessary for high mitotic fidelity.
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Affiliation(s)
- Ana Maria G Dumitru
- Department of Biochemistry and Cell BiologyGeisel School of Medicine at DartmouthHanoverUnited States
- Norris Cotton Cancer CenterLebanonUnited States
| | - Scott F Rusin
- Department of Biochemistry and Cell BiologyGeisel School of Medicine at DartmouthHanoverUnited States
- Norris Cotton Cancer CenterLebanonUnited States
| | - Amber E M Clark
- Department of Biochemistry and Cell BiologyGeisel School of Medicine at DartmouthHanoverUnited States
- Norris Cotton Cancer CenterLebanonUnited States
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell BiologyGeisel School of Medicine at DartmouthHanoverUnited States
- Norris Cotton Cancer CenterLebanonUnited States
| | - Duane A Compton
- Department of Biochemistry and Cell BiologyGeisel School of Medicine at DartmouthHanoverUnited States
- Norris Cotton Cancer CenterLebanonUnited States
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26
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Kalsbeek D, Golsteyn RM. G2/M-Phase Checkpoint Adaptation and Micronuclei Formation as Mechanisms That Contribute to Genomic Instability in Human Cells. Int J Mol Sci 2017; 18:E2344. [PMID: 29113112 PMCID: PMC5713313 DOI: 10.3390/ijms18112344] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/27/2017] [Accepted: 10/28/2017] [Indexed: 01/30/2023] Open
Abstract
One of the most common characteristics of cancer cells is genomic instability. Recent research has revealed that G2/M-phase checkpoint adaptation-entering mitosis with damaged DNA-contributes to genomic changes in experimental models. When cancer cells are treated with pharmacological concentrations of genotoxic agents, they undergo checkpoint adaptation; however, a small number of cells are able to survive and accumulate micronuclei. These micronuclei harbour damaged DNA, and are able to replicate and reincorporate their DNA into the main nucleus. Micronuclei are susceptible to chromothripsis, which is a phenomenon characterised by extensively rearranged chromosomes that reassemble from pulverized chromosomes in one cellular event. These processes contribute to genomic instability in cancer cells that survive a genotoxic anti-cancer treatment. This review provides insight into checkpoint adaptation and its connection to micronuclei and possibly chromothripsis. Knowledge about these mechanisms is needed to improve the poor cancer treatment outcomes that result from genomic instability.
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Affiliation(s)
- Danî Kalsbeek
- Cancer Cell Laboratory, Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada.
| | - Roy M Golsteyn
- Cancer Cell Laboratory, Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada.
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27
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Bakhoum SF, Kabeche L, Compton DA, Powell SN, Bastians H. Mitotic DNA Damage Response: At the Crossroads of Structural and Numerical Cancer Chromosome Instabilities. Trends Cancer 2017; 3:225-234. [PMID: 28718433 DOI: 10.1016/j.trecan.2017.02.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 02/04/2017] [Accepted: 02/06/2017] [Indexed: 11/29/2022]
Abstract
DNA double-strand breaks (DSBs) prevent cells from entering mitosis allowing cells to repair their genomic damage. Little is known about the response to DSBs once cells have already committed to mitosis. Here, we review the genome-protective role of the mitotic DNA damage response (DDR) and evidence suggesting that its untimely activation induces chromosome segregation errors and paradoxically undermines genomic integrity. In contrast to normal cells, cancer cells coopt this pathway to propagate structural and numerical chromosomal instabilities. Cells derived from genomically unstable tumors exhibit evidence for a partially activated DDR during mitosis, which leads to ongoing chromosome segregation errors. Thus, a thorough understanding of the consequences of mitotic DNA damage is key to our ability to devise novel anticancer therapeutic strategies.
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Affiliation(s)
- Samuel F Bakhoum
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| | - Lilian Kabeche
- Massachusetts General Hospital Cancer Center, Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Duane A Compton
- Department of Biochemistry and the Norris-Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Simon N Powell
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Holger Bastians
- Institute of Molecular Oncology, Section for Cellular Oncology, Goettingen Center for Molecular Biosciences (GZMB) and University Medical Center, University of Göttingen, D-37077 Goettingen, Germany
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28
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Kisurina-Evgenieva OP, Sutiagina OI, Onishchenko GE. Biogenesis of Micronuclei. BIOCHEMISTRY (MOSCOW) 2017; 81:453-64. [PMID: 27297896 DOI: 10.1134/s0006297916050035] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The presence of micronuclei in a cell is an indicator of DNA damage and genetic instability. In this review, mechanisms of emergence of micronuclei, their functional activity, and pathways of elimination are discussed. It is supposed that morphological and functional varieties of micronuclei as well as their degradation pathways can be determined by the chromosomal material localized inside these cell structures.
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29
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Lampson MA, Grishchuk EL. Mechanisms to Avoid and Correct Erroneous Kinetochore-Microtubule Attachments. BIOLOGY 2017; 6:E1. [PMID: 28067761 PMCID: PMC5371994 DOI: 10.3390/biology6010001] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/24/2016] [Accepted: 12/28/2016] [Indexed: 12/19/2022]
Abstract
In dividing vertebrate cells multiple microtubules must connect to mitotic kinetochores in a highly stereotypical manner, with each sister kinetochore forming microtubule attachments to only one spindle pole. The exact sequence of events by which this goal is achieved varies considerably from cell to cell because of the variable locations of kinetochores and spindle poles, and randomness of initial microtubule attachments. These chance encounters with the kinetochores nonetheless ultimately lead to the desired outcome with high fidelity and in a limited time frame, providing one of the most startling examples of biological self-organization. This chapter discusses mechanisms that contribute to accurate chromosome segregation by helping dividing cells to avoid and resolve improper microtubule attachments.
