Fig. 4.

Role of JNK and FOXO1 in gastric tumor cell growth. SNU-638 cells were (a and c) cultured with or without 20 μM SP600125 (SP) for 14 days and/or (b and c) transfected with non-targeting shRNA (shCtrl) or FOXO1 shRNA (shFOXO1). Cell growth ability in vitro was evaluated by colony formation assay. Representative images of colonies are shown and the bar graphs represent the relative colony formation efficiencies. Percentage colony formations for control cells were arbitrarily set to 100 % and percentages for others were adjusted accordingly. a SP-treated cells showed a marked reduction in colony formation compared to DMSO control (* P = 0.013). b shFOXO1 transfection induced a significant enhancement in colony formation compared to shCtrl transfection (* P = 0.021). c SP treatment induced a marked suppression in colony formation compared to DMSO + shCtrl (* P = 0.01), and the combination with shFOXO1 transfection partially restored the colony formation compared to SP treatment (^# P < 0.001). Each bar represents the mean ± standard deviation