Expression of progesterone receptors A and B and insulin-like growth factor-I in human myometrium and fibroids after treatment with a gonadotropin-releasing hormone analogue.

OBJECTIVE

To determine mRNA and protein expression of the progesterone receptor (PR) and insulin-like growth factor-I (IGF-I) in myometrium and fibroids.

DESIGN

Retrospective clinical study.

SETTING

Hospital-based and university-affiliated research laboratories.

PATIENT(S): Twelve women in the proliferative phase and six women treated with GnRH analogue (GnRH-a).

INTERVENTION(S): Blood sampling and collection of myometrium and fibroids.

MAIN OUTCOME MEASURE(S): PR and IGF-I mRNA levels in fibroids and myometrium were analyzed by solution hybridization and in situ hybridization whereas the proteins were localized by immunohistochemistry.

RESULT(S): Fibroids and myometrium from women in the proliferative phase showed significantly higher PR mRNA than the corresponding tissues from GnRH-a-treated women. The amount of cells positively stained for PR-AB and PR-B in fibroids and myometrium decreased after GnRH-a treatment compared with in the proliferative phase. The IGF-I mRNA in both fibroids and myometrium in the proliferative phase was significantly higher than those after GnRH-a treatment. The immunostaining of IGF-I showed no difference between the two tissues. There was weaker immunostaining in the GnRH-a-treated group compared with in the proliferative phase group.

CONCLUSION(S): The shrinkage of fibroids after steroid deprivation is associated with alterations in PR and IGF-I expression.