Figure 1. Deficiency of TS and RRM2 induces senescence in melanoma cells.
(A) Cells were infected with control (CL) or MYC shRNA (M) lentiviral vectors. Five days post-infection, cells were harvested, lysed and total protein extracts were probed in western blotting with the antibodies indicated on the left. (B) Cells were infected with control shRNA lentiviral vector (V) or with a combination of vectors carrying shRNAs for TS or RRM2 shRNAs (T+R). Five days post-infection, cells were harvested, lysed and total protein extracts were probed in western blotting with the antibodies indicated on the left. (C) Cells were infected as in (A). Two days after infection cells were plated in 12-well plate in duplicate and counted every day for 3 days. Numbers below the graph correspond to the days post-infection. (D) Cells were infected as in (B). Five days post-infection, cells were fixed and processed to visualize SA-β-Gal activity, or stained with H2AX-γ-specific antibodies and DAPI. Numbers indicate the percentage of SA-β-Gal-positive cells in each population. The numbers were derived from counting cells in several view fields.