Differential responses to carboplatin treatment in PC9 and A549 cells.

<p>A: Carboplatin-induced growth inhibition in PC9 and A549 cells using a sulforhodamine B assay 72 h post treatment. B: Western blot analysis of the levels of uncleaved PARP, cleaved PARP and cleaved (active) caspase 3 72 h post carboplatin treatment (0–200 µM) in PC9 and A549 cells. Actin was used as a loading control. C, D: Flow cytometric analysis of PC9 (C) and A549 cells (D) treated with carboplatin (100 µM) or vehicle. Apoptotic cells were identified by Annexin V-Alexafluor488 (λ Ex/Em = 495/519 nm) and necrotic cells by 7-AAD (λ Ex/Em = 546/647 nm). Population Q4 represents viable cells, whereas population Q3 represents apoptotic cells that have low 7-AAD fluorescence and stain with Annexin V. Population Q2 represents secondary apoptotic/necrotic cells.