Fig. 8

The schematic diagram depicts the mechanism of CPP-induced enhancement of sensitivity to TRAIL in ESCC cells. In ESCC cells, high expression of FoxP3 can inhibit the expression of DR4 and DR5. CPP could upregulate the expression of DR4 and DR5 through downregulating the expression of FoxP3. In the presence of a sufficient level of DR4/DR5, TRAIL could induce the downstream death signaling. On the other hand, CPP could affect the nuclear localization of β-catenin to inhibit the activity of Wnt/β-catenin pathway, thus inhibiting the transcription of Survivin, which further promotes apoptosis of ESCC cells. Therefore, CPP can enhance the sensitivity of ECSS cells to TRAIL treatment in vitro and in vivo