异槲皮苷对HepG2细胞中Raf/MEK/ERK信号通路的干预作用

The inhibitory effect of isoquercitrin on Raf/MEK/ERK signaling pathway in HepG2 cells

目的研究异槲皮苷对Hep G2细胞中Raf/MEK/ERK信号通路的干预作用。方法采用异槲皮苷(0、40、80、160、320μmol·L^(-1))作用于Hep G2细胞,MTT法检测异槲皮苷对Hep G2细胞增殖的影响;倒置显微镜下观察24、48 h后,细胞形态及生长情况;流式细胞术检测异槲皮苷(0、40、80、160μmol·L^(-1))作用Hep G2细胞48 h后细胞周期情况;荧光定量PCR及Western blot检测异槲皮苷作用Hep G2细胞后Ras、Raf、MEK、ERK mRNA及相关蛋白的表达。结果MTT检测发现异槲皮苷对Hep G2细胞生长有明显抑制作用,且与异槲皮苷的浓度及作用时间呈正相关;不同浓度的异槲皮苷作用Hep G2细胞24、48 h后,倒置显微镜下观察发现随着浓度的增高及作用时间的延长,细胞生存数量逐渐减少,且细胞形态发生明显变化;流式细胞术检测发现随着异槲皮苷浓度的增高,细胞被阻滞在G1期的数量逐渐增加;荧光定量PCR及Western blot结果均表明,与空白组相比,异槲皮苷(80μmol·L^(-1))作用Hep G2细胞后Ras、Raf、MEK、ERK mRNA及其相关蛋白的表达均明显降低(P<0.05),差异有统计学意义。结论异槲皮苷有诱导Hep G2细胞凋亡的作用,其作用机制可能与对Raf/MEK/ERK信号通路中相关因子的干预有关。

Aim To study the inhibitory effect of isoquercitrin on Raf/MEK/ERK signaling pathway in Hep G2 cells. Methods MTT was used to detect the proliferation of human liver cancer Hep G2 cells after the treatment of isoquercitrin. The morphology and growth of cells were observed under inverted microscope after the different concentrations of isoquercitrin（ 0,40,80,160,320 μmol·L^（-1）） to treat Hep G2 cells for 24 and 48 h. Cell cycle was assessed by flow cytometry. Ras,Raf,MEK,ERK expression was assayed by Western blot,and mRNA expression was detected by quantitative fluorescence PCR. Results Isoquercitrin could inhibit the growth of Hep G2 cells in a concentration-and time-dependent manner. Typical morphological changes of apoptosis were observed by inverted microscopy after Hep G2 cells were treated with different concentrations of of isoquercitrin for 24 h or 48 h. The cell cycle assay showed that with the increasing concentration of isoquerditrin,the number of cells that was arrested in G1 phase gradually increased.Compared with the blank group, the expressions of Ras,Raf,MEK,ERK mRNA were down-regulated,and related proteins expression were also down-regulated（ P〈 0. 05）,and these results had statistical significance. Conclusion Isoquercitrin can induce the apoptosis of Hep G2 cells,which may be related to the Raf/MEK/ERK signaling pathway.