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

Document Type : Original Article


1 Departement of Biology, University of Sistan and Baluchestan, Zahedan, Iran

2 Department of Ophthalmology, Al-Zahra Eye Hospital, Zahedan University of Medical Sciences, Zahedan ,Iran

3 Department of Ophthalmology, Al-Zahra Eye Hospital, Zahedan University of Medical Sciences , Zahedan ,Iran


1)Background: Pterygium is a benign legion and is observed as aggressive growth of
conjunctiva fibro-vascular tissue on the cornea. The alkylating agents are observed as
considerable threats for human health because alkylated lesions lead to cytotoxic,
teratogenic and cancerizing effects. MGMT is one of the repair proteins of DNA which
repairs the alkylated lesions. Expression and activity of MGMT is controlled by
epigenetic mechanisms such as DNA methylation in the promoter regions like
transcription factors which are connected to MGMT promoter and lead to positive or
negative induction of that activity, protein-protein interactions, and negative regulation.
2)Materials and methods: In order to study methylation, DNA samples of 43 patients
and 40 healthy individuals were extracted, bisulfited and then were studied. Also in
order to study the expression, RNA was extracted from 15 other patients and 15 other
healthy 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 significant
relationship in the situation of promoter methylation between the patients and control
individuals (P value = 0.43; 95%Cl = 0.66-2.40; OR = 1.52). However, analysis of
MGMT gene expression showed significant difference between the patients and control
individuals (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 MGMT
gene, there seems to be other unknown procedures that regulate this gene’s expression
levels. In this respect, expression of MGMT gene in the pterygium increases through
unknown procedures. In order to approve this data, further studies are suggested in more
populations with bigger sample sizes by the use of advanced molecular techniques.


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