Effect of signal transducer and activator of transcription 3 antisense oligonucleotide on invasion and apoptosis of human U251 glioma cells

Abstract

Objective To investigate the role of signal transducer and activator of transcription 3 (STAT3) knockdown in regulating the invasion and apoptosis of glioma cells.Methods Liposome-mediated STAT3 antisense oligonucleotide was transfected into the U251 glioma cells;nonsense sequence group and blank control group were also established.The effect of STAT3 antisense oligonucleotide on the growth of U251 glioma cells was examined by MTT assay; the cell cycle and apoptosis were evaluated by flow cytometry; the cell migration was determined by Transwell invasion assay.Western blotting was employed to explore the protein expressions of STAT3 and pSTAT3,urokinase-type plasminogen activator receptor (uPAR),Bax and Bcl-2 in glioma cells.Results As compared with the nonsense sequence group and blank control group,liposome-mediated STAT3 antisense oligonucleotide group had lower survival rate,inhibited cell proliferation and cells being arrested at G0/G1 phases; Transwell invasion assay indicated that STAT3 antisense oligonucleotide suppressed the invasion and promoted the apoptosis of U251 cells.The STAT3,pSTAT3,uPAR and Bcl-2 expression levels in the iposome-mediated STAT3 antisense oligonucleotide group were signficantly decreased as compared with those in the nonsense sequence group and blank control group,while Bax level was obviously elevated (P＜0.05).Conclusion STAT3 antisense oligonucleotide can inhibit the invasion and promote the apoptosis of U251 cells by regulating its downstream gene expression; STAT3 can be used as an effective target for glioma gene therapy. Key words: Signal transducer and activator of transcription 3; Antisense oligonucleotide; Glioma; Upar