Fig. 4

miR-545 directly binds to PLK1 mRNA. a putative binding site between miR-545 and PLK1 predicted on Starbase; b PLK1 expression in OC and the paired normal tissues determined by IHC staining (n = 60, paired t test, *p < 0.05); c mRNA expression of PLK1 in the tissues determined by RT-qPCR (n = 60, paired t test, **p < 0.01); d a negative correlation between miR-545 and PLK1 expression (Pearson’s correlation analysis, miR-545 vs. PLK1 mRNA: r = − 0.6044, p < 0.0001; miR-545 VS IHC staining score of PLK1: r = − 0.6674, p < 0.0001); e PLK1 expression in SV40, OV-90 and ES-2 cells measured by RT-qPCR (one-way ANOVA, #p < 0.05); f-g mRNA (f) and protein (g) expression of PLK1 in OV-90 and ES-2 cells after miR-545 mimic administration measured by RT-qPCR and western blot analysis, respectively (relative to GAPDH, one-way ANOVA, &p < 0.05); h binding relationship between miR-545 and PLK1 validated by a dual luciferase reporter gene assay (two-way ANOVA, &p < 0.05). Representative images are provided. Data were collected from three independent experiments and expressed as mean ± SD