Jiang Sui, Chen Xi-Lin, Ding Yong, Chen Zhong-Wei, Zhu Li-Jun, Feng Hang, Zhen Mao-Chuan, Wang Qiang
Department of Stomatology, Guangdong Provincial People's Hospital, Guangzhou 510080, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2009 Jul;29(7):1381-3.
To explore the effects of epigallocatechin-3-gallate (EGCG) on the proliferation of human oral epithelial cancer cell line KB cells and the molecular mechanisms.
KB cells were treated with various concentrations of EGCG for 24 or 48 h. MTT assay was used to test the cell viability. The changes of cell cycle in KB cells treated with EGCG for 48 h were analyzed using flow cytometry. The expressions of cyclin A, cyclin D1 and cyclin E were detected by RT-PCR and Western blotting.
The viability of KB cells treated with various concentrations of EGCG (25, 50, 100, 200, 400, and 800 micromol/L) for 48 h were decreased to (85.4-/+2.4)%, (80.4-/+2.8)%, (51.5-/+4.5)%, (30.2-/+1.9)%, (25.3-/+1.5)%, (20.0-/+1.1)%, respectively, showing significant difference from that of the control group [(100.0-/+2.2)%, P<0.05). EGCG decreased the viabilities of KB cells in a dose-dependent manner. Flow cytometry demonstrated that treatment with EGCG significantly increased the cell percentage in sub-G1 phase, which was (73.5-/+4.4)% after a 48-h EGCG treatment, significantly different from that in the control group [(47.3-/+3.5)%, P<0.05). EGCG-induced G1 phase arrest was correlated to the down-regulation of cyclin A and cyclin E.
EGCG inhibits the proliferation of KB cells by inducing G1 phase arrest, which involves the downregulation of cyclin E.
探讨表没食子儿茶素没食子酸酯（EGCG）对人口腔上皮癌细胞系KB细胞增殖的影响及其分子机制。
用不同浓度的EGCG处理KB细胞24或48小时。采用MTT法检测细胞活力。用流式细胞术分析经EGCG处理48小时的KB细胞的细胞周期变化。通过RT-PCR和蛋白质印迹法检测细胞周期蛋白A、细胞周期蛋白D1和细胞周期蛋白E的表达。
用不同浓度（25、50、100、200、400和800微摩尔/升）的EGCG处理KB细胞48小时后，细胞活力分别降至（85.4±2.4）%、（80.4±2.8）%、（51.5±4.5）%、（30.2±1.9）%、（25.3±1.5）%、（20.0±1.1）%，与对照组[（100.0±2.2）%]相比有显著差异（P<0.05）。EGCG以剂量依赖性方式降低KB细胞的活力。流式细胞术表明，EGCG处理显著增加了亚G1期的细胞百分比，经EGCG处理48小时后为（73.5±4.4）%，与对照组[（47.3±3.5）%]相比有显著差异（P<0.05）。EGCG诱导的G1期阻滞与细胞周期蛋白A和细胞周期蛋白E的下调有关。
EGCG通过诱导G1期阻滞抑制KB细胞增殖，这涉及细胞周期蛋白E的下调。
