Bioinformatics Analysis of DNA Methylation in the Promoters of LincRNA ？in Lung Adenocarcinoma

Background and objective Previous studies have found the lincRNAs play important roles in the occurrence and development of lung adenocarcinoma, but their regulated mechanims are still unclear. The aim of this study is to evaluate the relationship between DNA methylation and lincRNA expression, and the effect of prognosis in lung adenocarcinoma. Methods The whole genome Illumina Methylation 450 DNA methylatiuon data and RNAseq for lung adenocarcinoma were download from TCGA. DNA methylation around lincRNA and their relationship to gene expression were analyzed. Their contribution to lung adenocarcinoma were further analyzed by comparing DNA methylation and lincRNA expression in tumor and adjacent tissues. Results The methylation level in promoter region was lower than other positions in lincRNA, and was negatively correlated with gene expression. There were 427 lincRNA genes showed differential DNA methylation in their promoter regions in tumor and adjacent tissues. Among these, 15 lincRNA genes showed differential gene expression and negatively correlated with DNA methylation, including FENDRR (a tumor progression and metastasis gene) whose high methylation in its promoter showed poor survival in lung adenocarcinoma. Conclusion The expression of lincRNA can be regulated by DNA methylation in their promoter regions, and the level of DNA methylation is related to patient prognosis in lung adenocarcinoma.？