Figure 1.

Proliferative bystander effect of drug-induced senescent prostate cancer cells in vitro. (A) Bright-field images of DU145 cells cultured on cover slips ±25 nM doxorubicin (DOX) for 3 days, fixed and stained for SA β-gal activity (400 ×). (B) Number of proliferating DU145-GFP⁽⁺⁾or LNCaP-GFP⁽⁺⁾ cells after coculture with proliferating or senescent non-tagged cancer cells measured by flow cytometry. Replicate results were averaged from four independent experiments. These results represent the average fold increase of cell numbers in senescent cocultures relative to proliferative cell data. Error bars represent standard error (^*P<0.0001; ^**P=0.022). (C) BrdU+ incorporation in cells after direct coculture (left) and in transwells (right) after 30 min incubation with 20 uM BrdU. The results of three independent experiments were averaged and the numbers of cells from senescent cocultures were normalised to that of proliferating cocultures. Error bars represent standard error (^*P=0.003, ^**P<0.0001).