Emetine dihydrochloride suppresses the invasiveness and motility of hepatocellular carcinoma cells through MAPK pathway inhibition and Twist1 protein destabilization.

Epithelial-mesenchymal transition (EMT) is a crucial step in the development and metastasis of cancer. Emetine was previously proposed as an antiemetic and a protein synthesis inhibitor, but its effect on cancer metastasis has not been evaluated. Therefore, this study sought to investigate the mechanisms regulating cell migration in the context of EMT using emetine dihydrochloride (EDH) in various HCC cell lines (Huh7, Hep3B, SNU449, SNU886, and PLC-PRF-5). EDH inhibited the migration and invasion of HCC cell lines at non-toxic concentrations. EDH inhibited cancer cell motility by reducing Twist1 protein levels, a key transcription factor involved in EMT. This reduction in Twist1 suppressed the expression of mesenchymal markers (N-cadherin and vimentin) while increasing the expression of epithelial marker E-cadherin. MG132 rescue and cycloheximide chase assays suggested that EDH may reduce Twist1 protein stability. EDH also suppressed JNK and p38 MAPK signaling, pathways previously implicated in the regulation of Twist1 phosphorylation at Serine 68 (S68). Consistently, EDH-induced reduction in Twist1 stability was attenuated in cells expressing the phosphorylation-deficient Twist1 S68A mutant, supporting a possible contribution of S68-associated MAPK signaling to EDH-mediated Twist1 regulation. Collectively, these findings suggest that EDH attenuates mesenchymal characteristics and motility in HCC cells, potentially through EMT-related mechanisms associated with altered Twist1 stability. Although further in vivo and mechanistic validation is required, our results suggest that EDH may have potential as an anti-metastatic candidate for HCC.