To study the role of DNA methylation in oral leukoplakia carcinogenesis.

DNA methylation was detected in forty cases of oral squamous cell carcinoma (OSCC), twenty-eight cases of oral leukoplakia (OLK) and forty cases of healthy oral mucosa. Download the expression profile data of OSCC, OLK and healthy oral mucosa from Gene Expression Omnibus (GEO) database. DNA methylation data and expression profile data were compared for repeatability, DNA methylation data for difference analysis and corresponding expression profile data for IPA pathway analysis.

The data analysis showed that DNA methylation had greater flexibility and instability. Ingenuity Pathway Analysis (IPA) analysis showed that genes related to OLK differential methylation sites were mainly concentrated in the process of cell movement and differentiation. Genes related to differential methylation sites of OSCC are mainly enriched in cell proliferation, migration, oxidation regulation, and anti-apoptosis processes. The genes associated with OLK and OSCC differential methylation sites are co-enriched in phosphoinositol metabolism and phospholipase C signaling pathway.

DNA methylation is involved in the formation of oral squamous cell carcinoma, and the activation of phosphoinositol metabolism may promote oral leukinoma.