Figure 3

TAp73β down-regulates cell proliferation by increasing the proportion of cells at G0/G1 phase at the expense of S and G2/M phase cells. Gene set enrichment analyses showing the repression of (A) Myc-target genes, (B) E2F target genes, (C) genes involved in G2/M cell cycle progression, and (D) mitotic spindle associated genes. (E) TAp73β causes moderate inhibition of cell cyle progression by increasing the relative number of cells at G0/G1 phase. Hep3BTAp73β cells were treated with doxycycline (1 µg/mL) for 72 h, and cell cycle distribution was evaluated by using flow cytometric DNA content analysis. (F) TAp73β decreases cell proliferation by 40%, but does not stop cell growth. Hep3BTAp73β cells were exposed to doxycycline (1 µg/mL) for 0 h, 24 h, 48 h and 72 h. At the end of the indicated times, cell proliferation was measured by the SRB method. Columns and error bars indicate ± SD from triplicate experiments. ** p < 0.001 and *** p < 0.0001 for significant differences between cells treated and not treated with doxycycline.