EINCR1 is an EGF inducible lincRNA overexpressed in lung adenocarcinomas

Complexities in the role of acetylation dynamics in modifying inducible gene activation parameters

High levels of histone acetylation are associated with the regulatory elements of active genes, suggesting a link between acetylation and gene activation. We revisited this model, in the context of EGF-inducible gene expression and found that rather than a simple unifying model, there are two broad classes of genes; one in which high lysine acetylation activity is required for efficient gene activation, and a second group where the opposite occurs and high acetylation activity is inhibitory. We examined the latter class in more detail using EGR2 as a model gene and found that lysine acetylation levels are critical for several activation parameters, including the timing of expression onset, and overall amplitudes of the transcriptional response. In contrast, DUSP1 responds in the canonical manner and its transcriptional activity is promoted by acetylation. Single cell approaches demonstrate heterogenous activation kinetics of a given gene in response to EGF stimulation. Acetylation levels modify these heterogenous patterns and influence both allele activation frequencies and overall expression profile parameters. Our data therefore point to a complex interplay between acetylation equilibria and target gene induction where acetylation level thresholds are an important determinant of transcriptional induction dynamics that are sensed in a gene-specific manner.

[Bioinformatics Analysis of DNA Methylation in the Promoters of LincRNA in Lung Adenocarcinoma]

BACKGROUND

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.

CONCLUSIONS

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.