【摘要】 目的 探讨核仁素对伯基特淋巴瘤细胞长春新碱敏感性的影响及其机制。方法 体外传代培养伯基特淋巴瘤CA46细胞。取传3代、对数生长期、生长状态良好的CA46细胞，随机分为Control组、核仁素-NC组、核仁素-KD组和核仁素-OE组，核仁素-NC组、核仁素-KD组、核仁素-OE组分别转染对照质粒、核仁素shRNA质粒、核仁素mRNA质粒，Control组不予转染。采用RT-qPCR法检测各组CA46细胞核仁素、Bcl-2 mRNA表达；采用MTT法检测细胞存活率，并计算长春新碱的半数抑制浓度(IC₅₀)；采用流式细胞术检测细胞凋亡率；采用蛋白免疫印迹实验检测Bcl-2蛋白表达；采用免疫共沉淀实验观察核仁素免疫沉淀复合物中Bcl-2 mRNA富集强度。结果 Control组和核仁素-NC组CA46细胞核仁素mRNA相对表达量、长春新碱的IC₅₀、长春新碱诱导后凋亡率以及Bcl-2 mRNA与蛋白相对表达量比较差异均无统计学意义（P均>0.05）。核仁素-KD组CA46细胞核仁素mRNA相对表达量、长春新碱的IC₅₀、长春新碱诱导后凋亡率以及Bcl-2 mRNA与蛋白相对表达量均低于Control组和核仁素-NC组（P均<0.05），而核仁素-OE组上述指标均高于Control组和核仁素-NC组（P均<0.05）。在核仁素免疫沉淀复合物中可见Bcl-2 mRNA显著富集。结论 核仁素可能通过上调Bcl-2表达，并直接与Bcl-2 mRNA结合而促进其稳定性，从而降低伯基特淋巴瘤细胞对长春新碱的敏感性。更多还原

【Abstract】 Objective To investigate the effect of nucleolin on the sensitivity of Burkitt lymphoma cells to vincristine and its mechanism. Methods Burkitt lymphoma CA46 cells were cultured in vitro. CA46 cells in the third generation, which were in logarithmic growth phase and had good growth status, were randomly divided into the Control group, nucleolin-NC group, nucleolin-KD group, and nucleolin-OE group. The control plasmid, shRNA plasmid and mRNA plasmid were transfected into the nucleolin-NC group, nucleolin-KD group and nucleolin-OE group, respectively. Cells in the Control group were not transfected. RT-qPCR was used to detect the mRNA expression levels of nucleolin and Bcl-2 in CA46 cells of each group. The cell survival rate was measured by MTT assay, and the median inhibitory concentration(IC₅₀) of vincristine was calculated. The apoptosis rate was detected by flow cytometry. The expression of Bcl-2 protein was detected by Western blotting. The concentration of Bcl-2 mRNA in nucleolin immunoprecipitation complex was observed by immunoprecipitation experiment. Results There were no significant differences in the relative expression of nucleolin mRNA, the IC₅₀ of vincristine, the apoptosis rate after vincristine induction or the relative expression levels of Bcl-2 mRNA and protein in CA46 cells between the Control group and the nucleolin-NC group（all P>0. 05）. The relative expression of nucleolin mRNA, vincristine IC₅₀, vincristine-induced apoptosis rate and the relative expression of Bcl-2mRNA and protein in CA46 cells in the nucleolin-KD group were significantly lower than those in the Control group and nucleolin-NC group（all P<0. 05）. The above indexes in the nucleolin-OE group were significantly higher than those in the Control group and nucleolin-NC group（all P<0. 05）. Bcl-2 mRNA was significantly enriched in the nucleolin immunoprecipitation complex. Conclusion Nucleolin may promote the stability of Bcl-2 by up-regulating Bcl-2 expression and directly binding to Bcl-2 mRNA, and reduce the sensitivity of Burkitt lymphoma cells to vincristine.更多还原