Discovery of novel aromatase inhibitors using a homogeneous time-resolved fluorescence assay
Abstract
Jin-zi Ji1, Ke-jing Lao4, Jie Hu1, Tao Pang1, 3, Zhen-zhou Jiang1, 2, Hao-liang Yuan5, Jing-shan Miao1, Xin Chen1, Shan-shan NING4, Hua XIANG4, Yu-meng Guo1, Ming Yan1, 3, *, Lu-yong Zhang1, 6, *
1Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China; 2Key Laboratory of Drug Quality Control and Pharmacovigilance (China Pharmaceutical University), Ministry of Education, Nanjing 210009, China; 3Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; 4Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China; 5Laboratory of Molecular Design and Drug Discovery, School of Science, China Pharmaceutical University, Nanjing 210009, China; 6State Key laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
Aim: 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.
Conclusion: 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.
Keywords: aromatase; breast cancer; imidazolyl quinoline; triptoquinone A; homogeneous time-resolved fluorescence assay; high-throughput screening; molecular docking; drug discovery
This project was supported by “National Natural Science Foundation of China” (No 81102876, 81373179); Major Scientific and Technological Special Project for Significant New Drugs Creation (No 2012ZX09504001-001); Jiangsu Province Science and Technology Support Program of Social Development Projects (BE2012745); and this study was partially supported by the 111 Project (111-2-07). Thanks to Mr Peng GAO for assistance with the experiments, Mounia GUERRAM for revision in language of the manuscript, and Dr Ya-dong CHEN for valuable suggestions.
* To whom correspondence should be addressed.
E-mail brookming@163.com (Ming YAN); lyzhang@cpu.edu.cn (Lu-yong ZHANG)
Received 2014-03-18 Accepted 2014-05-20
Keywords:
1Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China; 2Key Laboratory of Drug Quality Control and Pharmacovigilance (China Pharmaceutical University), Ministry of Education, Nanjing 210009, China; 3Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; 4Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China; 5Laboratory of Molecular Design and Drug Discovery, School of Science, China Pharmaceutical University, Nanjing 210009, China; 6State Key laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
Aim: 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.
Conclusion: 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.
Keywords: aromatase; breast cancer; imidazolyl quinoline; triptoquinone A; homogeneous time-resolved fluorescence assay; high-throughput screening; molecular docking; drug discovery
This project was supported by “National Natural Science Foundation of China” (No 81102876, 81373179); Major Scientific and Technological Special Project for Significant New Drugs Creation (No 2012ZX09504001-001); Jiangsu Province Science and Technology Support Program of Social Development Projects (BE2012745); and this study was partially supported by the 111 Project (111-2-07). Thanks to Mr Peng GAO for assistance with the experiments, Mounia GUERRAM for revision in language of the manuscript, and Dr Ya-dong CHEN for valuable suggestions.
* To whom correspondence should be addressed.
E-mail brookming@163.com (Ming YAN); lyzhang@cpu.edu.cn (Lu-yong ZHANG)
Received 2014-03-18 Accepted 2014-05-20