Correlation between Promoter Hypermethylation and Expression Profiles of P15INK4b and P16INK4a Genes on Development of Pterygium Disease

It is not thoroughly clear that what is the exact etiology of pterygium. Recently, it has been illustrated that pterygium is a benign and destructive condition. The aim of this study was to examine the correlation between promoter hypermethylation of P15INK4band P16INK4a genes on progress of pterygium.

We extracted DNA from 81 primary pterygium and 75 normal conjunctiva tissues. Methylation specific polymerase chain reaction (MSP) technique was used to analyze of promoter hypermethylation of P15INK4b and P16INK4a genes. The expression levels ofthesegenes were also assessed in mRNA from 23 pterygium and 18 normal conjunctiva tissue samples using real-time quantitative reverse transcriptase PCR.  

The frequency of methylation for P15INK4b was 97.5% and 72% among cases and controls respectively. P16INK4 gene methylation at promoter was 69.1% and 33.3% for pterygium and normal conjunctiva tissue respectively. A statistically significant relationship was found for methylation of P15INK4b and P16INK4a genes between cases and controls (p