Fig. 7.

p53-dependent apoptosis and cell migration are mediated by modulation of TFF2 expression. A and B: effects of exogenous TFF2 on p53-induced apoptosis in gastric cancer cells. Kato-III cells were transfected with p53WT and control vector in absence and presence of 600 nM TFF2 for 24 h (A) and 48 h (B). Cell apoptosis was detected by FACS using Annexin V-PE apoptosis kit. Representative FACS blot are shown and the data shown represent means ± SE of 3 independent experiments. C and D: downregulation of TFF2 expression sensitized gastric cancer to drug-induced apoptosis. MKN-74 cells were transfected with TFF2 siRNA and control siRNA and then incubated with and without 10 mM 5-fluorouracil (5-FU) for 48 h. Cells were harvested. TFF2 expression was detected by real-time PCR (C) and apoptosis were measured by FACS. The data shown represent means ± SD of 3 independent experiments. E: p53R175H protects gastric cancer cells from apoptosis induced by downregulation of TFF2. MKN-74 cells were cotransfected with TFF2 siRNA or control siRNA in combination with p53R175H or control plasmids for 48 h. Cells were harvested and apoptosis was measured by FACS. The data shown represent means ± SD of 3 independent experiments. F: addition of recombinant TFF2 reverses p53-induced inhibition of cell migration in gastric cancer cells. Transient Kato-III cells transfected with P53WT and control vector in the presence and absence of 600 nM TFF2 were seeded on a Transwell filter inset in a modified Boyden chamber. The migrating cells were fixed on the filter after 6 h, stained, and counted under the microscope. Representative microphotographs are shown and the data represent means ± SE of 3 independent experiments (*P < 0.05 vs. Vector; #P < 0.05 vs. PBS group).