Fig. 7

LncRNA BCRT1 was transcriptionally regulated by HIF-1α during hypoxia. a-b The expression levels of HIF-1α protein (a) or lncRNA BCRT1 mRNA (b) in MDA-MB-231 and MDA-MB-468 cells were measured after culture under normoxia or hypoxia for 48 h by western blot or RT-PCR. c-d The efficiency of HIF-1α knockdown was detected using RT-PCR and western blot. e HIF-1α knockdown inhibited the expression of lncRNA BCRT1 in MDA-MB-231 and MDA-MB-468 cells under normoxia or hypoxia. f The recognition motif of HIF-1α from the JASPAR database. g Schematic illustration of the proximal region of the lncRNA BCRT1 promoter and the putative hypoxia responsive elements (HREs). h MDA-MB-231 cells were transfected with a lncRNA BCRT1 promoter-containing pGL3 reporter vector and further treated with hypoxia or hypoxia combined with siHIF-1α. After 48 h, Luciferase activity was measured with the dual-luciferase reporter assay system. i ChIP assays with anti-HIF-1α antibody were performed to verify the binding between HIF-1α and the HREs of the lncRNA BCRT1 promoter under normoxia and hypoxia. j PTBP3 and HIF-1α expression from the TCGA breast cancer dataset was analyzed by the starBase database. k The mRNA and protein expression of PTBP3 was elevated under hypoxic conditions. l After HIF-1α knockdown, the expression of PTBP3 was evaluated by RT-PCR and western blot in MDA-MB-231 and MDA-MB-468 cells under normoxia or hypoxia. (*P < 0.05, **P < 0.01, and ***P < 0.001)