AbstractBecause cells are sensitive to mechanical forces, weightlessness might act on stress-dependent cell changes. Human breast cancer cells MCF-7, flown in space in a Photon capsule, were fixed after 1.5, 22 and 48 h in orbit. Cells subjected to weightlessness were compared to 1g in-flight and ground controls. Post-flight, fluorescent labeling was performed to visualize cell proliferation (Ki-67), three cytoskeleton components and chromatin structure. Confocal microscopy and image analysis were used to quantify cycling cells and mitosis, modifications of the cytokeratin network and chromatin structure. Several main phenomena were observed in weightlessness: The perinuclear cytokeratin network and chromatin structure were looser. More cells were cycling and mitosis was prolonged. Finally, cell proliferation was reduced as a consequence of a cell-cycle blockade. Microtubules were altered in many cells. The results reported in the first point are in agreement with basic predictions of cellular tensegrity. The prolongation of mitosis can be explained by an alteration of microtubules. We discuss here the different mechanisms involved in weightlessness alteration of microtubules: i) alteration of their self-organization by reaction-diffusion processes, and a mathematical model is proposed, ii) activation or desactivation of microtubules stabilizing proteins, acting on both microtubule and microfilament networks in cell cortex.


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    Titel :

    Weightlessness acts on human breast cancer cell line MCF-7


    Beteiligte:
    Vassy, J. (Autor:in) / Portet, S. (Autor:in) / Beil, M. (Autor:in) / Millot, G. (Autor:in) / Fauvel-Lafève, F. (Autor:in) / Gasset, G. (Autor:in) / Schoevaert, D. (Autor:in)

    Erschienen in:

    Advances in Space Research ; 32 , 8 ; 1595-1603


    Erscheinungsdatum :

    2003-02-03


    Format / Umfang :

    9 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch