RESUMO
BACKGROUND: Sex steroid hormones are believed to play an important role in the genesis and growth of uterine myoma. Several studies suggest a possible role of insulin-like growth factor(IGF) as a mediator of estradiol in uterine myama. We have recently demonstrated that some IGF binding proteins(IGFRPs) messenger ribonucleic acid(mRNA) expressions in myoma are dependent on the in vivo esttogen status. The purposes of this study are to evaluate the in vitro effects of sex steroid hormones including estrogen on the IGFBPs gene expression in tissues from uterine myoma and adjacent normal myometrium. METHODS: Tissues from myoma and adjacent normal myometrium of patients with uterine myoma during early proliferative phase of menstrual cycle were cultured in the absence(control) and presence of 17b-estradiol(10M/L) or/and progesterone(10M/L) for 3 days. The IGFBPs mRNA expressions in these explants were analyzed by Nothern blot using specific human complementary deoxyribonucleic acid(cDNA) probes. RESULTS: The addition of 17b-estradiol, progesterone alone and in combination to conditioned media of explants from myoma and adjacent normal myornetrium did not result in any changes in the expression of IGFBP-2, IGFBP-4, IGFBP-5, and IGFBP-6 mRNA. With progesterone addtion, lGFBP-3 rnRNA expression was significantly reduced in myoma explant but not in adjacent ncemal myometrium explant. There was no significant change in the IGFBP-3 mRNA expression with 17b-estradiol and with the combination of both 17b-estradiol and progesterone. CONCLUSION: 17b-estradiol does not affect IGFBPs gene expression in the myoma and adjacent normal myometrium explant regardless of the presence of progesterone in vitro. However progesterone alone induces a decrease in IGFBP-3 synthesis in myoma explant.