Full Length Research Paper

Curcumin induces cleavage of β-catenin by activation of capases and downregulates the β-catenin/Tcf signaling pathway in HT-29 cells

L. L. Qi¹, J. B. Wang^{1, 2}*, H. Z. Wang¹, Y. T. Luo¹ and T. X. Wu²

¹Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China.

²Department of Chemistry, Zhejiang University, Hanzhou 310027, China.

*Corresponding author. E-mail: wjb@nit.net.cn. Fax: +86-574-88229516.

Tel: +86-574-88229516.

Accepted 8 September, 2009

   Abstract

β-Catenin/Tcf-4 signaling pathway plays important roles in colorectal tumorigenesis. RT-PCR, western blotting and immunoprecipitation were used to study the effects of curcumin on β-catenin/Tcf-4 signaling pathway in HT-29 cells. Treatment of curcumin could induce cleavage of β-catenin and the cleavage could be inhibited by caspase inhibitors. The association of β-catenin with Tcf-4 in nucleus could be inhibited by curcumin. The expression of c-myc and cyclinD1 was downregulated by curcumin, which could not be blocked by Z-DEVD-FMK. The results showed curcumin could induce the cleavage of β-catenin by activition of caspases and downregulate the activity of β-catenin/Tcf signaling pathway independent of the caspases in HT-29 cells.

Key words: Curcumin, β-catenin/Tcf signaling pathway, HT-29 cells.