ArticleJournal of neuro-oncology2008
Variation of O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation in serial samples in glioblastoma.
Article in Journal of neuro-oncology, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 45 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
45 citing papers in PubMed, 1 synthesis or guideline pooled it, 93 citations in OpenAlex.
- Pooled it
- A new schedule of fotemustine in temozolomide-pretreated patients with relapsing glioblastoma.Journal of neuro-oncology · 2011Trial
- Phase II trial of erlotinib with temozolomide and radiation in patients with newly diagnosed glioblastoma multiforme.Journal of neuro-oncology · 2010Trial
- Analysis of DNA Methylation in Gliomas: Assessment of Preanalytical Variables.Laboratory investigation; a journal of technical methods and pathology · 2024Article
- Genetic and epigenetic instability as an underlying driver of progression and aggressive behavior in IDH-mutant astrocytoma.Acta neuropathologica · 2024Review
- Image-localized biopsy mapping of brain tumor heterogeneity: A single-center study protocol.PloS one · 2023Article
- Beyond Imaging and Genetic Signature in Glioblastoma: Radiogenomic Holistic Approach in Neuro-Oncology.Biomedicines · 2022Review
- Review
- MGMT Promoter Methylation and IDH1 Mutations Do Not Affect [International journal of molecular sciences · 2020Article
- Changes of OCancers · 2019Review
- Intratumor DNA methylation heterogeneity in glioblastoma: implications for DNA methylation-based classification.Neuro-oncology · 2019Article
- Prognostic value of subventricular zone involvement in relation to tumor volumes defined by fused MRI and O-(2-[Radiation oncology (London, England) · 2019Article
- The impact of adjuvant radiotherapy on molecular prognostic markers in gliomas.OncoTargets and therapy · 2019Article
- Defining a prognostic score based on O6-methylguanine-DNA methyltransferase cut-off methylation level determined by pyrosequencing in patients with glioblastoma multiforme.Journal of neuro-oncology · 2018Article
- Prediction of survival in patients affected by glioblastoma: histogram analysis of perfusion MRI.Journal of neuro-oncology · 2018Article
- Stereotactic image-based histological analysis reveals a correlation betweenOncology letters · 2018Article
- Glioblastoma Recurrence Correlates With Increased APE1 and Polarization Toward an Immuno-Suppressive Microenvironment.Frontiers in oncology · 2018Article
- Assessment of molecular markers demonstrates concordance between samples acquired via stereotactic biopsy and open craniotomy in both anaplastic astrocytomas and glioblastomas.Journal of neuro-oncology · 2017Article
- Role ofThe oncologist · 2017Article
- Intratumoral heterogeneity identified at the epigenetic, genetic and transcriptional level in glioblastoma.Scientific reports · 2016Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Methylation of the promoter region of the O ( 6 ) -methylguanine-DNA methyltransferase (MGMT) gene is known to be predictive of response to temozolomide treatment in patients with glioblastoma. Contrastingly, little is known about variation in the methylation status of the MGMT promoter after treatment or across different regions of the same tumor. About 22 samples from 10 patients who had undergone multiple resections of a glioblastoma were examined with promoter sequencing. Of these, 20 were also analyzed using Methylation Specific PCR (MSP). The methylation status of the MGMT promoter was altered in the specimens obtained pre and post treatment in 2 of 9 samples as assessed by MSP and 7 out of 10 patients as assessed by promoter sequencing. In four patients, the MGMT promoter was unmethylated at primary surgery, but displayed some methylation (32, 44, 12, and 4%) on post-treatment sampling. Alteration in MSP status from unmethylated to methylated was also observed in 2 of these 4 patients. In another patient, methylation increased from 40% on initial sampling to 68% on the second sample. The remaining two patients initially demonstrated some degree of methylation (72% and 12%); subsequent sampling showed no methylation of the MGMT promoter. To ensure variable methylation status was not due to intra-tumoral variability, three to four specimens were sampled from different regions of large glioblastomas (n = 7). Promoter sequencing revealed minimal variation in methylation in all but two sites examined. Immunohistochemistry also demonstrated minimal change in MGMT expression across the tumors. This suggests that variation in MGMT promoter methylation can occur within the same tumor after treatment, necessitating caution in clinical decision-making based on this analysis.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.