Intranuclear microtubules are hallmarks of an unusual form of cell death in cisplatin-treated C6 glioma cells
| Autor: | Maria Grazia Bottone, Dimitrolos Krajčí, V. Lisá, Carlo Pellicciari, Vladislav Mareš |
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| Rok vydání: | 2005 |
| Předmět: |
Programmed cell death
Histology Population Antineoplastic Agents Biology Microfilament Microtubules chemistry.chemical_compound Microscopy Electron Transmission Tubulin Cell Line Tumor In Situ Nick-End Labeling Inner membrane Humans Propidium iodide Annexin A5 Enzyme Inhibitors education Coloring Agents Molecular Biology Mitosis Cell Nucleus education.field_of_study Microscopy Confocal Cell Death Brain Neoplasms Cell Cycle Cell Biology DNA Neoplasm Glioma Spindle apparatus Cell biology Medical Laboratory Technology Actin Cytoskeleton chemistry Microscopy Fluorescence Cytoplasm Cytophotometry Cisplatin Propidium |
| Zdroj: | Histochemistry and cell biology. 125(1-2) |
| ISSN: | 0948-6143 |
| Popis: | We describe an unusual form of non-accidental cell death marked by ectopic microtubules in the nucleus of a subpopulation of cisplatin-treated C6 glioma astrocytes in culture. At electron microscopy, the perinuclear condensed chromatin did not completely adhere to the nuclear envelope of these cells being separated by single or loosely bundled 20-nm-thick microtubules located in an electron-lucid slit-like zone; the presence of alpha-tubulin lining the inner membrane of the nuclear envelope was confirmed by immunolabeling at confocal microscopy. Since tufts of microfilaments-like fibers also occurred in their central nuclear areas, these cells are referred to as CIMMs (Cells with Intranuclear Microtubules and Microfilaments). The nuclear reorganization of CIMMs also involved nucleolar segregation and formation of heterogeneous ectopic ribonucleoprotein (RNP)-derived structures, indicating disruption of the RNP-based transcription machinery. The cytoplasmic organelles of CIMMs were structurally intact, and propidium iodide did not accumulate intracellularly under vital conditions while the plasma membrane was often Annexin V-positive. All these findings suggest that CIMMs were lethally damaged and committed to an atypical programmed cell death resembling early apoptosis (this is also supported by the presence of a limited number of TUNEL-positive CIMMs). CIMMs appeared well before the main cisplatin-induced cycling arrest of the cell population (G2/M block at 72 h) and had mostly G1 DNA content: this suggests that they may represent the cohort of cells which passed cisplatin-altered mitoses with intranuclear retention of microtubules from an incompletely disassembled mitotic spindle. |
| Databáze: | OpenAIRE |
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