VEGF基因沉默对人肺癌A549细胞放射增敏作用的体内研究

Effect of VEGF gene silencing on radiosensitivity of lung cancer A549 cells

目的:探讨RNA干扰(RNA interfering,RNAi)沉默血管内皮生长因子受体(vascular endothelial growth factor,VEGF)基因表达载体siVEGF对人肺腺癌A549细胞放射敏感性的影响。方法:体外培养人肺腺癌A549细胞株,用A549细胞建立荷瘤鼠模型。荷瘤鼠瘤内注射siVEGF/RNAi-Mate^(TM)脂质体混合物,再经放射治疗,第24天处死裸鼠剥离瘤体称重。利用RT-PCR、免疫组化和Western blot检测VEGF的mRNA和蛋白表达水平,并评价siVEGF对放射敏感性的影响。结果:RT-PCR、Western blot和免疫组化检测结果表明,siVEGF可显著降低VEGF的mRNA水平及蛋白水平(P<0.05)。与siMock组相比,siVEGF+放疗组的肿瘤生长和坏死程度存在显著性差异(P<0.05)。结论:siVEGF合并放射治疗能显著抑制A549细胞移植瘤的生长,增加其对放射治疗的敏感性。

Objective:To research the radiosensitivity of lung cancer A549 cells in tumor-bearing mouse model by knock down VEGF gene.Methods:The tumor-bearing mouse model was built by lung cancer A549 cells cultured in vitro.After the tumor-bearing mouse model was successfully established,siVEGF/RNAi-MateTM mixture was injected in tumor and the tumor was radiotherapy.Twenty-four days later,the tumor-bearing mouse were euthanasia.The expressions of VEGF were detected by immunohistochemical,RT-PCR and Western blot.Results:Both the protein and mRNA levels of VEGF in VEGF knock down and radiotherapy group were markedly decreased compared with the control group(P<0.05).The volume of tumor were decreased and the necrotic area of tumor were increased distinctly in siVEGF transfected and radiotherapy group compared with siMock group(P<0.05).Conclusion:Knock down VEGF and radiotherapy can inhibit tumor grows clearly,and increase the radiosensitivity to lung cancer radiotherapy.