Hormonal regulation of c-KIT receptor and its ligand: implications for human infertility?

The c-KIT, a tyrosine kinase receptor, and its ligand the stem cell factor (SCF) play an important role in the production of male and female gametes. The interaction of SCF with c-KIT is required for germ cell survival and growth, and abnormalities in the activity of the SCF/c-KIT system have been associated with human infertility. Recently, it was demonstrated that gonadotropic and sex steroid hormones, among others, regulate the expression of SCF and c-KIT in testicular and ovarian cells. Therefore, the hormonal (de)regulation of SCF/c-KIT system in the testis and ovary may be a cause underpinning infertility. In the present review, we will discuss the effects of hormones modulating the expression levels of SCF and c-KIT in the human gonads. In addition, the implications of hormonal regulation of SCF/c-KIT system for germ cell development and fertility will be highlighted.