Schisandrin B inhibits tumor progression of hepatocellular carcinoma by targeting the RhoA/ROCK1 pathway

BACKGROUND: Schisandrin B (Sch. B) performs various pharmacological properties, including anticancer activities. However, the pharmacological mechanisms of Sch. B in hepatocellular carcinoma (HCC) are not fully elucidated. We investigated the impact and mechanism on progression in HCC, and to provide new experimental evidence for HCC treatment. METHODS: To determine the inhibitory effect of Sch. B on HCC in vivo, 32 Balb/c nude mice were used to prepare the tumor-bearing mice model by subcutaneously inoculating HCC cells (Huh-7). As tumor volume grew to 100 mm(3), mice were randomly divided into Saline (control group), 100 mg/kg Sch. B group (Sch. B-L), 200 mg/kg Sch. B group (Sch. B-M), and 400 mg/kg Sch. B group (Sch. B-H) (n=8). Saline or different concentration Sch. B was used to treat mice via gavage administration for 21 days. After mice were euthanized, tumor weight and volume were evaluated. Cell apoptosis was detected by TUNEL. Ki-67 and PCNA were detected by immunohistochemical staining. The RhoA and Rho-associated protein kinase 1 (ROCK1) were determined by western blot. In vitro experiment, Huh-7 cell were treated by Sch. B at 40, 30, 20, 10, 5, 1, and 0 µM to detect cell proliferation by Cell Counting Kit-8 (CCK-8). Huh-7 cells were divided as a control group, Sch. B group, and Sch. B + RhoA overexpression (Sch. B + RhoA) group. RhoA and ROCK1 were examined. The colony formation assay and flow cytometry were used to detect cell proliferation and apoptosis. The wound healing and Transwell assays were used for cell metastasis detection. RESULTS: Our results showed 100, 200 and 400 mg/kg Sch. B significantly reduced tumor weight and volume. And 200 and 400 mg/kg Sch. B increased apoptosis, and reduced Ki-67 and PCNA levels, inhibited the RhoA and ROCK1 in vivo (P<0.05). In vitro experiment, Sch. B inhibited Huh-7 cell proliferation at concentration more than 10 μM (P<0.05). Sch. B decreased cell duplication, promoted apoptosis and blocked migration and invasion of Huh-7 (P<0.05). Sch. B inhibited RhoA and ROCK1 level as compared with control group (P<0.05). RhoA overexpression reversed the effect of Sch. B (P<0.05). CONCLUSIONS: Sch. B inhibits Huh-7 cells progression via RhoA/ROCK1 pathway. The results provide new evidence for the clinical treatment of HCC.