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Affiliation(s)
- Michael A Lampson
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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30
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Redli PM, Gasic I, Meraldi P, Nigg EA, Santamaria A. The Ska complex promotes Aurora B activity to ensure chromosome biorientation. J Cell Biol 2016; 215:77-93. [PMID: 27697923 PMCID: PMC5057281 DOI: 10.1083/jcb.201603019] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 08/31/2016] [Indexed: 12/15/2022] Open
Abstract
Chromosome biorientation and accurate segregation rely on the plasticity of kinetochore-microtubule (KT-MT) attachments. Aurora B facilitates KT-MT dynamics by phosphorylating kinetochore proteins that are critical for KT-MT interactions. Among the substrates whose microtubule and kinetochore binding is curtailed by Aurora B is the spindle and kinetochore-associated (Ska) complex, a key factor for KT-MT stability. Here, we show that Ska is not only a substrate of Aurora B, but is also required for Aurora B activity. Ska-deficient cells fail to biorient and display chromosome segregation errors underlying suppressed KT-MT turnover. These defects coincide with KNL1-Mis12-Ndc80 network hypophosphorylation, reduced mitotic centromere-associated kinesin localization, and Aurora B T-loop phosphorylation at kinetochores. We further show that Ska requires its microtubule-binding capability to promote Aurora B activity in cells and stimulates Aurora B catalytic activity in vitro. Finally, we show that protein phosphatase 1 counteracts Aurora B activity to enable Ska kinetochore accumulation once biorientation is achieved. We propose that Ska promotes Aurora B activity to limit its own microtubule and kinetochore association and to ensure that KT-MT dynamics and stability fall within an optimal balance for biorientation.
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Affiliation(s)
- Patrick M Redli
- Growth and Development, Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Ivana Gasic
- Department of Cell Physiology and Metabolism, Medical Faculty, University of Geneva, 1211 Geneva, Switzerland
| | - Patrick Meraldi
- Department of Cell Physiology and Metabolism, Medical Faculty, University of Geneva, 1211 Geneva, Switzerland
| | - Erich A Nigg
- Growth and Development, Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Anna Santamaria
- Growth and Development, Biozentrum, University of Basel, 4056 Basel, Switzerland Cell Cycle and Cancer, Group of Biomedical Research in Gynecology, Vall d'Hebron Research Institute (VHIR)-UAB, 08035 Barcelona, Spain
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31
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Abstract
Generation of high-contrast and high-signal fluorescent 3D speckles allows fluorescent speckle microscopy to be performed in readily available libraries of cell lines and primary tissues for the measurement of microtubule turnover and sliding. The understanding of cytoskeleton dynamics has benefited from the capacity to generate fluorescent fiducial marks on cytoskeleton components. Here we show that light-induced imprinting of three-dimensional (3D) fluorescent speckles significantly improves speckle signal and contrast relative to classic (random) fluorescent speckle microscopy. We predict theoretically that speckle imprinting using photobleaching is optimal when the laser energy and fluorophore responsivity are related by the golden ratio. This relation, which we confirm experimentally, translates into a 40% remaining signal after speckle imprinting and provides a rule of thumb in selecting the laser power required to optimally prepare the sample for imaging. This inducible speckle imaging (ISI) technique allows 3D speckle microscopy to be performed in readily available libraries of cell lines or primary tissues expressing fluorescent proteins and does not preclude conventional imaging before speckle imaging. As a proof of concept, we use ISI to measure metaphase spindle microtubule poleward flux in primary cells and explore a scaling relation connecting microtubule flux to metaphase duration.
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Affiliation(s)
- António J Pereira
- Chromosome Instability and Dynamics Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal
| | - Paulo Aguiar
- Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
| | - Michael Belsley
- Center of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Helder Maiato
- Chromosome Instability and Dynamics Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal Cell Division Unit, Department of Experimental Biology, Faculty of Medicine, Universidade do Porto, 4200-319 Porto, Portugal
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32
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Chromosomal instability: A common feature and a therapeutic target of cancer. Biochim Biophys Acta Rev Cancer 2016; 1866:64-75. [PMID: 27345585 DOI: 10.1016/j.bbcan.2016.06.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 01/31/2023]
Abstract
Most cancer cells are aneuploid, containing abnormal numbers of chromosomes, mainly caused by elevated levels of chromosome missegregation, known as chromosomal instability (CIN). These well-recognized, but poorly understood, features of cancers have recently been studied extensively, unraveling causal relationships between CIN and cancer. Here we review recent findings regarding how CIN and aneuploidy occur, how they affect cellular functions, how cells respond to them, and their relevance to diseases, especially cancer. Aneuploid cells are under various kinds of stresses that result in reduced cellular fitness. Nevertheless, genetic heterogeneity derived from CIN allows the selection of cells better adapted to their environment, which supposedly facilitates generation and progression of cancer. We also discuss how we can exploit the properties of cancer cells exhibiting CIN for effective cancer therapy.
