We established stable HEK293 cell lines expressing double isoforms, UGT1A1 and UGT1A9, UGT1A4 and UGT1A9, or UGT1A6 and UGT1A9, as well as stable cell lines expressing each single isoform. To analyze the protein-protein interaction between the UGT1As, we investigated the thermal stability and resistance to detergent. UGT1A9 uniquely demonstrated thermal stability, which was enhanced in the pres...

Recent developments in the field of human genomics have greatly enhanced the potential for precision and personalized medicine. We have developed a novel DNA microarray, using a 3-mm square chip coated with diamond-like carbon to enhance the signal-to-background ratio, for use as an in vitro diagnostic tool in precision medicine. To verify the genotyping effectiveness of this newly developed DN...

Obesity and pregnancy both place the liver under metabolic stress, but interactions between obstetric obesity and bilirubin metabolism have not been studied. We determined associations between obesity, maternal/neonatal bilirubin levels, and uridine 5'diphosphate-glucuronosyltransferase 1A1 (UGT1A1) enzyme that eliminates bilirubin. Adult livers were analyzed for UGT1A1 expression, activity, an...

BACKGROUND A genetic TA repeat length polymorphism in the UGT1A1 promoter has been shown to affect UDP-glucuronosyltyransferase (UGT1A1) expression levels with significant clinical implications. The presence of 7 TA repeats has been associated with lowered UGT1A1 expression and the mild hyperbilinrubinemia manifested in Gilbert's syndrome. Furthermore, cancer patients carrying this variant exhi...

Arachidonic acid (AA) can be metabolized to various metabolites, which can act as mediators of cellular processes. The objective of this work was to identify whether AA, prostaglandin (PG) B1 and E2, and 15- and 20-hydroxyeicosatetraenoic acids (15- and 20-HETE) are metabolized via glucuronidation. Assays with human recombinant UDP-glucuronosyltransferase 1A (UGT1A) isoforms revealed that AA an...

In this study, we evaluated inhibitory potentials of popularly-consumed berries (bilberry, blueberry, cranberry, elderberry, and raspberry ketones) as herbal supplements on UGT1A1, UGT1A4, UGT1A6, UGT1A9, and UGT2B7 in vitro. We also investigated the potential herb-drug interaction via UGT1A1 inhibition by blueberry in vivo. We demonstrated that these berries had only weak inhibitory effects on...

Substrates that are specific for certain UDP-glucuronosyltransferase (UGT) isoforms are usually used as specific inhibitors to identify UGT isoforms responsible for the glucuronidation of drugs. 1-Naphthol and 4-nitrophenol are probe substrates for human UGT1A6. In the present study, we found that UGT1A1-catalyzed estradiol 3-O-glucuronide formation and UGT1A4-catalyzed imipramine N-glucuronide...

Chemoprevention by isothiocyanates from cruciferous vegetables occurs partly through up-regulation of phase II conjugating enzymes, such as UDP-glucuronosyltransferases (UGT). UGT1A1 glucuronidates bilirubin, estrogens, and several dietary carcinogens. The UGT1A1*28 polymorphism reduces transcription compared with the wild-type, resulting in decreased enzyme activity. Isothiocyanates are metabo...

PURPOSE To determine whether uridine diphosphate-glucuronosyltransferase 1A1, UGT1A7, and UGT1A9 polymorphisms affect the pharmacokinetics (PK) of irinotecan and treatment outcome of Korean patients with advanced non-small-cell lung cancer (NSCLC). METHODS Eighty-one patients with advanced NSCLC were treated with irinotecan (80 mg/m2) on day 1 and 8 and cisplatin (60 mg/m2) on day 1 intraveno...

7-Ethyl-10-hydroxycamptothecin (SN-38) is the pharmacologically active metabolite of irinotecan, in addition to being responsible for severe toxicity. Glucuronidation is the main metabolic pathway of SN-38 and has been shown to protect against irinotecan-induced gastrointestinal toxicity. The purpose of this study was to determine whether common polymorphic UDP-glucuronosyltransferase (UGT) aff...