Related Experiment Video
Updated: Jun 10, 2026
Continuous Fluorescence-Based Endonuclease-Coupled DNA Methylation Assay to Screen for DNA Methyltransferase Inhibitors
Published on: August 5, 2022
Hypomethylation of the DNMT3L promoter in ocular surface squamous neoplasia
Guru Prasad Manderwad1, Gopinathan Gokul, Chitra Kannabiran
1Ophthalmic Pathology Services, Kallam Anji Reddy Campus, L. V. Prasad Eye Institute, Hyderabad, India.
Context:
Cancer is known to have epigenetic inputs, with events like genomewide hypomethylation and gene-specific hypermethylation of DNA. The DNA methyltransferase enzymes act as effectors of this reprogramming. A previous study revealed that hypomethylation at the DNA methyltransferase 3-like (DNMT3L) promoter could be a potential biomarker in cervical tumors. Because the pathobiology of ocular surface squamous neoplasia (OSSN) is similar to that of cervical tumors, we wanted to determine whether similar changes occur in the methylation pattern at the DNMT3L promoter in OSSN.
Objective:
To evaluate the methylation status of the DNMT3L promoter in OSSN compared with healthy conjunctiva.
Design:
We evaluated DNA methylation at the DNMT3L promoter in the tumor tissues of 6 patients with histologically proven OSSN and in healthy conjunctiva tissue from 7 individuals for controls using the sodium bisulfite-assisted conversion of genomic DNA. Extracted genomic DNA was treated with sodium bisulfite and amplified with specific primers for the DNMT3L promoter region. The specific polymerase chain reaction products were cloned and sequenced.
Results:
The mean age of these patients was 50.2 years (range, 35-65 years). Histologically, 4 OSSN cases were invasive; 2 were intraepithelial. Healthy conjunctival tissues exhibited a methylated promoter region, whereas a variable loss of methylation was observed in all 6 OSSN cases.
Conclusions:
We have, for the first time to our knowledge, identified loss of methylation at the DNMT3L promoter in OSSN cases, but its physiologic significance is yet to be understood. Further studies are warranted to substantiate our results.
Insights
Researchers found a loss of DNA methylation at the DNMT3L promoter in ocular surface squamous neoplasia (OSSN) tumors. This epigenetic change, previously seen in cervical cancer, may offer new insights into OSSN development.
Area of Science:
- Epigenetics
- Oncology
- Ophthalmology
Background:
- Cancer development involves epigenetic alterations, including DNA hypomethylation and hypermethylation.
- DNA methyltransferase enzymes mediate these epigenetic changes.
- Hypomethylation of the DNA methyltransferase 3-like (DNMT3L) promoter is a potential biomarker in cervical tumors.
Purpose of the Study:
- To investigate the methylation status of the DNMT3L promoter in ocular surface squamous neoplasia (OSSN).
- To compare DNMT3L promoter methylation in OSSN with healthy conjunctiva tissue.
Main Methods:
- DNA methylation analysis of the DNMT3L promoter in 6 OSSN tumor tissues and 7 healthy conjunctiva controls.
- Sodium bisulfite conversion of genomic DNA followed by PCR amplification, cloning, and sequencing.
Main Results:
- All 6 OSSN cases showed a variable loss of methylation at the DNMT3L promoter.
- Healthy conjunctiva tissues exhibited a methylated DNMT3L promoter.
- The mean age of OSSN patients was 50.2 years, with 4 invasive and 2 intraepithelial cases.
Conclusions:
- Loss of methylation at the DNMT3L promoter is identified in OSSN for the first time.
- The physiological significance of this finding in OSSN requires further investigation.
- Additional studies are needed to validate these results.
Related Concept Videos
01:37Epigenetic Regulation
X-chromosome...
01:46Epigenetic Regulation
02:23Abnormal Proliferation