SR-90011

SR9011 is a REV-ERBα/β agonist with IC₅₀s of 790 nM and 560 nM for REV-ERBα and REV-ERBβ, respectively.

SR9011 dose-dependently increases the REV-ERB-dependent repressor activity assessed in HEK293 cells expressing a chimeric Gal4 DNA Binding Domain (DBD) - REV-ERB ligand binding domain (LBD) α or β and a Gal4-responsive luciferase reporter (REV-ERBα IC₅₀=790 nM, REV-ERBβ IC₅₀=560 nM). SR9011 potently and efficaciously suppresses transcription in a cotransfection assay using full-length REV-ERBα along with a luciferase reporter driven by the Bmal1 promoter (SR9011 IC₅₀=620 nM). SR9011 suppresses the expression ofBMAL1 mRNA in HepG2 cells in a REV-ERBα/β-dependent manner^[1] SR9011 suppresses proliferation of the breast cancer cell lines regardless of their ER or HER2 status. SR9011 appears to pause the cell cycle of the breast cancer cells prior to M phase. Cyclin A (CCNA2) is identified as a direct target gene of REV-ERB suggesting that suppression of expression of this cyclin by SR9011 may mediate the cell cycle arrest. Treatment with SR9011 results in an increase in cells in the G₀/G₁ phase and a decrease of cells in S and G₂/M phase suggesting that activation of REV-ERB may be resulting in decreased transition from G₁ to S phase and/or from S to G₂/M phase^[2].

[2]. Wang Y, et al. Anti-proliferative actions of a synthetic REV-ERBα/β agonist in breast cancer cells. Biochem Pharmacol. 2015 Aug 15;96(4):315-22.