Identifying genetic variants regulating MGMT gene expression - A study in monozygotic Danish twins

Area of Science:

• Genetics
• Cancer Biology
• Epigenetics

Background:

• The O-6-Methylguanine-DNA Methyltransferase (MGMT) gene plays a crucial role in DNA repair and is important in various cancers, including glioblastoma.
• Understanding the genetic regulation of MGMT is vital for predicting patient response to alkylating agent therapies.

Purpose of the Study:

• To identify genetic factors influencing the regulation of the MGMT gene.
• To estimate the genetic contribution to MGMT gene expression using monozygotic twin pairs.
• To explore the relationship between MGMT gene variants and sensitivity to therapeutic alkylating agents.

Main Methods:

• Utilized gene expression data from whole blood of 448 monozygotic twins from the Middle Age Danish Twins (MADT) study.
• Performed a genome-wide association study (GWAS) to analyze variations in MGMT gene expression.
• Calculated within-pair correlation of gene expression to assess genetic influence.

Main Results:

• Identified 243 single nucleotide polymorphisms (SNPs) significantly associated with MGMT expression (p < 5e-8), all located on chromosome 10 near the MGMT gene.
• Discovered 7 novel cis-eQTLs among the significant SNPs.
• Identified 11 suggestive trans-eQTLs on chromosome 17, located near or within seven genes potentially regulating MGMT expression.

Conclusions:

• Genetic variations, including cis- and trans-acting SNPs, significantly regulate MGMT gene expression.
• Within-pair correlations of MGMT, TRIM37, and SEPT4 expression indicate their genetic influence.
• Findings contribute to a better understanding of MGMT gene function and its implications for therapeutic strategies in cancer treatment.