(A) Genomic organization of lncEGFL7OS and its host gene EGFL7/miR-126. Exons are shown in orange and the introns are shown in blue. Direction of gene transcription is indicated by arrows. Scale = 1 kb; (B) Relative lncEGFL7OS expression level in different human tissues. GAPDH served as the normalization control. (C) Expression of lncEGFL7OS in the nucleus and cytoplasm of HUVECs shown by semi-quantitative RT-PCR. RT-PCR showing nuclear and cytoplasmic expression of lncEGFL7OS. SENCR was used a marker for cytoplasmic-enriched lncRNA, while NEAT-1 was used as a marker for nuclear-enriched lncRNA. (D) Expression of lncEGFL7OS in the nucleus and cytoplasm of HUVECs shown by high-resolution RNA FISH analysis (a–c). RNaseA-treated samples were used as negative control (a) and Ad-lncEGFL7OS-overexpressed HUVECs were used as positive control (b). Scale Bar equals 10 µm. (E) Upregulation of lncEGFL7OS, EGFL7B and C, and pri-miR-126 om the hearts of DCM patients. *p<0.05; **p<0.01. N = 6 for control samples and N = 7 for DCM samples. (F) Schematic potential promoter region (boxed) for EGFL7/lncEGFL7OS. Exons are shown in orange and the introns are shown in blue. Direction of gene transcription is indicated by red arrows. The peaks show regions with elevated H3K4Me1, H3K4Me3 and H3K27Ac binding as predicted by ENCODE, respectively. The boxed region was shown by ENCODE to bind MAX, MYC, ETS1, RNA PolR II, H3K4Me1, H3K4Me3 and H3K27Ac (https://genome.ucsc.edu). Eight cell types were tracked in the image. Light blue indicates HUVEC cells, while dark color indicates H7-ES cells. Scale = 1 kb. (G) Testing bidirectional lncEGFL7OS promoter. LncEGF7OS promoter was fused to a promoter-less Luciferase vector in forward (F) and reverse (R) directions, and tested for Luciferase activity with or without co-transfection of ETS1 or ETS1 mutant expression plasmid in 293 T cells. Shown here is the representative results from three repeats. (H) qRT-PCR showing that silencing of ETS1/2 result in the downregulation of lncEGFL7OS and pri-miR-126 (n = 3). *p<0.05; ***p<0.001.