methylguanine-DNA methyltransferase
DNA repair enzyme whose expression level affects response to alkylating chemotherapy agents in brain tumors.
Full Definition
Methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that removes alkyl groups from the O6 position of guanine, thereby protecting cells from DNA damage. In neuro-oncology, MGMT expression is a critical biomarker because tumors with high MGMT activity can repair DNA damage caused by alkylating agents like temozolomide, leading to treatment resistance. Conversely, tumors with low MGMT expression (often due to promoter methylation) are more sensitive to these chemotherapeutic agents. This biomarker helps guide treatment decisions and provides prognostic information for patients with glioblastoma and other brain tumors.
Usage
Usage note: Often abbreviated as MGMT enzyme to distinguish from MGMT methylation status.
In Context
- "Low methylguanine-DNA methyltransferase expression predicted favorable response to alkylating therapy." — Molecular pathology report
- "The tumor showed high methylguanine-DNA methyltransferase activity, suggesting potential resistance to temozolomide." — Treatment planning discussion