scholarly journals Coordinated Requirements of Human Topo II and Cohesin for Metaphase Centromere Alignment under Mad2-dependent Spindle Checkpoint Surveillance

2006 ◽  
Vol 17 (5) ◽  
pp. 2287-2302 ◽  
Author(s):  
Yusuke Toyoda ◽  
Mitsuhiro Yanagida
Keyword(s):  
Topoisomerase Ii ◽  
Dependent Manner ◽  
Mitotic Progression ◽  
Dna Topoisomerase ◽  
Direct Observations ◽  
Anaphase Onset ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
Topo Ii ◽  
Kinetochore Function

Cohesin maintains sister chromatid cohesion until its Rad21/Scc1/Mcd1 is cleaved by separase during anaphase. DNA topoisomerase II (topo II) maintains the proper topology of chromatid DNAs and is essential for chromosome segregation. Here we report direct observations of mitotic progression in individual HeLa cells after functional disruptions of hRad21, NIPBL, a loading factor for hRad21, and topo II α,β by RNAi and a topo II inhibitor, ICRF-193. Mitosis is delayed in a Mad2-dependent manner after disruption of either or both cohesin and topo II. In hRad21 depletion, interphase pericentric architecture becomes aberrant, and anaphase is virtually permanently delayed as preseparated chromosomes are misaligned on the metaphase spindle. Topo II disruption perturbs centromere organization leading to intense Bub1, but no Mad2, on kinetochores and sustains a Mad2-dependent delay in anaphase onset with persisting securin. Thus topo II impinges upon centromere/kinetochore function. Disruption of topo II by RNAi or ICRF-193 overrides the mitotic delay induced by cohesin depletion: sister centromeres are aligned and anaphase spindle movements occur. The ensuing accumulation of catenations in preseparated sister chromatids may overcome the reduced tension arising from cohesin depletion, causing the override. Cohesin and topo II have distinct, yet coordinated functions in metaphase alignment.

Synthesis and anticancer evaluation of sulfur containing 9-anilinoacridines

2021 ◽  
Vol 16 ◽  
Author(s):  
Pranav Gupta ◽  
Radhika V. Kumar ◽  
Chul-Hoon Kwon ◽  
Zhe-Sheng Chen
Keyword(s):  
Cell Cycle ◽  
Anticancer Activity ◽  
Topoisomerase Ii ◽  
Critical Role ◽  
K562 Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
In Vivo Models ◽  
Topo Ii ◽  
Sulfur Containing

Background: DNA topoisomerases are a class of enzymes that play a critical role in fundamental biological processes of replication, transcription, recombination, repair and chromatin remodeling. Amsacrine (m-AMSA), the best-known compound of 9-anilinoacridines series was one of the first DNA-intercalating agents to be considered as a Topoisomerase II inhibitor. Objective: A series of sulfur containing 9-anilinoacridines related to amsacrine were synthesized and evaluated for their anticancer activity. Methods: Cell viability was assessed by the MTT assay. The topoisomerase II inhibitory assay was performed using the Human topoisomerase II Assay kit and flow cytometry was used to evaluate the effects on cell cycle of K562 cells. Molecular docking was performed using Schrödinger Maestro program. Results: Compound 36 was found to be the most cytotoxic of the sulfide series against SW620, K562, and MCF-7. The limited SAR suggested the importance of the methansulfonamidoacetamide side chain functionality, the lipophilicity and relative metabolic stability of 36 in contributing to the cytotoxicity. Topoisomerase II α inhibitory activity appeared to be involved in the cytotoxicity of 36 through inhibition of decatenation of kinetoplast DNA (kDNA) in a concentration dependent manner. Cell cycle analysis further showed the Topo II inhibition through accumulation of K562 cells in G2/M phase of cell cycle. Docking of 36 into the Topo II α-DNA complex suggested that it may be an allosteric inhibitor of Topo II α. Conclusion: Compound 36 exhibits anticancer activity by inhibiting topoisomerase II and it could further be evaluated in in vivo models.

