Expression of transcription factor GATA-4 during human testicular development and disease.

GATA-4 is a highly conserved transcription factor that plays a critical role in regulating embryonic morphogenesis and cellular differentiation. Given the emerging role of GATA-4 in the development and function of murine gonads, we have now studied its role in human testis. We find that GATA-4 is expressed from early human fetal testicular development to adulthood. This transcription factor is evident in Sertoli cells through fetal and postnatal development. Expression of GATA-4 in Sertoli cells peaks at 19-22 weeks gestation at the time of high circulating fetal FSH. In Leydig cells, GATA-4 is expressed during fetal period and after puberty, coinciding with the periods of active androgen synthesis in the testis; this suggests a link between GATA-4 and steroidogenesis. Also, fetal germ cells and prepubertal spermatogonia express GATA-4, and it is down-regulated in these cells after puberty. As hormonal regulation of GATA-4 in human testis was not possible to study directly, we used testicular samples from patients who had endocrine abnormalities or were hormonally treated. Testicular expression of GATA-4 in hCG-treated cryptorchidism does not differ from that in controls. In androgen resistance, GATA-4 expression in Sertoli and germ cells is weak or totally absent. GATA-4 protein is abundantly present in Sertoli and Leydig cell tumors, suggesting a relationship to tumorigenesis or tumor progression in somatic cell-derived testicular neoplasms.