Biotransformation is important in the metabolism of endobiotics and
xenobiotics. This process comprises the activity of phase I and phase II
enzymes.
Estrogen sulfotransferase (SULT1E1 or EST) is a phase II conjugating
enzyme that belongs to the family of cytosolic
sulfotransferases. The expression of SULT1E1 can be detected in many tissues, including the liver. SULT1E1 catalyzes the transfer of a
sulfate group from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to any available
hydroxyl group in estrogenic molecules. The substrates of SULT1E1 include the endogenous and
synthetic estrogens. Upon SULT1E1-mediated sulfation, the hydrosolubility of
estrogens increases, preventing the binding between the sulfated
estrogens and the
estrogen receptor (ER). This sulfated state of the
estrogens is not irreversible, as the
steroid sulfatase (STS) can convert sulfoconjugated
estrogens to free
estrogens. The expression of SULT1E1 is inducible by several diseases that involve tissue
inflammation, such as
type 2 diabetes,
sepsis, and
ischemia-reperfusion injury. Areas covered: This systematic literature review aims to summarize the role of SULT1E1 in the metabolism of estrogenic drugs and
xenobiotics, and the role of SULT1E1 in the pathogenesis of several diseases, including
cancer,
metabolic disease,
sepsis, liver injury, and
cystic fibrosis. Meanwhile, ablation or pharmacological inhibition of SULT1E1 can affect the outcomes of the aforementioned diseases. Expert opinion: In addition to its role in metabolizing estrogenic drugs, SULT1E1 is unexpectedly being unveiled as a mediator for the disease effect on
estrogen metabolism and homeostasis. Meanwhile, because the expression and activity of SULT1E1 can affect the outcome of diseases, the same
sulfotransferase and the reversing
enzymes STS can be potential therapeutic targets to prevent or manage diseases. Accumulating evidence suggest that the physiological and pathophysiological effects of SULT1E1 can be
estrogen-independent and it is necessary to elucidate what other possible substrates may be recognized by the
enzyme. Moreover, human studies are paramount to confirm the human relevance of the animal studies.