甘蔗叶多糖对CNE_2细胞的体外抑制作用研究

Inhibition in vitro of human nasopharyngeal carcinoma cell CNE_2 proliferation by polysaccharide from sugarcane leaves

目的:研究甘蔗叶多糖对鼻咽癌CNE2细胞株的体外抑制作用,并初步探讨其作用机制。方法:采用热水浸提及DEAE-纤维素层析柱法提纯甘蔗叶多糖,以MTT法观察其体外抗肿瘤活性,透射电子显微镜观察凋亡细胞的超微结构,采用流式细胞术检测肿瘤细胞凋亡率,实时荧光定量PCR检测凋亡相关促凋亡基因(Bax)、凋亡抑制基因(Bcl-2)的变化。结果:浓度为10、20、40、80、160μg/mL的甘蔗叶多糖作用后,CNE2细胞抑制率及凋亡率均明显增加(P<0.01),且呈浓度依赖性。电镜下可见160μg/mL浓度的甘蔗叶多糖可使CNE2细胞出现凋亡小体。荧光定量PCR技术测定Bax在CNE2细胞中表达上调,Bcl-2则表达下调,并呈浓度依赖关系。结论:甘蔗叶多糖能明显抑制人鼻咽癌CNE2细胞增殖,诱导细胞凋亡,可能通过提高Bax表达及降低Bcl-2的表达,从而发挥抗肿瘤作用。

Objective： To evaluate the anfitumor activity of polysaccharide from Sugarcane Leaves （GZY） on human nasopharyngeal carcinoma （NPC） cell line CNE2 in vitro, and further to explore the underlying mechanism. Methods： GZY were extracted by hot-water extraction, further purified by DEAE-cellulose （OH-） ion-exchange. The anti-tumor activity of GZY in vitro was analyzed by MTT assay. The morphological changes of apoptotic cells were evaluated by transmission electronic microscopy. Cell apoptosis of CNE2 treated with GZY was examined by Annexin V-FITC/PI double staining assay. The expression levels of Bax and Bcl-2 were detected by real-time PCR. Results： The effect of inhibition on CNE2 cells by GZY was significantly increased in the concentration of 10, 20, 40, 80, 160 μg/mL （P〈0.01）. Flow cytometry showed that GZY could induce apoptosis of CNE2. With the increasing concentration of GZY, apoptosis rates increased （P〈0.01）. Apoptotic body could be found in CNE2 cells induced by conditioned medium at 160 μg/mL by GZY. With concentration increasing the expression of Bax in CNE2 cells, the Bcl-2 decreased. Conclusion： GZY had obvious inhibition on NPC cell CNE2, it would induce apoptosis to inhibite the growth of CNE2 cells. The activation of Bax and the suppression of Bcl-2 may contribute to the apoptosis mechanism.