scholarly journals Rearrangements of the MLL gene in therapy-related acute myeloid leukemia in patients previously treated with agents targeting DNA- topoisomerase II

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3705-3711 ◽  
Author(s):  
HJ Super ◽  
NR McCabe ◽  
MJ Thirman ◽  
RA Larson ◽  
MM Le Beau ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Topoisomerase Ii ◽  
De Novo ◽  
Chromosome Band ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Mll Gene ◽  
Topo Ii ◽  
Acute Myeloid

Chromosome band 11q23 is frequently involved in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) de novo, as well as in myelodysplastic syndromes (MDS) and lymphoma. Five percent to 15% of patients treated with chemotherapy for a primary neoplasm develop therapy-related AML (t-AML) that may show rearrangements, usually translocations involving band 11q23 or, less often, 21q22. These leukemias develop after a relatively short latent period and often follow the use of drugs that inhibit the activity of DNA-topoisomerase II (topo II). We previously identified a gene, MLL (myeloid-lymphoid leukemia or mixed-lineage leukemia), at 11q23 that is involved in the de novo leukemias. We have studied 17 patients with t-MDS/t-AML, 12 of whom had cytogenetically detectable 11q23 rearrangements. Ten of the 12 t-AML patients had received topo II inhibitors and 9 of these, all with balanced translocations of 11q23, had MLL rearrangements on Southern blot analysis. None of the patients who had not received topo II inhibitors showed an MLL rearrangement. Of the 5 patients lacking 11q23 rearrangements, some of whom had monoblastic features, none had an MLL rearrangement, although 4 had received topo II inhibitors. Our study indicates that the MLL gene rearrangements are similar both in AML that develops de novo and in t-AML. The association of exposure to topo II- reactive chemotherapy with 11q23 rearrangements involving the MLL gene in t-AML suggests that topo II may play a role in the aberrant recombination events that occur in this region both in AML de novo and in t-AML.

Immunocytometric detection of the α-and β-isoforms of DNA topoisomerase II (topo II) in human ovarian cancers

1993 ◽  
Vol 29 ◽  
pp. S136
Author(s):  
C. Oliani ◽  
E. Prosperi ◽  
P. Biondani ◽  
C. Griso ◽  
F. Pavanel ◽  
...  
Keyword(s):  
Topoisomerase Ii ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Ovarian Cancers ◽  
Topo Ii

scholarly journals Topoisomerase II SUMOylation activates a metaphase checkpoint via Haspin and Aurora B kinases

2019 ◽  
Vol 219 (1) ◽  
Author(s):  
Nootan Pandey ◽  
Daniel Keifenheim ◽  
Makoto Michael Yoshida ◽  
Victoria A. Hassebroek ◽  
Caitlin Soroka ◽  
...  
Keyword(s):  
Topoisomerase Ii ◽  
Histone H3 ◽  
Aurora B ◽  
Additional Time ◽  
Checkpoint Activation ◽  
Present Evidence ◽  
The Core ◽  
Anaphase Onset ◽  
Topo Ii ◽  
Insight Into

Topoisomerase II (Topo II) is essential for mitosis since it resolves sister chromatid catenations. Topo II dysfunction promotes aneuploidy and drives cancer. To protect from aneuploidy, cells possess mechanisms to delay anaphase onset when Topo II is perturbed, providing additional time for decatenation. Molecular insight into this checkpoint is lacking. Here we present evidence that catalytic inhibition of Topo II, which activates the checkpoint, leads to SUMOylation of the Topo II C-terminal domain (CTD). This modification triggers mobilization of Aurora B kinase from inner centromeres to kinetochore proximal centromeres and the core of chromosome arms. Aurora B recruitment accompanies histone H3 threonine-3 phosphorylation and requires Haspin kinase. Strikingly, activation of the checkpoint depends both on Haspin and Aurora B. Moreover, mutation of the conserved CTD SUMOylation sites perturbs Aurora B recruitment and checkpoint activation. The data indicate that SUMOylated Topo II recruits Aurora B to ectopic sites, constituting the molecular trigger of the metaphase checkpoint when Topo II is catalytically inhibited.

scholarly journals An RNase-sensitive particle containing Drosophila melanogaster DNA topoisomerase II.

