Figure 4

Dkk1 blocks Dkk3 activity. Dkk3 (white bars) and control (black bars) stable cell lines (HEK293 cells) were transfected with the control vector ("no Dkk1") and TOP-FLASH and LacZ plasmids then treated with Wnt3a. The Dkk3 cell line had more Wnt signaling than the vector control line (Luciferase Activity units shown). Transfection of Dkk1 completely abolished Wnt signaling in both the Dkk3 stable cell line and the control cell line. This result suggests that Dkk3 acts in a Dkk1-dependent pathway. * = p < 0.05. Mean ± standard deviation is shown.