Adoptive expression of CDCA2 promotes cell cycle progression in Etoposide-Induced Senescence.

<p>A) CDCA2 and ID4 coding sequences were transfected in PDL 33 IMR90 cells. Cells transfected with CMV-NEO plasmid were used as control. After 24 h, transfected cells were treated with 20 µM etoposide or 150 µM DEM for 24 h and then incubated with BrdU for 4 h. Coverslips were then fixed, incubated with primary anti-BrdU and secondary fluorescein-conjugated antibodies, counterstained with Hoechst-33258 and counted by immunofluorescence. Counts of at least 800 cells were averaged and expressed as fold changes±SD, with respect to control transfected cells (***p<0.01). B) and C) PDL 33 IMR90 cells were transfected with the coding sequence of CDCA2. After 24 h, transfected cells were treated with 20 µM etoposide for 24 h and then were collected to obtain protein extracts. Cell extracts from CMV-neo over-expressing cells served as control. Western Blot analysis was used to detect the levels of phosphorylated ATM (p-ATM Ser1981), ATM, phosphorylated p53 (p-p53 Ser15), p53, p21^Cip1 and CDCA2 in the cell lysates. β-actin was used as a loading control.