Activins and activin antagonists in the human ovary and ovarian cancer

• We review the role and distribution of activins and antagonists in human ovaries.
• Activin subunits are present in most histological subtypes of ovarian cancer.
• Activin A stimulates or inhibits proliferation in different ovarian cancer cell lines.
• Expression levels of activin antagonists are altered in ovarian cancer.
• These antagonists may contribute to tumour growth by blocking activin signalling.

Activins are members of the transforming growth factor β superfamily that play an important role in controlling cell proliferation and differentiation in many organs including the ovary. It is essential that activin signalling be tightly regulated as imbalances can lead to uncontrolled cell proliferation and cancer. This review describes the expression and function of the activins and their known antagonists in both normal and cancerous human ovaries.