G protein-coupled estrogen receptor 1 expression in normal myometrium, leiomyoma, and adenomyosis tissues of premenopausal women.

To verify the different expression of G protein-coupled estrogen receptor 1 (GPER1) among normal uterine, leiomyoma, and adenomyosis tissues. Normal uterine, leiomyoma, and adenomyosis tissue samples were obtained from women aged 35-52 years from a tertiary university hospital. The tissue samples were subjected to immunohistochemical, Western blot, and reverse-transcription polymerase chain reaction (RT-PCR) analyses of GPER1. GPER1 protein expression was confirmed in the tissues by immunohistochemical and Western blot analyses and compared with GPER1 mRNA levels using RT-PCR. GPER1 was detected in the tissue samples of leiomyoma and adenomyosis, which are estrogen-dependent diseases. GPER1 expression was similar between normal uterine and leiomyoma tissues but was reduced in adenomyosis tissue. The level of phosphorylated extracellular signal-regulated kinases 1/2 was lower and higher in leiomyoma and adenomyosis tissues, respectively, than in normal tissue, but the differences among the groups were not statistically significant. Our immunohistochemical, Western blot, and RT-PCR results suggest that GPER1 expression is involved in cell proliferation in leiomyoma and in cell invasion and migration in adenomyosis. Functional studies of GPER1 involving larger sample sizes should be performed to confirm the adenomyosis and leiomyoma disease mechanisms and eventually to develop new therapeutic interventions for these diseases.