TY - JOUR T1 - Epirubicin Upregulates UDP Glucuronosyltransferase 2B7 Expression in Liver Cancer Cells Via the p53 Pathway JF - Molecular Pharmacology JO - Mol Pharmacol DO - 10.1124/mol.114.091603 SP - mol.114.091603 AU - Dong Gui Hu AU - Anne Rogers AU - Peter Ian Mackenzie Y1 - 2014/01/01 UR - http://molpharm.aspetjournals.org/content/early/2014/03/19/mol.114.091603.abstract N2 - Anthracyclines are effective genotoxic anticancer drugs for treating human malignancies; however, their clinical use is limited by tumour resistance and severe cardiotoxicity (e.g. congestive heart failure). Epirubicin (EPI) is less cardiotoxic compared to other canonical anthracyclines (e.g, doxorubicin). This has been attributed to its unique glucuronidation detoxification pathway. EPI is primarily inactivated by UDP-glucuronosyltransferase 2B7 (UGT2B7) in the liver. Hence, the regulation of hepatic UGT2B7 expression is critical for EPI systemic clearance but remains poorly characterized. We show herein that EPI upregulates UGT2B7 expression in hepatocellular carcinoma (HCC) HepG2 and Huh7 cells. Our analyses of deleted and mutated UGT2B7 promoter constructs identified a p53 response element (p53RE) in the UGT2B7 promoter. EPI stimulated UGT2B7 promoter activity via this p53RE and enhanced in vivo p53 binding at this p53RE in HepG2 cells. Knockdown of p53 expression by siRNA silencing technology significantly repressed the capacity of EPI to stimulate UGT2B7 transcription. Furthermore, the p53 activator nutlin-3α significantly enhanced UGT2B7 expression and recruited the p53 protein to the UGT2B7 p53RE in HepG2 cells. Collectively, our results demonstrated that EPI promotes its own detoxification via the p53-mediated pathway. This regulation may contribute to tumour resistance to EPI-containing HCC chemotherapy and may also provide a new explanation for the reduced cardiotoxicity of EPI compared to other anthracyclines. Our finding also suggests that upon exposure to genotoxic agents, detoxifying genes are activated by the p53-mediated pathway to clear genotoxic agents locally within the tumour site or even systemically through the liver. ER -