HuR modulated the intracellular Epi accumulation by regulating the expressions of genes associated with β-catenin/GSK-3β pathway, oncogenes, and MDR transporters in SW620 cells.

<p><b>(A-B) HuR silencing or overexpression affected the intracellular accumulation of Epi in SW620 cells.</b> SW620 cells were transfected with 75 nM siC or siHuR (A) or with 2μg HA or HuR (B). After 24 h, cells were treated with Epi (5 μg/ml) for 24 h. The relative fluorescence intensity of each group in the cells was measured by flow cytometry. It was calculated by setting the fluorescence intensity of siC + Epi (A) or HA + Epi (B) group as 100%. Data are presented as mean percentages ± S.D. from three independent experiments. ^<b>Δ</b>P<0.05 compared to the siC + Epi (A) or HA + Epi (B) group. The relative fluorescence intensity % of siC, siHuR, HA, and HuR were also shown here to demonstrate that the auto-fluorescence of siC, siHuR, HA, and HuR was negligible. <b>(C-D) HuR knockdown or overexpression affected the mRNA expressions of β-catenin/GSK-3β pathway-related genes, including galectin-3, GSK-3β, and β-catenin in SW620 cells. (E-F) HuR knockdown or overexpression affected the mRNA expressions of oncogenes, such as cyclin D1 and c-Myc in SW620 cells. (G-H) HuR silencing or overexpression affects the mRNA expressions of MDR transporter-related genes in SW620 cells.</b> For (C-H), the cells were transfected with 75 nM siC or siHuR (C, E, G), or 2 μg HA or HuR (D, F, H), separately. After 24 h, the cells were treated with Epi (5 μg/ml) for 24 h. RNA was extracted from the cells as treated above for measurement of mRNA expressions by real-time PCR. The relative expression levels of genes were calculated by setting siC (C, E, G) or HA (D, F, H) group as 1, respectively. Means ± S.D. from three independent experiments were plotted. ^#P<0.05 compared to the siC or HA group; ^ΦP<0.05 compared to the siHuR or HuR group; ^ΔP<0.05.