title: Enzymatic synthesis of uracil glucuronide, labeling with 125/131I, and in vitro evaluation on adenocarcinoma cells.
abstract: Human UDP-glucuronosyltransferases (UGTs) are a family of membrane-bound enzymes of the endoplasmic reticulum. They catalyze the glucuronidation of various endogenous and exogenous compounds, converting them into more polar glucuronides. In this study, uracil glucuronide was enzymatically synthesized using a UGT-rich microsome preparate, which was separated from Hutu-80 cells. Two different glucuronide derivatives were obtained, with a total reaction yield of 22.95% +/- 2.4% (n = 4). The glucuronide ligands were defined as uracil-n-glucuronide (UNG) and uracil-o-glucuronide (UOG). These were then analyzed by high-performance liquid chromatography-mass spectrometry and labeled with I-125 and I-131, separately. The radiolabeled (125/131)I-UNG and (125/131)I-UOG presented good incorporation ratios for Hutu-80, Caco-2, Detroit 562, and ACBRI 519 cells. The incorporation ratios of (125/131)I-UOG were higher than those of (125/131)I-UNG and of other labeled components for all cell types, and were also statistically significant compared to the values of (125/131)I-UNG for primary human intestinal epithelial cells (ACBRI 519) and human intestinal adenocarcinoma cells. Cell incorporation rates of n-glucuronides and o-glucuronides were higher compared to uracil, with o-glucuronides being more selective. The results suggest that both I-125- and I-131-labeled glucuronides can be used in imaging and therapy, and further research should be done in preclinical stages.
authors.affiliation: Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Bornova, Izmir, Turkey. ilkermedine@yahoo.com
authors.forename: Ilker Emin
authors.initials: IE
authors.lastname: Medine
authors.forename: Perihan
authors.initials: P
authors.lastname: Unak
authors.forename: Serhan
authors.initials: S
authors.lastname: Sakarya
authors.forename: Feriha
authors.initials: F
authors.lastname: Toksöz
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D005966:Glucuronidase / Q000378:metabolism; D020719:Glucuronides / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007457:Iodine Radioisotopes / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods*; D008861:Microsomes / Q000737:chemistry / Q000201:enzymology; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D000090264:UDP-Glucuronosyltransferase 1A9; D014498:Uracil / Q000031:analogs & derivatives* / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D014535:Uridine Diphosphate Glucuronic Acid / Q000378:metabolism
chemical_list: D020719:Glucuronides; D007457:Iodine Radioisotopes; D014535:Uridine Diphosphate Glucuronic Acid; D014498:Uracil; D014453:Glucuronosyltransferase; D000090264:UDP-Glucuronosyltransferase 1A9; D005966:Glucuronidase