Glucuronosyltransferase ; genetics ; Humans ; Infant, Newborn ; Jaundice, Neonatal ; genetics

PURPOSE: Irinotecan (CPT-11) is hydrolyzed to an active SN-38, which is further detoxicated to SN-38G through conjugation by uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) enzymes. There are many reports that UGT1A1 polymorphisms are associated with irinotecan related dose-limiting toxicity. The aim of the present study is to determine whether UGT1A1 polymorphisms affect individual variations of the toxicity due to and the tumor response to irinotecan via the alteration of bioavailability of SN-38 in Korean patients with locally advanced rectal cancer. METHODS: Twenty patients with locally advanced rectal cancer, who had received surgery after irinotecan-containing chemoradiation from 2003 to 2006, were enrolled. We analyzed the association of UGT1A1 genotypes with toxicity and tumor response to chemoradiation therapy. A tumor response was assumed when a tumor regression grade I or II was obtained. Toxicity was graded in accordance with the NCI common toxicity criteria. RESULTS: The frequence of square53(TA)6>7 (UGT1A1*28), 211G>A (UGT1A1*6), 686C>A (UGT1A1*27), square3279T>G (UGT1A1*60), and square3156G>A were 25% (5/20), 25% (5/20), 0% (0/20), 55% (11/20), and 20% (4/20), respectively. There were five grade III neutropenia and one severe diarrhea. Patients with UGT1A1*28 and square3156G>A showed higher complete tumor response rates (40% vs. 6.7%, P=0.07; 50% vs. 6.3%, P=0.08), but there was no differences in toxicity and tumor response between responders and non-responders. Patients with square3279T>G (UGT1A1*60) showed a tendency for lower tumor response in tumor responders, but there was no statistically significant difference (P=0.07). CONCLUSIONS: This study suggested that square3279T>G (UGT1A1*60) may be useful in predicting tumor response of irinotecan. In the future, further study is warranted using large numbers of cases to reach statistical significance.
Biological Availability ; Colorectal Neoplasms ; Diarrhea ; Genotype ; Glucuronosyltransferase ; Humans ; Neutropenia ; Rectal Neoplasms* ; Uridine Diphosphate

OBJECTIVETo develop a RP-HPLC method for the determination of quercetin in UGT1A3 cDNA-transfected cells.

METHODSThe lysate of cells transfected with human recombinant uridine 5-diphosphate glucuronosyltransferases UGT1A3 cDNA was co-incubated with quercetin, the reaction was terminated with acetonitrile, and luteolin was used as internal standard. The determination was performed on a C(1) reversed phase column with a mobile phase of methanol-0.1% formic acid (V/V) at a flow rate of 1.0 ml/min. The gradient elution was as follows: 0 - 25 min (30:70-80:20, methanol:0.1% formic acid), > 25-25.5 min (80:20), >25.5-27 min (80:20-30:70), > 27-30 min (30:70). A UV-VIS detector was operated at 368 nm.

RESULTThe standard curve was linear over the concentration range of 5-200 μmol/L (r = 0.9999). The limit of detection was 1.25 μmol/L(S/N ≥ 3), and the limit of quantification was 5 μmol/L (S/N >10, RSD = 6.99%). The method afforded recoveries of 99.1%-103.5%, and precisions for inter- and intra-assay were < 2.5% and < 8%, respectively. In addition, kinetic analysis indicated that the K(m), V(max) and CL(int) (V(max)/K(m)) values for quercetin glucuronide were (62.95 ± 13.16) μ mol/L, (284.50 ± 24.35)nmol*min⁻¹*g⁻¹ and 4.52 ml*min⁻¹*g⁻¹, respectively.

CONCLUSIONThe method established is accurate and simple and suitable for the determination of quercetin in UGT1A3 cDNA-expressed cells.

