RNA干扰沉默Aurora A基因表达对胶质瘤细胞增殖及凋亡的影响

目的 探讨RNA干扰技术抑制人胶质瘤U251细胞中Aurora A基因的表达，研究其对U251细胞增殖及凋亡的影响。 方法 设计并合成特异性针对Aurora A基因的siRNA，转染至U251细胞中，采用RT-PCR和Western blotting检测Aurora A mRNA和蛋白的表达情况，同时利用四甲基偶氮唑盐(MTT)实验和流式细胞仪观察转染后U251细胞增殖抑制率和细胞凋亡，透射电镜观察细胞凋亡超微结构改变。 结果 转染Aurora A siRNA后，U251细胞Aurora A mRNA表达受到抑制(P<0.01)，蛋白表达水平降低；U251细胞增殖的抑制率和细胞凋亡率显著增高 (P<0.01)，且U251细胞发生了显著的凋亡形态改变。 结论 体外合成的针对Aurora A基因的特异性siRNA成功地抑制了U251细胞中Aurora A基因的表达，并能抑制胶质瘤细胞增殖、促进凋亡，提示Aurora A可能成为胶质瘤基因治疗的新靶点。

Effects of Aurora A silence by RNA interference on the apoptosis and proliferation of glioma cells

Objective To investigate the inhibitory effect of RNA interference on the expression of Aurora A in U251 cells, and the influence on proliferation and apoptosis of U251 cells. Methods The siRNA specific for Aurora A was synthesized and transfected into U251 cells in vitro. Aurora A mRNA expression and protein content were detected by RT-PCR and Western blotting respectively. The cell proliferation and apoptosis were observed by methyl thiazolyl tetrazolium(MTT) and flow cytometry(FCM). Transmission electron microscope was used to observe the ultrastructural changes of U251 cells. Results After transfection, the expression level of Aurora A mRNA was significantly decreased(P<0.01), and the protein content of Aurora A was also obviously reduced. The inhibitory rate of cell proliferation reached up to 67.57% 72 hours after transfection, which was significantly higer than that of normal control group(P<0.01). The apoptosis rate of U251 cells was significantly increased from (3.69±0.87)% to (15.34±2.16)% (P<0.01). Under the transmission electron microscope, it was observed that the U251 cells showed typical morphologic changes of apoptosis after transfection, such as karyopyknosis, chromatin condensation and margination, intracytoplasmic vacuoles formed, and apoptotic bodies formed. Conclusion The expression of Aurora A gene can be inhibited by siRNA successfully, and it results in the suppression of cell growth and induce apoptosis of human glioma cells in vitro. Aurora A may become a new target for the gene therapy of gliomas.