title: Thyroid hormone upregulates ecto-5'-nucleotidase/CD73 in C6 rat glioma cells.
abstract: Thyroid hormones have profound effects on the central nervous system, such as proliferation, secretion of growth factors and gene expression regulation. Ecto-NTPDases and ecto-5'-nucleotidase can control the extracellular ATP/adenosine levels, which have been described as proliferation factors. Here, we investigated the influence of T(3) on the enzyme cascade which catalyzes interconversion of purine nucleotides in rat C6 glioma cells. Exposure of C6 cells to T(3) caused a dose dependent increase of 30% in the AMP hydrolysis up to 0.25 nM, which was suppressed by actinomycin. No significant alteration was observed on ATP/ADP hydrolysis and T(4) at higher concentrations (10-1000 nM) promoted an increase in AMP hydrolysis that was not dose dependent. T(3) treatment also increased the expression of CD73 mRNA. Besides the importance of the ecto-5'-NT in the cell proliferation and differentiation, its overexpression can enhance extracellular adenosine levels, which could also be an important proliferation signal.
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Rua Ramiro Barcelos, 2600-anexo, CEP 90035-003, Porto Alegre, RS, Brazil.
authors.forename: M R
authors.initials: MR
authors.lastname: Wink
authors.forename: A S K
authors.initials: AS
authors.lastname: Tamajusuku
authors.forename: E
authors.initials: E
authors.lastname: Braganhol
authors.forename: E A
authors.initials: EA
authors.lastname: Casali
authors.forename: M L M
authors.initials: ML
authors.lastname: Barreto-Chaves
authors.forename: J J F
authors.initials: JJ
authors.lastname: Sarkis
authors.forename: A M O
authors.initials: AM
authors.lastname: Battastini
mesh_terms: D015720:5'-Nucleotidase / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D045744:Cell Line, Tumor; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005910:Glioma / Q000201:enzymology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013974:Thyroxine / Q000378:metabolism / Q000494:pharmacology*; D014284:Triiodothyronine / Q000378:metabolism / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D014284:Triiodothyronine; D003609:Dactinomycin; D015720:5'-Nucleotidase; D013974:Thyroxine