background: high-grade astrocytoma (grade 4) or glioblastoma multiforme (gbm) are deadly brain tumors. new therapies attempt to increase lifetime and quality of life in patients with malignant astrocytoma. o6-methylguanine-dna methyltransferase (mgmt) enzyme expression may be effective in prognosis and response to treatment of these patients. the aim of this study was assessment of mgmt enzyme ...

aim :  to evaluate the association of dnmt1 and mgmt amino acid substitution polymorphisms and colorectal cancer in iranian population. background : the mgmt and dnmt1 are two important methyltransferase enzymes. amino acid substitution polymorphisms in mgmt and dnmt1 genes may be associated with the genetic susceptibility to sporadic colorectal cancer. patients and methods : we assessed eight ...

We have generated mice deficient in O6-methylguanine DNA methyltransferase activity encoded by the murine Mgmt gene using homologous recombination to delete the region encoding the Mgmt active site cysteine. Tissues from Mgmt null mice displayed very low O6-methylguanine DNA methyltransferase activity, suggesting that Mgmt constitutes the major, if not the only, O6-methylguanine DNA methyltrans...

results methylation in at least one gene was reported about 93.8%. the methylation of sfrp2 was reported in 39 out of the 48 subjects (81.2%) whereas methylation of mgmt was observed in 32 subjects (66.6%). conclusions the current study results showed that methylation of sfrp2 and mgmt play an important role in polyp formation. materials and methods forty eight tissue samples of polyp and adeno...

O(6)-methylguanine-DNA methyltransferase plays vital roles in preventing induction of mutations and cancer as well as cell death related to alkylating agents. Mice defective in the MGMT: gene, encoding the methyltransferase, were used to evaluate cell death-inducing and tumorigenic activities of therapeutic agents which have alkylation potential. MGMT(-/-) mice were considerably more sensitive ...

A plasmid encoding a recombinant human O6-methylguanine-DNA methyltransferase (MGMT) fused to a fragment of the bacteriophage lambda N protein has been constructed. The fusion protein retained methyltransferase activity when expressed at high levels in E.coli and was purified to essential homogeneity by a simple procedure. Antisera raised against the purified fusion protein recognized MGMT in w...

Nickel (Ni) compounds are potent carcinogens and can induce malignant transformation of rodent and human cells. To uncover the molecular mechanisms of nickel sulfide (NiS)-induced cell transformation, we investigated epigenetic alterations in a set of DNA repair genes. The silencing of the O(6)-methylguanine DNA methyltransferase (MGMT) gene locus and upregulation of DNA methyltransferase 1 (DN...

The aim of the present study was to investigate the association between O6-methylguanine-DNA methyltransferase (MGMT) gene expression levels, and DNA methylation status and histone modifications in laryngeal squamous cell carcinoma (LSCC). Chromatin immunoprecipitation, methylation-specific polymerase chain reaction (PCR), and reverse transcription-quantitative PCR were performed to analyze his...

transcription start site and silencing of the heterochromatinization of the MGMT (MGMT) CpG island is associated with O6-methylguanine DNA methyltransferase Methylation of discrete regions of the