title: Regulation of UDP-Glucuronosyltransferases UGT2B4 and UGT2B7 by MicroRNAs in Liver Cancer Cells.
abstract: The transcriptional regulation of UDP-glucuronosyltransferasesUGT2B4andUGT2B7has been well studied using liver cancer cell lines, and post-transcriptional regulation of these twoUGTsby microRNA (miRNA/miR) miR-216b-5p was recently reported. This study describes novel miRNA-mediated regulation of UGT2B4 and UGT2B7 in liver cancer cells. Bioinformatic analyses identified a putative miR-3664-3p binding site in the UGT2B7 3'-untranslated region (UTR) and binding sites for both miR-135a-5p and miR-410-3p in the UGT2B4 3'-UTR. These sites were functionally characterized using miRNA mimics and reporter constructs. A miR-3664-3p mimic induced repression of a luciferase reporter carrying the UGT2B7 3'-UTR in liver cancer cell lines; mutation of the miR-3664-3p site abrogated the response of the reporter to the mimic. Similarly, mutation of the miR-135a-5p site or miR-410-3p site in a luciferase reporter bearing UGT2B4 3'-UTR abrogated the ability of miR-135a-5p or miR-410-3p mimics to reduce reporter activity. Transfection of miR-3664-3p mimics in HepG2 liver cancer cells significantly reduced mRNA and protein levels of UGT2B7, and this led to reduced enzymatic activity. Transfection of miR-135a-5p or miR-410-3p mimics significantly decreased UGT2B4 mRNA levels in Huh7 liver cancer cells. The expression levels of miR-410-3p were inversely correlated with UGT2B4 mRNA levels in The Cancer Genome Atlas cohort of liver hepatocellular carcinoma (371 specimens) and a panel of ten normal human tissues. Similarly, there was an inverse correlation between miR-135a and UGT2B4 mRNA levels in a panel of 18 normal human liver tissues. Together, these data suggest that miR-135a and miR-410 controlUGT2B4and that miR-3664 controlsUGT2B7expression in liver cancer and/or normal liver cells.
authors.affiliation: Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, South Australia, Australia.
authors.forename: Dhilushi D
authors.initials: DD
authors.lastname: Wijayakumara
authors.affiliation: Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, South Australia, Australia.
authors.forename: Peter I
authors.initials: PI
authors.lastname: Mackenzie
authors.affiliation: Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, South Australia, Australia.
authors.forename: Ross A
authors.initials: RA
authors.lastname: McKinnon
authors.affiliation: Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, South Australia, Australia robyn.meech@flinders.edu.au donggui.hu@flinders.edu.au.
authors.forename: Dong Gui
authors.initials: DG
authors.lastname: Hu
authors.affiliation: Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, South Australia, Australia robyn.meech@flinders.edu.au donggui.hu@flinders.edu.au.
authors.forename: Robyn
authors.initials: R
authors.lastname: Meech
mesh_terms: D001665:Binding Sites / Q000502:physiology; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000502:physiology*; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*
chemical_list: D035683:MicroRNAs; C491474:UGT2B7 protein, human; D014453:Glucuronosyltransferase; C486404:UGT2B4 protein, human