Triptonide inhibits growth and metastasis in HCC by suppressing EGFR/PI3K/AKT signaling.

Liver cancer represents one of the deadliest cancers, with a rising incidence worldwide. Triptonide is found in the traditional Chinese medicinal plant Tripterygium wilfordii Hook. This study aimed to examine the anticancer properties of triptonide in human hepatocellular carcinoma (HCC). HCC cells were administered with triptonide at various levels, and CCK-8 and colony formation assays were carried out for detecting HCC cell proliferation. Then, cell apoptosis and cell cycle distribution were evaluated by flow cytometry. Tumor growth was monitored noninvasively by ultrasound imaging. Cell migration and invasion were quantitated by wound healing and Transwell assays. A metastasis model was established via tail vein injection of HCC cells in nude mice. Immunoblot was performed to quantitate the expression of proteins involved in the EGFR/PI3K/AKT signaling and its downstream effectors. Triptonide repressed cell proliferation and induced cell cycle arrest and apoptosis in cultured HCC cells, and suppressed tumor growth in vivo. In addition, triptonide inhibited EMT, migration and invasion in cultured HCC cells, and lung metastasis in nude mice. Mechanistically, triptonide acted by inhibiting the EGFR/PI3K/AKT signaling and downregulated its downstream effectors, e.g., the cell cycle-associated protein cyclin D1, the apoptosis-related protein Bcl-2, the EMT marker E-cadherin, and the invasion-related protein MMP9. Triptonide suppresses proliferation, EMT, migration and invasion, and promotes apoptosis and cell cycle arrest by repressing the EGFR/PI3K/AKT signaling. Therefore, triptonide might be considered for liver cancer treatment.