Fig. 4

circACTR2 reverse GEM resistance by acting as an miRNA sponge for miR-221-3p

A qRT-PCR analysis for predicted miRNAs pulled-down by circACTR2. B Schematic illustration of wild-type and mutant circACTR2 luciferase reporter vectors. C Dual-luciferase reporter assays using the linear form of wild-type and mutant circACTR2 in SW1990 cells transfected with NC or miR-221-3p mimic. D FISH images showed the co-localization of circACTR2 labeled with Cy3 (red) and miR-221-3p labeled with FITC (green) in the cytoplasm of PC cells. nuclei were stained with DAPI. Scale bar, 25 μm. E and F The relative expression levels of miR-221-3p in PC cells stably transfected with OE-circ or sh-circ vector were detected by qRT-PCR. G Pearson correlation analysis of circACTR2 and miR-221-3p expression in 25 PC tissues. H and I Relative cell viability of PC cell transfected with miR-221-3p inhibitor or mimic compared with NC controls under GEM treatment was determined by CCK-8 assay. *P < 0.05; **P < 0.01