The Effects And Mechanism Of MTOR Inhibitor AZD8055in HepG₂Cells

Aims:Liver cancer is one of the most common malignant tumors, the incidence of which is high in our country. mTOR signaling pathway is crucial in the development of various tumors. AZD8055is a latest developed oral ATP competitive mTOR kinase inhibitor, having a very strong inhibition of mTOR activity. This study aims to investigate the effect of AZD8055on the proliferation and apoptosis in human hepatoma cell line HepG2,as well as to explore the molecular mechanism.Methods:HCC cell line HepG2were cultured, cells were treated with AZD8055at different times and then the cell proliferation, cell cycle and cell apoptosis were measured. In the situations of per-and post-treatment of AZD8055, variation of cell morphology was observed by microscope.The phosphorylation levels of S6K and Akt in PI3K/Akt/mTOR pathway were detected by immunohistochemical analysis.The mRNA expressions of invasion-related MMP2and MMP9detected by RT-PCR.Results:Cultured cells were treated with10nM AZD8055for different times.24h after treatment of AZD8055, the HepG2cell density was depressed and morphology of cell became smaller androunder. The proliferation of HCC cells was significantly inhibited by AZD8055in a time-dependent manner(P<0.05). Meanwhile, AZD8055treatment induced G0/G1phase cell cycle arrest and cell apoptosis in HCC cells.During the prolonged treatment with AZD8055, the express of MMP2and MMP9were decreased. The phosphorylation levels of S6K and Akt in PI3K/Akt/mTOR pathway were also reduced in a time dependent manner.Conclusion:In virto, AZD8055inhibits the growth of HCC cells through inducing G0/G1phase cell arrest and cell apoptosis.MMP2and MMP9are important factors in tumor invasion and metastasis, the mRNA expressions of invasion-related MMP2and MMP9were gradually decreased with the prolonged duration of the treatment of AZD8055, indicating that AZD8055might inhibit invasion and metastasis of human hepatic carcinoma cells.The phosphorylation of the AKt and S6K were deregulated, suggesting that the activity of mTOR was downregulated.