Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.

Temozolomide (TMZ) is a drug of choice in glioblastoma treatment. Its therapeutic applications expand also beyond high grade gliomas. However, a significant number of recurrences and resistance to the drug is observed. The key factor in each chemotherapy is to achieve the therapeutic doses of a drug...

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Main Authors: Agnieszka Belter, Jakub Barciszewski, Anna-Maria Barciszewska
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2020-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0229534
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author Agnieszka Belter
Jakub Barciszewski
Anna-Maria Barciszewska
author_facet Agnieszka Belter
Jakub Barciszewski
Anna-Maria Barciszewska
author_sort Agnieszka Belter
collection DOAJ
description Temozolomide (TMZ) is a drug of choice in glioblastoma treatment. Its therapeutic applications expand also beyond high grade gliomas. However, a significant number of recurrences and resistance to the drug is observed. The key factor in each chemotherapy is to achieve the therapeutic doses of a drug at the pathologic site. Nonetheless, the rate of temozolomide penetration from blood to cerebrospinal fluid is only 20-30%, and even smaller into brain intestinum. That makes a challenge for the therapeutic regimens to obtain effective drug concentrations with minimal toxicity and minor side effects. The aim of our research was to explore a novel epigenetic mechanism of temozolomide action in therapeutic conditions. We analyzed the epigenetic effects of TMZ influence on different glioblastoma cell lines in therapeutically achieved TMZ concentrations through total changes of the level of 5-methylcytosine in DNA, the main epigenetic marker. That was done with classical approach of radioactive nucleotide post-labelling and separation on thin-layer chromatography. In the range of therapeutically achieved temozolomide concentrations we observed total DNA hypomethylation. The significant hypermethylating effect was visible after reaching TMZ concentrations of 10-50 μM (depending on the cell line). Longer exposure time promoted DNA hypomethylation. The demethylated state of the glioblastoma cell lines was overcome by repeated TMZ applications, where dose-dependent increase in DNA 5-methylcytosine contents was observed. Those effects were not seen in non-cancerous cell line. The increase of DNA methylation resulting in global gene silencing and consecutive down regulation of gene expression after TMZ treatment may explain better glioblastoma patients' survival.
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spelling doaj.art-954a4cf83a7547c59fb37e250127f6f92022-12-21T20:40:16ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-01152e022953410.1371/journal.pone.0229534Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.Agnieszka BelterJakub BarciszewskiAnna-Maria BarciszewskaTemozolomide (TMZ) is a drug of choice in glioblastoma treatment. Its therapeutic applications expand also beyond high grade gliomas. However, a significant number of recurrences and resistance to the drug is observed. The key factor in each chemotherapy is to achieve the therapeutic doses of a drug at the pathologic site. Nonetheless, the rate of temozolomide penetration from blood to cerebrospinal fluid is only 20-30%, and even smaller into brain intestinum. That makes a challenge for the therapeutic regimens to obtain effective drug concentrations with minimal toxicity and minor side effects. The aim of our research was to explore a novel epigenetic mechanism of temozolomide action in therapeutic conditions. We analyzed the epigenetic effects of TMZ influence on different glioblastoma cell lines in therapeutically achieved TMZ concentrations through total changes of the level of 5-methylcytosine in DNA, the main epigenetic marker. That was done with classical approach of radioactive nucleotide post-labelling and separation on thin-layer chromatography. In the range of therapeutically achieved temozolomide concentrations we observed total DNA hypomethylation. The significant hypermethylating effect was visible after reaching TMZ concentrations of 10-50 μM (depending on the cell line). Longer exposure time promoted DNA hypomethylation. The demethylated state of the glioblastoma cell lines was overcome by repeated TMZ applications, where dose-dependent increase in DNA 5-methylcytosine contents was observed. Those effects were not seen in non-cancerous cell line. The increase of DNA methylation resulting in global gene silencing and consecutive down regulation of gene expression after TMZ treatment may explain better glioblastoma patients' survival.https://doi.org/10.1371/journal.pone.0229534
spellingShingle Agnieszka Belter
Jakub Barciszewski
Anna-Maria Barciszewska
Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.
PLoS ONE
title Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.
title_full Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.
title_fullStr Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.
title_full_unstemmed Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.
title_short Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions.
title_sort revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions
url https://doi.org/10.1371/journal.pone.0229534
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AT annamariabarciszewska revealingtheepigeneticeffectoftemozolomideonglioblastomacelllinesintherapeuticconditions