Abstract:

o establish oxidative stress model of HeLa cells copied by vitamin K3 (VK3),and to investigate the role of external signal-

regulated kinase (ERK) pathway in autophagy induced by oxidative stress in HeLa cells. Methods HeLa cells were divided into control

group,VK3 group (30  μmol•L^-1)， U0126 group (10 μmol•L^-1)，and VK3 (30  μmol•L^-1)+ U0126 group (10  μmol•L^-1).The survival

rate of HeLa cells in each group was measured by MTT assay;the expression levels of external signal-regulated kinase 1/2

(ERK1/2),phosphorylated ERK 1/2 (Phospho-ERK1/2),microtubule-associated protein light chain 3-Ⅱ (LC3-Ⅱ),and cysteine aspartic

acid specific protease-3 (caspase-3),and its activated fragment cleaved caspase-3 were determined by Western blotting method;the

morphological changes of nuclear and apoptotic rate of HeLa cells  in each group were detected by Hoechst staining.Results Compared

with VK3 group,the survival rate of HeLa cells in VK3+U0126 group was decreased (P<0.05).The expressions of Phospho-ERK1/2 in HeLa

cells were increased after treated with VK3 for 2,4,and 8 h (P<0.05).Compared with control group， the expression of LC3-Ⅱ protein

 in VK3 group was increased(P<0.05).Compared with VK3 group,the expression of LC3-Ⅱ in HeLa cells in  VK3+U0126  group was

decreased(P<0.05),and the expression of cleaved caspase-3 protein was increased (P<0.05).Compared with VK3 group,the morphological

changes of nuclear appeared and the  apoptotic  rate  of  HeLa cells in   VK3+U0126 group was increased(P<0.05).Conclusion

Oxidative stress activates autophagy of HeLa cells induced by ERK signal pathway,and  the autophagy can inhibit the apoptosis of

HeLa cells induced by VK3.

Key words: oxidative stress, external signal-regulated kinase, autophagy, HeLa cells