Fig. 1
GATA6-AS1 is responsive to hypoxia and its low expression predicts dismal prognosis in PDAC. A Heatmap plots of significantly downregulated lncRNAs (P < 0.05, fold change > 2 or < 0.5) detected with lncRNA array in Panc-1 cells exposed to 1% O2 compared with those exposed to 20% O2. The red (higher expression) or blue (lower expression) color represents the normalized expression value of indicated lncRNAs. B RT-qPCR assay of expression levels of top 10 downregulated lncRNAs in Panc-1 cells exposed to 1% O2 compared with those exposed to 20% O2. C RT-qPCR assay of expression levels of GATA6-AS1 in PDAC cells exposed to 1% O2 compared with those exposed to 20% O2. D RT-qPCR assay of expression levels of GATA6-AS1 in Panc-1 and BxPC 3 cells exposed to hypoxia conditions at varying time intervals (0, 12, and 24 h) and concentrations of oxygen (1%, 5% or 20%). E RT-qPCR assay of expression levels of GATA6-AS1 in Panc-1 and BxPC 3 cells treated with CoCl2 for varying dose (0, 100, and 200 µmol/l) or time intervals (0, 12, and 24 h). F In situ hybridization assay of GATA6-AS1 expression in PDAC samples and matched adjacent nontumor tissues (Cohort A, n = 116). Scale bar, 200 μm. G–I GATA6-AS1 was expressed at a lower level in PDAC tumor tissues compared to that in adjacent nontumor tissues from cohort A, B (n = 72), and GSE15471 (n = 39), respectively. J, K Low GATA6-AS1 expression was more frequently observed in patients with advanced clinical parameters in cohort A (J) and cohort B (K) of PDAC patients. L–N Kaplan–Meier curves for overall survival rates associated with GATA6-AS1 expression in our cohort A, cohort B or TCGA-PAAD database. CoCl2: cobalt chloride; T: tumor tissues; N: adjacent nontumor tissues. Data represent mean ± S.D. from three independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001