标题：Exopolysaccharide of Antarctic bacterium Pseudoaltermonas sp S-5 induces apoptosis in K562 cells
作者：Chen, Guochuang; Qian, Wen; Li, Jing; Xu, Yanghui; Chen, Kaoshan
作者机构：[Qian, Wen; Li, Jing; Xu, Yanghui; Chen, Kaoshan] Wannan Med Coll, Dept Pharm, Anhui Prov Key Lab Act Biol Macromol, Anhui Prov Engn Res Ctr Polysacch 更多
通讯作者地址：[Chen, KS]Shandong Univ, Sch Life Sci, 27 South Shanda Rd, Jinan 250100, Peoples R China.
关键词：Antarctic bacterium; Exopolysaccharide; Apoptosis; Intrinsic pathway;; Human leukemia; K562 cells
摘要：The aim of this study was to investigate the anticancer activity of exopolysaccharide (PEP) of Antarctic bacterium Pseudoaltermonas sp. S-5 and elucidate the underlying molecular mechanisms. PEP significantly inhibited the growth of human leukemia K562 cells. Results of morphological characterization showed that PEP-treated cells displayed typical morphological characteristics of apoptosis such as condensation of chromatin and formation of apoptotic bodies. Flow cytometry analyses and colorimetric assay demonstrated that PEP induced collapse of mitochondrial membrane potential and activation of caspase-9, which indicated that intrinsic apoptotic signaling pathway was involved in apoptosis induced by PEP in K562 cells. Western blot analysis showed that PEP increased the ratio of Bax/Bcl-2. In addition, calcium signal might contribute to the cytotoxicity of PEP against K562 cells. These findings suggest that PEP may be potentially effective drug against human leukemia. (C) 2014 Elsevier Ltd. All rights reserved.