Novel Promising Estrogenic Receptor Modulators: Cytotoxic and Estrogenic Activity of Benzanilides and Dithiobenzanilides

PLoS One. 2016 Jan 5;11(1):e0145615. doi: 10.1371/journal.pone.0145615. eCollection 2016.


The cytotoxicity of 27 benzanilides and dithiobenzanilides built on a stilbene scaffold and possessing various functional groups in aromatic rings previously described for their spasmolytic properties was assayed on three human cancer cell lines (A549 -lung adenocarcinoma, MCF-7 estrogen dependent breast adenocarcinoma and MDA-MB-231 estrogen independent breast adenocarcinoma) and 2 non-tumorigenic cell lines (CCD39Lu-lung fibroblasts, MCF-12A - breast epithelial). Three compounds (6, 15 and 18) showed selective antiproliferative activity against estrogen dependent MCF-7 cancer cells and their estrogenic activity was further confirmed in MCF-7 transfected with an estrogen receptor reporter plasmid and in HEK239 cells over-expressing the estrogen receptor alpha (ERα). Compound 18 is especially interesting as a potential candidate for therapy since it is highly toxic and selective towards estrogen dependent MCF7 cell lines (IC50 = 5.07 μM versus more than 100 μM for MDA-MB-231) and almost innocuous for normal breast cells (IC50 = 91.46 μM for MCF-12A). Docking studies have shown that compound 18 interacts with the receptor in the same cavity as estradiol although the extra aromatic ring is involved in additional binding interactions with residue W383. The role of W383 and the extended binding mode were confirmed by site-directed mutagenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anilides / chemistry
  • Anilides / metabolism
  • Anilides / pharmacology*
  • Binding Sites / genetics
  • Cell Line
  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Cell Survival / drug effects
  • Estradiol / chemistry
  • Estradiol / metabolism
  • Estradiol / pharmacology
  • Estrogen Receptor Modulators / chemistry
  • Estrogen Receptor Modulators / metabolism
  • Estrogen Receptor Modulators / pharmacology*
  • Estrogens / chemistry
  • Estrogens / metabolism
  • Estrogens / pharmacology
  • HEK293 Cells
  • Humans
  • MCF-7 Cells
  • Models, Molecular
  • Molecular Structure
  • Mutation
  • Protein Binding
  • Protein Structure, Tertiary
  • Receptors, Estrogen / chemistry
  • Receptors, Estrogen / genetics
  • Receptors, Estrogen / metabolism
  • Thioamides / chemistry
  • Thioamides / metabolism
  • Thioamides / pharmacology*


  • Anilides
  • Estrogen Receptor Modulators
  • Estrogens
  • Receptors, Estrogen
  • Thioamides
  • Estradiol
  • benzanilide

Grant support

This work was funded by Polish National Science Center, grant number UMO-2011/01/B/NZ4/03499, Ministerio Español de Ciencia e Innovación (cofinanced by FEDER funds) and Fundación Marcelino Botín (awarded to R. S.), CTQ2011-29299-C02-02. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.