Fig. 6

Gene expression and CHIP analysis of senescence master regulators. A Histogram showing the mRNA expression levels of the indicated genes under different experimental conditions as detected by qRT-PCR. The mRNA levels were normalized to GAPDH mRNA expression, which served as an internal control. CT: untreated samples; rIGFBP5, ATRA, and ATRA + rIGFBP5 indicate samples incubated for one hour with the indicated molecules. The symbols * p < 0.05, ** p < 0.01, *** p < 0.001 indicate statistical significance between samples incubated with rIGFBP5 and/or ATRA and the untreated cells (CT), with the latter condition chosen as the reference. B The picture shows the putative RARE motifs, identified by JASPAR or PATCH, on the promoters of the indicated genes. For each gene promoter, the analyzed regions span from -1,000 to + 100 nucleotides. The dashed yellow rectangles represent the CHIP-PCR analyzed regions for each promoter. Data were normalized using the input percent method. The histogram displays the fold changes in CHIP values in cells treated with rIGFBP5, ATRA, or both, with respect to control samples (CT) set at a value of 1. The symbols * p < 0.05, ** p < 0.01, *** p < 0.001 indicate statistical significance between samples incubated with rIGFBP5 and/or ATRA and the CT