ABSTRACT
Background:Esophageal cancer is a common gastrointestinal cancer with poor prognosis,and effective chemotherapy is lacking currently. Studies have shown that cardiac glycosides can inhibit tumor cells growth,but its mechanism has not been fully clarified. Aims:To investigate the effect and mechanism of ouabain in regulating proliferation of human esophageal carcinoma cells. Methods:OE19 human esophageal carcinoma cells were treated with ouabain,and cells in control group were treated with DMSO. Cell proliferation was assessed by cell counting method. mRNA expressions of Sox2,Sox4,Sox7,Sox9 and Sox10 were determined by real-time PCR. Protein expression of Sox4 was determined by Western blotting. Gene expressions of phospho-histone3( ph3),a cell proliferation marker and Sox4 were detected by immunofluorescence staining. Results:Ouabain( ≥ 40 nmol/ L)could significantly inhibit OE19 cells proliferation. mRNA and protein expressions of Sox4 were significantly decreased in OE19 cells in ouabain(40 nmol/ L)group than those in control group(P 0. 05). Gene expressions of ph3 and Sox4 in nucleus of OE19 cells were decreased in ouabain (40 nmol/ L)group than those in control group. Conclusions:Ouabain is effective in inhibiting human esophageal carcinoma cells proliferation,the underlying mechanism might be related with down-regulation of Sox4 expression and the subsequent cell cycle modulation.