靶向STAT3的decoy核酸抑制膀胱癌细胞生长的实验研究

目的观察特异性靶向STAT3的decoy寡核苷酸(ODNs)对膀胱癌细胞增殖和凋亡的影响,并探讨其作用机理。方法通过体外细胞培养技术,将STAT3 decoy ODNs转染入膀胱癌T24细胞内,台盼蓝排斥试验检测细胞活力,MTT法检测细胞增殖状态,Hoechst33258/PI荧光双染检测细胞凋亡特征,流式细胞仪检测细胞周期和早期凋亡,凝胶阻滞电泳检测STAT3的DNA结合活性,RT-PCR检测STAT3下游靶基因Cyclin D1和Bcl-xL的mRNA表达水平。结果STAT3 decoyODNs使膀胱癌细胞生长速度减慢,细胞增殖抑制率达75.0%;使细胞周期阻滞,S期细胞比率明显减少,由29.83%下降至16.26%,而G0~G1期细胞比率明显增多,由50.82%上升至71.20%;促进膀胱癌细胞凋亡,细胞早期凋亡率高达50.75%;使STAT3的DNA结合活性下降,并使Cyclin D1、Bcl-xL的mRNA表达水平明显下降。结论STAT3 decoy ODNs可特异性靶向作用于STAT3蛋白,阻断STAT3的过度激活效应,通过下调Cyclin D1和Bcl-xL的表达抑制膀胱癌细胞增殖,促进其凋亡。

An experimental study on decoy oligodeoxynucleotides targeting activated STAT3 to suppress bladder cancer cell growth

Objective To investigate the effects of STAT3 decoy oligodeoxynucleotides on the proliferation and apoptosis of bladder cancer T24 cell and explore the mechanism.Methods STAT3 decoy oligodeoxynucleotides were transfected into bladder cancer T24 cells.The cell vitality and proliferation were detected by Trypan Blue staining rejection,cell counting and MTT assay.Fluorescence dyestuff Hoechst33258 and PI staining assay were used to investigate the cell apoptosis characteristics.Flow cytometry was applied to analyze the cell cycle and apoptosis.The DNA-binding activity of STAT3 was detected by EMSA.The expressions of Cyclin D1 and Bcl-xL were measured by RT-PCR.Results STAT3 decoy oligodeoxynucleotides remarkably inhibited the proliferation of bladder cancer T24 cell by 75.0%,decreased the cell number of S phase from 29.83% to 16.26%,increased the cell number of G0/G1 phase from 50.82% to 71.20%,facilitated the apoptosis of bladder cancer cell with 50.75% of apoptosis rate,decreased the DNA-binding activity of STAT3,and resulted in less mRNA expressions of Cyclin D1 and Bcl-xL.Conclusions Decoy oligodeoxynucleotides targeting activated STAT3 could block constitutive activation of STAT3,inhibit the proliferation of bladder cancer cells and induce their apoptosis by attenuating expressions of Cyclin D1 and Bcl-xL.