title: Aspafilioside B induces G2/M cell cycle arrest and apoptosis by up-regulating H-Ras and N-Ras via ERK and p38 MAPK signaling pathways in human hepatoma HepG2 cells.
abstract: We recently establish that aspafilioside B, a steroidal saponin extracted from Asparagus filicinus, is an active cytotoxic component. However, its antitumor activity is till unknown. In this study, the anticancer effect of aspafilioside B against HCC cells and the underlying mechanisms were investigated. Our results showed that aspafilioside B inhibited the growth and proliferation of HCC cell lines. Further study revealed that aspafilioside B could significantly induce G2 phase cell cycle arrest and apoptosis, accompanying the accumulation of reactive oxygen species (ROS), but blocking ROS generation with N-acetyl-l-cysteine (NAC) could not prevent G2/M arrest and apoptosis. Additionally, treatment with aspafilioside B induced phosphorylation of extracellular signal-regulated kinase (ERK) and p38 MAP kinase. Moreover, both ERK inhibitor PD98059 and p38 inhibitor SB203580 almost abolished the G2/M phase arrest and apoptosis induced by aspafilioside B, and reversed the expression of cell cycle- and apoptosis-related proteins. We also found that aspafilioside B treatment increased both Ras and Raf activation, and transfection of cells with H-Ras and N-Ras shRNA almost attenuated aspafilioside B-induced G2 phase arrest and apoptosis as well as the ERK and p38 activation. Finally, in vivo, aspafilioside B suppressed tumor growth in mouse xenograft models, and the mechanism was the same as in vitro study. Collectively, these findings indicated that aspafilioside B may up-regulate H-Ras and N-Ras, causing c-Raf phosphorylation, and lead to ERK and p38 activation, which consequently induced the G2 phase arrest and apoptosis. This study provides the evidence that aspafilioside B is a promising therapeutic agent against HCC.
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Wei
authors: W
authors: Liu
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Rui
authors: R
authors: Ning
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Rui-Ni
authors: RN
authors: Chen
authors: Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, China.
authors: Xue-Feng
authors: XF
authors: Huang
authors: Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China.
authors: Qin-Sheng
authors: QS
authors: Dai
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Jin-Hua
authors: JH
authors: Hu
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Yu-Wen
authors: YW
authors: Wang
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Li-Li
authors: LL
authors: Wu
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Jing
authors: J
authors: Xiong
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Gang
authors: G
authors: Hu
authors: Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, Nanjing, China.
authors: Qing-Long
authors: QL
authors: Guo
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, China.
authors: Jian
authors: J
authors: Yang
authors: Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, China.
authors: Hao
authors: H
authors: Wang
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage* / Q000494:pharmacology; D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D011905:Genes, ras / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics; D020935:MAP Kinase Signaling System / Q000187:drug effects; D051379:Mice; D012503:Saponins / Q000008:administration & dosage* / Q000494:pharmacology; D013150:Spirostans / Q000008:administration & dosage* / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D012503:Saponins; D013150:Spirostans; C068180:aspafilioside B
keywords: G2 arrest; H-Ras; N-Ras; apoptosis; aspafilioside B