Effect of MPC309 (AR-targeting Multivalent Peptoid Conjugate) treatment on gene expression in LNCaP-ABL cells (castration-resistant prostate cancer cell line) in comparison to Vehicle control and another AR ligand, Ethisterone (partial agonist): ChIP-Seq

To establish wehther the genes stimulated or inhibited by MPC309 are directly influenced by the AR, we conducted ChIP-seq of AR from LNCaP-abl cells that had been treated with vehicle (DMSO), MPC309, Backbone, DHT, or Enzalutamide overnight. Our results revealed a more pronounced AR presence in cells exposed to MPC309 and DHT as compared to control groups and those treated with enzalutamide, reinforcing the idea that MPC309 facilitates distinct AR interactions with chromatin. Genes linked with AR occupancy mirrored similar GO terms as those seen in RNA-seq experiments. Out of the 251 genes repressed by MPC309 compared to controls (vehicle and backbone), 246 (98%) had an AR binding site within 15 kb upstream or downstream of the gene promoter. Similarly, of the 405 genes stimulated by MPC309, 387 (96%) had an AR binding site within 15 kb of the gene promoter. These observations suggest that the gene regulation driven by MPC309 stems from AR interactions with chromatin, resulting in varying impacts on gene expression compared to DHT or enzalutamide, consequently inhibiting the growth of prostate cancer cells. Overall design: LNCaP-abl cells were cultured under androgen deprivation and treated with vehicle (DMSO), 1µM backbone, 1µM MPC309, 10nM DHT, or 10µM enzalutamide overnight, and AR ChIP-seq performed. AR occupancy profiling analysis was performed using the Rosalind software.