RT Journal Article
T1 Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression.
A1 Perazzoli, Gloria
A1 Prados, Jose
A1 Ortiz, Raul
A1 Caba, Octavio
A1 Cabeza, Laura
A1 Berdasco, Maria
A1 Gónzalez, Beatriz
A1 Melguizo, Consolación
K1 Antineoplásicos alquilantes
K1 Azacitidina
K1 Línea celular tumoral
K1 Metilación de ADN
K1 Metilasas de modificación del ADN
K1 Enzimas reparadoras del ADN
K1 Tumor Suppressor Proteins
K1 Dacarbazina
K1 Resistencia a antineoplásicos
K1 Epigénesis genética
K1 Expresión génica
K1 Regulación neoplásica de la expresión génica
K1 Glicoproteínas
K1 Guanina
K1 Concentración 50 inhibidora
K1 Glicoproteína P
K1 Péptidos
K1 Regiones promotoras genéticas
K1 Proteínas supresoras de tumor
K1 Antígenos CD
K1 Regiones promotoras genéticas
AB BACKGROUNDThe use of temozolomide (TMZ) has improved the prognosis for glioblastoma multiforme patients. However, TMZ resistance may be one of the main reasons why treatment fails. Although this resistance has frequently been linked to the expression of O6-methylguanine-DNA methyltransferase (MGMT) it seems that this enzyme is not the only molecular mechanism that may account for the appearance of drug resistance in glioblastoma multiforme patients as the mismatch repair (MMR) complex, P-glycoprotein, and/or the presence of cancer stem cells may also be implicated.METHODSFour nervous system tumor cell lines were used to analyze the modulation of MGMT expression and MGMT promoter methylation by TMZ treatment. Furthermore, 5-aza-2'-deoxycytidine was used to demethylate the MGMT promoter and O(6)-benzylguanine to block GMT activity. In addition, MMR complex and P-glycoprotein expression were studied before and after TMZ exposure and correlated with MGMT expression. Finally, the effect of TMZ exposure on CD133 expression was analyzed.RESULTSOur results showed two clearly differentiated groups of tumor cells characterized by low (A172 and LN229) and high (SF268 and SK-N-SH) basal MGMT expression. Interestingly, cell lines with no MGMT expression and low TMZ IC50 showed a high MMR complex expression, whereas cell lines with high MGMT expression and high TMZ IC50 did not express the MMR complex. In addition, modulation of MGMT expression in A172 and LN229 cell lines was accompanied by a significant increase in the TMZ IC50, whereas no differences were observed in SF268 and SK-N-SH cell lines. In contrast, P-glycoprotein and CD133 was found to be unrelated to TMZ resistance in these cell lines.CONCLUSIONSThese results may be relevant in understanding the phenomenon of TMZ resistance, especially in glioblastoma multiforme patients laking MGMT expression, and may also aid in the design of new therapeutic strategies to improve the efficacy of TMZ in glioblastoma multiforme patients.
PB Public Library of Science
YR 2015
FD 2015-10-08
LK http://hdl.handle.net/10668/2596
UL http://hdl.handle.net/10668/2596
LA en
NO Perazzoli G, Prados J, Ortiz R, Caba O, Cabeza L, Berdasco M, et al. Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression. PLoS ONE. 2015; 10(10):e0140131
NO Journal Article; Research Support, Non-U.S. Gov't;
DS RISalud
RD Apr 17, 2025