Fig. 1
Clinical role of exosomal circZNF451 in immunotherapy and prognosis of LUAD patients. A Differential expression profiles of circRNAs (FC > 2 and P < 0.05) enriched in the peripheral blood of PR (n = 3) and PD (n = 3) patients receiving PD1 monotherapy (Opdivo) were measured by circRNA sequencing and are presented in a heat map. B Representative electron micrograph of exosomes detected in the sera of six LUAD patients receiving PD1 monotherapy; scale bar, 100 nm. C Exosome markers including TSG101 and CD63, in the exosomes of the six LUAD patients were detected by western blotting. D The back splicing site of circZNF451 (has-circ-0002638) was confirmed by Sanger sequencing. E Enrichment of circZNF451 in the exosomes of five LUAD cell lines (A549, H1299, Calu-3, H1975, and H1395) was measured by qRT-PCR. One-way ANOVA test was performed after adjusting for multiple comparisons. F After digestion with RNase R (10U) for 30 min, circZNF451 and ZNF451 stability in A549 and H1299 cells was measured by qRT-PCR. G Change in exosomal circZNF451 enrichment in four LUAD patients before and after surgery, as measured by qRT-PCR. H Localization of circZNF451 in A549 and H1299 cells as detected by FISH; scale bar, 50 μm. I Expression of circZNF451 was detected in a TMA containing tumor and paratumor tissues of 113 LUAD patients by FISH; scale bar, 100 μm. The paired Student’s t test was performed to analyze the difference. J Recurrence-free survival and overall survival of circZNF451low and circZNF451high groups in LUAD patients were analyzed by Kaplan–Meier and log-rank tests. K Factors that contribute to poor prognosis of the 113 LUAD patients according to the univariate and multivariate Cox regression analysis. All experiments with statistical analysis have been repeated for at least three times