Fig. 1

Identification of LINC01977 as a super-enhancer-associated cancer-testis lncRNA. A Volcano plot of gene expression microarray results. The x-axis shows fold change between normal and LUAD samples and the y-axis shows one-way ANOVA P value; points corresponding to twofold change cutoff and P < 0.05 are colored red (increasing) and blue (decreasing), points corresponding to significantly decreasing or increasing lncRNAs are colored green, respectively. B The circos plot showing dysregulated lncRNAs found with SE-associated lncRNAs microarray analysis of 5 tumor-normal pairs LUAD samples. C Tissue-specific gene expression from GTEx data for LINC01977. D Density plots are shown expression of LINC01977 in cancer cells from CCLE, CGP and Genentech data. E Volcano plot of LINC01977 expression from ImmLnc database (http://bio-bigdata.hrbmu.edu.cn/ImmLnc/). The x-axis shows fold change between normal and tumor samples, and the y-axis shows one-way ANOVA P value; points corresponding to twofold change cutoff and P < 0.05 are colored red (significantly increasing). F qPCR detection of LINC01977 expression in LUAD (n = 40) tumor-normal paired tissues. G RNAscope ISH detection of LINC01977 expression in LUAD (n = 98) tumor-normal paired tissue microarray. Arrows denote LINC01977 RNAscope ISH red dots. Scale bar: 20um. H Kaplan–Meier survival curves of LUAD patients on tissue microarray grouped by LINC01977 expression. I Gene tracks depicting the gene body and super-enhancer region of LINC01977 in LUAD cells A549 and PC-9, as well as normal lung tissue with measured H3K27ac and H3K4me1 marks. The data were retrieved from Encode project. (J) LINC01977 in A549 cell line topologically associated domain (TAD) region was predicted on the basis of the Hi-C data (http://promoter.bx.psu.edu/hi-c/view.php). K Schematic representation of constructing enhancer-promoter dual-luciferase reporter plasmids strategy. (L) The luciferase activities of six enhancer elements were measured through dual-luciferase reporter assay in A549 and PC-9 cells. Data in L are representative of three independent experiments and presented as mean ± S.D., n = 3 biologically independent samples, and the P value was determined by a two-tailed unpaired Student’s t test and one-way ANOVA, respectively. *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; n.s. not significantly