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Bulletin Du Cancer Oct 2011Genomic DNA is constantly under stress of endogenous and exogenous DNA damaging agents. Without proper care, the DNA damage causes an alteration of the genomic structure... (Review)
Review
Genomic DNA is constantly under stress of endogenous and exogenous DNA damaging agents. Without proper care, the DNA damage causes an alteration of the genomic structure and can lead to cell death or the occurrence of mutations involved in tumorigenesis. During the process of evolution, organisms have acquired a series of response mechanisms and repair of DNA damage, thereby ensuring the maintenance of genome stability and faithful transmission of genetic information. The checkpoints are the major mechanisms by which a cell can respond to DNA damage, either by actively stopping the cell cycle or by induction of apoptosis. Two parallel signalling pathways, ATM and ATR respond to genotoxic stress by activating their downstream target proteins including the two effectors kinases CHK1 and CHK2. Promising preliminary data render these proteins potential targets for therapeutic development against cancer.
Topics: Aneuploidy; Apoptosis; Ataxia Telangiectasia Mutated Proteins; Cell Cycle; Cell Cycle Proteins; Checkpoint Kinase 1; Checkpoint Kinase 2; DNA Damage; DNA Repair; DNA-Binding Proteins; Enzyme Activation; Genomic Instability; Humans; Interphase; Mitosis; Molecular Targeted Therapy; Neoplasms; Phosphorylation; Protein Kinases; Protein Serine-Threonine Kinases; Signal Transduction; Tumor Suppressor Proteins
PubMed: 21669563
DOI: 10.1684/bdc.2011.1382 -
Medecine Sciences : M/S Mar 2003The mitotic checkpoint is essential to ensure accurate chromosome segregation by allowing a mitotic delay in response to a spindle defect. This checkpoint postpones the... (Review)
Review
The mitotic checkpoint is essential to ensure accurate chromosome segregation by allowing a mitotic delay in response to a spindle defect. This checkpoint postpones the onset of anaphase until all the chromosomes are attached and correctly aligned onto the mitotic spindle. The checkpoint functions by preventing an ubiquitin ligase called the anaphase-promoting complex (APC) from ubiquitinylating proteins whose degradation is required for anaphase onset. Loss of this checkpoint results in chromosome missegregation in higher eukaryotes and may contribute to the genomic instability observed in most of the tumour cells.
Topics: Anaphase-Promoting Complex-Cyclosome; Animals; Chromosomes; Gene Expression Regulation; Humans; Ligases; Mitosis; Neoplasms; Spindle Apparatus; Ubiquitin-Protein Ligase Complexes
PubMed: 12836413
DOI: 10.1051/medsci/2003193309 -
Acta Neuropathologica Communications Apr 2020Although abnormal mitosis with disarranged metaphase chromosomes or many micronuclei in astrocytes (named "Alzheimer I type astrocytes" and later "Creutzfeldt-Peters...
Although abnormal mitosis with disarranged metaphase chromosomes or many micronuclei in astrocytes (named "Alzheimer I type astrocytes" and later "Creutzfeldt-Peters cells") have been known for nearly 100 years, the origin and mechanisms of this pathology remain elusive. In experimental brain insults in rats, we show that abnormal mitoses that are not followed by cytokinesis are typical for reactive astrocytes. The pathology originates due to the inability of the cells to form normal mitotic spindles with subsequent metaphase chromosome congression, which, in turn may be due to shape constraints aggravated by cellular enlargement and to the accumulation of large amounts of cytosolic proteins. Many astrocytes escape from arrested mitosis by producing micronuclei. These polyploid astrocytes can survive for long periods of time and enter into new cell cycles.
Topics: Animals; Astrocytes; Brain Diseases; Gliosis; Mitosis; Rats; Rats, Sprague-Dawley; Rats, Wistar
PubMed: 32293551
DOI: 10.1186/s40478-020-00919-4 -
Bulletin de L'Association Des... Mar 1979The mitotic chromosome movements are discussed in relation with recent studies on tubulins, their assembly and disassembly, and the associated proteins. The role of... (Review)
Review
The mitotic chromosome movements are discussed in relation with recent studies on tubulins, their assembly and disassembly, and the associated proteins. The role of contractile proteins in the mitotic spindle is considered, and also that of the calcium regulating protein (CDR) which has been demonstrated recently in the mitotic spindle. The study of more "primitive" mitoses underlines the differences between polar and chromosomal MT. The linear growth of the first, and the sliding movements of MT from opposing poles, explain the growth in length of the mitotic figure and the separation of chromosomes. The complex relations between various types of MT and the possibility of biochemical varieties of tubulins, are discussed.
