MGMT promoter methylation

MGMT encodes a DNA repair enzyme that removes cytotoxic O⁶-alkylguanine lesions generated by alkylating agents such as temozolomide (TMZ)...Building on these mechanistic insights, this review discusses emerging strategies to overcome MGMT-mediated resistance, including next-generation alkylating agents, epigenetic modulators, combination immunotherapies, and radiogenomic approaches for precision medicine. Understanding MGMT methylation biology may improve patient stratification and support precision-based therapeutic interventions in GBM.

SFRT was associated with longer survival in non-elderly patients, possibly reflecting selection of poorer-risk patients for HFRT. In elderly patients, HFRT was noninferior regardless of MGMTp status, supporting its use as a less intensive approach with comparable survival and reduced treatment burden.

Additionally, the manuscript emphasizes novel therapeutic strategies, such as nanomedicine, oncolytic virotherapy, immunotherapy, tumor-treating fields, and phytochemical-based interventions, as well as the increasing significance of artificial intelligence and machine learning in diagnosis and personalized treatment. Lastly, this review integrates mechanistic and translational insights to establish a framework addressing blood-brain barrier limitations, therapeutic resistance, and immune evasion, thereby facilitating the advancement of precision medicine approaches for enhanced GBM outcomes.

Radial transition analysis using the Mann-Whitney U-test demonstrated that transition slopes between the T1-weighted contrast-enhancing and T2/FLAIR hyperintense regions, as well as between the T2/FLAIR hyperintense and peritumoral regions, were significantly associated with biomarker status. Radiomic features extracted from spherical surfaces at varying radial distances from the tumor centroid demonstrate stronger associations with key molecular markers and patient survival compared to conventional Euclidean radiomics, highlighting the value of spatially structured radiomic analysis for improved GBM characterization.

This international clinical dataset of adults diagnosed with glioblastoma since the introduction of the WHO CNS 5 criteria supports the use of conventionally fractionated chemoradiation in fit patients < 70, while hypofractionated regimens are appropriate for those ≥ 70. Surgical extent, treatment intensity, and MGMT methylation remain key determinants of survival in older patients with glioblastoma.

Glioblastoma (GBM) response to Temozolomide (TMZ) critically depends on O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation...Correlation analysis demonstrated: (1) a positive correlation of SFA content (1444 cm-1) with methylation levels in MGMT-HYPER tumors; (2) an inverse association of DNA levels (1093 cm-1) with methylation in intermediate-methylation GBMs; and (3) a negative correlation between UFA content (1266 cm-1) and methylation in unmethylated GBMs. This study confirms RS potential for assessing MGMT methylation status in tumors and elucidates metabolic signatures associated with differential methylation in GBMs, providing targets for metabolic intervention against TMZ resistance.

Concurrent cancers do not appear to adversely affect survival outcomes or probabilities compared with GBM alone, within the limits of statistical power. Age remained a strong independent predictor of both PFI and OS, regardless of concurrent cancers or sex.

Our findings indicate that GBM alters functional brain organization on a widespread scale, and these global effects are informative of patient outcomes.

Landmark analysis showed no evidence for early treatment failure itself to be associated with OS (P = .40), whereas MGMT promoter methylation status was associated with long-term survival and reduced hazard of death (HR: 0.31, 95% CI: 0.17-0.55; P < .001). Pretreatment MRI perfusion metrics may predict short-term treatment failure and may guide early experimental therapy, while the MGMT status remains the primary determinant of long-term survival.

MiR-148 is associated with MGMT methylation and can have prognostic significance. Reduced miR-194 with MGMT methylation and increased miR-130 with high Ki-67 and TP53 indicate involvement of these microRNAs in formation of aggressive glioblastoma phenotype and their potential as prognostic biomarkers.

One important prognostic factor is the methylation status of the O⁶-methylguanine DNA methyltransferase (MGMT) gene, as MGMT promoter methylation is associated with a better response to temozolomide chemotherapy...These results suggest that imaging examinations capture complementary information regarding tumor morphology and anatomical origin. The anatomical location of glioblastoma may therefore provide useful clues for classifying MGMT gene methylation status.

A clinically relevant, survival informed three-tier classification of MGMT promoter methylation is proposed for the pyrosequencing kit analyzing CpGs 76-79 in glioblastoma. A threshold of ≤ 8% identifies a subgroup with truly unmethylated tumors, while ≥ 11% defines a clearly methylated group. The intermediate range represents a gray zone. These cut-offs support individualized therapy by improving clinically relevant stratification and facilitate future clinical trials focusing on patients with truly unmethylated MGMT.