Fig. 3: Identification of PLK-4 as a miR-126 target in HCC.

a PLK-4 commonly was found as the effector of miR-126 based on the 3′ untranslated regions of PLK-4. b The expression of PLK-4 were detected in HCC cell lines after miR-126 mimics transfection by western blot. c The expression of PLK-4 was detected in HCC cell lines after miR-126 mimics transfection by RT-PCR. d Overexpression of miRNA-126 decreased PLK-4 3′-UTR dependent luciferase activity. Cells were cotransfected with either miRNA-126 mimics or PLK-4 3′-UTR reporter wild-type (WT) or mutant (MT) plasmid. The dual luciferase activity was measured by illuminometer. e The expression level of PLK-4 in Pan-cancer and non-tumor tissues from TCGA database. f The expression level of PLK-4 in liver cancer and non-tumor tissues from TCGA and GEO database. g The negative correlation between miR-126 and PLK4 expressions. h The positive correlation of PLK-4 levels with Ki67 from TCGA-LIHC cohort database was analyzed. i Comparison of the expression level of PLK-4 levels in non-recurrence patients with that in present-recurrence patients. j Comparison of the expression level of PLK-4 levels in different clinical stages. k, l OS analysis and DFS analysis of the patients based on PLK-4 expression in TCGA-LIHC cohort. Mean ± SD, unpaired Student’s t test or Kaplan–Meier analysis. The HCC gene-expression data set from TCGA was sorted into PLK-4 low and high expression groups. m, n Stratified analyses between TNM stages and PLK-4 expression on OS and DFS. o, p The Gene Set Enrichment Analysis plot indicated a significant correlation between PLK-4 expression and the genes highly expressed in HCC with a good survival prognosis (LEE_LIVER_CANCER_SURVIVAL_UP) and a poor survival prognosis (LEE_LIVER_CANCER_SURVIVAL_DN). Mean ± SD, unpaired Student’s t test or Kaplan–Meier analysis