Expression of ETS-1 related to angiogenesis in uterine endometrium during the menstrual cycle.

ETS-1 has been identified as a transcription factor for angiogenesis, which is essential for the development and growth of the uterine endometrium. This characteristic prompted us to study whether ETS-1 functions as an angiogenic mediator in uterine endometrium. Immunohistochemical staining revealed that the localization of ETS-1 was similar to that of vascular endothelial cells. There was a significant correlation between microvessel counts and both ETS-1 histoscores and ets-1 mRNA levels in uterine endometrium. The ETS-1 histoscores and ets-1 mRNA levels increased in the proliferative phase, reached a peak during peri-ovulation and decreased in the secretory phase. Furthermore, the ETS-1 histoscores and ets-1 mRNA levels correlated with vascular endothelial growth factor (VEGF) levels in the proliferative phase. This indicates that ETS-1 might be an angiogenic mediator in uterine endometrium linked to VEGF in the proliferative phase.