Detection and Analysis of RNAs Expression Profile for Methylated Candidate Tumor Suppressor Genes in Nasopharyngeal Carcinoma

Background: DNA methylation, which acts as an expression regulator for multiple Tumor Suppressor Genes (TSGs), is believed to play an important role in Nasopharyngeal Carcinoma (NPC) development. Methods: We compared the effects of 5-aza-2-deoxycytidine (decitabine, DAC) on gene expression using RNA sequencing in NPC cells. Results: We analyzed Differentially Expressed Genes (DEGs) in NPC cells using DAC demethylation treatment and found that 2182 genes were significantly upregulated (>= 2-fold change), suggesting that they may play a key role in cell growth, proliferation, development, and death. For data analysis, we used the Gene Ontology database and pathway enrichment analysis of the DEGs to discover differential patterns of DNA methylation associated with changes in gene expression. Furthermore, we evaluated 74 methylated candidate TSGs from the DEGs in NPC cells and summarized these genes in several important signaling pathways frequently disrupted by promoter methylation in NPC tumorigenesis. Conclusion: Our study analyzes the DEGs and identifies a set of genes whose promoter methylation in NPC cells is reversed by DAC. These genes are potential substrates of DNMT inhibitors and may serve as tumor suppressors in NPC cells.