Expression and Promoter-Hyper Methylation Analysis of MGMT Gene in Patients with Pterygium

1)Background: Pterygium is a benign legion and is observed as aggressive growth ofconjunctiva fibro-vascular tissue on the cornea. The alkylating agents are observed asconsiderable threats for human health because alkylated lesions lead to cytotoxic,teratogenic and cancerizing effects. MGMT is one of the repair proteins of DNA whichrepairs the alkylated lesions. Expression and activity of MGMT is controlled byepigenetic mechanisms such as DNA methylation in the promoter regions liketranscription factors which are connected to MGMT promoter and lead to positive ornegative induction of that activity, protein-protein interactions, and negative regulation.2)Materials and methods: In order to study methylation, DNA samples of 43 patientsand 40 healthy individuals were extracted, bisulfited and then were studied. Also inorder to study the expression, RNA was extracted from 15 other patients and 15 otherhealthy individuals; and then, the technique of Real-time PCR was used. 3)Results:analysis of promoter methylation of MGTM gene showed that there is no significantrelationship in the situation of promoter methylation between the patients and controlindividuals (P value = 0.43; 95%Cl = 0.66-2.40; OR = 1.52). However, analysis ofMGMT gene expression showed significant difference between the patients and controlindividuals (Mean ± SD: 1.25 ± 0.10 and 1.52 ± 2.91, respectively; P value = 0.009). 4)Conclusion: since there are no significant changes of promoter methylation of MGMTgene, there seems to be other unknown procedures that regulate this gene’s expressionlevels. In this respect, expression of MGMT gene in the pterygium increases throughunknown procedures. In order to approve this data, further studies are suggested in morepopulations with bigger sample sizes by the use of advanced molecular techniques.

Expression and Promoter-Hyper Methylation Analysis of MGMT Gene in Patients with Pterygium Keywords:

Pterygium , MGMT gene , promoter methylation , gene expression , epigenetic mechanisms