Identification and characterization of lipopolysaccharide binding protein (LBP) as an estrogen receptor α specific serum biomarker.

Estrogen Receptor alpha (ER alpha) and Estrogen Receptor beta (ER beta) are steroid nuclear receptors that transduce estrogen signaling to control diverse physiological processes linked to reproduction, bone remodeling, behavior, immune response and endocrine-related diseases. In order to differentiate between ER alpha and ER beta mediated effects in vivo, ER subtype selective biomarkers are essential. We utilized ER alpha knockout (AERKO) and ER beta knockout (BERKO) mouse liver RNA and genome wide profiling to identify novel ER alpha selective serum biomarker candidates. Results from the gene array experiments were validated using real-time RT-PCR and subsequent ELISA's to demonstrate changes in serum proteins. Here we present data that Lipopolysacharide Binding Protein (LBP) is a novel liver-derived ER alpha selective biomarker that can be measured in serum.