1. 5-Azacytidine-induced DNA demethylation partially inhibits Aur-B driven phosphorylation of histone H3 at pericentromeres in interphase nuclei.
5-Azacytidine-induced DNA demethylation partially inhibits Aur-B driven phosphorylation of histone H3 at pericentromeres in interphase nuclei. (A) Images of NT2 nuclei, control (a) or treated with 5-azacytidin (b), counterstained with DAPI and immunodetected with 5-methylcytosine (green). For comparison purposes, 5-methylcytosine images are displayed with the same dynamic scale. Nuclear intensity of 5-methylcytosine signals was quantified on control and 5-AzaC-treated populations (c). Histogram of the integrated intensity per nucleus for both populations normalized by the nuclear integrated intensity of negative control population (c, third column, no HCl). Error bars correspond to s.d. of the analyzed populations and n corresponds to the number of analyzed nuclei. (B) Cell-cycle analysis of exponentially growing NT2 cells by flow cytometry. The ModFit LT software was used to estimate the percentage of cells with a G1, S and G2-M content in control (a) and 5-azacytidin treated populations (b). (C) Western blot analysis of whole NT2 extracts detected with Aur-B (top) and H3S10P (bottom), in equally loaded populations of control (lane 1) and 5-AzaC-treated cells (lanes 2 and 3). (D,E) Analysis of cyclin B1 expression in NT2 cells treated with 5-AzaC. Representative fields of views of control (Da) and 5-AzaC treated NT2 cells (Db) counterstained with DAPI (insets, grey) and labelled with cyclin B1 (green) and H3S10P (red). Table shows the percentages of cyclin B1 and H3S10P positive nuclei (E, second and third row, respectively) and of doubly labelled nuclei (E, fourth row) obtained in control (E, second column) and in 5-AzaC treated NT2 cells (E, third column). The total number of analyzed cells, n, is indicated. (F,G) Analysis of HS10P and Aur-B expression in NT2 cells treated with 5-AzaC. Representative field of views of NT2 cells, control (Fa) or treated with 5-AzaC (Fb), counterstained with DAPI (insets, grey) and immunodetected with H3S10P (green) and Aur-B (red). (G) Table of the percentage of cells exhibiting H3S10P foci and uniform H3S10P labelling obtained in control and in 5-AzaC-treated NT2 cells. The total number of analyzed cells, n, is indicated. Bars, 10 μm.
Karine Monier et al. J Cell Sci 2007;120:
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