title: Diosgenin induces ROS-dependent autophagy and cytotoxicity via mTOR signaling pathway in chronic myeloid leukemia cells.
abstract: BACKGROUND
  Diosgenin, a steroidal saponin isolated from legumes and yams, has been confirmed to possess potent anticancer effect on multifarious tumors including chronic myeloid leukemia (CML).
  
  
  OBJECTIVE
  We aimed to further determine the anti-cancer activity of diosgenin and its mechanisms in CML cells.
  
  
  METHODS
  The cell vitality was detected by MTT assay. Autophagic flux and reactive oxygen species (ROS) production were analyzed by laser scanning confocal microscope. Apoptosis was observed by flow cytometry. All proteins expression was examined by western blotting.
  
  
  RESULTS
  Autophagy induction was demonstrated by examination of autophagic flux including autophagosomes accumulation, autophagosome-lysosome fusion and degradation of autophagosomes. Moreover, blocking autophagy with inhibitor chloroquine (CQ) and 3-methyladenine (3-MA), enhanced diosgenin-induced apoptosis, indicating the protective effect of autophagy in diosgenin-treated CML cells. Further study suggested that diosgenin-induced autophagy and cytotoxicity were accompanied by reactive oxygen species (ROS) generation and mammalian target of rapamycin (mTOR) signaling pathway inhibition. N-acetyl-L-cysteine (NAC) administration, a scavenger agent of ROS, could down-regulate diosgenin-induced autophagy via reversion of mTOR pathway inhibition.
  
  
  CONCLUSIONS
  These results indicate that diosgenin obviously generates ROS and this oxidative pressure not only produces cytotoxic effect on CML cells but also induces autophagy. What's more, autophagy functions as a cytoprotective mechanism to overcome cytotoxicity of diosgenin in tumor cells and inhibition of autophagy can enhance the anti-CML activity of diosgenin.
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Jiajun
authors.initials: J
authors.lastname: Fan
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Dianwen
authors.initials: D
authors.lastname: Ju
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Meiqing
authors.initials: M
authors.lastname: Feng
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Jiyang
authors.initials: J
authors.lastname: Li
authors.affiliation: Shanghai Institute For Food And Drug Control, Shanghai, China.
authors.forename: Zhong-Bin
authors.initials: ZB
authors.lastname: Guan
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Duopeng
authors.initials: D
authors.lastname: An
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Biosynthesis & Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China. Electronic address: yelil@fudan.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Ye
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D045744:Cell Line, Tumor; D004144:Diosgenin / Q000494:pharmacology*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D051379:Mice; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D017382:Reactive Oxygen Species; D058570:TOR Serine-Threonine Kinases; D004144:Diosgenin
keywords: Autophagy; Chronic myeloid leukemia; Cytotoxicity; Diosgenin; Reactive oxygen species