Anticancer Activity of Sageretia thea Through β-catenin Proteasomal Degradation in Human Colorectal Cancer and Lung Cancer Cells

Anticancer Activity of Sageretia thea Through β-catenin Proteasomal Degradation in Human Colorectal Cancer and Lung Cancer Cells

In this study, we evaluated the anti-cancer activity and potential molecular mechanism of 70% ethanol extracts of branches from Taxillus yadoriki parasitic to Neolitsea sericea (TN-NS-B) against human lung cancer cells, A549. TY-NS-B dose-dependently suppressed the growth of A549 cells. TY-NS-B decreased <TEX>${\beta}$</TEX>-catenin protein level, but not mRNA level in A549 cells. The downregulation of <TEX>${\beta}$</TEX>-catenin protein level by TY-NS-B was attenuated in the presence of MG132. Although TY-NS-B phosphorylated <TEX>${\beta}$</TEX>-catenin protein, the inhibition of <TEX>$GSK3{\beta}$</TEX> by LiCl did not blocked the reduction of <TEX>${\beta}$</TEX>-catenin by TY-NS-B. In addition, TY-NS-B decreased <TEX>${\beta}$</TEX>-catenin protein in A549 cells transfected with Flag-tagged wild type <TEX>${\beta}$</TEX>-catenin or Flag-tagged S33/S37/T41 mutant <TEX>${\beta}$</TEX>-catenin construct. Our results suggested that TN-NS-B may downregulate <TEX>${\beta}$</TEX>-catenin protein level independent on <TEX>GSK3${\beta}$</TEX>-induced <TEX>${\beta}$</TEX>-catenin phosphorylation. Based on these findings, TY-NS-B may be a potential candidate for the development of chemopreventive or therapeutic agents for human lung cancer.