A paraptosis-like cell death induced by δ-tocotrienol in human colon carcinoma SW620 cells is associated with the suppression of the Wnt signaling pathway

Tocotrienol is considered a beneficial effect agent on inhibition of tumor development. In this study, we focused on the effects of delta-tocotrienol and its possible mechanism on induction of death in human colon cancer SW620 cells. delta-Tocotrienol inhibited proliferation of SW620 cell in a dose-dependent manner. Our findings showed that delta-tocotrienol effectively induced paraptosis-like death in SW620 cells, correlated with the vacuolation that may be from welling and fusion of mitochondria and/or the endoplasmic reticulum (ER) as well as caspase-3 nonactivated. However, there were no changes in apoptosis based on flow cytometry analysis. Of being noted. delta-tocotrienol reduced the expression of beta-catenin and wnt-1 proteins by about 50% at the highest dose (20 mu mol/L). delta-Tocotrienol also decreased cyclin D1, c-jun and MMP-7 protein levels in SW620 cells. Altogether, these data indicate that delta-tocotrienol induces paraptosis-like cell death, which is associated with the suppression of the Wnt signaling pathway. Thus, our findings may provide a novel application in treatment of human colon carcinoma. Crown Copyright (C) 2011 Published by Elsevier Ireland Ltd. All rights reserved.