title: The role of ecto-5'-nucleotidase/CD73 in glioma cell line proliferation.
abstract: Malignant gliomas are the most common and devastating primary tumors in the brain and, despite treatment, patients with these tumors have a poor prognosis. The participation of ecto-5'-NT/CD73 per se as a proliferative factor, being involved in the control of cell growth, differentiation, invasion, migration and metastasis processes has been previously proposed. In the present study, we evaluated the activity and functions of ecto-5'-NT/CD73 during the proliferation process of rat C6 and human U138MG glioma cell lines. Increasing confluences and culture times led to an increase in ecto-5'-NT/CD73 activity in both C6 and U138MG glioma cells. RT-PCR analysis and flow cytometry analysis showed a significant increase in ecto-5'-NT/CD73 mRNA and protein levels, respectively, comparing confluent with sub-confluent cultures in human U138MG glioma cells. Ecto-5'-nucleotidase/CD73 may regulate the extracellular adenosine 5'-monophosphate (AMP) and adenosine levels. Treatment with 1 microM APCP, a competitive ecto-5'-NT/CD73 inhibitor, caused a significant reduction of 30% in glioma cell proliferation. In addition, 100 microM adenosine increases cell proliferation by 36%, and the treatment with adenosine plus NBTI and dipyridamole, produced an additional and significant increase of on cell proliferation. The inhibitory effect on cell proliferation caused by APCP was reverted by co-treatment with NBTI and dipyridamole. AMP (1 mM and 3 mM) decreased U138MG glioma cell proliferation by 29% and 42%, respectively. Taken together, these results suggest the participation of ecto-5'-NT/CD73 in cell proliferation and that this process is dependent upon the enzyme's production of adenosine, a proliferative factor, and removal of AMP, a toxic molecule for gliomas.
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, Porto Alegre, RS, Brazil.
authors.forename: Luci
authors.initials: L
authors.lastname: Bavaresco
authors.forename: Andressa
authors.initials: A
authors.lastname: Bernardi
authors.forename: Elizandra
authors.initials: E
authors.lastname: Braganhol
authors.forename: Angélica Regina
authors.initials: AR
authors.lastname: Cappellari
authors.forename: Liliana
authors.initials: L
authors.lastname: Rockenbach
authors.forename: Patrícia Fernandes
authors.initials: PF
authors.lastname: Farias
authors.forename: Márcia Rosângela
authors.initials: MR
authors.lastname: Wink
authors.forename: Andrés
authors.initials: A
authors.lastname: Delgado-Cañedo
authors.forename: Ana Maria Oliveira
authors.initials: AM
authors.lastname: Battastini
mesh_terms: D015720:5'-Nucleotidase / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D000241:Adenosine / Q000378:metabolism / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000378:metabolism; D000345:Affinity Labels / Q000494:pharmacology; D000818:Animals; D001932:Brain Neoplasms / Q000201:enzymology* / Q000473:pathology; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D005910:Glioma / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D051381:Rats; D013868:Thioinosine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000345:Affinity Labels; D004791:Enzyme Inhibitors; D000249:Adenosine Monophosphate; D013868:Thioinosine; D015720:5'-Nucleotidase; C001789:4-nitrobenzylthioinosine; D000241:Adenosine