Impact of FKBP52 on cell proliferation and hormone‐dependent cancers

FK506 binding protein 52 (FKBP52) (gene name FKBP4) is a 52 kDa protein that belongs to the FKBP family; it binds to the immunosuppressant FK506 and has proline isomerase activity. In addition to its FK domain‐containing peptidylprolyl isomerase activity, FKBP52 also acts as a cochaperone through the tetratricopeptide repeat domain that mediates binding to heat shock protein 90. Previous studies have reported that FKBP52 is associated with hormone‐dependent, stress‐related, and neurodegenerative diseases, revealing its diverse functions. In particular, the effects of FKBP52 on cancer have attracted considerable attention. FKBP52 promotes the growth of hormone‐dependent cancers by activating steroid hormone receptors. Recent studies have shown that the expression of FKBP52 is increased not only in steroid hormone‐dependent cancer cells but also in colorectal, lung, and liver cancers, revealing its diverse functions that contribute to cancer growth. This review summarizes reports related to hormone‐dependent cancer and cell proliferation in terms of the structure of FKBP52 and its function on interacting molecules.