人参皂苷Rg3诱导膀胱癌细胞系EJ的凋亡作用

目的：探讨Rg3抑制膀胱癌细胞的作用及其诱导凋亡的机制。方法：用一定质量浓度的Rg3 处理膀胱癌细胞系EJ细胞,MTT法检测细胞增殖活力和抑制率50%的时候药物的浓度(IC₅₀)；Hoechst33258荧光染色观察凋亡细胞的形态；流式细胞仪分析细胞周期及细胞凋亡率；免疫细胞化学观察caspase-3的表达变化；琼脂糖凝胶电泳测定DNA梯状带。结果：Rg3抑制EJ细胞生长,呈浓度依赖关系,Rg3处理细胞48 h的IC₅₀为125.5 mg·L^-1；经150 mg·L^-1Rg3处理细胞24 h和48 h后,观察到典型的凋亡细胞形态,即染色质凝集、核片段化、凋亡小体、核内致密的颗粒状荧光及caspase-3的表达增加；并呈时效依赖关系；用75 mg·L^-1Rg3处理细胞24,48,150 mg·L^-1的Rg3处理细胞48 h后,Rg3诱导了细胞凋亡和调节细胞周期,S期和G₂/M期的细胞比率增加,G₀/G₁的细胞比率下降；凋亡率从对照组的(1.05±0.17)%分别上升到(8.41±0.98)%,(18.57±2.20)% 和(33.98±1.64)%,琼脂糖凝胶电泳检测出典型的DNA梯形条带,其效应随药物浓度的增加和作用时间的延长而增强。结论：Rg3可通过诱导EJ细胞凋亡而发挥其抑制细胞增殖的作用。

Inducement effect of ginsenoside Rg3 on apoptosis of human bladder transitional cell carcinoma cell line EJ

Objective: To explore the effect of Rg3 on inhibiting and inducing apoptosis of bladder cancer cells. Method: The bladder cancer cell line EJ was treated with Rg3 of various concentrations. Cell proliferation was measured by MTT assay. Morphological changes of cells were observed by fluorescent staining of Hoechst 33258. Cell cycle and apoptosis rate were analyzed by flow cytometry (FCM). The expression of caspase-3 in cells was detected by immunocytochemistry. DNA ladder was showed by agarose gel electrophoresis. Result: Rg3 inhibited proliferation of EJ cells in a manner of concentration-dependent relationship, IC₅₀ of Rg3 in 48 h treatment was 125.5 mg·L^-1 to EJ cells. When treated with 150 mg·L^-1 of Rg3 for 24 h and 48 h, the cells showed apoptotic morphological characteristics including the condensed chromatin, the nuclear fragmentation, the apoptotic body and bright fluorescent granules as well as a higher caspase-3 expression. FCM assay indicated that Rg3 regulated cell cycle and induced apoptosis of EJ cells. When treated for 24 h and 48 h with 75 mg·L^-1 of Rg3 as well as for 48 h with 150 mg·L^-1 of Rg3, the percentages of cells in S phase and G₂/M phase were increased, whereas the percentage of cells in G₀-G₁ was decreased.The apoptosis rates were increased from(1.05±0.17)% in control group cells to (8.41±0.98)%, (18.57±2.20)% and (33.98±1.64)%,respectively.Remarkable DNA ladders were revealed.The effects showed a manner in dose and time dependent of Rg3. Conclusion: The results suggest that ginsenoside Rg3 exerts an inhibiting effect on proliferation of EJ cells by inducing apoptosis.