Fig. 3: FOXM1 as a regulator of cell proliferation activated at the early stage after treatment.
a Attenuated proliferation of KU + Y-treated senescent HDF cultures by FOXM1 knockdown (top) and immunoblots of FOXM1 in senescent HDF cultures after FOXM1 knockdown (bottom). Cell proliferation was measured at 8 DPT. The data are shown as the mean ± s.d. values; N = 10 per condition. NT, nontargeting shRNA. b Immunoblots of the cytosolic and nuclear fractions probed with the anti-FOXM1 antibody after KU + Y treatment (1 and 3 DPT) and quantification of nuclear FOXM1. Lamin A and GAPDH were used as the loading controls for the nuclear and cytoplasmic fractions, respectively. The data are shown as the mean ± s.d. values; N = 3 per experiment. c Immunocytochemistry and quantification of nuclear FOXM1 in senescent cells after KU + Y treatment (1 DPT). Representative images showing the localization of FOXM1 (yellow; top and bottom) and costaining of FOXM1 and DAPI (blue, bottom) under each condition. The ratios of the nuclear FOXM1 intensity to the cytoplasmic FOXM1 intensity, defined as the DAPI-overlapping and non-DAPI-overlapping FOXM1 intensities, respectively, were quantified from the images. Scale bar = 50 μm. The data are shown as the mean ± s.d. values; N > 30 independent cells per sample. d Binding affinity of FOXM1 for the promoters of the indicated target genes, as measured by ChIP-qPCR. The data are shown as the mean ± s.d. values; N = 2 per experiment. For statistical analyses, a–c *P < 0.05; ***P < 1.0 × 10−3; ****P < 1.0 × 10−4 by one-way ANOVA with Tukey’s post hoc correction. d *P < 0.05; ***P < 1.0 × 10−3; ****P < 1.0 × 10−4 by two-way ANOVA with Tukey’s post hoc correction.
