RESUMO
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.
RESUMO
Objective To explore the effect ofmiR-137 on proliferation and apoptosis of U87 glioma cells.Methods The miR-137 mimics were transfected to human glioma cell line U87 as miR-137 transfection group; blank control group and negative control group were also employed in our study.The expression ofmiR-137 was identified by real-time polymerase chain reaction (PCR) after transfection.Methylthiazol tetrazoliu (MTT) assay,flow cytometry-Annexin V/PI assay and fluorescence microscope were employed to detect the cell proliferation and apoptosis.MiR-137 and its relative targeting protein expressions were detected by Westem blotting.Results MTT assay showed that the relative cell survival rates in the blank control group,negative control group and miR-137 transfection group were (105.16±8.57)％,(98.57±8.21)％ and (45.84±6.93)％,with significant differences (F=82.157,P=0.000).Annexin V/PI assay showed that the cell apoptosis rates in the blank control group,negative control group and miR-137 transfection group were (4.3±0.63)％,(4.7±0.77)％ and (16.6±1.98)％,with significant differences (F=63.837,P=0.000); and apoptotic body was detected by fluorescence microscope.Moreover,CDC42,pERK1/2,AKT and pAKT protein expression levels were inhibited after transfected by miR-137 mimics.Conclusion MiR-137 inhibits proliferation and induces apoptosis of U87 glioma cells,suggesting that miR-137 could be tumor suppressor gene in glioma.