Effect of VPA on STAT3 expression in glioma cells in the presence or absence of oHSV infection.

<p><b>A</b>: Expression of nuclear phosho-STAT3 (p-STAT3), total cellular STAT3, activated NF-kappaB (p52), and Histone H3. Twenty hours after incubation with or without 3 mM VPA, U251 cells were infected with oHSV (MOI 1.0). At the indicated times following infection, total cellular or nuclear fractions were collected and analyzed by Western blot. The 0, 0.5 and 1.0 hour (hr) times indicates time after oHSV infection. Before infection, cells were incubated with VPA or vehicle for 20 hours. The results of blot densitometry are also provided in tabular format in the lower part of the panel. <b>B</b>: Gene expression level of STAT3 was detected using quantitative RT-PCR at the indicated time points following VPA treatment (3 mM) of U251 cells. Each data point represents the mean of triplicate samples. Error bars indicate standard deviation. **<i>P</i> < 0.01, ***<i>P</i> < 0.001. <b>C</b>: Activity of the STAT3 binding promoter was detected following oHSV infection (MOI 1.0) in the presence or absence of VPA. U251 cells were transfected with an expression vector, encoding a STAT3-responsive transcriptional element driving luciferase. After oHSV infection, cells were harvested at the indicated time points and luciferase activity was assayed. White bars = Vehicle, black bars= VPA. Each data point represents the mean of triplicate samples. Error bars indicate standard deviation. **<i>P</i> < 0.01, ***<i>P</i> < 0.001 (Student’s <i>t</i>-test).