Lactate promotes the epithelial-mesenchymal transition of liver cancer cells via TWIST1 lactylation

Elevated lactate levels increase the risk of liver cancer progression. However, the mechanisms by which lactate promotes liver cancer progression remain poorly understood. Epithelial-mesenchymal transition (EMT), characterized by the loss of epithelial cells polarity and cell-cell adhesion, leading to the acquisition of mesenchymal-like phenotypes, is widely recognized as a key contributor to liver cancer progression. TWIST1 (Twist Family BHLH Transcription Factor 1) plays a central role in inducing EMT. Here, we investigated the role of lactate in promoting EMT in liver cancer and the underlying regulatory mechanisms. High levels of lactate significantly promoted EMT progression in liver cancer cells. Mechanistically, lactate-induced lactylation of TWIST1 in vivo and in vitro. Mutation assay confirmed that Lysine 33 (K33) is the major site of TWIST1 lactylation. Moreover, cell fractionation & luciferase reporter assay results identified that TWIST1-K33R mutant impaired the EMT process via inhibiting nuclear import and the transcriptional activity. Thus, our findings provide novel insights into the regulatory role of lactate in EMT in liver cancer pathogenesis. Additionally, targeting of lactate-driven lactylation of TWIST1 may boost the therapeutic strategy for liver cancer.