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33
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Tanaka AJ, Cho MT, Retterer K, Jones JR, Nowak C, Douglas J, Jiang YH, McConkie-Rosell A, Schaefer GB, Kaylor J, Rahman OA, Telegrafi A, Friedman B, Douglas G, Monaghan KG, Chung WK. De novo pathogenic variants in CHAMP1 are associated with global developmental delay, intellectual disability, and dysmorphic facial features. Cold Spring Harb Mol Case Stud 2016; 2:a000661. [PMID: 27148580 PMCID: PMC4849844 DOI: 10.1101/mcs.a000661] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We identified five unrelated individuals with significant global developmental delay and intellectual disability (ID), dysmorphic facial features and frequent microcephaly, and de novo predicted loss-of-function variants in chromosome alignment maintaining phosphoprotein 1 (CHAMP1). Our findings are consistent with recently reported de novo mutations in CHAMP1 in five other individuals with similar features. CHAMP1 is a zinc finger protein involved in kinetochore–microtubule attachment and is required for regulating the proper alignment of chromosomes during metaphase in mitosis. Mutations in CHAMP1 may affect cell division and hence brain development and function, resulting in developmental delay and ID.
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Affiliation(s)
- Akemi J Tanaka
- Department of Pediatrics, Columbia University Medical Center, New York, New York 10032, USA
| | | | | | - Julie R Jones
- Greenwood Genetic Center, Greenwood, South Carolina 29646, USA
| | - Catherine Nowak
- Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Jessica Douglas
- Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Yong-Hui Jiang
- Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | | | - Julie Kaylor
- Arkansas Children's Hospital, Little Rock, Arkansas 72202, USA
| | - Omar A Rahman
- Divisions of Medical Genetics and Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
| | | | | | | | | | - Wendy K Chung
- Department of Pediatrics, Columbia University Medical Center, New York, New York 10032, USA;; Department of Medicine, Columbia University Medical Center, New York, New York 10032, USA
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34
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Li C, Zhang Y, Yang Q, Ye F, Sun SY, Chen ES, Liou YC. NuSAP modulates the dynamics of kinetochore microtubules by attenuating MCAK depolymerisation activity. Sci Rep 2016; 6:18773. [PMID: 26733216 PMCID: PMC4702128 DOI: 10.1038/srep18773] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 11/26/2015] [Indexed: 11/15/2022] Open
Abstract
Nucleolar and spindle-associated protein (NuSAP) is a microtubule-associated protein that functions as a microtubule stabiliser. Depletion of NuSAP leads to severe mitotic defects, however the mechanism by which NuSAP regulates mitosis remains elusive. In this study, we identify the microtubule depolymeriser, mitotic centromere-associated kinesin (MCAK), as a novel binding partner of NuSAP. We show that NuSAP regulates the dynamics and depolymerisation activity of MCAK. Phosphorylation of MCAK by Aurora B kinase, a component of the chromosomal passenger complex, significantly enhances the interaction of NuSAP with MCAK and modulates the effects of NuSAP on the depolymerisation activity of MCAK. Our results reveal an underlying mechanism by which NuSAP controls kinetochore microtubule dynamics spatially and temporally by modulating the depolymerisation function of MCAK in an Aurora B kinase-dependent manner. Hence, this study provides new insights into the function of NuSAP in spindle formation during mitosis.
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Affiliation(s)
- Chenyu Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, 117543, Republic of Singapore
| | - Yajun Zhang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, 117543, Republic of Singapore
| | - Qiaoyun Yang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, 117543, Republic of Singapore
| | - Fan Ye
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, 117543, Republic of Singapore
| | - Stella Ying Sun
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, 117543, Republic of Singapore
| | - Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Republic of Singapore
| | - Yih-Cherng Liou
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 14 Science Drive 4, 117543, Republic of Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117573, Republic of Singapore
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35
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Radford SJ, Hoang TL, Głuszek AA, Ohkura H, McKim KS. Lateral and End-On Kinetochore Attachments Are Coordinated to Achieve Bi-orientation in Drosophila Oocytes. PLoS Genet 2015; 11:e1005605. [PMID: 26473960 PMCID: PMC4608789 DOI: 10.1371/journal.pgen.1005605] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/24/2015] [Indexed: 11/21/2022] Open
Abstract
In oocytes, where centrosomes are absent, the chromosomes direct the assembly of a bipolar spindle. Interactions between chromosomes and microtubules are essential for both spindle formation and chromosome segregation, but the nature and function of these interactions is not clear. We have examined oocytes lacking two kinetochore proteins, NDC80 and SPC105R, and a centromere-associated motor protein, CENP-E, to characterize the impact of kinetochore-microtubule attachments on spindle assembly and chromosome segregation in Drosophila oocytes. We found that the initiation of spindle assembly results from chromosome-microtubule interactions that are kinetochore-independent. Stabilization of the spindle, however, depends on both central spindle and kinetochore components. This stabilization coincides with changes in kinetochore-microtubule attachments and bi-orientation of homologs. We propose that the bi-orientation process begins with the kinetochores moving laterally along central spindle microtubules towards their minus ends. This movement depends on SPC105R, can occur in the absence of NDC80, and is antagonized by plus-end directed forces from the CENP-E motor. End-on kinetochore-microtubule attachments that depend on NDC80 are required to stabilize bi-orientation of homologs. A surprising finding was that SPC105R but not NDC80 is required for co-orientation of sister centromeres at meiosis I. Together, these results demonstrate that, in oocytes, kinetochore-dependent and -independent chromosome-microtubule attachments work together to promote the accurate segregation of chromosomes. In acentrosomal oocytes, spindle assembly depends on the chromosomes. The nature of the chromosome-microtubule interactions in oocytes that organize spindle bipolarity and orientation of the homologs has been unclear. We have found that several types of functional chromosome-microtubule interactions exist in oocytes, and that each type participates in unique aspects of chromosome orientation and spindle assembly. We present here a model for chromosome-based spindle assembly and chromosome movements in oocytes that highlights the multiple and unappreciated roles played by the kinetochores and has implications for how homologous chromosomes bi-orient during meiosis.
