title: A polysaccharide from Glycyrrhiza inflata Licorice inhibits proliferation of human oral cancer cells by inducing apoptosis via mitochondrial pathway.
abstract: In the present study, we isolated and characterized a water-soluble polysaccharide (GIP1) from the roots of Glycyrrhiza inflata. The goal of this study was to investigate the anti-tumor effect of GIP1 on the human oral cancer SCC-25 cell line and to explore the possible mechanism. Our experimental result showed that GIP1 (50, 100, and 200 μg/mL) specifically decreased cell viability of SCC-25 cells in a concentration-dependent manner via the induction of apoptosis. Furthermore, Western blot analysis showed that exposure of SCC-25 cells to GIP1 led to down-regulation of anti-apoptotic protein Bcl-2 and up-regulation of pro-apoptotic protein Bax, thus causing a loss of mitochondrial membrane potential and the release of cytochrome c to the cytosol. Moreover, we observed activation of the initiator caspaes-9, and the effector caspases-3, but not caspase-8. Concomitantly, GIP1-induced apoptosis can be blocked by caspase-3- or caspase-9-specific inhibitor, but not caspase-8 inhibitor. As well, the cleaved poly (ADP-ribose) polymerase, as a caspae-3 substrate, occurred in SCC-25 cells following GIP1 treatment at three concentrations. Collectively, our results showed that the GIP1 induced apoptosis in SCC-25 cells involving a caspase-dependent mitochondrial signaling pathway.
authors: Department of Stomatology, The General Hospital of the Second Artillery Corps of Chinese PLA, Beijing, 100088, People's Republic of China.
authors: Huan
authors: H
authors: Shen
authors: Guang
authors: G
authors: Zeng
authors: Bin
authors: B
authors: Sun
authors: Xingwei
authors: X
authors: Cai
authors: Lixia
authors: L
authors: Bi
authors: Guo
authors: G
authors: Tang
authors: Yongjin
authors: Y
authors: Yang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006035:Glycyrrhiza / Q000737:chemistry; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009062:Mouth Neoplasms / Q000188:drug therapy*; D011134:Polysaccharides / Q000008:administration & dosage* / Q000737:chemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D015398:Signal Transduction / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis
chemical_list: D011134:Polysaccharides; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein