system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Adaptor Proteins, Signal Transducing, Eukaryotic Initiation Factor-2, Gene Expression Regulation, Neoplastic, Humans, JNK Mitogen-Activated Protein Kinases, Male, Mitogen-Activated Protein Kinases, Neuregulin-1, Orchiectomy, Phosphorylation, Polyribosomes, Prostatic Neoplasms, Protein Biosynthesis, RNA, Messenger, RNA-Binding Proteins, Receptors, Androgen, Transfection.
user
Does eBP1 inhibit translation of androgen receptor mRNA in castration resistant prostate cancer cells? Context: Therapies that inhibit androgen receptor (AR) are needed for treatment of castration-resistant prostate cancer (CRPC). The ErbB3 binding protein 1 (EBP1) reduces protein expression of both AR and its target genes in CRPC. Although EBP1 regulates AR in hormone-sensitive prostate cancer cells, by both destabilizing AR mRNA and inhibiting protein translation, the mechanism of EBP1 down regulation of AR in CRPC is unknown. Western blot and quantitative PCR analysis of cell lysates and polysomes were used to assess AR mRNA, protein expression and translation. In contrast to hormone- dependent cells, EBP1 did not change steady state levels of AR mRNA or AR mRNA stability in hormone refractory cells. EBP1 did slow protein translation of AR mRNA. The ErbB3/4 ligand heregulin further diminished AR translation in EBP1 -transfected cells, but not in control cells.
assistant
These studies suggest that one pathway of EBP1 down-regulation of AR levels may be lost in CRPC. Final Decision: yes