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Affiliation(s)
- Sarah J. Radford
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Tranchau L. Hoang
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - A. Agata Głuszek
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Hiroyuki Ohkura
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Kim S. McKim
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- * E-mail:
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36
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Agarwal S, Varma D. How the SAC gets the axe: Integrating kinetochore microtubule attachments with spindle assembly checkpoint signaling. BIOARCHITECTURE 2015; 5:1-12. [PMID: 26430805 DOI: 10.1080/19490992.2015.1090669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Mitosis entails the bona fide segregation of duplicated chromosomes. This process is accomplished by the attachment of kinetochores on chromosomes to microtubules (MTs) of the mitotic spindle. Once the appropriate attachment is achieved, the spindle assembly checkpoint (SAC) that delays the premature onset of anaphase needs to be silenced for the cell to proceed to anaphase and cytokinesis. Therefore, while it is imperative to preserve the SAC when kinetochores are unattached, it is of paramount importance that SAC components are removed post kinetochore microtubule (kMT) attachment. Precise knowledge of how kMT attachments trigger the removal of SAC components from kinetochores or how the checkpoint proteins feedback in to the attachment machinery remains elusive. This review aims to describe the recent advances that provide an insight into the interplay of molecular events that coordinate and regulate the SAC activity in response to kMT attachment during cell division.
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Affiliation(s)
- Shivangi Agarwal
- a Department of Cell and Molecular Biology ; Feinberg School of Medicine; Northwestern University ; Chicago , IL USA
| | - Dileep Varma
- a Department of Cell and Molecular Biology ; Feinberg School of Medicine; Northwestern University ; Chicago , IL USA
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37
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Zaytsev AV, Grishchuk EL. Basic mechanism for biorientation of mitotic chromosomes is provided by the kinetochore geometry and indiscriminate turnover of kinetochore microtubules. Mol Biol Cell 2015; 26:3985-98. [PMID: 26424798 PMCID: PMC4710231 DOI: 10.1091/mbc.e15-06-0384] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/22/2015] [Indexed: 12/22/2022] Open
Abstract
Accuracy of chromosome segregation relies on the ill-understood ability of mitotic kinetochores to biorient, whereupon each sister kinetochore forms microtubule (MT) attachments to only one spindle pole. Because initial MT attachments result from chance encounters with the kinetochores, biorientation must rely on specific mechanisms to avoid and resolve improper attachments. Here we use mathematical modeling to critically analyze the error-correction potential of a simplified biorientation mechanism, which involves the back-to-back arrangement of sister kinetochores and the marked instability of kinetochore-MT attachments. We show that a typical mammalian kinetochore operates in a near-optimal regime, in which the back-to-back kinetochore geometry and the indiscriminate kinetochore-MT turnover provide strong error-correction activity. In human cells, this mechanism alone can potentially enable normal segregation of 45 out of 46 chromosomes during one mitotic division, corresponding to a mis-segregation rate in the range of 10(-1)-10(-2) per chromosome. This theoretical upper limit for chromosome segregation accuracy predicted with the basic mechanism is close to the mis-segregation rate in some cancer cells; however, it cannot explain the relatively low chromosome loss in diploid human cells, consistent with their reliance on additional mechanisms.
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Affiliation(s)
- Anatoly V Zaytsev
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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38
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Zhu L, Wang Z, Wang W, Wang C, Hua S, Su Z, Brako L, Garcia-Barrio M, Ye M, Wei X, Zou H, Ding X, Liu L, Liu X, Yao X. Mitotic Protein CSPP1 Interacts with CENP-H Protein to Coordinate Accurate Chromosome Oscillation in Mitosis. J Biol Chem 2015; 290:27053-27066. [PMID: 26378239 DOI: 10.1074/jbc.m115.658534] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Indexed: 12/23/2022] Open
Abstract
Mitotic chromosome segregation is orchestrated by the dynamic interaction of spindle microtubules with the kinetochores. During chromosome alignment, kinetochore-bound microtubules undergo dynamic cycles between growth and shrinkage, leading to an oscillatory movement of chromosomes along the spindle axis. Although kinetochore protein CENP-H serves as a molecular control of kinetochore-microtubule dynamics, the mechanistic link between CENP-H and kinetochore microtubules (kMT) has remained less characterized. Here, we show that CSPP1 is a kinetochore protein essential for accurate chromosome movements in mitosis. CSPP1 binds to CENP-H in vitro and in vivo. Suppression of CSPP1 perturbs proper mitotic progression and compromises the satisfaction of spindle assembly checkpoint. In addition, chromosome oscillation is greatly attenuated in CSPP1-depleted cells, similar to what was observed in the CENP-H-depleted cells. Importantly, CSPP1 depletion enhances velocity of kinetochore movement, and overexpression of CSPP1 decreases the speed, suggesting that CSPP1 promotes kMT stability during cell division. Specific perturbation of CENP-H/CSPP1 interaction using a membrane-permeable competing peptide resulted in a transient mitotic arrest and chromosome segregation defect. Based on these findings, we propose that CSPP1 cooperates with CENP-H on kinetochores to serve as a novel regulator of kMT dynamics for accurate chromosome segregation.
