c-FLIPL-mediated Wnt activation dependent on TIP49 expression.
A, 293T cells were transfected with control siRNA or target TIP49 siRNA. Endogenous TIP49 and c-FLIPL expression were examined after transfection for 48 h. B, 293T cells were first transfected with TIP49 siRNA or control siRNA for 24 h, then co-transfected with TOPFLASH and expression vector as indicated for an additional 24 h. Luciferase activities in fold-change were determined. The protein expression was measured by Western blot. C, 293T cells were co-transfected with TOPFLASH or FOPFLASH, and the indicated expression vector. Luciferase activities in fold-change were determined. D, TOPFLASH luciferase activity was detected in the cells cotransfected with HA-FLIPL and an increasing amount of TIP49D302N expression vector after transfection for 24 h. Cell lysates were analyzed by Western blot analysis using antibodies as indicated. *, p < 0.05; **, p < 0.01. E, A549 cells were transfected with siRNAs as indicated. After 36 h, cells were stimulated with 20 mm LiCl for 12 h and harvested for luciferase assay and Western blot analysis.