Pyrazolo-1-carbothioamides as EGR-1–DNA binding disruptors

Early growth response 1 (EGR-1) is a key transcription factor that boosts the inflammatory response. Therefore, targeting EGR-1 with small-molecule drugs may be a novel strategy for treating inflammatory diseases, such as atopic dermatitis. (E)-2-(2,4-dimethoxy-6-(4-methoxystyryl)phenyl)-3-hydroxy-6-nitro-4H-chromen-4-one (AB1711) was previously found to be an active compound that disrupts EGR-1–DNA binding. Structural modifications were performed to identify compounds with better activity. Seventy compounds with pyrazolo-1-carbothioamide moieties were derived. Fifty-one compounds showed greater disruption of EGR-1 DNA binding than that induced by AB1711. To determine why the compounds tested in this study showed good activity, pharmacophores were derived based on comparative molecular field and comparative molecular similarity index analyses. Of the 70 compounds tested, compound 36, N-(2,4-dimethoxyphenyl)-3-(1-hydroxynaphthalen-2-yl)-5-(2,4,6-trimethoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide showed the best activity. The binding mode between EGR-1 and compound 36 was elucidated using in silico docking. Pharmacophores derived from quantitative structure–activity relationships matched well with the results obtained from in silico docking. To determine the role of compound 36 in cells, further experiments, including electrophoretic mobility shift and reverse-transcription polymerase chain reaction assays, were carried out. These findings demonstrated that compound 36 is a good disruptor of EGR-1–DNA binding.