Wilms' tumor (WT1) (±KTS) variants decreases the progesterone secretion of bovine ovarian theca cells.

Wilms' tumor gene WT1 encodes a nuclear transcriptional factor, which has been shown to regulate granulosa cell steroidogenesis in bovine; however, it is not known whether the functions of theca cells are regulated by WT1. Here, we determined the effects of this gene on theca cell proliferation, apoptosis, and steroidogenesis in vitro. In cultured bovine theca cells, the downregulation of WT1 increased the secretion of progesterone but had no effect on proliferation and apoptosis. WT1 includes the variants WT1(+KTS) and WT1(-KTS), which differ by 3 amino acids KTS (lysine, threonine, and serine). WT1(±KTS) upregulation increased the messenger RNA (mRNA) expression of STAR and CYP17A1 and decreased the progesterone secretion and CYP11A1 mRNA expression. In contrast to WT1(+KTS), WT1(-KTS) upregulation also decreased the mRNA expression of 3β-HSD. In both variants, WT1(-KTS) has more obvious effects. In conclusion, WT1 can decrease progesterone secretion, likely due in part to the inhibition of CYP11A1 and 3β-HSD.