Oxymatrine DownregulatesHPV16E7Expression and Inhibits Cell Proliferation in Laryngeal Squamous Cell Carcinoma Hep-2 Cells In Vitro
Objective. To investigate the possible mechanisms of oxymatrine’s role in anti laryngeal squamous cell carcinoma.Methods. We examined the effects of oxymatrine on the proliferation, cell cycle phase distribution, apoptosis, and the protein and mRNA expression levels ofHPV16E7gene in laryngeal carcinoma Hep-2 cells in vitro. TheHPV16E7siRNA inhibition was also done to confirm the effect of downregulatingHPV16E7on the proliferation in Hep-2 cells.Results. Oxymatrine significantly inhibited the growth and proliferation of Hep-2 cells in a dose-dependence and time-dependence manner. Oxymatrine blocked Hep-2 cells in G0/G1 phase, resulting in an obvious accumulation of G0/G1 phase cells while decreasing S phase cells. Oxymatrine induced apoptosis of Hep-2 cells, whose apoptotic rate amounted to about 42% after treatment with 7 mg/mL oxymatrine for 72 h. Oxymatrine also downregulated the expression ofHPV16E7gene, as determined by the western blotting and reverse transcription-polymerase chain reaction analysis. Knockdown ofHPV16E7effectively inhibited the proliferation of Hep-2 cells.Conclusions. Oxymatrine inhibits the proliferation and induces apoptosis of laryngeal carcinoma Hep-2 cells, which might be mediated by a significant cell cycle arrest in G0/G1 phase and downregulation ofHPV16E7gene. Oxymatrine is considered to be a likely preventive and curative candidate for laryngeal cancer.