GMC1 inhibits a new pharmacologic target, the FKBP52 co-chaperone, which is critical to Androgen Receptor (AR) signaling.

GMC1 is a FKBP52 co-chaperone-inhibitor for prostate cancer. GMC1 engages a new pharmacologic target (FKBP52) to inhibit AR signaling. FKBP52 is a cofactor required for stabilization and activity of AR. GMC1 binding to FKBP52 prevents AR-regulated gene expression and tumor cell growth. “Indirect” inhibition of AR-signaling will not be affected by resistance mechanisms common to standard-of-care drugs in prostate cancer.

FKBP52 is a TPR (tetratricopeptide repeat) domain-containing co-chaperone that plays a critical role in the chaperone dependent folding of steroid hormone receptors (SHRs) into their functionally mature conformations necessary for hormone binding. Given the functional roles of FKBP52 in receptor-specific phenotypes, and its direct participation in the aberrant AR hyperactivity observed in prostate cancer, FKBP52 has emerged as a novel therapeutic target with the potential to treat castration-resistant prostate cancer, thereby filling a major unmet need in treatment. FKBP52 acts as a specific positive regulator of AR, PR, and GR functions through the interaction of the proline-rich loop with the ligand binding domain (LBD) of the SHRs.

Literature:

Guy, N., Garcia, Y.A., and Cox, M.B(2015)Therapeutic targeting of the FKBP52 cochaperone in steroid hormone receptor-regulated physiology and disease. Current Molecular Pharmacology. May 19. https://www.ncbi.nlm.nih.gov/pubmed/25986565

Marc B. Cox and Jill L. Johnson. Evidence for Hsp90 Co-chaperones in Regulating Hsp90 Function and Promoting Client Protein Folding. In: Stuart K. Calderwood and Thomas L. Prince (eds.), Chaperones: Methods and Protocols, Methods in Molecular Biology, vol. 1709. https://www.ncbi.nlm.nih.gov/pubmed/29177674