Epigenetic regulation of drug transporter expression in human tissues

Introduction: Drug transporters are expressed in a number of tissues such as the intestine, liver, and kidney, and play key roles in drug absorption, distribution, and excretion. Variations in drug transporter gene expression significantly contribute to interindividual differences in drug responses. Epigenetic regulation of drug transporter genes has recently emerged as an important mechanism. Epigenetic regulation alters the expression of genes without changing DNA sequences. Epigenetic control mechanisms are associated with DNA methylation, histone modifications, and microRNAs. Herein we discuss recent advances in the study of the transcriptional and post-transcriptional mechanisms of drug transporters with a focus on epigenetic regulation. Areas covered: This review summarizes recent research on the epigenetic regulation of drug transporter genes, and highlights the importance of identifying novel biomarkers based on epigenetics for use in individualized drug therapy. Expert opinion: Researchers are actively attempting to elucidate the epigenetic mechanisms that control the expression of drug transporters, which affect the pharmacokinetics of drugs. Current evidence suggests that epigenetic changes play an important role in drug transporter function. A clearer understanding of epigenetic regulation in drug transporter genes will provide an insight into novel approaches to individualized drug therapy.