ABSTRACT
Tissue-specific expression of human UGT1A6, a UDP-glucuronosyltransferase isoform conjugating a wide variety of planar phenols, has been studied using a reverse transcriptase-polymerase chain reaction. Use of intron-overlapping forward and reverse primers from exon 1 and 2 and of a "hot start" modification led to selective amplification of a UGT1A6 mRNA fragment. In addition, homologous competitor mRNA was synthesized, reverse transcribed, and coamplified to allow quantitation of UGT1A6 mRNA. Using these methods UGT1A6 mRNA could be demonstrated in liver, kidney, duodenum, and lung. Cell-specific regulation of UGT1A6 by TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) was studied in various cell systems. TCDD induction was found in the human colon carcinoma cell line Caco-2 and in hepatocyte primary cultures. In contrast, in lung carcinoma A549 cells this isoform was constitutively expressed and not induced by TCDD.
Subject(s)
Glucuronosyltransferase/biosynthesis , Liver/enzymology , Polychlorinated Dibenzodioxins/pharmacology , Duodenum/enzymology , Enzyme Induction , Humans , Intestinal Mucosa/enzymology , Introns , Polymerase Chain Reaction , RNA, Messenger/biosynthesis , Reference Values , Smoking , Transcription, GeneticABSTRACT
Ultrasound examination of a 27-year-old primigravida at 26 weeks' gestation revealed fetal growth retardation, malformation of the ventricular septum, and a neck fold. Chromosome analysis of the amniotic fluid showed an abnormal 46,XY karyotype with an obvious metacentric chromosome 17. Chromosome analysis of the mother revealed a balanced t (17;22) (p13;q12) translocation. The fetus thus has a rare familial duplication 22q12----qter. Eight live-born and severely malformed infants with this duplication have been reported in the literature.
