Abstract
Objective: To explore the effects of O-GlcNAc glycosylation and its key enzyme OGT on the biological behaviors and etoposide (Vp16) -induced apoptosis of Nalm-6 cells. Methods: Low O-GlcNAc modified Nalm-6 cells model was established with Alloxan, an inhibitor of OGT. The influence of Alloxan on Nalm-6 cells proliferation was checked by CCK-8 assay, apoptosis and cell cycle by flow cytometry. Nalm-6 cells were treated with different concentrations of Vp16 for 12 h, and then the O-GlcNAc level and the expressions of OGT were examined by Western blot. After treating Nalm-6 with Alloxan for 24 h and then 5 μg/ml of Vp16 for 12 h, the apoptosis of different groups were measured with flow cytometry, and the expression of apoptosis-associated proteins Bax and Bcl-2 were examined by Western blot. Results: With the concentration of Vp16 increasing, the O-GlcNAc modified levels of total protein and the expression of OGT were up regulated (P<0.05, n=6) ; Alloxan could slow down the proliferation capacity, induce apoptosis[ (15.190±2.539) % vs (21.910±4.105) %, P=0.007], arrest cell cycle[G1 phase: (43.534±4.453) % vs (57.322±6.091) %, P=0.003; S phase: (50.747±5.937) % vs (37.201±4.661) %, P=0.001]. Alloxan could inhibit the apoptosis caused by Vp16[ (75.195±13.845) % vs (52.741±10.815) %, P=0.011]along with Bax decreasing (5.496±1.998 vs 2.950±0.703, P=0.015) and Bcl-2 increasing (0.454±0.125 vs 0.803±0.223, P=0.013) . Conclusion: Changes of O-GlcNAc modified level of Nalm-6 cells along with the inhibition of OGT could influence the biological behaviors and inhibit apoptosis induced by Vp16.