Fig. 1

Dose-dependent responses of A549, NCI-H661 and MRC-5 cells to LCSE. Cells were treated with increasing concentrations of LCSE as indicated and then incubated at 37 °C for 24 h to obtain a dose-dependent response. Viable cells were stained with trypan blue and counted under a microscope. Cell viability was expressed as the percentage of untreated cells. a. Colony formation of LCSE-treated cells was assessed by seeding 200 cells in a 6-well plate and treating with LCSE (1 ~ 50 μg/mL), followed by incubation at 37 °C for 14 days. On day 14, the colonies were fixed in 70% ethanol and stained with 0.2% crystal violet. Colonies of >50 cells were counted and the colony-forming potential of LCSE-treated NSCLC cells was expressed as the percentage of colonies of the untreated cells (b). Data are the average of three independent experiments and are expressed as means ± SD. *P < 0.05 (compared with untreated control); # P <0.01 (compared within A549 and NCI-H661)