三七皂苷诱导人肺腺癌A549细胞凋亡作用

目的 探讨三七皂苷（panax notoginseng saponins,PNS）对人肺腺癌A549（hA549）细胞的致凋亡作用.方法 体外培养的hA549细胞,经不同浓度的PNS或联合应用磷脂酰肌醇3-激酶（PI3K）特异性抑制剂LY294002处理.采用MTT比色法检测肺腺癌A549细胞存活率,Hoechst33258荧光染色法检测其细胞形态学变化,流式细胞术检测细胞凋亡率,Western blot检测凋亡抑制基因Bcl-2、Bax和蛋白激酶B（Akt）蛋白的表达.结果 PNS能降低肺腺癌细胞的存活率,且其效应随剂量和作用时间的增加有增强的趋势;在PNS组可见细胞核出现固缩、边集和凋亡小体,并发现肺癌细胞凋亡率提高,细胞内Bax蛋白表达上调,Bcl-2、Akt蛋白表达下调.各浓度PNS组与空白对照组及溶剂对照组相比,差异均有统计学意义（P＜0.05）;PNS与LY294002联合应用则具有协同作用,可进一步促进肺癌细胞的凋亡及其细胞内的Bax蛋白表达上调和Bcl-2及Akt蛋白表达下调,与单用PNS组相比差异具有统计学意义（P＜0.05）.结论 PNS具有降低肺癌细胞存活率、诱导癌细胞凋亡的作用,并与PI3K特异性抑制剂LY294002具有协同作用,这可能与抑制PI3K/Akt信号通路、促进凋亡蛋白表达有关.

Panax notoginseng saponins induces the apoptosis of human lung adenocarcinoma A549 cells

Objective To investigate the underlying mechanism by which panax notoginseng saponins （PNS） induces the apoptosis of human lung adenoearcinoma A549 （hA549） cells. Methods Human A549 cells were treated with different concentrations of PNS alone or in combination with LY294002 （ a specific inhibitor of PI3K）. The MTT colorimetry was used to detect the survival rates of hA549 cells. The Heochst 33258 staining was employed to observe the morphological changes of the cells. The apoptotic rate was detected by flow cytometry. The expressions of Bax, Bel - 2, and Akt were detected by western blotting. Results PNS treatment rould significantly decreased the survival rate of lung adenocareinoma cells in dose - and time - dependent ways. When exposed to PNS, the cells presented morphological changes, such as pyknosis, chromatin margination, and apoptotic bodies, with an increased apoptotic rate. Also, the expression of Bax was enhanced, in contrast with lowered levels of Bcl - 2 and Akt in the PNS groups. The results above were significantly different from those obtained from either the control or vehicle group （ P 〈 0.05 ）. Meanwhile, PNS and LY294004 could synergistically function to stimulate the apoptosis of A529 cells, enhance the expression of Bax and down - regulate the levels of Bel - 2 and Akt, when compared with PNS treatment alone （ P 〈 0.05 ）. Conclusions PNS has abilities to promote the survival rate of A529 cells by stimulating apoptosis, which can be synergistically enhanced when concurrently treated with LY294002.