Objective To observe the expression of signal transducer and activator of transcription (STAT3) in chronic myeloid leukemia cells K562 and analyze the influence of these changes to the cell proliferation,differentiation and drug resistance.Methods We constructed recombinant eukaryotic expression vector siRNA-STAT3,and transfected them into K562 cells with the help of lipofactamine 3000.Then stable monoclonal cells would be screened by puromycin and validated by Western blot.Inhibition rate of the cell growth to imatinib(IM) was determined by MTT method.Meanwhile,the related protein of BCR/ABL fusion protein was detected.Results Compared with the control group,low expression of STAT3 in the K562 cell group using IM treatment had a high inhibition rate,under different concentrations,the inhibition rate was statistically significant(P ＜ 0.05).While in the high expression of STAT3 cells,at the same concentration gradient under the action of IM,and the differences between groups were also statistically significant(P ＜ 0.05).However,there was no statistically significant difference of the inhibition rate in the two control groups.We also detected the similar expression levels of the related protein of BCR/ABL fusion protein,P53,HAUSP and PTEN.Conclusion Low expression of the STAT3 protein enhances the sensitivity of K562 cells to IM,which may result in a further reduction in the subsequent resistance of the K562 cells to IM treatment by inhibiting the STAT3 protein.%目的 升高或者降低信号转导因子与转录激活因子3(STAT3)的表达,分析其变化对于细胞的增殖分化以及敏感性有何意义.方法 构建重组质粒真核表达载体siRNA-STAT3,将重组表达质粒用脂质体Lipofactamine 3000转染人慢性粒细胞白血病K562细胞,通过嘌呤霉素持续单克隆筛选,Western blot法鉴定,进而筛选出稳定低表达组(低表达对照组、低表达1组、低表达2组)和高表达组(高表达对照组、高表达组)STAT3细胞株.将正处于增殖周期的细胞经不同浓度的伊马替尼作用后,MTT法检测细胞生长抑制率,绘制细胞增殖曲线.同时检测转染后细胞株BCR/ABL融合基因相关蛋白的表达变化.结果 与低表达对照组相比,低表达STAT3(低表达1组、低表达2组)的K562细胞组使用伊马替尼治疗有着较高的抑制率,在不同浓度作用下,其抑制率差异有统计学意义(P＜0.05).过表达STAT3后,与高表达对照组相比,在相同浓度梯度伊马替尼作用下,其抑制率差异有统计学意义(P＜0.05).低表达对照组与高表达对照组中伊马替尼抑制率差异无统计学意义.伊马替尼治疗靶向基因BCR/ABL相关蛋白中的P53、HAUSP和PTEN蛋白表达趋势和STAT3基本一致.结论 低表达STAT3蛋白可加强K562细胞对伊马替尼的敏感性,抑制STAT3蛋白有望提高伊马替尼对慢性粒细胞白血病的疗效.
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