Human non-small cell lung cancer (NSCLC) cell lines included the parental cell line A549 and the cell subline A549/DDP.

Pt levels were expressed as μM/1 × 106 cells, with the cell number determined by counting (Nexcelom Cellometer Auto T4 cell counter, USA) in parallel cultures. Experiments were performed in duplicate and the values expressed were the means ± SD of the three independent experiments.