Fig. 5

The target gene of miR-615-3p, RPN6, is upregulated in pancreatic cancer and is associated with a poor prognosis. A The potential target mRNAs of miR-615-3p were predicted in ENCORI, miRDB, mirDIP, miRTarBase, and TargetScan databases. B Schematic diagram of the RPN6-WT and RPN6-Mut luciferase vectors. C Relative luciferase activities in PANC-1-GR and BxPC-3-GR cells co-transfected with RPN6-WT or RPN6-Mut and the miR-615-3p mimic, inhibitor or corresponding negative control. D-E The relative expression of RPN6 in PANC-1-GR or BxPC-3-GR cells was analyzed by qRT-PCR and western blot after indicated transfection. F-G The expression levels of RPN6 in PADC cells (8988, AsPC-1, BxPC-3, PANC-1, SW1990) and normal human pancreatic duct epithelial (HPDE) were analyzed by qRT-PCR and western blot assays. H-I The expression levels of RPN6 in tumor and matched non-tumor tissues from 96 gemcitabine-treated PADC patients were analyzed by qRT-PCR (H). There are representative images of RPN6 protein levels in PDAC tumors and adjacent normal tissues by western blot assays (I). J-K Kaplan-Meier survival analysis showed that PADC patients with low and high circ-MTHFD1L expression of overall survival and PFS. The median circ-MTHFD1L expression was used as the cutoff value. L Relative RNA level of RPN6 in PFS < 10 months group and PFS ≥ 10 months group. M-N IHC staining shows the abundances of RPN6 in the indicated groups (M). The IHC scores of RPN6 were further quantified (N). O Box-plot of RPN6 expression in TCGA PDAC tumor and matched TCGA normal pancreatic tissues along with GTEx data. P-Q Overall survival and DFS of PDAC patients (N = 178) from TCGA project with high or low RPN6 expression levels. R-S The correlation between RPN6 and circ-MTHFD1L and miR-615-3p in PDAC was analyzed by Pearson correlation analysis. Data are shown as mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.001, between the indicated groups