<i>PXR</i> Pharmacogenetics: Association of Haplotypes with Hepatic <i>CYP3A4</i> and <i>ABCB1</i> Messenger RNA Expression and Doxorubicin Clearance in Asian Breast Cancer Patients

Abstract

This study showed that PXR*1B was associated with reduced hepatic mRNA expression of PXR and its downstream targets, CYP3A4 and ABCB1. Genotype-phenotype correlates in breast cancer patients showed PXR*1B to be significantly associated with lower doxorubicin clearance, suggesting that PXR haplotype constitution could be important in influencing interindividual and interethnic variations in disposition of its putative drug substrates.