title: Discovery of novel aromatase inhibitors using a homogeneous time-resolved fluorescence assay.
abstract: OBJECTIVE
  Aromatase is an important target for drugs to treat hormone-dependent diseases, including breast cancer. The aim of this study was to develop a homogeneous time-resolved fluorescence (HTRF) aromatase assay suitable for high-throughput screening (HTS).
  
  
  METHODS
  A 384-well aromatase HTRF assay was established, and used to screen about 7000 compounds from a compound library. Anti-proliferation activity of the hit was evaluated using alamarBlue(R) assay in a hormone-dependent breast cancer cell line T47D. Molecular docking was conducted to elucidate the binding mode of the hit using the Discovery Studio program.
  
  
  RESULTS
  The Z' value and signal to background (S/B) ratio were 0.74 and 5.4, respectively. Among the 7000 compounds, 4 hits (XHN22, XHN26, XHN27 and triptoquinone A) were found to inhibit aromatase with IC50 values of 1.60±0.07, 2.76±0.24, 0.81±0.08 and 45.8±11.3 μmol /L, respectively. The hits XHN22, XHN26 and XHN27 shared the same chemical scaffold of 4-imidazolyl quinoline. Moreover, the most potent hit XHN27 at 10 and 50 μmol/L inhibited the proliferation of T47D cells by 45.3% and 35.2%, respectively. The docking study revealed that XHN27 docked within the active site of aromatase and might form a hydrogen bond and had a π-cation interaction with amino acid residues of the protein.
  
  
  CONCLUSIONS
  XHN27, an imidazolyl quinoline derivative of flavonoid, is a potent aromatase inhibitor with anti-proliferation activity against breast cancer in vitro. The established assay can be used in HTS for discovering novel aromatase inhibitor.
authors.affiliation: Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Jin-zi
authors.initials: JZ
authors.lastname: Ji
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Ke-jing
authors.initials: KJ
authors.lastname: Lao
authors.affiliation: Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Hu
authors.affiliation: 1] Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China [2] Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Pang
authors.affiliation: 1] Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China [2] Key Laboratory of Drug Quality Control and Pharmacovigilance (China Pharmaceutical University), Ministry of Education, Nanjing 210009, China.
authors.forename: Zhen-zhou
authors.initials: ZZ
authors.lastname: Jiang
authors.affiliation: Laboratory of Molecular Design and Drug Discovery, School of Science, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Hao-liang
authors.initials: HL
authors.lastname: Yuan
authors.affiliation: Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Jing-shan
authors.initials: JS
authors.lastname: Miao
authors.affiliation: Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Shan-shan
authors.initials: SS
authors.lastname: Ning
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Xiang
authors.affiliation: Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Yu-meng
authors.initials: YM
authors.lastname: Guo
authors.affiliation: 1] Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China [2] Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: 1] Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China [2] State Key laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Lu-yong
authors.initials: LY
authors.lastname: Zhang
mesh_terms: D001141:Aromatase / Q000737:chemistry / Q000378:metabolism; D047072:Aromatase Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D001940:Breast / Q000187:drug effects / Q000201:enzymology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D005260:Female; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D057166:High-Throughput Screening Assays / Q000379:methods; D006801:Humans; D062105:Molecular Docking Simulation; D011804:Quinolines / Q000737:chemistry / Q000494:pharmacology; D054852:Small Molecule Libraries / Q000737:chemistry* / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D047072:Aromatase Inhibitors; D005419:Flavonoids; D011804:Quinolines; D054852:Small Molecule Libraries; D001141:Aromatase