【摘要】 目的:观察TNF-α对人髓系白血病细胞K562及其耐药细胞K562/ADM hTERT基因表达、端粒酶活性的抑制以及对多药耐药(multidrug resistance-1,mdrl)基因表达的影响。方法:K562及K562/ADM细胞传代培养,加入5×10~6U/L的TNF-α培养24h进行诱导实验;MTT法检测K562和K562/ADM细胞的增殖能力,流式细胞术检测K562和K562/ADM细胞的凋亡,RT-PCR检测hTERT和mdrl mRNA的表达,ELISA法检测端粒酶活性。结果:TNF-α诱导K562及K562/ADM细胞表现持续的生长抑制作用,且具有时效关系(P<0.05);TNF-α诱导K562及K562/ADM细胞的凋亡率增加(P<0.05),而且耐药细胞K562/ADM凋亡的增加更明显(P<0.01);hTERT基因与端粒酶活性的表达密切相关(r=0.983,P<0.05),TNF-α诱导后两者也同时下调(P<0.01);多药耐药mdrl基因伴随着hTERT基因的下调而下调(r=0.966,P<0.05)。结论:TNF-α能诱导白血病K562及K562/ADM细胞系hTERT基因表达的抑制,端粒酶活性下调的同时多药耐药基因mdrl的表达也下调。更多还原

【Abstract】 Objective:To investigate the inhibitory effect of TNF-αon hTERT gene expression in human myelogenous leukemia cell line K562 and K562/ADM and to study the influence of changed telomerase activity on expression of multi- drug resistance-1(mdr 1)gene.Methods:K562 and K562/ADM cells were treated with 5×10~6 U/L TNF-αfor 24 h, then cell proliferation was detected by MTT assay and cell apoptosis was detected by flow cytometry.The expression of hTERT and mdrl mRNA was detected by RT-PCR and the telomerase activity was detected by ELISA.Results:TNF-αin- hibited the growth of K562 and K562/ADM cells and the inhibition showed a time-effect relationship(P<0.05).TNF-αalso significantly increased the apoptosis rates of K562 and K562/ADM cells(P<0.05),with the increase in drug-resist- ant K562/ADM cells more significantly(P<0.01).hTERT gene expression was correlated with telomerase activity (Pearson correlation coefficient r=0.983,P<0.05).TNF-αtreatment decreased hTERT expression and telomerase ac- tivity.Mdr1 gene expression decreased with the decrease of hTERT gene(r=0.966,P<0.05).Conclusion:TNF-αcan inhibit the expression of hTERT gene in human K562 and K562/ADM cells;the down-regulation of telomerase activity is accompanied by the down-regulation of mdr1 gene expression.更多还原