Topics: Actins; Animals; Cell Cycle; Centrioles; Chromosomes; Microtubules; Mitosis; Movement; Myosins; Tubulin
PubMed: 393326
DOI: No ID Found -
Postepy Biochemii 2010During cell division the bipolar microtubular mitotic spindle ensures faithful segregation of daughter chromosomes and appearance of the cytokinetic membrane in an... (Review)
Review
During cell division the bipolar microtubular mitotic spindle ensures faithful segregation of daughter chromosomes and appearance of the cytokinetic membrane in an equatorial area separating genetically identical daughter cells. This process proceeds in consecutive morphological stages of prophase, metaphase, anaphase and cytokinesis. The progress in embryology and oncology concerns the new data about intervening mechanisms of rotation of a bipolar spindle in prophase and the change of the position of a mitotic spindle in anaphase that result in an asymmetric and differential mitoses. The aim of this review is a discussion of some of molecular and signaling mechanisms which regulate position of mitotic spindles in different types of cells. It turns out that the knowledge of receptor-dependent and receptor-independent molecular mechanisms controlling geometry and localization of cytokinesis in some human cells and in early stages of development of C. elegans opens the new important research fields.
Topics: Anaphase; Animals; Caenorhabditis elegans; Cell Cycle; Cytokinesis; Fibronectins; Humans; Metaphase; Mitosis; Prometaphase; Signal Transduction
PubMed: 20499679
DOI: No ID Found -
International Review of Cytology 1980
Review
Topics: Animals; Biological Evolution; Cell Nucleus; Chromatin; Eukaryota; Mitosis; Spindle Apparatus
PubMed: 20815116
DOI: 10.1016/s0074-7696(08)60235-1 -
Medecine Sciences : M/S Mar 2003
Topics: Animals; Cell Division; Cell Physiological Phenomena; Eukaryotic Cells; Gene Expression Regulation; Humans; Microtubules; Mitosis
PubMed: 12836400
DOI: 10.1051/medsci/2003193259 -
The Journal of Biophysical and... Apr 1961A study of mitosis in Lipomyces has been carried out because preliminary observations by Ganesan and Roberts, 1959 (9), had indicated that the nucleus of this yeast...
A study of mitosis in Lipomyces has been carried out because preliminary observations by Ganesan and Roberts, 1959 (9), had indicated that the nucleus of this yeast might be unusually favourable for morphological observations. This impression has proved correct. The chromosomes of Lipomyces are visible as separate, countable bodies for the greater part of mitosis. The pattern of mitosis differs from the common one in that in Lipomyces the proper distribution of sister chromosomes is accomplished without the help of a spindle apparatus. At the end of prophase sister chromosomes are found in pairs which align themselves parallel to one another to form a palisade or stack whose long axis coincides with the axis of the impending division. At anaphase-telophase the stack of paired chromosomes fuses into a seemingly homogeneous cord which divides by constriction.
Topics: Anaphase; Cell Division; Cell Nucleus; Chromosomes; Lipomyces; Mitosis; Prophase; Saccharomyces cerevisiae; Telophase; Yeasts
PubMed: 13742260
DOI: 10.1083/jcb.9.4.879 -
European Journal of Histochemistry : EJH 2001
Review
Topics: Animals; Chromosome Aberrations; Humans; Mitosis; Neoplasms
PubMed: 11845999
DOI: 10.4081/1640 -
Cells Apr 2022A conserved feature of virtually all higher eukaryotes is that the centromeres are embedded in heterochromatin. Here we provide evidence that this tight association... (Review)
Review
A conserved feature of virtually all higher eukaryotes is that the centromeres are embedded in heterochromatin. Here we provide evidence that this tight association between pericentric heterochromatin and the centromere is essential for proper metaphase exit and progression into telophase. Analysis of chromosome rearrangements that separate pericentric heterochromatin and centromeres indicates that they must remain associated in order to balance Cohesin/DNA catenation-based binding forces and centromere-based pulling forces during the metaphase-anaphase transition. In addition, a centromere embedded in heterochromatin facilitates nuclear envelope assembly around the entire complement of segregating chromosomes. Because the nuclear envelope initially forms on pericentric heterochromatin, nuclear envelope formation proceeds from the pole, thus providing time for incorporation of lagging and trailing chromosome arms into the newly formed nucleus. Additional analysis of noncanonical mitoses provides further insights into the functional significance of the tight association between heterochromatin and centromeres.
Topics: Anaphase; Centromere; Heterochromatin; Metaphase; Mitosis
PubMed: 35406810
DOI: 10.3390/cells11071247