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Affiliation(s)
- Lijuan Zhu
- Laboratory for Cellular Dynamics, University of Science and Technology of China, Hefei 230027, China
| | - Zhikai Wang
- Laboratory for Cellular Dynamics, University of Science and Technology of China, Hefei 230027, China; the Morehouse School of Medicine and Atlanta Cardiovascular Research Institute, Atlanta, Georgia 30310
| | - Wenwen Wang
- Laboratory for Cellular Dynamics, University of Science and Technology of China, Hefei 230027, China; the Morehouse School of Medicine and Atlanta Cardiovascular Research Institute, Atlanta, Georgia 30310,; the Airforce General Hospital, Beijing 100036, China
| | - Chunli Wang
- the National Chromatographic Research and Analysis Center, Chinese Academy of Sciences, Dalian 116023, China
| | - Shasha Hua
- Laboratory for Cellular Dynamics, University of Science and Technology of China, Hefei 230027, China; the Airforce General Hospital, Beijing 100036, China
| | - Zeqi Su
- the Beijing University of Chinese Medicine, Beijing 100029, China
| | - Larry Brako
- the Morehouse School of Medicine and Atlanta Cardiovascular Research Institute, Atlanta, Georgia 30310
| | - Minerva Garcia-Barrio
- the Morehouse School of Medicine and Atlanta Cardiovascular Research Institute, Atlanta, Georgia 30310
| | - Mingliang Ye
- the National Chromatographic Research and Analysis Center, Chinese Academy of Sciences, Dalian 116023, China
| | - Xuan Wei
- the Airforce General Hospital, Beijing 100036, China
| | - Hanfa Zou
- the National Chromatographic Research and Analysis Center, Chinese Academy of Sciences, Dalian 116023, China
| | - Xia Ding
- the Beijing University of Chinese Medicine, Beijing 100029, China
| | - Lifang Liu
- the Airforce General Hospital, Beijing 100036, China.
| | - Xing Liu
- Laboratory for Cellular Dynamics, University of Science and Technology of China, Hefei 230027, China; the Morehouse School of Medicine and Atlanta Cardiovascular Research Institute, Atlanta, Georgia 30310,.
| | - Xuebiao Yao
- Laboratory for Cellular Dynamics, University of Science and Technology of China, Hefei 230027, China.
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39
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Accurate chromosome segregation by probabilistic self-organisation. BMC Biol 2015; 13:65. [PMID: 26264961 PMCID: PMC4533937 DOI: 10.1186/s12915-015-0172-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 06/25/2015] [Indexed: 11/16/2022] Open
Abstract
Background For faithful chromosome segregation during cell division, correct attachments must be established between sister chromosomes and microtubules from opposite spindle poles through kinetochores (chromosome bi-orientation). Incorrect attachments of kinetochore microtubules (kMTs) lead to chromosome mis-segregation and aneuploidy, which is often associated with developmental abnormalities such as Down syndrome and diseases including cancer. The interaction between kinetochores and microtubules is highly dynamic with frequent attachments and detachments. However, it remains unclear how chromosome bi-orientation is achieved with such accuracy in such a dynamic process. Results To gain new insight into this essential process, we have developed a simple mathematical model of kinetochore–microtubule interactions during cell division in general, i.e. both mitosis and meiosis. Firstly, the model reveals that the balance between attachment and detachment probabilities of kMTs is crucial for correct chromosome bi-orientation. With the right balance, incorrect attachments are resolved spontaneously into correct bi-oriented conformations while an imbalance leads to persistent errors. In addition, the model explains why errors are more commonly found in the first meiotic division (meiosis I) than in mitosis and how a faulty conformation can evade the spindle assembly checkpoint, which may lead to a chromosome loss. Conclusions The proposed model, despite its simplicity, helps us understand one of the primary causes of chromosomal instability—aberrant kinetochore–microtubule interactions. The model reveals that chromosome bi-orientation is a probabilistic self-organisation, rather than a sophisticated process of error detection and correction. Electronic supplementary material The online version of this article (doi:10.1186/s12915-015-0172-y) contains supplementary material, which is available to authorized users.
