Fig. 1.

Effect of GSNO treatment on STAT3 activation in HNSCC cells. (A) The HNSCC cells were treated with different concentrations of GSNO for 24 h and then levels of total or phosphorylated (Tyr⁷⁰⁵) STAT3 (pSTAT3) (i) and their ratios (ii) were analyzed by Western analysis. (B) GSNO mediated reversible inhibition of STAT3 phosphorylation was analyzed in SCC14a cell lines after single treatment with 250 µM GSNO. (C) SCC14a cells were treated with 250 μM GSNO for 3 h and then fixed and labeled with STAT3 or pSTAT3 antibodies (i) and the intensities of fluorescence were quantified (ii). The results in bar and line graphs were given as mean of more than three independent experiments. The vertical lines indicate the standard error of mean; *P<0.05; ***P<0.001; n.s. (not significant) compared with vehicle treated control groups.