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Effects of toxic doses of glutamate on Cu–Zn and Mn/superoxide
dismutases activities in human glioma cell lines Andrea Regner, Daniel Pretto Schunemann, Ivana Grivicich, Celito Luis Diel,
Caroline Brunetto Farias, Giovana Kowaleski,
Edlaine Mondadori, Gilberto Schwartsmann
and Adriana Brondani da Rocha
Centro de
Pesquisas em Ciências Médicas, Universidade Luterana do Brasil
(ULBRA), Rua Miguel Tostes, 101, Prédio 22, 5 andar, Bairro São
Luis, Canoas/RS, CEP: 9240-280 [A.R., D.P.S., I.G., C.B.F. G.K., E.M.,
A.B.R.]. Curso de Pós-Graduação em
Diagnostico Genético e Molecular da Universidade Luterana do Brasil,
Canoas, Brazil [A.R., D.P.S., A.B.R.]. South-American
Office for Anticancer Drug Development (SOAD), RS, Brazil [I.G.,
C.L.D., G.S.]. Correspondence to: Andrea Regner, Email:
regner@uol.com.br, Phone: +55-51-477-9219, Fax: +55-51-478-1747. Recent
research has implicated glutamate in the growth and invasive migration
of gliomas.
Superoxide dismutase (SOD) is involved in
excitotoxicity and may influence cellular proliferative status.
Thus, this study investigated the effects
of gliotoxic doses of glutamate on Cu–Zn and Mn/SODs activities in
human glioma cell lines.
To this end, glioma cell lines (U87MG,
U138MG and U251MG) were treated with glutamate (5–200 mM)
during 48 h.
Then, cell viability assays, clonogenic
assay and Cu–Zn and Mn/SODs activities of the cell lines were
performed.
IC50values of glutamate were
similar for both U87MG and U138MG cells (56 and 69 mM, respectively),
while a higher value was detected for U251MG cells (110 mM).
In the long term, 14 days
after glutamate was removed from the culture media, cells showed
partial or complete recovery.
The effects of glutamate treatment on
Cu–Zn and Mn/SODs activities varied among the distinct cell
lines.
While acute treatment with toxic doses of
glutamate caused a significant decrease in the Cu–Zn/SOD activity of
U138MG and U251MG cells, it did not affect Cu–Zn/SOD activity in
U87MG cells.
Only in U251MG cells, acute glutamate
treatment decreased significantly Mn/SOD activity.
In the long term (14 days
after the 48 h
treatment), glutamate did not affect either Cu–Zn or Mn/SODs
activities.
Thus, it may be suggested that SOD
vulnerability to glutamate-mediated effects may be related to distinct
tumoral cell behavior. Keywords: glioma - glutamate - human - neurotoxicity - superoxide
dismutase © Springer 2005 Source:
http://springerlink.metapress.com/openurl.asp?genre=article&eissn=1573-7373&volume=71&issue=1&spage=9
DOI: http://dx.doi.org/10.1007/s11060-004-9178-y
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