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Upregulation of centromere protein H is associated with progression of renal cell carcinoma. J Mol Histol 2015; 46:377-85. [DOI: 10.1007/s10735-015-9635-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 08/03/2015] [Indexed: 12/27/2022]
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The tumour suppressor DLC2 ensures mitotic fidelity by coordinating spindle positioning and cell-cell adhesion. Nat Commun 2014; 5:5826. [PMID: 25518808 PMCID: PMC4284802 DOI: 10.1038/ncomms6826] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 11/07/2014] [Indexed: 02/07/2023] Open
Abstract
Dividing epithelial cells need to coordinate spindle positioning with shape changes to maintain cell–cell adhesion. Microtubule interactions with the cell cortex regulate mitotic spindle positioning within the plane of division. How the spindle crosstalks with the actin cytoskeleton to ensure faithful mitosis and spindle positioning is unclear. Here we demonstrate that the tumour suppressor DLC2, a negative regulator of Cdc42, and the interacting kinesin Kif1B coordinate cell junction maintenance and planar spindle positioning by regulating microtubule growth and crosstalk with the actin cytoskeleton. Loss of DLC2 induces the mislocalization of Kif1B, increased Cdc42 activity and cortical recruitment of the Cdc42 effector mDia3, a microtubule stabilizer and promoter of actin dynamics. Accordingly, DLC2 or Kif1B depletion promotes microtubule stabilization, defective spindle positioning, chromosome misalignment and aneuploidy. The tumour suppressor DLC2 and Kif1B are thus central components of a signalling network that guides spindle positioning, cell–cell adhesion and mitotic fidelity. Epithelial cells must position their mitotic spindle correctly to maintain cell–cell adhesion. Here Vitiello et al. show that the tumour suppressor DLC2 and the mitotic kinesin Kif1b coordinate microtubule–actin interactions upstream of mDia3, guiding spindle positioning and mitotic fidelity.
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Regulation of kinetochore-microtubule attachments through homeostatic control during mitosis. Nat Rev Mol Cell Biol 2014; 16:57-64. [PMID: 25466864 DOI: 10.1038/nrm3916] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Faithful chromosome segregation during mitosis is essential for genome integrity and is mediated by the bi-oriented attachment of replicated chromosomes to spindle microtubules through kinetochores. Errors in kinetochore-microtubule (k-MT) attachment that could cause chromosome mis-segregation are frequent and are corrected by the dynamic turnover of k-MT attachments. Thus, regulating the rate of spindle microtubule attachment and detachment to kinetochores is crucial for mitotic fidelity and is frequently disrupted in cancer cells displaying chromosomal instability. A model based on homeostatic principles involving receptors, a core control network, effectors and feedback control may explain the precise regulation of k-MT attachment stability during mitotic progression to ensure error-free mitosis.
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Kononova O, Kholodov Y, Theisen KE, Marx KA, Dima RI, Ataullakhanov FI, Grishchuk EL, Barsegov V. Tubulin bond energies and microtubule biomechanics determined from nanoindentation in silico. J Am Chem Soc 2014; 136:17036-45. [PMID: 25389565 PMCID: PMC4277772 DOI: 10.1021/ja506385p] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
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Microtubules,
the primary components of the chromosome segregation
machinery, are stabilized by longitudinal and lateral noncovalent
bonds between the tubulin subunits. However, the thermodynamics of
these bonds and the microtubule physicochemical properties are poorly
understood. Here, we explore the biomechanics of microtubule polymers
using multiscale computational modeling and nanoindentations in silico of a contiguous microtubule fragment. A close
match between the simulated and experimental force–deformation
spectra enabled us to correlate the microtubule biomechanics with
dynamic structural transitions at the nanoscale. Our mechanical testing
revealed that the compressed MT behaves as a system of rigid elements
interconnected through a network of lateral and longitudinal elastic
bonds. The initial regime of continuous elastic deformation of the
microtubule is followed by the transition regime, during which the
microtubule lattice undergoes discrete structural changes, which include
first the reversible dissociation of lateral bonds followed by irreversible
dissociation of the longitudinal bonds. We have determined the free
energies of dissociation of the lateral (6.9 ± 0.4 kcal/mol)
and longitudinal (14.9 ± 1.5 kcal/mol) tubulin–tubulin
bonds. These values in conjunction with the large flexural rigidity
of tubulin protofilaments obtained (18,000–26,000 pN·nm2) support the idea that the disassembling microtubule is capable
of generating a large mechanical force to move chromosomes during
cell division. Our computational modeling offers a comprehensive quantitative
platform to link molecular tubulin characteristics with the physiological
behavior of microtubules. The developed in silico nanoindentation method provides a powerful tool for the exploration
of biomechanical properties of other cytoskeletal and multiprotein
assemblies.
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Affiliation(s)
- Olga Kononova
- Department of Chemistry, University of Massachusetts , Lowell, Massachusetts 01854, United States
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Stumpff J, Ghule PN, Shimamura A, Stein JL, Greenblatt M. Spindle microtubule dysfunction and cancer predisposition. J Cell Physiol 2014; 229:1881-3. [PMID: 24905602 DOI: 10.1002/jcp.24691] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 05/28/2014] [Indexed: 12/19/2022]
Abstract
Chromosome segregation and spindle microtubule dynamics are strictly coordinated during cell division in order to preserve genomic integrity. Alterations in the genome that affect microtubule stability and spindle assembly during mitosis may contribute to genomic instability and cancer predisposition, but directly testing this potential link poses a significant challenge. Germ-line mutations in tumor suppressor genes that predispose patients to cancer and alter spindle microtubule dynamics offer unique opportunities to investigate the relationship between spindle dysfunction and carcinogenesis. Mutations in two such tumor suppressors, adenomatous polyposis coli (APC) and Shwachman-Bodian-Diamond syndrome (SBDS), affect multifunctional proteins that have been well characterized for their roles in Wnt signaling and interphase ribosome assembly, respectively. Less understood, however, is how their shared involvement in stabilizing the microtubules that comprise the mitotic spindle contributes to cancer predisposition. Here, we briefly discuss the potential for mutations in APC and SBDS as informative tools for studying the impact of mitotic spindle dysfunction on cellular transformation.
