芦荟大黄素纳米脂质体介导的光动力对胃癌细胞的作用

Effects of aloe-emodin nanoliposome-induced photodynamic therapy on human gastric cancer cells

摘要:

目的：探讨芦荟大黄素纳米脂质体介导的光动力作用对胃癌细胞增殖、凋亡的影响。方法：体外培养人胃癌细胞SGC-7901，芦荟大黄素纳米脂质体（16 μg/ml）作用胃癌细胞（1、2、4、6、8 h）后，采用激光共聚焦显微镜检测芦荟大黄素纳米脂质体在胃癌细胞中的摄取情况；不同浓度芦荟大黄素纳米脂质体（0、2、4、8、16、32 μg/ml）作用胃癌细胞4 h后，不同能量紫外光处理（紫外光波长为430 nm，连续输出方式，功率密度40 mW/cm2）胃癌细胞，光能量密度分别为：0.0、0.8、1.6、3.2、6.4、12.8、25.6 J/cm2，采用MTT法检测胃癌细胞增殖率的变化；芦荟大黄素纳米脂质体（16 μg/ml）作用胃癌细胞4 h后，能量密度为（6.4 J/cm2）紫外光处理（紫外光波长为430 nm，连续输出方式，功率密度40 mW/cm2）胃癌细胞，采用Hoechst33342细胞核染色观察凋亡细胞形态学的变化；采用流式细胞仪检测胃癌细胞凋亡率的变化。结果：芦荟大黄素纳米脂质体在胃癌细胞中的吸收时间在4 h达到高峰；不同浓度芦荟大黄素纳米脂质体作用胃癌细胞4 h后，浓度低于8 μg/ml时对胃癌细胞的抑制作用差异无统计学意义（P=0.945，P=0.074）；单纯光照组与单纯芦荟大黄素纳米脂质体组对胃癌细胞抑制作用差异无统计学意义（P=0.125）；芦荟大黄素纳米脂质体（16 μg/ml）介导的光动力（6.4 J/cm2）作用胃癌细胞12 h后，胃癌细胞凋亡率芦荟大黄素纳米脂质体PDT组高于空白对照组、纳米脂质体组；Hoechst33342细胞核荧光染色可以观察到细胞核固缩、碎裂，可见凋亡小体。结论：芦荟大黄素纳米脂质体介导的光动力作用能有效的诱导胃癌细胞凋亡，芦荟大黄素纳米脂质体介导的光动力可能成为治疗胃癌的新方法。

Abstract:

Objective：To investigate the effects of aloe-emodin nanoliposome-induced photodynamic therapy（PDT） on the prolifera－tion and apoptosis of human gastric cancer cells. Methods：Human gastric cancer cells SGC-7901 were cultured in vitro with aloe-e－modin nanoliposome at the concentration of 16 μg/ml for 1，2，4，6，8 h and the uptake of aloe-emodin nanoliposome in the gastric cancer cells was detected by confocal laser scanning. The SGC-7901 were treated by different concentrations of aloe-emodin（0，2，4，8，16，32 μg/ml） for 4 h and then were given blue uv（wavelength of 430 nm，continuous output mode，power density of 40 mW/cm2） illumination with different energy densities（0.0，0.8，1.6，3.2，6.4，12.8，25.6 J/cm2）. Survival rate of gastric cancer cells was tested by MTT assay. Human gastric cancer cells SGC-7901 were dealt with aloe-emodin nanoliposome（16 μg/ml） for 4 h，and then received the blue uv（wavelength of 430 nm，continuous output mode，power density of 40 mW/cm2） illumination with 6.4 J/cm2 energy density. Cell apoptosis and apoptosis rate were analyzed by using Hoechst33342 and flow cytometry respectively. Results：Uptake time of aloe-emodin nanoliposome in gastric cancer cells peaked at 4 h. No significant difference was found in the cell survival rate when the human gastric cancer cells being dealt with aloe-emodin nanoliposome（concentration<8 μg/ml） for 4 h（P=0.945，P=0.074）. There was no significant difference in the inhibition of gastric cancer cells between single light irradiation group and nanoliposome group（P=0.125）. After gastric cancer cells being dealt with aloe-emodin nanoliposome（16 μg/ml） and blue uv illumination with the energy density of 6.4 J/cm2 for 4 h，the apoptosis rate in PDT group was higher than that in single light irradiation group and nanoliposome group based on results of flow cytometry. Karyopyknosis，fragmentation and apoptotic body were also found by Hoechst33342. Conclusions：Apoptosis of gastric cancer cells can be induced by aloe-emodin nanoli－posome-PDT significantly. Aloe-emodin nanoliposome-induced PDT may be used as a novel effective treatment for gastric can－cer.