Mechanism Of Inhibition Of Proliferation Of Lung Squamous Cell Carcinoma By Polyphyllin Ⅵ

Objective:Polyphyllin VI originated from Paris polyphylla Smith var.chinensis(Franch.)Hara,or Rhizome of Liliaceae Yunnan polyphylla Smith var.yunnanensis(Franch.)Hand.-Mazz.It was found from the proliferation,apoptosis,growth,differentiation and so on resplendentin can mechanism to achieve the role of tumor suppression,The molecular mechanism of inhibiting the proliferation of lung cancer has not been elucidated yet.To investigate the inhibitory effect of Polyphyllin VI on cell proliferation in lung squamous cell carcinoma cell line,the effect of Polyphyllin VI on the apoptosis rate and apoptosis related protein was analyzed to explore the molecular mechanism of Polyphyllin VI apoptosis in lung squamous cell carcinoma Mechanisms of cancer cells induced by Polyphyllin VI.Methods:Lung squamous cell carcinoma H226 and H520 cells were cultured in vitro.The effects of different concentrations of Polyphyllin on cell proliferation were analyzed by MTT method,respectively for 24,48 and 72 hours;cluster cloning experiment was conducted to analyze the effects of Polyphyllin VI on the cell’s proliferation capacities;Polyphyllin VI On the apoptosis rate.Western blotting was used to analyze the expression of mitochondrial apoptotic pathway proteins.Results:Polyphyllin VI inhibits the proliferation of lung squamous cell carcinoma cells in a dose-dependent manner.Compared with the control group H226 cells,cell viability decreased after Polyphyllin treatment(94.1%±5.6%,62.3%±3.7%,54.7%±4.7%,10.5%±2.6%,8.5%±2.7%)after cells were treated by Polyphyllin VI(0.5,1,2.5,5 and 10μM)for 24 hours,88.1%±5.3%,35.2%±4.0%,14.7%±3.2%,11.6%±3.8%,13.4%±2.1%after cells were treated for 48 hours,and 85.1%±6.0%,18.3%±3.1%,14.5%±4.3%,12.3%±2.4%,8.6%±1.3%after treated for 72 hours.And the H520 cells,the survival rates were decreased 93.8%±4.7%,76.7%±3.9%,48.5%±4.9%,18.2%±3.0%,9.6%±2.1%after cells were treated by Polyphyllin VI(0.5,1,2.5,5 and 10μM)for 24 hours,91.3%±4.2%,42.5%±5.1%,21.3%±3.8%,10.8%±2.2%,12.6%±3.4%after cells were treated for 48 hours,and 87.1%±6.4%,34.8%±4.2%,9.2%±3.7%,11.4%±2.4%,9.9%±1.8%.after treated for 72 hours.The apoptosis rates were 32.3%,83.5%,and 97.0%.after H226 cells were treated by Polyphyllin VI(2.5、5 and 10μM)for 24 hours.The expression of cleaved caspase3 and cleaved PARP was significantly higher than that of the control group in a dose-dependent manner.The use of Polyphyllin VI for 24 hours increased the expression of pro-apoptotic proteins Bax,Bak,cleaved Caspase9 and decreased the expression of the pro-apoptotic protein Bcl-2.Conclusion:Polyphyllin VI has the effect of inhibiting the proliferation of non-small cell lung squamous cell carcinoma,the molecular mechanism is through the up-regulation of Bax、Bak、cleaved Caspase9,down-regulation of Bcl-2.