Environmental Estrogens Stimulate Gene Transcription in the Prolactin Promoter

Abstract

The ability of environmental estrogens to regulate gene transcription on model and physiologically complex promoter was examined in GH 3 cells, a pituitary cell line. In transient transfection studies, the pGL3 model promoter and the physiologically complex prolactin promoter were both responsive to the xenoestrogen bisphenol A and the phytoestrogen daidzein in a dose related manner. These transcriptional responses were mediated by estrogen receptors, as responses were ameliorated in the presence of ICI 180, 782, a pure antiestrogen. Cotransfection of Pit-1 significantly enhanced the transcriptional response of the prolactin promoter to stimulation by environmental estrogens. The nature and magnitude of transcriptional responses to estradiol sensitive genes following challenge by environmental estrogens is likely dependent on regulatory elements found in the promoter and their ability to recruit transcription factors.

Vaccaria segetalis: A Review of Ethnomedicinal, Phytochemical, Pharmacological, and Toxicological Findings

“…Jun-Xian et al ( 2013 ) used V. segetalis water extract, which had a similar effect to estrogen and PRL, and its components could bind to an estrogen receptor to activate a STAT5-signaling pathway, thereby promoting the P-STAT5 expression and milk protein synthesis. Bryant ( 2009 ) found that the PRL promoter transcription and PRL synthesis can be induced by stimulating the estrogen receptor system and pituitary transcription factor Pit-1. PRL controls the regulation of milk protein at the translational level, thereby promoting the synthesis of milk proteins.…”