Differentiated super-enhancers in lung cancer cells.

Super-enhancers (SEs) are regulatory elements with enriched accumulation of key transcription factors. Few studies were done investigating SEs in lung cancers. Here we analyzed epigenetic profiling data to identify SEs in lung cancer cell lines. Enhancers were classified as SEs and typical enhancers (TEs). Most of the TEs were overlapped between normal cell and cancer cells. A great portion of SEs were differentiated comparing these cells. Analysis of GO terms associated with SEs revealed SE remodeling (lost on some sites while gain on others) between normal and lung cancer cells. By comparing the average number of SEs in each GO term in cancer cells with the number in control cells, surprisingly, no GO terms with significantly increased SE number in cancer condition were observed. On the contrary, in aspects such as "cell-cell adhesion", "receptor activity" and "negative regulation of canonical Wnt signaling pathway", the related SEs were significantly reduced in cancer cells. These findings suggest that in lung cancer, cells may not gain decisive gene expression in the related aspect, instead, they may have lost control of the fateful genes. Taken together, our work with the usability of omics data identified SEs in lung cancer cells and further showed cancer-specific features of SE-related terms.