Effect of S-phase kinase associated protein 2 gene silencing on the biological characteristics of human glioma U251 cells

Objective To observe the effect of S-phase kinase associated protein 2 (SKP2) gene silencing on the biological characteristics of human glioma U251 cells in vitro. Methods The U251 cells were treated with Ad-shSKP2 (shSKP2 group), Ad-shNC (shNC group) and PBS (control group) respectively. The proliferation of U251 was evaluated by cell counting kit-8 (CCK-8) assay, cell cycle and apoptosis were examined by flow cytometry, the invasion and metastasis of U251 cells were examined by wound scratch assay and Transwell assay respectively, and the protein levels of B cell lymphoma/leukemia-2 associated X protein (bax), B cell lymphoma/leukemia-2 (bcl-2), matrix metalloproteinase (MMP)-9 and MMP-2 were detected by Western blotting. Results The cell viability of shSKP2 group was (87.17±2.60)%, (79.63±1.74)% and (72.81±1.78)% of that of control group respectively 24, 48 and 72 h after Ad-shSKP2 transfection. The cell viability of the shNC group was not significantly different before and after transfection. The apoptosis rate of shSKP2 group, shNC group and control group was (18.27±2.44)%, (1.51±1.02)% and (1.11±1.20)%, and the ratio of G2/M phase was (26.65±2.51)%, (14.46±2.58)% and (14.89±3.81)%, respectively. The migration distances of shNC group and shSKP2 group were (93.45±16.77)% and (43.69±7.44)% of those of control group respectively. The number of transmembrane cells (per 200-fold field of view) passing through the Transwell chamber of the control group, shNC group and shSKP2 group was (87.50±5.66)%, (79.78±8.03)% and (38.24±6.64)% respectively. The expression of bax, bcl-2, MMP-9 and MMP-2 protein in shSKP2 group was down-regulated as compared with shNCK group and control group. Conclusion The results in this study implied that SKP2 gene silencing inhibited the proliferation of U251 cells, induced cell apoptosis and G2/M phase arrest, and attenuated the ability of invasion and metastasis of U251 cells. SKP2 gene silencing can decrease the bcl-2/bax ratio and expression of MMP-9 and MMP-2. Key words: Glioma; S-phase kinase associated protein 2; Apoptosis; Invasion; Metastasis