Fig. 7

circPRDM4 binds to CD274 promoter. A ChIRP assays were performed to determine the binding region between CD274 promoter and circPRDM4. B Position-wise minimal energy profile that visualizes the minimal energy for each intermolecular index pair in a heatmap style. C Sequences of binding region between circPRDM4 transcript and CD274 promoter. A base pairing between CD274 promoter (from -170 to -160 bp) and circPRDM4 281–291 nt (within the P3 fragment) was predicted. D WT or mutant circPRDM4 transcripts were immobilized onto membrane, followed by probing with biotin-labeled single-strand DNA probes. E Luciferase reporter assay was performed in HIF-1α-overexpressing cells using indicated CD274 promoters to validate circPRDM4 function on CD274 transcription activation with the presence of HIF-1α. F DNA in situ hybridization. G Expression levels of HIF-1α, PD-L1, and circPRDM4 in HCC tissue sections of circPRDM4 high and circPRDM4 low groups. H Expression levels of HIF-1α, PD-L1, and circPRDM4 in PDX mouse models treated with adoptive human TIL-CD8⁺ T cell transfer. Data are shown as mean ± SEM. **, P < 0.01; ***, P < 0.001; ns, no significance