ABSTRACT
Objective To elucidate the expression of gankyrin in human gastric cancer cells and it's role in nimesulide induced apoptosis. Methods Four human gastric cancer cell lines including MKN28 (well differentiated), AGS (poorly differentiated), MKN45 (poorly differentiated), and SGC7901(moderately differentiated) were cultured and treated with nimesulide. Nimesulide induced growth inhibition and apoptosis of the cells were detected by methyl thiazolyl tetrazolium assay, and confirmed by flow cytometry. The expressions of gankyrin gene and protein were further assessed by real-time PCR and Western blotting. Results Gankyrin mRNA and protein were detected in all four human gastric cancer cell lines. The proliferations of AGS and SGC7901 cell lines were significantly suppressed by nimesulide in a time-dose dependent manner. When treated with 400 μmol/L of nimesulide for 48 hours, the significant apoptosis was found in AGS cells (23.30%±2.50%) and SGC7901 cells (16.80%±1.55% ) in comparison with controls (0.57%±0.19% and 0.88%± 0.17%, respectively, all P values <0.01). Apoptosis of AGS cells induced by nimesulide was accompanied by a considerably decreased gankyrin expression that was more significant at 24 hours (0.0035±0.0014) and 36 hours (0.0980±0.0160) in comparison with controls (0.4690±0.1190, all P values<0.01). Conclusion Gankyrin expresses in human gastric cancer cell lines and may be involved in nimesulide induced apoptosis of AGS cells.