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

Objective: To evaluate the antitumor 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(P0.01). Flow cytometry showed that GZY could induce apoptosis of CNE2. With the increasing concentration of GZY, apoptosis rates increased(P0.01). 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.