Clinical implication of estrogen-related receptor (ERR) expression in uterine endometrial cancers

Estrogen receptor (ER)alpha and ER beta mRNAs levels decreased with clinical stage, myometrial invasion and dedifferentiation. On the other hand, ERR alpha mRNA levels and histoscores increased with clinical stage and myometrial invasion, regardless of dedifferentiation. ERR alpha can bind to the steroid receptor coactivator family without any ligands, and drive transcription activity of the target genes. The competitive interaction of ERR alpha/ER expression associated with the use of common cofactors during loosing estrogen dependency might cause their expression manner. The up-regulation of ERR alpha might be related to tumor growth and advancement in uterine endometrial cancers. It is speculated that ERR alpha is a candidate for prognostic factors in uterine endometrial cancer, although ERRs are not directly related to growth of uterine endometrial cancer. (C) 2009 Elsevier Ltd. All rights reserved.