Figure 1.

LncRNA-NEAT1 expression is enhanced by hypoxia via transcriptional regulation of HIF-1α in HCC cells. (A,B) HIF-1α knock-down and control SNU-182 and HUH7 cells were cultured for 24 h under normoxic vs. hypoxic conditions (Panel a) or without and with CoCl₂ treatment (Panel b). Changes in the expression level of lncRNA-NEAT1 were detected by qRT-PCR. (C) The correlation of HIF-1α with lnc-NEAT1 in tumor tissues from TCGA-LIHC is shown. (D) Left: A putative HRE (ACGTGC) was identified in the promoter of lncRNA-NEAT1. Right: Binding of HIF-1α to the HRE (ACGTGC) was validated by ChIP assay in SNU-182 and HUH7 cells. HIF-1α antibody or IgG was added to the reaction. DNA fragments were amplified and analyzed by qRT-PCR with specific primers. (E) SNU-182 and HUH7 cells were transfected with a luciferase reporter containing the WT or mutant putative HRE (ACGTGC) sequence. Cells were treated with CoCl₂ for 24 h, where indicated, and relative luciferase activity was detected. (F) HIF-1α knock-down SNU-182 and HUH7 cells were transfected with a luciferase reporter containing the WT or mutant putative HRE (ACGTGC) sequence. Cells were treated with CoCl₂ for 24 h, and relative luciferase activity was detected. In Panels a and b, *P < 0.05 compared with normoxia condition or control. ^#P < 0.05 compared with siRNA-negative control (siRNA-NC). In Panels e and f, *P < 0.05 compared with normoxia control or siRNA-NC.