Fig. 1

Oncogenic circRNA discovery and characterization of circHERC1 in NSCLC. (a) Heatmap of RNA-Seq data of differentially expressed circRNAs generated from plasma from lung cancer patients and cancer-free individuals. (b) Schematic illustration indicating the generation of circHERC1 from its host gene HERC1 and validation by Sanger sequencing. (c) qRT‒PCR assessment of the stability of circHERC1 and HERC1 under RNase R treatment in NCI-H3255 cells. ***p < 0.001. (d) qRT‒PCR detection of the expression of circHERC1 and its parent gene after circHERC1 overexpression or knockdown. ***p < 0.001. (e, f) qRT‒PCR analysis of circHERC1, GAPDH, and U6 in the cytoplasm and nucleus in NCI-H3255 cells. (g) FISH assay showed that circHERC1 primarily localized in the cytoplasm of NCI-H3255 and A549 cells. The scale bars are 25 μm. (h) qRT‒PCR was applied to analyze circHERC1 expression in plasma of LUAD patients (n = 111), LUSC patients (n = 23) and cancer-free individuals (n = 23). *p < 0.05, ****p < 0.0001. (i) Receiver-operating characteristic (ROC) curve analysis of circHERC1 expression in lung cancer (n = 134) and cancer-free patient (n = 23) plasma. (j) qRT‒PCR analysis of circHERC1 in tumor tissues and peritumoral tissues (n = 16). *p < 0.05