MYC-mediated ribosomal gene expression sensitizes enzalutamide-resistant cells to EP300/CREBBP inhibitors

Various mechanisms have been reported to be responsible for enzalutamide resistance in prostate cancer. In our previous studies, we have demonstrated that the histone acetyltransferase EP300 is highly expressed in castration therapy-resistant prostate cancer. In the present study, we investigated the role of EP300/CREBBP in enzalutamide-resistant prostate cancer. Enzalutamide resistant and control DuCaP cells generatd previously were treated with histone acetyltransferase (C646) and bromodomain (I-CBP112) inhibitors of EP300/CREBBP. Additionally Enzalutamide resistant cells under 5 µM enzalutamide treatment and control LNCaP cells were analyzed. DuCaP and LNCaP cells were seeded in 6-well-plates at 8 x 10^5 and 6 x 10^5 cells per well. The following day, DuCaP cells were treated with 8 µM enzalutamide, 10 µM C646, 10 µM I-CBP112 or DMSO equivalent for 24 hr. Illumina sequencing and examination of differentially expressed genes of parental and resistant cell lines derived from DuCaP and LNCaP. DuCaP cells were also treated with enzalutamide, C646 and I-CBP112.