Clinical implications of steroid receptor coactivator (SRC)-3 in uterine endometrial cancers

Estrogen is recognized as a significant modifier in the development, growth and invasion of uterine endometrial cancer. Steroid receptor coactivator-3 (SRC-3; AIB1, ACTR, RAC3, TRAM-1, and pCIP) is a member of the p160 family of coactivator for nuclear hormone receptors including estrogen receptor (ER). It is reported that SRC-3 is overexpressed in various cancers. However, SRC-3 expression manner in uterine endometrial cancer is not fully understood. In this study, we showed SRC-3 mRNA expression correlates with clinical stage, depth of myometrial invasion and dedifferentiation. The prognosis of the 25 patients with higher expression of SRC-3 mRNA in uterine endometrial cancers was extremely poor (36%), whereas the 24-month survival rate of the 15 patients with lower expression of SRC-3 mRNA was 96%. These data indicate that SRC-3 might be an important indicator of uterine endometrial cancer advancement and survival.