Study identifies potential biomarker for ocular surface squamous neoplasia

This pilot study investigated the methylation pattern at the DNA methyltransferase 3-like (DNMT3L) promoter in ocular surface squamous neoplasia (OSSN). The authors previously reported the loss of methylation at the DNMT3L promoter in cervical cancers. Since the pathobiology of OSSN is similar to cervical squamous cell carcinoma, they hypothesized that it may harbor similar epigenetic changes.

The authors compared the methylation status of the DNMT3L promoter in tumor tissue from six OSSN patients with healthy conjunctiva tissue from seven individuals. They extracted genomic DNA and amplified it with specific primers for the DNMT3L promoter region. Then they cloned and sequenced the specific polymerase chain reaction products.

Histologically, four OSSN cases were invasive and two were intraepithelial. Healthy conjunctival tissue exhibited a methylated promoter region, whereas variable loss of methylation was observed in all six OSSN cases.

The authors conclude that they have for the first time identified loss of methylation at the DNMT3L promoter in OSSN cases. They say these results suggest that epigenetic events play a role in the genesis of OSSN and raise the possibility that changes in methylation at this locus are a potential biomarker for OSSN. They recommend further study of methylation and activity of the DNMT3L gene in a larger number of cases in order to confirm these possibilities.