Activins and activin antagonists in the prostate and prostate cancer

Activins are members of the TGF-β super-family. There are 4 mammalian activin subunits (βA, βB, βC and βE) that combine to form functional proteins. The role of activin A (βAβA) is well characterized and known to be a potent growth and differentiation factor. Two of the activin subunits (βC and βE) were discovered more recently and little is known about their biological functions. In this review the evidence that activin-βC is a significant regulator of activin A bioactivity is presented and discussed. It is concluded that activin-βC, like other antagonists of activin A, is an important growth regulator in prostate health and disease.

► Activin A is a negative growth regulator in the prostate.
► Insensitivity to negative growth signals is an acquired capability in cancer.
► Increased activin A is associated with prostate cancer progression.
► Activin A antagonists are also up-regulated in prostate cancer.
► We propose targeting activin signaling may have therapeutic utility in prostate cancer.