Mechanism of Polyinosinic Polycytidylic Acid Promoting the Inhibitory Effect of Luteolin on Proliferation ofNalm6 Cell
OBJECTIVE To investigate the mechanism of polyinosinic polycytidylic acid[Poly(I:C)]enhancing luteolin(LTN)to inhibit the proliferation of acute lymphoblastic leukemia cell line Nalm6.METHODS Using CCK-8 method and flow cytometry to detect the proliferation and apoptosis of Nalm6 cells treated with LTN alone or combined with Poly(I:C),and explored the effect of programmed apoptosis inhibitor(ZVAD)and necrotic cell death inhibitor(Nec-1)on the combined treatment.Flow cytometry was performed to analyze the effects of LTN alone or combined with Poly(I:C)on cell apoptosis of Nalm6 cells at different time points,cell cycle states at 24 h,and TLR3 expression.The protein expression of p-IRF3,p-mTOR,p-NFKB-65,p-p70S6K,p-ERK1/2,PARP,Caspase 3 and Caspase 8 were detected by Western blotting.RESULTS Compared with LTN group,Poly(I:C)combined with LTN group significantly inhibited the proliferation of Nalm6 cells(P＜0.05);ZVAD could completely block the proliferation-inhibiting effects of Poly(I:C)combined with LTN in Nalm6 cells(P＜0.05).Under Poly(I:C)combined with LTN treatment,cell apoptosis occurred at 3 h and reached the late stage of apoptosis after 24 h.Cell cycle results showed that Poly(I:C)significantly promoted LTN-induced DNA breakage(P＜0.05).Neutralization of TLR3 pathway did not affect the apoptosis-enhancing effects of Poly(I:C)combined with LTN in Nalm6 cells.Westem blotting analysis showed that compared with LTN alone,Poly(I:C)combined with LTN activated PARP,Caspase 3 and Caspase 8 to initiate apoptosis of Nalm6 cells for 6 h,but did not affect the NF-κB and PI3K-AKT signaling pathways.LTN alone activated p-ERKl/2 phosphorylation,inhibiting cell proliferation by activating the MEK/ERK signaling pathway.CONCLUSION Poly(I:C)induced apoptosis by activating PARP,Caspase 3 and Caspase 8 rather than necrosis,to enhance the proliferation-inhibiting effects of LTN on proliferation of Nalm6 cell.
万方数据
维普
