Fig. 1

circPRDM4 is a hypoxia-associated circRNA in HCC. A Profiling of the differentially expressed circRNAs in HCCLM3 cells under hypoxia. B Expression levels of the five most regulated circRNAs were verified using RT-qPCR in HCCLM3 cells under hypoxic conditions. C Expression levels of hsa_circ_0007468 were examined in HCC cell lines. D Structure of circPRDM4. The back-splicing junction was confirmed by Sanger sequencing. E Agarose gel electrophoresis to check for the presence of circPRDM4. F RT-qPCR assays for circPRDM4 and PRDM4 mRNA using the template cDNA reverse-transcribed by random primers and oligo dT primers. G Expression levels of circPRDM4 and PRDM4 mRNA were evaluated in HCC cell lines treated with RNase R. H circPRDM4 and PRDM4 mRNA levels were detected in MHCC97H cells after actinomycin D treatment. I circPRDM4 and PRDM4 mRNA levels were detected in Hep3B cells after actinomycin D treatment. J FISH results showing that circPRDM4 was predominantly expressed in the nucleus of HCC cells. K Subcellular fractionation assays showing circPRDM4 was mainly observed in the nucleus of HCC cells. Data are shown as mean ± SEM. **, P < 0.01; ***, P < 0.001; ns, no significance