Figure 4.

NML knockdown compromises cell cycle regulation. (A) A549 NML knockdown cells were treated with 0.1 µM doxorubicin or 0.3 µM CX5461 for 3 and 7 d. Expression levels of cell cycle markers were analyzed by protein gel blot. Numbers in boxes show pair-wise quantitation of control shRNA and NML shRNA. (B) The level of phosphorylated ribosomal protein S6 (Ser240/Ser244) was determined in A549 NML and TIP5 knockdown cells by western blot. Numbers represent relative quantitation of bands. (C) A549 cells were co-treated with doxorubicin and rapamycin for 7 d and cultured in drug-free medium for 21 d to detect colony formation over the senescent monolayer. (D) A549 cells were co-treated with doxorubicin and rapamycin for 7 d and the percentage of SA-β-gal positive cells was determined.