title: Retinoic acid increases hydroxyindole-O-methyltransferase activity and mRNA in human Y-79 retinoblastoma cells.
abstract: Hydroxyindole-O-methyltransferase (HIOMT) plays an important role as the final enzyme in the synthesis of melatonin. Here we present the first evidence that retinoic acid (RA) stereoisomers are potent regulators of HIOMT in the human retinoblastoma-derived Y-79 cell line. Treatment with all-trans-, 13-cis-, and 9-cis-RA induced a gradual 10-fold increase in HIOMT activity and mRNA, without changing the levels of mRNA encoding glyceraldehyde-3-phosphate dehydrogenase, actin, S-antigen, and interphotoreceptor retinoid-binding protein. These findings point to the possibility that RA may play a physiological role in the regulation of human HIOMT.
authors: Section on Neuroendocrinology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors: M
authors: M
authors: Bernard
authors: D C
authors: DC
authors: Klein
mesh_terms: D000121:Acetylserotonin O-Methyltransferase / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D015152:Blotting, Northern; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D012175:Retinoblastoma; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000201:enzymology
chemical_list: D012333:RNA, Messenger; D014212:Tretinoin; D000121:Acetylserotonin O-Methyltransferase