title: Expression of hydroxyindole-O-methyltransferase enzyme in the human central nervous system and in pineal parenchymal cell tumors.
abstract: Pineal parenchymal tumor (PPT) cells usually show immunoreactivity for synaptophysin, neuron-specific enolase, neurofilament protein, class III beta-tubulin, tau protein, PGP9.5, chromogranin, serotonin, retinal S-antigen, and rhodopsin, but these markers are not specific for PPTs. Melatonin is produced and secreted mainly bypineal parenchymal cells; hydroxyindole-O-methyltransferase (HIOMT) catalyzes the final reaction in melatonin biosynthesis. We hypothesized that HIOMT could serve as a tumor marker of PPTs, and we investigated HIOMT localization and HIOMT expression in samples of normal human tissue and in PPTs, primitive neuroectodermal tumors, and medulloblastomas. In normal tissue, HIOMT was expressed in retinal cells, pineal parenchymal cells, neurons of the Edinger-Westphal nucleus, microglia, macrophages, thyroid follicular epithelium, principal and oxyphil cells of parathyroid gland, adrenal cortical cells, hepatic parenchymal cells, renal tubule epithelium, and enteroendocrine cells of stomach and duodenum. The HIOMT was also expressed in all 46 PPTs studied. The proportions of HIOMT-immunoreactive cells successively decreased in the following tumors: pineocytoma, pineal parenchymal tumor of intermediate differentiation, and pineoblastoma. A few HIOMT-immunoreactive cells were observed in one of 6 primitive neuroectodermal tumors and 23 of 42 medulloblastomas. These results indicate that HIOMT immunohistochemistry may be useful for the diagnosis of PPTs and be a prognostic factor in PPTs.
authors.affiliation: Division of Neuropathology, Department of Neuroscience, ResearchCenter for Medical Sciences, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan. fukuda-t@jikei.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fukuda
authors.forename: Nobutake
authors.initials: N
authors.lastname: Akiyama
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ikegami
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sasaki
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Oka
authors.forename: Takashi
authors.initials: T
authors.lastname: Komori
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Youichi
authors.initials: Y
authors.lastname: Nakazato
authors.forename: Jiro
authors.initials: J
authors.lastname: Akimoto
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Okada
authors.forename: Saburo
authors.initials: S
authors.lastname: Saito
mesh_terms: D000121:Acetylserotonin O-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D019393:Arrestin / Q000378:metabolism; D001932:Brain Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D002490:Central Nervous System / Q000201:enzymology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D010870:Pineal Gland / Q000473:pathology*; D010871:Pinealoma / Q000473:pathology*; D037121:Plant Lectins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000473:pathology; D014162:Transfection / Q000379:methods
chemical_list: D019393:Arrestin; D005136:Eye Proteins; D009419:Nerve Tissue Proteins; D037121:Plant Lectins; D012333:RNA, Messenger; C017707:Ricinus communis agglutinin-1; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D000121:Acetylserotonin O-Methyltransferase