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Affiliation(s)
- Jason Stumpff
- Vermont Cancer Center and Department of Molecular Physiology and Biophysics, University of Vermont College of Medicine, Burlington, Vermont
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Chen J, Liu QJ, Wang DA, Zhou XY, Xiong D, Li HJ, Li CL. Hepatoma upregulated protein expression is involved in the pathogenesis of human breast carcinogenesis. Oncol Lett 2014; 8:2543-2548. [PMID: 25364424 PMCID: PMC4214440 DOI: 10.3892/ol.2014.2614] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Accepted: 07/25/2014] [Indexed: 02/05/2023] Open
Abstract
In the last decade, the overexpression of hepatoma upregulated protein (HURP) has been reported in hepatocellular carcinoma, adrenocortical tumors and urogenital carcinoma. However, the role of HURP in breast cancer remains unknown. In the present study, a comprehensive analysis was performed to examine the HURP expression level in 43 breast cancer tumor samples and paired adjacent normal tissues. The correlation between the HURP expression level and the clinicopathological characteristics was evaluated. The role of HURP in breast cancer was investigated by quantitative polymerase chain reaction, western blot analysis and cell proliferation assays. HURP expression was found to be significantly increased in the breast cancer samples. The HURP expression level was higher in the tumors with advanced-grade metastasis and was strongly associated with tumor-node-metastasis staging (P=0.003). Transfection and cell proliferation assays suggested that the suppression of HURP expression or the interference in HURP activity in the breast cancer cells inhibited cell proliferation significantly. These data suggest that HURP is associated with the degree of malignancy and the proliferation of breast cancer. HURP could be a tumor biomarker for prognosis and a potential therapeutic drug target for human breast cancer.
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Affiliation(s)
- Jin Chen
- Department of Biochemistry and Molecular Biology, Sichuan University, Chengdu, Sichuan 610072, P.R. China
| | - Qiu-Jun Liu
- Department of Biochemistry and Molecular Biology, Sichuan University, Chengdu, Sichuan 610072, P.R. China
| | - DA Wang
- Department of Biochemistry and Molecular Biology, Sichuan University, Chengdu, Sichuan 610072, P.R. China
| | - Xian-Yao Zhou
- Department of Biochemistry and Molecular Biology, Sichuan University, Chengdu, Sichuan 610072, P.R. China
| | - Ding Xiong
- Department of Biochemistry and Molecular Biology, Sichuan University, Chengdu, Sichuan 610072, P.R. China
| | - Hong-Jiang Li
- Department of Thyroid and Breast Surgery, West China Hospital of Sichuan University, Chengdu, Sichuan 610072, P.R. China
| | - Chang-Long Li
- Department of Biochemistry and Molecular Biology, Sichuan University, Chengdu, Sichuan 610072, P.R. China
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Synthetic genetic array screen identifies PP2A as a therapeutic target in Mad2-overexpressing tumors. Proc Natl Acad Sci U S A 2014; 111:1628-33. [PMID: 24425774 DOI: 10.1073/pnas.1315588111] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The spindle checkpoint is essential to ensure proper chromosome segregation and thereby maintain genomic stability. Mitotic arrest deficiency 2 (Mad2), a critical component of the spindle checkpoint, is overexpressed in many cancer cells. Thus, we hypothesized that Mad2 overexpression could specifically make cancer cells susceptible to death by inducing a synthetic dosage lethality defect. Because the spindle checkpoint pathway is highly conserved between yeast and humans, we performed a synthetic genetic array analysis in yeast, which revealed that Mad2 overexpression induced lethality in 13 gene deletions. Among the human homologs of candidate genes, knockdown of PPP2R1A, a gene encoding a constant regulatory subunit of protein phosphatase 2, significantly inhibited the growth of Mad2-overexpressing tumor cells. PPP2R1A inhibition induced Mad2 phosphorylation and suppressed Mad2 protein levels. Depletion of PPP2R1A inhibited colony formation of Mad2-overexpressing HeLa cells but not of unphosphorylated Mad2 mutant-overexpressing cells, suggesting that the lethality induced by PP2A depletion in Mad2-overexpressing cells is dependent on Mad2 phosphorylation. Also, the PP2A inhibitor cantharidin induced Mad2 phosphorylation and inhibited the growth of Mad2-overexpressing cancer cells. Aurora B knockdown inhibited Mad2 phosphorylation in mitosis, resulting in the blocking of PPP2R1A inhibition-induced cell death. Taken together, our results strongly suggest that PP2A is a good therapeutic target in Mad2-overexpressing tumors.
