miR-221 Augments TRAIL-Mediated Apoptosis in Prostate Cancer Cells by Inducing Endogenous TRAIL Expression and Targeting the Functional Repressors SOCS3 and PIK3R1

Figure 3

PIK3R1 as a direct target gene of miR-221 in PCa. (a) Bioinformatically predicted miR-221-PIK3R1 binding site. (b) Luciferase reporter assays showing the relative Luciferase activity of pre-miR-Ctr and pre-miR-221 transfected LNCaP cells. The right column shows the luciferase activity for pre-miR-221 transfected LNCaP cells with a mutated PIK3R1 binding site. Data represent mean + SD from five independent experiments, *, **. (a, b) ANOVA with Bonferroni post hoc testing. (c) qRT-PCR results showed no significant change in PIK3R1 expression depending on miR-221 expression levels in PC3 cells (pre-miR-221 vs. pre-miR-Ctr, 48 h p. t.). Data represent mean + SD from five independent experiments. (d) Western blotting experiments showed a decrease in protein expression of PIK3R1 after restoration of cellular miR-221 expression (PC3 cells, 48 h p. t.). ERK2 was used as housekeeping protein.

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