FTY720Attenuates Motility And Invasion Of Hepatocellular Carcinoma Cells Via Inhibition Of STAT3

Objective:To investigate the anti-proliferation and anti-metastasis activity of a novel immunosuppressant-FTY720against hepatocellular carcinoma cells and to preliminarily explore the underlying mechanisms. We aimed to provide scientific evidence for the application of this novel immunosuppressant in the treatment of hepatocellular carcinoma.Methods1. MTT assay was used to assess cytostatic activity on SMMC-7721and Huh7cell induced by FTY720with different concentrations (0μM to20μM).2. The SMMC-7721cell was treated with FTY720of various concentrations (0μM to10μM), and wound healing assay and Transwell experiment were used to observe the inhibition of the migration and invasion.3. The SMMC-7721and Huh7cell were treated with FTY720of various concentrations (0μM to10μM), and then we examined S1PR1and phospho-STAT3protein levels by western blot.4. The quantification of IL-6from SMMC-7721and Huh7cell culture supernatants, treated with FTY720of various concentrations (0μM to10μM).was examined by enzyme-linked immunosorbent assay (ELISA).5. We established a liver orthotopic xenografttumor model.The SMMC-7721tumor-bearing mice were randomly assigned into two groups and were treated by intraperitoneal injection with FTY720(5mg/kg body weight) or DMSO vehicle every day. After14days, the mice were sacrificed. Tumor volume and intrahepatic metastasis were assessed.Results:1. MTT assay indicated that proliferation of SMMC-7721and Huh7was inhibited by FTY720at various concentrations (0μM to20μM), As the concentration increased, the inhibitory effect was more obvious;2. The migration of SMMC-7721was significantly inhibitedby FTY720in a dose-dependent manner;3. FTY720inhibited S1PR1and phospho-STAT3protein levels in a dose-dependent manner;4. FTY720significantly inhibited IL-6secretion of SMMC-7721and Huh7in a dose-dependent manner;5. The treatment of FTY720decreased the tumor growth and intrahepatic metastasis in the orthotopic xenograft hepatocellular carcinoma model.Conclusion:1. FTY720inhibits the proliferation, migration and invasion of hepatocellular carcinoma cells;2. The mechanism of these antitumor activities is attributed to the inhibition of S1PR1and subsequently on the phosphorylation of STAT3by FTY720;3. The inhibition of IL-6secretion may play an important role in the antineoplastic activity of FTY720.