Fig. 3

CBR3-AS1 functions as a sponge for miR-25-3p in the MAPK pathway. a DIANA-LncBase website showing CBR3-AS1-targeted miRNAs. b The expression of miR-25-3p in MCF-7 and MCF-7/ADR cells. c The correlation of CBR3-AS1 with miR-25-3p and JNK1/MEK4 mRNA expression in the TCGA breast cancer data. d The binding sites for miR-25-3p in the wild-type 3′UTR of JNK1 and MEK4 mRNA and the mutated sites in the 3′UTR of JNK1 and MEK4 mRNA. e Relative luciferase activity by luciferase reporter assays in MCF-7 cells co-transfected with wild-type (JNK1/MEK4-WT) or JNK1/MEK4-MUT and miR-25-3p or miR negative control (NC). f, g RNA pulldown shows that CBR3-AS1 directly binds with miR-25-3p. h RNA from the nucleus and cytoplasm of MCF-7 cells was extracted separately, and the proportion of CBR3-AS1 contained in the cell fractions was detected by qRT-PCR. i-j JNK1/MEK4 expression was measured by western blot and qRT-PCR after CBR3-AS1 was overexpressed in MCF-7 cells. k-l JNK1/MEK4 expression was measured by western blot and qRT-PCR after CBR3-AS1 was silenced in MCF-7/ADR cells. m ISH detected the expression of CBR3-AS1 and miR-25-3p, and IHC assays determined JNK1 and MEK4 expression in breast cancer patient tissues (n = 96). n Linear correlation pattern showing a negative relationship between the expression of CBR3-AS1 and miR-25-3p. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001