Disrupting β-tubulin/CCT-β complexes induces apoptosis and suppresses migration and invasion of CL1-5 cells through MMP-2 and AKT/GSK-3β inhibition

• Main Authors: Yu-Ting Kuo, 郭育廷
• Other Authors: Po-Huang Liang
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/4jgwn2

碩士 === 國立臺灣大學 === 生化科學研究所 === 105 === We have previously demonstrated that I-Trp with an iodomethyl ketone warhead to alkylate Cys354 of β-tubulin, thereby disrupting the protein-protein interaction (PPI) of -tubulin with chaperonin-containing TCP-1β (CCT-β), causes cancer cell apoptosis [1]. In this study, we found that in CL1-5 cells, I-Trp activates both ER stress related proteins and proteasome activity to eliminate the imbalance proteins loading in ER, thereby mitigating ER stress, at the onset of β-tubulin/CCT-β complexes disruption. In addition, ER stress-associated apoptotic signaling is usually accompanied with intracellular Ca2+ release and the activation of MAPKs. We also observed the elevated intracellular Ca2+ levels, activation of MAPKs and caspase over-activation. Since CL1-5 cells are a highly metastatic lung cancer cell line, we assayed for its migration/invasion in the presence of I-Trp, where there were 80% survived cells to ensure most of the cells were not killed. The experimental results demonstrate the dose-dependent inhibition of CL1-5 cell migration and invasion. Furthermore, the mechanistic studies revealed that I-Trp inhibited phosphorylation AKT, and GSK-3β of CL1-5 cells, thereby downregulating MMP-2 expression and activation. In conclusion, this study reveals a novel therapeutic strategy potential for evoking apoptotic signaling by targeting β-tubulin/CCT-β complexes, and its anti-migration/invasion activity against human lung adenocarcinoma.