Figure 2.

HBx up‐regulates PTN expression, and PTN is a target of miR‐384. (A) The expression of PTN was up‐regulated in HBV‐infected cells and HBx‐transfected cells compared with control cells. Our results indicated that the expression level of PTN was much higher in cells with low concentrations of HBV particles (1.0 × 10³ copies/ml) than in cells with high concentrations of HBV particles (1.0 × 10⁵ copies/ml). (B) The expression of PTN was up‐regulated in HBV‐infected cells compared with control cells. The expression of PTN was down‐regulated in HBV‐infected Huh‐7‐miR‐384 cells compared with HBV‐infected Huh‐7 cells. (C) The seed sequence of miR‐384 matched the 3′UTR of the PTN gene. The sequences shown include the mutated target mRNA site, the mature miR‐384 and the target mRNA site bound by miR‐384. (D) Luciferase assays of Huh‐7 cells transfected with the PTN reporter plasmid containing wild‐type (WT) regulatory sequences, controls (NCs), the miR‐384 precursor or the mutated PTN reporter (mut). We found that PTN 3′UTR luciferase reporter activity was regulated by miR‐384 cotransfection. The luciferase assay demonstrated that PTN was a direct target of miR‐384. (E) PCR and Western blotting of Huh‐7 cells transfected with the miRNA negative control (NC) and miR‐384. The results demonstrated that miR‐384 repressed PTN expression. *P value <0.05.