Differential gene regulation by the human and mouse aryl hydrocarbon receptor

Aryl hydrocarbon receptor as a new therapeutic target for cancer and immune disorders

The aryl hydrocarbon receptor (AhR) was discovered more than three decades ago, and initially was characterized as a transcription factor with a role in xenobiotic metabolism. However, based on subsequent observations that AhR remains active under physiological conditions, exhibits constitutive expression during development, and has a high degree of conservation among species, it was hypothesized that AhR is responsible for functions in addition to its role in detoxification. Correspondingly, recent studies have elucidated novel physiological roles for this ligand-dependent transcription factor that link it to several pathways associated with disease development. In this review, studies are presented that support a role for AhR in cell proliferation, apoptosis, and immune homeostasis, thereby highlighting the therapeutic potential of this receptor for cancer and immune disorders.