Novel ADAM-17 Inhibitor ZLDI-8 Inhibits the Metastasis of Hepatocellular Carcinoma by Reversing Epithelial-mesenchymal Transition in Vitro and in Vivo

Aims: Epithelial-mesenchymal transition (EMT) is one of the important regulators of metastasis in advanced hepatocellular carcinoma (HCC). Blocking the Notch signaling pathway and then reversing the EMT process is a hot spot in clinical tumor research. Here, we aimed to investigate the effect and underlying mechanisms of ADAM-17 (a key cleavage enzyme of Notch pathway) inhibitor ZLDI-8 we found before on the metastasis of hepatocellular carcinoma in vitro and in vivo.

Main Methods: The cell viability of HCC cells was evaluated by MTT and colony formation assays. Migration and invasion were assessed respectively with wound healing and transwell assays. The expression and location of proteins were detected by western blot and immunofluorescence, respectively. The effects of ZLDI-8 on metastasis of liver cancer in vivo were investigated in a tail vein injection model.

Key Findings: In the present work, ZLDI-8 significantly inhibited proliferation, migration, invasion and EMT phenotype of highly aggressive MHCC97-H and LM3 cells. Moreover, ZLDI-8 could inhibit the migration and invasion of HepG2 and Bel7402 cells induced by TGF-β1. ZLDI-8 suppressed the protein expression of interstitial markers and increased that of epithelial markers. Meanwhile, ZLDI-8 decreased the expression of proteins in the Notch signaling pathway. Finally, ZLDI-8 blocks metastasis in the lung metastasis model in vivo.

Significance: ZLDI-8 suppressed the metastasis of hepatocellular carcinoma, which was associated with reversing the EMT process and regulating Notch signaling pathway. The study laid the foundation for the discovery of drugs that reverse EMT to inhibit advanced HCC metastasis.