Steroid hormones, endometrial gene regulation and the Sp1 family of proteins

Abstract

Endometrial gene expression can be regulated exquisitely by cyclical changes in ovarian steroid concentration. Although hormonal induction of many of these genes occurs through classical steroid response elements, other endometrial genes respond to steroids at the transcriptional level but do not contain steroid response elements. A family of transcription factors, namely the Sp1 family, has now been implicated as important mediators of steroid hormone action in the endometrium during the periimplantation and postimplantation periods. This review summarizes the current literature regarding the role of the Sp1 protein family in regulating the response to steroid hormones of genes for tissue factor, plasminogen activator inhibitor-1, insulin-like growth factor binding protein-1, uteroglobin, and uteroferrin in the endometrium.