Flavone Of Yunnan Purpleblow Maple Is A Potent Apoptosis Inducer In YTMLC Cells

[Objective] To evaluate the apoptosis-inducing effect of flavone(which was extracted from Yunnan purpleblow maple) on YTMLC cells and Changes in gene expression induced by this effect, and to explore the possible inhibitive mechanism on Lung squamous cell carcinoma in vitro by this effect, the research would provide an experimental basis and a new method and approach for the therapy lung cancer.[Methods] 1.MTT (Methy thiazolyl tetrazolium) assay was used to evaluate the inhitory effects of flavone of Yunnan purpleblow maple in different concentration and time. MTT (Methy thiazolyl tetrazolium) assay was used to evaluate the inhibitory effects of flavone of Yunnan purpleblow maple on cells YTMLC in different time and different concentration, calculating the half inhibiting concentration,in order to find out the experimental dose.2.The morphology of apoptosis cells induced by flavone were observed by invert microscope, fluorescence microscope, sanning electron microscope and transmission electron microscope. FCM(the fluorescence flow cytomtry) were applied to detect the changes of apoptotic rate at early and late apoptosis process and cell proliferation and alteration of cell cycle phase. DNA fragmentation (DNA ladder) assay indicate that flavone induced the apoptosis on YTMLC cell line.3.p53,p21,Bcl-2,Bax and Caspase-3 gene expression of YTMLC cells was tested by reverse transcriptive-polymerase chain reaction(RT-PCR).4. The levels of albumen were tested by western-blot after treatment with the flavone.[Results] 1.Flavone of Yunnan purpleblow maple could inhibit the proliferation of the YTMLC cancerous cells in vitro and the inhibition depended on the dose and exposure time. The IC50(μg/ml) value of YTMLC cells was 151.24±13.16ug/ml,108.53±8.22ug/m,70.21±9.62 ug/ml;after treated with the flavone for 24h,48h, and 72h respectively.2.Apoptotic morphology changes were observed by invert microscope, fluorescence microscope and transmission electron microscope. Flow cytometry showed that the flavone can induce both apoptosis and necrosis. The results of DNA ladder also certified that there are apoptosis.3.RT-PCR results showed that: the YTMLC cells treated with the flavone for 48 h and 72h, p53,p21,Bax,Caspase-3 gene expression were relative increased respectively, Bcl-2 gene expression decreased relative, Compared with the control group,p<0.01,with a highly significant difference.4. Western-blot results showed:After the flavone treated with YTMLC cells for 24h, there is no significant change in the relative expression of p53 protein and Bcl-2 protein;48h and 72h later, the relative expression of p53 protein increased, while the Bcl-2 protein reduced.[Conclusion]1.Flavone of Yunnan Purpleblow Maple can inhibit the growth of YTMLC cells in vitro.2. The mechanism of the flavone inhibiting the growth of YTMLC cells, may be related to up regulating the expression of p53,p21,Bax,Caspase-3 gene and down regulating the expression of Bcl-2 gene.3.Flavone of Yunnan Purpleblow Maple might promote the expression of p53,p21 protein and ihhibite the expression of Bcl-2 protein.