Transcriptomic profiling of A549 cells in response to Dexamethasone, in the context of GR inhibition based on antagonists as well as a novel GR-PROTAC

Glucocorticoid receptors (GR) are important therapeutic targets due to regulation of stress hormones, glucocorticoids (GCs). GCs are altered in neuropsychiatric diseases, but also in cancers and autoimmunes. GR antagonists show some success in modulating GC levels. Yet, occupancy-driven mode of action of the available inhibitors, prevents full inhibition and requires high doses, causing risks in the long-term. To complement the existing tools, we present a highly potent novel catalytic-driven GR degrader, KH-103. We show highly efficient and rapid GR chemical knockdown at nanomolar concentrations. KH-103 is selective for GR, has almost no transcriptional side-effects, and shows higher efficiency in blocking ligand-induced genomic effects compared to other antagonists. Application in cortical cultures, revealed a GR-dependent GC-induced increase in calcium peak-intervals negatable by KH-103 pretreatment. Finally, an in-vivo proof-of-concept application of KH-103 is presented. KH-103 opens new opportunities for more lucid interpretation of GR-functions without disadvantages of genetic-interventions with clinically translatable potentials. Overall design: We cultured A495 cells and exposed them to different treatment regimes including dexamethasone (100nM), mifepristone (1uM), CORT113176 (1uM) and KH-103 (100nM) or a combination there-of with varying exposure time and order. For exact timescales see column "title"/"B", then harvested cells to extract RNA using Quick-RNA Microprep Kit (Zymoresearch, R1051). RNA samples at 25 ng/ul concentration were processed at Novogene, UK. Non-directional Poly-A library preparations were performed according to the manufacturer's recommendations (Next® Ultra RNA Library Prep Kit for Illumina®)