The role of intracellular signaling in insulin-mediated regulation of drug metabolizing enzyme gene and protein expression

Pharmacol Ther. 2007 Jan;113(1):88-120. doi: 10.1016/j.pharmthera.2006.07.004. Epub 2006 Nov 13.


Endogenous factors, including hormones, growth factors and cytokines, play an important role in the regulation of hepatic drug metabolizing enzyme expression in both physiological and pathophysiological conditions. Diabetes, fasting, obesity, protein-calorie malnutrition and long-term alcohol consumption produce changes in hepatic drug metabolizing enzyme gene and protein expression. This difference in expression alters the metabolism of xenobiotics, including procarcinogens, carcinogens, toxicants and therapeutic agents, potentially impacting the efficacy and safety of therapeutic agents, and/or resulting in drug-drug interactions. Although the mechanisms by which xenobiotics regulate drug metabolizing enzymes have been studied intensively, less is known regarding the cellular signaling pathways and components which regulate drug metabolizing enzyme gene and protein expression in response to hormones and cytokines. Recent findings, however, have revealed that several cellular signaling pathways are involved in hormone- and growth factor-mediated regulation of drug metabolizing enzymes. Our laboratory has reported that insulin and growth factors regulate drug metabolizing enzyme gene and protein expression, including cytochromes P450 (CYP), glutathione S-transferases (GST) and microsomal epoxide hydrolase (mEH), through receptors which are members of the large receptor tyrosine kinase (RTK) family, and by downstream effectors such as phosphatidylinositol 3-kinase, mitogen activated protein kinase (MAPK), Akt/protein kinase B (PKB), mammalian target of rapamycin (mTOR), and the p70 ribosomal protein S6 kinase (p70S6 kinase). Here, we review current knowledge of the signaling pathways implicated in regulation of drug metabolizing enzyme gene and protein expression in response to insulin and growth factors, with the goal of increasing our understanding of how disease affects these signaling pathways, components, and ultimately gene expression and translational control.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cytochrome P-450 Enzyme System / biosynthesis
  • Cytochrome P-450 Enzyme System / genetics
  • Epoxide Hydrolases / biosynthesis
  • Epoxide Hydrolases / genetics
  • Gene Expression Regulation, Enzymologic* / drug effects
  • Glutamate-Cysteine Ligase / biosynthesis
  • Glutamate-Cysteine Ligase / genetics
  • Glutathione Transferase / biosynthesis
  • Glutathione Transferase / genetics
  • Humans
  • Hypoglycemic Agents / metabolism*
  • Hypoglycemic Agents / pharmacology
  • Insulin / metabolism*
  • Insulin / pharmacology
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Isoenzymes
  • Liver / drug effects
  • Liver / enzymology*
  • MAP Kinase Signaling System / drug effects
  • Metabolic Detoxication, Phase II / genetics
  • Phosphoric Monoester Hydrolases / metabolism
  • Receptor, Insulin / metabolism
  • Receptors, Growth Factor / metabolism
  • Signal Transduction* / drug effects


  • Hypoglycemic Agents
  • Insulin
  • Intercellular Signaling Peptides and Proteins
  • Isoenzymes
  • Receptors, Growth Factor
  • Cytochrome P-450 Enzyme System
  • Glutathione Transferase
  • Receptor, Insulin
  • Phosphoric Monoester Hydrolases
  • Epoxide Hydrolases
  • Glutamate-Cysteine Ligase