Magnesium cantharidate inhibits hepatocellular cancer by targeting RACK1

Objective: The aim of this study was to investigate whether magnesium cantharidate (MC) exerts anti-hepatocellular carcinoma (anti-HCC) effects by targeting receptor for activated C kinase 1 (RACK1). Methods: The Cancer Genome Atlas (TCGA) database was used to analyze the expression of RACK1 in liver tissues. Molecular docking was used to examine the binding interactions between MC and RACK1. Huh-7 and SK-Hep-1 liver cancer cells' viability, proliferation, and apoptosis were assessed by using the Cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry, respectively. RNA sequencing was used to explore the underlying mechanisms. Quantitative real-time PCR, immunohistochemistry, and western blotting were performed to explore the expression of key genes and proteins. Results: TCGA analysis revealed significant upregulation of RACK1 in liver cancer tissues that was correlated with tissue type, grade, TP53 mutation, and overall survival. Molecular docking results revealed that the minimum binding energy between MC and RACK1 was -5.8 kcal/mol. Moreover, RACK1 overexpression significantly promoted cell viability and proliferation, and inhibited apoptosis in liver cancer cells. However, MC significantly reversed the viability, proliferation, and apoptosis effects induced by RACK1 overexpression in liver cancer cells. MC significantly inhibited the growth of subcutaneously transplanted tumors in vivo. RNA sequencing revealed that MC inhibited proliferation and apoptosis by targeting RACK1 to regulate calcium ion transport, ion channels, and cell adhesion in liver cancer cells. Conclusion: MC exerts anti-HCC effects by targeting RACK1.