2. Academic Validation
  3. Evaluation of known and novel inhibitors of Orai1-mediated store operated Ca2+ entry in MDA-MB-231 breast cancer cells using a Fluorescence Imaging Plate Reader assay

Evaluation of known and novel inhibitors of Orai1-mediated store operated Ca2+ entry in MDA-MB-231 breast cancer cells using a Fluorescence Imaging Plate Reader assay

  • Bioorg Med Chem. 2017 Jan 1;25(1):440-449. doi: 10.1016/j.bmc.2016.11.007.
Iman Azimi 1,  Jack U Flanagan 2,  Ralph J Stevenson 3,  Marco Inserra 4,  Irina Vetter 4,  Gregory R Monteith 1,  William A Denny 5
Affiliations

Affiliations

  • 1 The School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia; Mater Research Institute, The University of Queensland, Brisbane, Queensland, Australia; Translational Research Institute, Brisbane, Queensland, Australia.
  • 2 Auckland Cancer Society Research Centre, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
  • 3 Auckland Cancer Society Research Centre, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
  • 4 Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4102, Australia.
  • 5 Auckland Cancer Society Research Centre, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. Electronic address: b.denny@auckland.ac.nz.
PMID: 27856238 DOI: 10.1016/j.bmc.2016.11.007
Abstract

The Orai1 CA2+ permeable ion channel is an important component of store operated CA2+ entry (SOCE) in cells. It's over-expression in basal molecular subtype breast cancers has been linked with poor prognosis, making it a potential target for drug development. We pharmacologically characterised a number of reported inhibitors of SOCE in MDA-MB-231 breast Cancer cells using a convenient Fluorescence Imaging Plate Reader (FLIPR) assay, and show that the rank order of their potencies in this assay is the same as those reported in a wide range of published assays. The assay was also used in a screening project seeking novel inhibitors. Following a broad literature survey of classes of Calcium Channel inhibitors we used simplified ligand structures to query the ZINC on-line database, and following two iterations of refinement selected a novel Orai1-selective dichlorophenyltriazole hit compound. Analogues of this were synthesized and evaluated in the FLIPR assay to develop structure-activity relationships (SAR) for the three domains of the hit; triazole (head), dichlorophenyl (body) and substituted phenyl (tail). For this series, the results suggested the need for a lipophilic tail domain and an out-of-plane twist between the body and tail domains.

Keywords

Breast cancer; Calcium signalling; Orai1; Pharmacological inhibitors; Pharmacophore modelling; Store-operated calcium entry (SOCE).

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