Fig. 2.

Characterization of circPOLR2A. a Schematic illustration of circPOLR2A originating from the POLR2A gene on chromosome 17 (top). The backsplice junction site of circPOLR2A was identified via Sanger sequencing (bottom). b The existence of circPOLR2A and POLR2A mRNA in cDNA and gDNA was determined by PCR and electrophoresis analysis. c, d The abundance of circPOLR2A and POLR2A mRNA after RNase R treatment was detected via qRT-PCR. e, f The RNA abundance of circPOLR2A and POLR2A mRNA in cRCC cells treated with actinomycin D was determined at different time points. g Representative FISH images of circPOLR2A in 786O cells. h, i Nuclear and cytoplasmic fractionation revealed the level of circPOLR2A in the nucleus and cytoplasm. U6 and GAPDH were used as positive controls in the nucleus and cytoplasm, respectively