Aim: Epigenetic modifications, such as DNA methylation, are considered important in the regulation of target genes in cancer development. 5-Hydroxymethylcytosine (5hmC) was recently discovered to be related to the process of malignant transformation. The influence of DNA methylation in oral squamous cell carcinomas (OSCC) is not fully-understood. Therefore, the aim of the present study was to investigate the DNA methylation pattern in OSCC compared to healthy oral epithelium.
Materials and methods: Oral mucosal samples from patients with OSCC (n=15) and healthy mucosa (n=12) were analyzed using immunohistochemistry with antibodies against 5hmC, 5mC and ten-eleven-translocation-2 (TET2).
Results: A significant decrease in 5hmC and TET2 expression was found in OSCC compared to healthy oral epithelium. In contrast, there was a significant increase in 5mC expression in OSCC compared to healthy epithelium.
Conclusion: Our results indicate that loss of 5hmC is an epigenetic event of OSCC.
Keywords: 5-hydoxymethylcytosine; DNA methylation; Oral cancer; biological markers; ten-eleven-translocation 2.