SUN-124 GR potentiates DHT-induced gene regulation by AR

Abstract T. Sueyoshi: None. J.A. Cidlowski: None. GR crosstalk with other nuclear receptors has been known for many years but molecular mechanical details or biological significances have not been well established to date. We have recently revealed MR has blunting effects on GR-mediated gene regulations by directly interacting through an interface localized in LBD of the receptors. Here we have established cell lines expressing GR, AR, or both GR and AR using U-2OS cell line and named GR cell, AR cell, and AR/GR cell, respectively. We examined the responses of these cell lines for DHT or DEX treatment and analyzed their gene regulations by RNAseq analysis. DHT changed 1215 and 4702 gene expressions in AR cells and AR/GR cells, respectively, while only 1 gene each in GR cells or host U-2OS cells (Padj<0.001). This striking difference between AR cells and AR/GR cells suggested that GR potentiated AR cell response to DHT. Canonical pathway analysis revealed indeed androgen signaling pathway was strongly enhanced in AR/GR cells but not in AR cells by the DHT treatment. DEX treatment of these cell lines revealed 6529, 1049, and 5361 genes in GR cells, AR cells, and AR/GR cells, respectively. These results indicated that AR has a marginal effect on DEX-activated GR-dependent gene regulations in contrast to GR potentiation of AR response. To investigate molecular mechanisms behind this GR - AR functional interaction, we employed NanoBit and NanoBret technology to analyze the direct interaction between the two receptors and found that GR and AR interacted in living cells in a few minutes after the additions of DHT and DEX. These results also implied that multiple modes of heterodimer formation exist between GR and AR. Overall, our results uncovered the critical roles of GR in AR-dependent gene regulations by directly interacting with AR. Sunday, June 2, 2024