International Journal of Molecular Sciences Article Chrysoeriol Prevents TNFα-Induced CYP19 Gene Expression via EGR-1 Downregulation in MCF7 Breast Cancer Cells Dong Yeong Min 1, Euitaek Jung 1, Sung Shin Ahn 1, Young Han Lee 1,2 , Yoongho Lim 3 and Soon Young Shin 1,2,* 1 Department of Biological Sciences, Sanghuh College of Lifesciences, Konkuk University, Seoul 05029, Korea;
[email protected] (D.Y.M.);
[email protected] (E.J.);
[email protected] (S.S.A.);
[email protected] (Y.H.L.) 2 Cancer and Metabolism Institute, Konkuk University, Seoul 05029, Korea 3 Division of Bioscience and Biotechnology, BMIC, Konkuk University, Seoul 05029, Korea;
[email protected] * Correspondence:
[email protected]; Tel.: +82-2-2030-7946 Received: 27 August 2020; Accepted: 9 October 2020; Published: 12 October 2020 Abstract: Estrogen overproduction is closely associated with the development of estrogen receptor-positive breast cancer. Aromatase, encoded by the cytochrome P450 19 (CYP19) gene, regulates estrogen biosynthesis. This study aimed to identify active flavones that inhibit CYP19 expression and to explore the underlying mechanisms. CYP19 expression was evaluated using reverse transcription PCR, quantitative real-time PCR, and immunoblot analysis. The role of transcription factor early growth response gene 1 (EGR-1) in CYP19 expression was assessed using the short-hairpin RNA (shRNA)-mediated knockdown of EGR-1 expression in estrogen receptor-positive MCF-7 breast cancer cells. We screened 39 flavonoids containing 26 flavones and 13 flavanones using the EGR1 promoter reporter activity assay and observed that chrysoeriol exerted the highest inhibitory activity on tumor necrosis factor alpha (TNFα)-induced EGR-1 expression.