1994 ◽  
Vol 126 (6) ◽  
pp. 1331-1340 ◽  
Author(s):  
V H Meller ◽  
M McConnell ◽  
P A Fisher
Keyword(s):  
Rna Polymerase Ii ◽  
Topoisomerase Ii ◽  
Sedimentation Coefficient ◽  
Rnase A ◽  
Micrococcal Nuclease ◽  
Nuclear Antigen ◽  
Nuclear Pore ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Topo Ii

Most DNA topoisomerase II (topo II) in cell-free extracts of 0-2-h old Drosophila embryos appears to be nonnuclear and remains in the supernatant after low-speed centrifugation (10,000 g). Virtually all of this apparently soluble topo II is particulate with a sedimentation coefficient of 67 S. Similar topo II-containing particles were detected in Drosophila Kc tissue culture cells, 16-19-h old embryos and extracts of progesterone-matured oocytes from Xenopus. Drosophila topo II-containing particles were insensitive to EDTA, Triton X-100 and DNase I, but could be disrupted by incubation with 0.3 M NaCl or RNase A. After either disruptive treatment, topo II sedimented at 9 S. topo II-containing particles were also sensitive to micrococcal nuclease. Results of chemical cross-linking corroborated those obtained by centrifugation. Immunoblot analyses demonstrated that topo II-containing particles lacked significant amounts of lamin, nuclear pore complex protein gp210, proliferating cell nuclear antigen, RNA polymerase II subunits, histones, coilin, and nucleolin. Northern blot analyses demonstrated that topo II-containing particles lacked U RNA. Thus, current data support the notion that nonnuclear Drosophila topo II-containing particles are composed largely of topo II and an unknown RNA molecule(s).

scholarly journals A noncatalytic function of the topoisomerase II CTD in Aurora B recruitment to inner centromeres during mitosis

2016 ◽  
Vol 213 (6) ◽  
pp. 651-664 ◽  
Author(s):  
Heather Edgerton ◽  
Marnie Johansson ◽  
Daniel Keifenheim ◽  
Soumya Mukherjee ◽  
Jeremy M. Chacón ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Binding Site ◽  
Chromosome Segregation ◽  
Topoisomerase Ii ◽  
Histone H3 ◽  
Aurora B ◽  
Topoisomerase Iiα ◽  
Dna Topoisomerase ◽  
Topo Ii ◽  
Dna Topoisomerase Iiα

Faithful chromosome segregation depends on the precise timing of chromatid separation, which is enforced by checkpoint signals generated at kinetochores. Here, we provide evidence that the C-terminal domain (CTD) of DNA topoisomerase IIα (Topo II) provides a novel function at inner centromeres of kinetochores in mitosis. We find that the yeast CTD is required for recruitment of the tension checkpoint kinase Ipl1/Aurora B to inner centromeres in metaphase but is not required in interphase. Conserved CTD SUMOylation sites are required for Ipl1 recruitment. This inner-centromere CTD function is distinct from the catalytic activity of Topo II. Genetic and biochemical evidence suggests that Topo II recruits Ipl1 via the Haspin–histone H3 threonine 3 phosphorylation pathway. Finally, Topo II and Sgo1 are equally important for Ipl1 recruitment to inner centromeres. This indicates H3 T3-Phos/H2A T120-Phos is a universal epigenetic signature that defines the eukaryotic inner centromere and provides the binding site for Ipl1/Aurora B.

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