Cells, Cultured ; Chromatography, High Pressure Liquid ; methods ; Glucuronosyltransferase ; genetics ; Humans ; Quercetin ; analysis ; pharmacokinetics ; Transfection

We present a case of severe persisting unconjugated hyperbilirubinemia in a Uigur infant boy, eventually diagnosed as Crigler-Najjar syndrome type I. DNA analysis of his blood of the UGT1A1 gene sequence demonstrated that he was homozygous for an insertion mutation causing a change of the coding exons with a frame-shift, resulting in the substitution of 27 abnormal amino acid residues in his hepatic bilirubin uridine diphosphoglucuronyl transferase enzyme. Both of his parents were heterozygous for the same mutation. A novel frame-shifting mutation of the UGT1A1 gene was found, confirming the diagnosis of Crigler-Najjar syndrome type I for this patient.
Crigler-Najjar Syndrome ; diagnosis ; genetics ; Frameshift Mutation ; genetics ; Glucuronosyltransferase ; genetics ; Humans ; Infant, Newborn ; Male

OBJECTIVETo study major human UGT isoforms involved in trans-resveratrol (TR) phase II metabolism.

METHODtrans-resveratrol and 12 major human UGT isoforms were incubated in vitro and then glucuronic acid metabolites were determined by HPLC-MS, in order to preliminarily analyze the structure and observe the effect of different UGT isoforms on the generation rate of glucuronic acid metabolites.

RESULTIn in vitro metabolic system, two metabolites-4'-O-monoglucuronide resveratrol (M-1) and 3-0-monoglucuronide resveratrol (M-2)-were generated from trans-resveratrol after being catalyzed by UGT. During the cause, generation of M-1 and M-2 were catalyzed by UGT1A1, UGT1A3, 1A8, 1A9 andlA10, whereas only UGT1A6 and 1A7 contributed to the forma-tion of M-2. Both the formation rate of M-1 and M-2 catalyzed by UGT1A1, 1A10 and the formation of M-2 catalyzed by UGT1A8 slowed down with the increasing concentration of substrates, causing the phenomenon of "substrate inhibition".

CONCLUSIONUGT1A1, 1A8, 1A9, 1A10 get involved in the formation of M-1, and of them UGTIA9 is the most important contributor. UGT1A3 also makes small contribution to the formation of M-1 and M-2, while other UGT isoforms show hardly any reaction with the trans-resveratrol phase II metabolites.

Glucuronic Acid ; metabolism ; Glucuronosyltransferase ; metabolism ; Humans ; Isoenzymes ; metabolism ; Kinetics ; Stilbenes ; chemistry ; metabolism

OBJECTIVENeonatal unconjugated hyperbilirubinemia is one of the most common conditions encountered by the practicing pediatricians. Although it is usually self-limited and benign, the condition is of importance because of the rare instances in which severe hyperbilirubinemia can lead to bilirubin encephalopathy or kernicterus. The uridine diphosphate-glucuronosyl transferase 1A1 (UGT 1A1) gene controls bilirubin conjugation by determining the structure of the enzyme glucuronosyltransferase, which is synthesized in the hepatocyte. In the recent years much has been learned about the relationship between UGT 1A1 gene mutation and neonatal hyperbilirubinemia. This study aimed to investigate the roles of UGT 1A1 gene mutation in the development of neonatal hyperbilirubinemia in Guangxi.

METHODSA total of 73 cases with hyperbilirubinemia and 31 healthy neonates were enrolled. UGT 1A1 G71R genotypes were identified by the (amplification refractory mutation system, ARMS) and direct sequencing method in all the neonates. To analyze the incidence of bilirubin encephalopathy, the peak (total serum bilirubin, TSB) concentration after 72 hours of age, and the possibility of TSB > 20 mg/dl of each group.

RESULTS(1) The frequencies of allele G71R were 0.1915 in this study, 0.2329 in hyperbilirubinemia group vs. 0.097 in healthy groups. The allele gene frequency of G71R in neonatal hyperbilirubinemia was higher than that in the normal group (P < 0.05). (2) Homozygous neonates had higher possibility to develop bilirubin encephalopathy and higher TSB concentration 72 hours after birth (28.57%, 23.12 ± 4.58) than the normal group (0%, 17.68 ± 2.69). The difference between the former two was significant (P < 0.001). (3) The TSB of the 5 neonates was > 20 mg/dl in G71R homozygous type, the odds ratio and 95%CI were 7.955 (1.349, 46.899).

