title: Annosquacin B induces mitochondrial apoptosis in multidrug resistant human breast cancer cell line MCF-7/ADR through selectively modulating MAPKs pathways.
abstract: BACKGROUND
  Multidrug resistance (MDR) is a major obstacle to efficient therapy of cancers. It is a prime concern for researchers to find compounds with anti-proliferative activity on MDR cell lines. In recent years, annonaceous acetogenins (ACGs) were reported to have anti-proliferative activity. However, the underlying mechanisms are still unknown.
  
  
  OBJECTIVE
  This study determines the mechanisms of anti-proliferative activity induced by Annosquacin B (AB) against MCF-7/ADR cells.
  
  
  METHODS
  The cytotoxicity of AB at varying concentrations (0.64, 1.6, 4, 10, 25, 62.5, 156.25 μM) on MCF-7/ADR cells was assessed using the MTT assay. Annexin V-FITC/propidium iodide staining and Acrinidine orange and ethidium bromide (AO/EB) staining were employed to investigate whether AB (14, 7, 3.5 μM) could induce apoptosis in MCF-7/ADR cells. Levels of caspase-3 and caspase-9, Bax, Bcl-2 and MAPKs kinases were evaluated by western blot assay following treatment with various concentrations of AB (3.5, 7, 14 μM) at different time points (0, 0.5, 1, 2, 4, 8, 12 h).
  
  
  CONCLUSIONS
  MTT assay showed that AB significantly decreased cell viability on MCF-7/ADR (IC50of 14.69 μM). AB-induced apoptosis in MCF-7/ADR cells through mitochondrial apoptosis pathways. It induced typical apoptosis by morphologic changes; elevate levels of caspase-3, caspase-9 as well as the ratio of Bax/Bcl-2. In addition, AB increased the expression of p-p38 MAPK and decreased the expression of p-JNK, while whether ERK1/2 had an effect on the MCF-7/ADR apoptosis remains to be determined.
authors.affiliation: a College of Pharmacy, Nanjing University of Chinese Medicine , Nanjing , China.|b Nanjing University of Chinese Medicine Hanlin College , Taizhou , China.
authors.forename: Fei
authors.initials: F
authors.lastname: Yuan
authors.affiliation: a College of Pharmacy, Nanjing University of Chinese Medicine , Nanjing , China.|c Taizhou Institute for Food and Drug Control , Taizhou , China.
authors.forename: Ganggang
authors.initials: G
authors.lastname: Bai
authors.affiliation: a College of Pharmacy, Nanjing University of Chinese Medicine , Nanjing , China.
authors.forename: Yunjie
authors.initials: Y
authors.lastname: Miao
authors.affiliation: a College of Pharmacy, Nanjing University of Chinese Medicine , Nanjing , China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: a College of Pharmacy, Nanjing University of Chinese Medicine , Nanjing , China.|d Jiangsu Key Laboratory for Chinese Material Medica Processing , Nanjing , China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: a College of Pharmacy, Nanjing University of Chinese Medicine , Nanjing , China.|e Jiangsu Key Laboratory for TCM Formulae Research , Nanjing , China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Chen
mesh_terms: D031041:Annona; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D045786:Diterpenes, Kaurane / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018432:Drug Resistance, Multiple / Q000187:drug effects* / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000502:physiology; D061986:MCF-7 Cells; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology
chemical_list: D045786:Diterpenes, Kaurane; C100909:annosquamosin B
keywords: Bax; Bcl-2; JNK; caspase-3; caspase-9; p38 MAPK