Uterine
leiomyoma is the most common benign gynecological
tumor in women of reproductive age and represents the single most common indication for
hysterectomy. A development of new treatments is necessary for a medical management, and in this direction, several hormonal drugs are under investigation.
Ulipristal acetate (UPA; a selective
progesterone receptor modulator) is considered as one of the most promising because
progesterone has a critical role in development and growth of uterine
leiomyoma. The effect of
steroids is partly mediated by
growth factors like
activin A which increases extracellular matrix expression contributing to the growth of
leiomyoma. The present study aimed to test whether UPA acts on
leiomyoma cells affecting expression and functions of
activin A system. Cultured myometrial and
leiomyoma cells were treated with UPA, and
messenger RNA (
mRNA) expression levels of
activin A (
inhibin βA [INHBA] subunits), its
binding proteins (
follistatin [FST] and FST-related gene), and its
receptors (activin receptor-like
kinase 4 [ALK4],
activin receptor type [ActR] II, and ActRIIB) were evaluated. The effect of UPA on
activin A modulation of
fibronectin and
vascular endothelial growth factor A (
VEGF-A)
mRNA expression in cultured myometrial and
leiomyoma cells was also studied.
Ulipristal acetate decreased INHBA, FST, ActRIIB, and Alk4
mRNA expressions in
leiomyoma cultured cells. In addition, UPA was able to block the
activin A-induced increase in
fibronectin or
VEGF-A mRNA expression in myometrial and in
leiomyoma cultured cells. The present data show that UPA inhibits
activin A expression and functions in
leiomyoma cells, and this may represent a possible mechanism of action of the drug on uterine
leiomyoma.