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Kabeche L, Compton DA. Cyclin A regulates kinetochore microtubules to promote faithful chromosome segregation. Nature 2013; 502:110-3. [PMID: 24013174 PMCID: PMC3791168 DOI: 10.1038/nature12507] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/26/2013] [Indexed: 01/04/2023]
Abstract
The most conspicuous event in the cell cycle is the alignment of chromosomes in metaphase. Chromosome alignment fosters faithful segregation through the formation of bi-oriented attachments of kinetochores to spindle microtubules. Strikingly, numerous kinetochore-microtubule (k-MT) attachment errors are present in early mitosis (prometaphase)1, and the persistence of those errors is the leading cause of chromosome mis-segregation in aneuploid human tumor cells that continually mis-segregate whole chromosomes (e.g. chromosomal instability)2–7. How robust error correction is achieved in prometaphase to ensure error-free mitosis remains unknown. Here we show that k-MT attachments in prometaphase cells are significantly less stable than in metaphase cells. The switch to more stable k-MT attachments in metaphase requires the proteasome-dependent destruction of cyclin A in prometaphase. Persistent cyclin A expression prevents k-MT stabilization even in cells with aligned chromosomes. In contrast, k-MTs are prematurely stabilized in cyclin A-deficient cells. Consequently, cells lacking cyclin A display higher rates of chromosome mis-segregation. Thus, the stability of k-MT attachments increases decisively in a coordinated fashion among all chromosomes as cells transit from prometaphase to metaphase. Cyclin A creates a cellular environment that promotes microtubule detachment from kinetochores in prometaphase to ensure efficient error correction and faithful chromosome segregation.
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Affiliation(s)
- Lilian Kabeche
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
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Lu G, Shan T, He S, Ren M, Zhu M, Hu Y, Lu X, Zhang D. Overexpression of CENP-H as a novel prognostic biomarker for human hepatocellular carcinoma progression and patient survival. Oncol Rep 2013; 30:2238-44. [PMID: 23970101 DOI: 10.3892/or.2013.2675] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 07/09/2013] [Indexed: 11/06/2022] Open
Abstract
Centromere protein H (CENP-H) has been shown to be significantly upregulated in many types of cancers and is associated with disrupted cell cycle regulation, cell proliferation and genetic instability. The aim of the present study was to explore the expression and localization of CENP-H in hepatocellular carcinoma (HCC) and determine whether its overexpression is a prognostic biomarker for HCC. Reverse transcription-polymerase chain reaction (pcr), real-time qPCR and western blotting were used to compare CENP-H expression at the mRNA and protein levels in HCC samples and corresponding adjacent non-cancerous samples. CENP-H protein levels were determined in 60 paired paraffin-embedded HCC tissues using immunohistochemistry (IHC), and the correlation with clinicopathological features and patient prognosis was analyzed. In addition, an immunofluorescence assay was performed to test the expression and localization of CENP-H protein in HCC cells. Results showed that levels of CENP-H mRNA and protein were higher in HCC samples than in the corresponding adjacent non-cancerous samples. In 60 paired paraffin-embedded tissues, CENP-H was upregulated in the HCC samples (38/60, 63.3%) relative to the adjacent non-cancerous samples (21/60, 35%, P=0.003), and a higher level of upregulation was associated with tumor size (P=0.032); higher histological grade (P=0.001); more advanced TNM stage (P=0.002) and Chinese clinical stage (P=0.008); and poorer prognosis. In addition, consistent with the results of IHC, the immunofluorescence assay showed that CENP-H was localized in the nucleus of Hep3B cells. CENP-H was overexpressed in HCC, and its level of upregulation was an independent prognostic indicator, suggesting that CENP-H may be an effective therapeutic strategy for the treatment of HCC.
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Affiliation(s)
- Guifang Lu
- Department of Gastroenterology, First Affiliated Hospital of the Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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Abstract
The microtubule (MT) cytoskeleton supports a broad range of cellular functions, from providing tracks for intracellular transport, to supporting movement of cilia and flagella, to segregating chromosomes in mitosis. These functions are facilitated by the organizational and dynamic plasticity of MT networks. An important class of enzymes that alters MT dynamics is the depolymerizing kinesin-like proteins, which use their catalytic activities to regulate MT end dynamics. In this review, we discuss four topics surrounding these MT-depolymerizing kinesins. We provide a historical overview of studies focused on these motors and discuss their phylogeny. In the second half, we discuss their enzymology and biophysics and give an overview of their known cellular functions. This discussion highlights the fact that MT-depolymerizing kinesins exhibit a diverse range of design principles, which in turn increases their functional versatility in cells.
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Affiliation(s)
- Claire E Walczak
- Medical Sciences, Indiana University, Bloomington, Indiana 47405;
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End-binding proteins sensitize microtubules to the action of microtubule-targeting agents. Proc Natl Acad Sci U S A 2013; 110:8900-5. [PMID: 23674690 DOI: 10.1073/pnas.1300395110] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Microtubule-targeting agents (MTAs) are widely used for treatment of cancer and other diseases, and a detailed understanding of the mechanism of their action is important for the development of improved microtubule-directed therapies. Although there is a large body of data on the interactions of different MTAs with purified tubulin and microtubules, much less is known about how the effects of MTAs are modulated by microtubule-associated proteins. Among the regulatory factors with a potential to have a strong impact on MTA activity are the microtubule plus end-tracking proteins, which control multiple aspects of microtubule dynamic instability. Here, we reconstituted microtubule dynamics in vitro to investigate the influence of end-binding proteins (EBs), the core components of the microtubule plus end-tracking protein machinery, on the effects that MTAs exert on microtubule plus-end growth. We found that EBs promote microtubule catastrophe induction in the presence of all MTAs tested. Analysis of microtubule growth times supported the view that catastrophes are microtubule age dependent. This analysis indicated that MTAs affect microtubule aging in multiple ways: destabilizing MTAs, such as colchicine and vinblastine, accelerate aging in an EB-dependent manner, whereas stabilizing MTAs, such as paclitaxel and peloruside A, induce not only catastrophes but also rescues and can reverse the aging process.
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