Figure 2.

Cell viability of NCI-H460 cells.

Notes: (A and B) Cell viability (percentage of control) of NCI-H460 cells at the end of 24 hours following treatment with increasing concentrations of TPT (A) and Tx (B). n=3. (C) Cell viability (percentage of control) of NCI-H460 cells at the end of 48 hours (24-hour drug incubation, followed by 24-hour drug-free incubation) following combination (simultaneous) treatment with TPT and Tx (ratio 5:1). n=3. (D) Cell viability (percentage of control) of NCI-H460 cells at the end of 72 hours (treatment with Tx [5 hours], followed by drug-free incubation period [19 hours], followed by treatment with various concentrations of TPT [24 hours], followed by drug-free incubation period for 24 hours). *Indicates significance (P<0.05) between additive effect of Tx and TPT when treated individually vs their sequential treatment. n=3.

Abbreviations: TPT, topotecan; Tx, paclitaxel.