CONCLUSION(1) G71R mutation gene was associated with neonatal jaundice in Guangxi region. (2) The possibility of TSB > 20 mg/dl in G71R homozygous was higher than those of the wild-type. (3) The incidence of bilirubin encephalopathy and TSB concentration after 72 hours of age for neonates who were homozygous to G71R gene were higher than the wild-type.

Case-Control Studies ; China ; epidemiology ; Genotype ; Glucuronosyltransferase ; genetics ; Humans ; Hyperbilirubinemia, Neonatal ; epidemiology ; genetics ; Infant, Newborn ; Mutation

A two-year-old girl was admitted due to repeated yellowing of the skin and sclera for 2 years and had no other specific symptoms or signs. The use of phenobarbital could relieve the symptoms of jaundice. Multiple examinations showed increased indirect bilirubin levels, and the results of aminotransferases and liver imaging were normal. There was no evidence of hemolysis. The analysis of UGT1A1 gene in her family found that this child had double homozygous mutation of c.211G>A(G71R) and c.1456T>G(Y486D), which had been reported as the pathogenic mutation for Gilbert syndrome. Her parents carried double heterozygous mutation of G71R and Y486D and had no symptom of jaundice. The child was diagnosed as having Gilbert syndrome. It is concluded that as for patients with unconjugated hyperbilirubinemia which cannot be explained by liver damage and hemolysis, their family history should be investigated in detail and gene analysis should be performed as early as possible, in order to identify congenital bilirubin metabolic disorders.
Child, Preschool ; Female ; Gilbert Disease ; diagnosis ; Glucuronosyltransferase ; genetics ; Humans ; Mutation ; Sclera ; pathology ; Skin ; pathology

OBJECTIVETo detect potential mutation of the UGT1A1 gene in a child affected with Crigler-Najjar syndrome type II.

METHODSBlood samples were collected from the patient and his parents for the extraction of genomic DNA. Potential mutation of the UGT1A1 gene was detected with polymerase chain reaction (PCR) and direct sequencing. The child was followed up until the age of 3 years and 6 months.

RESULTSThe patient showed persistent unconjugated hyperbilirubinemia. Sequencing of the UGT1A1 gene has detected a rare heterozygous c.610 A>G (p.Met204Val) mutation in the exon 1, in addition with a heterozygous c.1091 C>T (p.Pro364Leu) mutation in exon 4. The two mutations were inherited from his father and mother, respectively. The patient was diagnosed with Crigler-Najjar syndrome type II and received oral phenobarbital treatment.

CONCLUSIONThe compound UGT1A1 gene mutation probably accounts for the disease in the patient manifesting persistent mild unconjugated hyperbilirubinemia. Genetic counseling and prenatal diagnosis should be provided for his family.

Crigler-Najjar Syndrome ; genetics ; Glucuronosyltransferase ; genetics ; Humans ; Infant ; Male ; Mutation ; Sequence Analysis, DNA

Congenital hemolytic anemia is mainly developed due to intrinsic defects of erythrocytes, but in some cases the cause of hemolytic anemia is unclear. Gilbert's syndrome shows mild, chronic unconjugated hyperbilirubinemia that is due to reduced UDP glucuronosyltransferase (UGT-1A1) activity and this develops because of UGT-1A1 gene mutation. We report here on a case of severe hyperbilirubinemia in a 17-year-old male who was diagnosed with congenital hemolytic anemia of an unknown cause combined with Gilbert's syndrome.
Adolescent ; Anemia, Hemolytic ; Anemia, Hemolytic, Congenital ; Erythrocytes ; Gilbert Disease ; Glucuronosyltransferase ; Humans ; Hyperbilirubinemia ; Male

A case of Gilbert syndrome (GS) with a heterozygous mutation in the gene is reported. The patient had no symptoms except for recurrent sclera icterus since childhood. Laboratory examinations revealed an elevated unconjugated bilirubin. Biliary obstruction, hemolysis and other diseases that might cause jaundice were excluded. *28 and c.211G>A heterozygous mutations in gene were found, which may be another type of mutation causing GS in Chinese population.
Asian Continental Ancestry Group ; Bilirubin ; Gilbert Disease ; genetics ; Glucuronosyltransferase ; genetics ; Heterozygote ; Humans ; Mutation