Hormonal regulation of CYP1A expression.

Aryl hydrocarbon receptor (AhR) is primarily involved in the transcriptional regulation of CYP1A enzymes, which are the main catalysts of the metabolic activation or inactivation of numerous procarcinogens, carcinogens, environmental toxicants, or therapeutic agents. Several endogenous factors, including hormones, can modify CYP1A induction, directly influencing CYP1A gene expression or AhR function or indirectly via crosstalks with other transcription factors. In this article, we summarize the current knowledge about the role of hormones (i.e., glucocorticoids, estrogens, progesterone, androgens, insulin, and glucagon) and hormone receptors as well as other essential factors (e.g., vitamin D, retinoids) in the modulation of CYP1A expression.