The expression of estrogen receptor isoforms , and insulin-like growth factor-I in uterine leiomyoma

Background. A prospective study focusing on leiomyoma was conducted to investigate the expression of estrogen receptor- (ER), estrogen receptor- (ER) and insulin-like growth factor-I (IGF-I) to elucidate their roles in the pathogenesis of leiomyoma. Methods. Twenty-one leiomyomal and six paired myometrial tissues were included in the study. The levels of ER, ER and IGF-I mRNAs in leiomyoma and adjacent myometrium were analyzed by quantitative reverse transcription-polymerase chain reaction. Results. All tissues showed a higher ER expression level. The correlation between ER mRNA and IGF-I mRNA levels was significantly positive (r=0.527, p=0.014). The correlation between ER mRNA and IGF-I mRNA levels was also positive, but not statistically significant. In six paired leiomyoma and myometrium samples, the levels of ER and ER mRNA exhibited no difference, and IGF-I mRNA levels were elevated in leiomyoma compared with paired myometrium (p0.05). Conclusions. The expression of IGF-I mRNA increases in leiomyoma and ER mRNA is positively correlated with IGF-I mRNA, which implies that estrogen upregulates the gene encoding IGF-I through ER in leiomyoma; ER may also be involved in the IGF-I signaling pathway in leiomyoma.