Fig. 4

SETD3 is not the target of circSETD3 whereas circSETD3 acts as a sponge for miR-421 in HCC. a The expression level of SETD3 mRNA in 56 pairs of HCC and non-tumorous tissues. b CircSETD3 positively correlated with SETD3 mRNA in HCC tissues. c and d The mRNA and protein levels of SETD3 were not changed after artificially changed the expression of circSETD3 in HCC cells. e 10 most possible miRNAs that could be sequestered by circSETD3 were identified. Among them, miR-421 is a well-demonstrated tumor promoter. f miR-421 was significantly upregulated in HCC tissues compared with matched non-tumorous tissues. g The expression of miR-421 was negatively associated with circSETD3 in HCC tissues. h and i Kaplan-Meier’s survival curves depicted the correlations between miR-421 and RFS or OS of HCC patients (the patients were stratified into two groups according to median of Mr-421). Log-rank test was used. j Schematic of circSETD3 wild-type (WT) and mutant (Mut) luciferase reporter vectors. k The relative luciferase activities were analyzed in 293 T cells co-transfected with miR-421 mimics, miR-mimics-NC, miR-421 inhibitors or miR-inhibitors-NC and WT or Mut luciferase reporter vectors. l The Ago2 RIP showed that Ago2 significantly enriched circSETD3 and miR-421. m Expression change of circSETD3 did not affect the expression of miR-421. n Expression change of miR-421 did not affect the expression of circSETD3. HCC, hepatocellular carcinoma; NS, not significant; RIP, RNA immunoprecipitation. **P < 0.01, ***P < 0.001. Error bars indicate SD