Celastrol inhibits ezrin-mediated migration of hepatocellular carcinoma cells.

Progression of hepatocellular carcinoma involves multiple genetic and epigenetic alterations that promote cancer invasion and metastasis. Our recent study revealed that hyperphosphorylation of ezrin promotes intrahepatic metastasis in vivo and cell migration in vitro. Celastrol is a natural product from traditional Chinese medicine which has been used in treating liver cancer. However, the mechanism of action underlying celastrol treatment was less clear. Here we show that ROCK2 is a novel target of celastrol and inhibition of ROCK2 suppresses elicited ezrin activation and liver cancer cell migration. Using cell monolayer wound healing, we carried out a phenotype-based screen of natural products and discovered the efficacy of celastrol in inhibiting cell migration. The molecular target of celastrol was identified as ROCK2 using celastrol affinity pull-down assay. Our molecular docking analyses indicated celastrol binds to the active site of ROCK2 kinase. Mechanistically, celastrol inhibits the ROCK2-mediated phosphorylation of ezrin at Thr567 which harnesses liver cancer cell migration. Our findings suggest that targeting ROCK2-ezrin signaling is a potential therapeutic niche for celastrol-based intervention of cancer progression in hepatocellular carcinoma.

Shenqi Fuzheng Injection (SFI) Enhances IFN-α Inhibitory Effect on Hepatocellular Carcinoma Cells by Reducing VEGF Expression: Validation by Gene Silencing Technique.

Shenqi Fuzheng Injection (SFI) is a traditional Chinese medicine injection with anticancer properties and is mainly composed of ginseng and astragalus. Its efficacy has been confirmed in clinical trials, but the mechanism remains unclear. We investigated the effect of SFI on vascular endothelial growth factor (VEGF) gene expression in hepatocellular carcinoma (HCC) cells and identified its possible mechanism of synergistic effects when combined with the chemotherapeutic drug interferon (IFN-) α. An MTT assay was used to measure the inhibition effects of low-dose IFN-α (6000 IU) with or without SFI (0.5 g/L) on the HCC cell line MHCC97. VEGF-silenced MHCC97L-mir200 cell lines were prepared using lentiviral vectors and evaluated by real-time PCR to determine the inhibition effect. We examined MHCC97L-mir200 and MHCC97L cells by MTT assay, using IFN-α alone or in combination with SFI. The inhibition ratio of IFN-α (6000 IU) was -29.5%, while that for IFN-α (6000 IU) + SFI (0.5 g/L) was 17.0%, which was significantly higher than that for the IFN-α group (P < 0.01). The VEGF gene was silenced successfully in MHCC97-L cells. After interference of VEGF, the inhibition by SFI and IFN-α in MHCC97L-mir200 did not differ from that in MHCC97-L cells (P > 0.05). SFI can reduce the expression of VEGF in HCC, which can increase the efficacy of IFN-α, providing a theoretical basis for clinical application.