Inhibitory Effect Of Lycorine On Human Colorectal Cancer Cells And Its Mechanism

Aim:To investigate the effect of lycorine on proliferation,migration,invasion,apoptosis,cell cycle distribution as well as underlying molecular mechanism in human colorectal cancer cells.Methods:After treatment with lycorine at different concentrations?1,2,4,8?mol/L?,cell proliferation ability was detected by crystal violet staining and MTT assay in HCT116,LoVo and SW480 cell lines;Cell migration and invasion ability was evaluated by wound-healing and Transwell chamber assay;Cell apoptosis was analyzed by Hoechst 33258staining and Flow cytometry;Cell cycle distribution was determined by Flow cytometry;Protein levels of matrix metalloproteinases?MMPs?,epithelial-mesenchymal transition?EMT?-related markers?Snail,Vimentin,N-cadherin,E-cadherin?,apoptosis-associated proteins?Bcl-2,Bad,Bax,and effector Caspase-3?,cyclins?CyclinB1,CyclinD1,CyclinE1?and regulator factors(p21^WAF1/Cip1,Smad4)were analyzed by Western blot.The phosphorylations of AKT and p38 were detected by Western blot.Results:Compared with control group,the growth of HCT116,LoVo,SW480 cell lines was dramatically inhibited in a dose-time dependent manner after exposure to lycorine?P<0.05?;Migration and invasion abilities were dampened in HCT116,LoVo cell lines?P<0.05?.In LoVo cells,protein levels of MMP-2,MMP-7,MMP-9,Snail,Vimentin and N-cadherin were down-regulated.And the change of E-cadherin was the opposite;After lycorine treatment,karyopyknosis,karyorrhexis,and apoptotic body were rare.Also,the number of apoptotic cells detected by Flow cytometry was changeless?P>0.05?.Protein level of anti-apoptosis Bcl-2 was decreased.But protein levels of pro-apoptosis Bad,Bax or effector Caspase-3 had no changes.AKT signaling pathway was active,which is a major mediator of cell survival;Lycorine resulted in a higher proportion of HCT116 cells in G2/M phase,while cell cycle of LoVo cells was arrested in S and G2/M phase?P<0.05?.Protein levels of CyclinB1,p21^WAF1/Cip1,and Smad4 were increased,and that of cyclinD1,cyclinE1were significantly decreased;Additionally,lycorine activated p38MAPK signaling pathway.And protein level of p-p38 was up-regulated.Conclusion:Lycorine inhibited the proliferation,migration,invasion and induced cell cycle arrest.However,it had little effect on apoptosis,which indicating it mainly exerted cytostatic effect.Lycorine-induced anti-tumor activity may be related to Smad4 and p38MAPK signaling pathway.