VEGF基因沉默对人肺癌A549细胞放射增敏作用的体内研究

Investigation on Radiosensitivity Impact of Lung Cancer A549 Cells by Vascular Endothelial Growth Factor Silencing in vivo

目的探讨RNA干扰血管内皮生长因子(VEGF)基因表达载体siVEGF对人肺腺癌A549细胞荷瘤鼠的放射敏感性的影响。方法用体外培养人肺腺癌A549细胞株建立荷瘤裸小鼠模型,荷瘤鼠瘤内注射siVEGF/RNAi-MateTM脂质体混合物,再经放射治疗24 d后,处死裸小鼠,剥离瘤体称重,利用实时定量PCR (q-PCR)、免疫组织化学和Western blotting检测VEGF的基因和蛋白表达水平,评价siVEGF对放射敏感性的影响。结果 q-PCR、Western blotting和免疫组织化学检测结果表明siVEGF可显著降低VEGF的蛋白水平(P<0.05)。与对照组相比si VEGF联合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 A549 cells in tumor-bearing mouse model by knock down vascular endothelial growth factor(VEGF) gene. Methods The tumorbearing mouse model was established by using A549 cells which was cultured in vitro. The siVEGF/RNAi-MateTM mixture was injected into the tumor of model mice and with radiotherapy. The nude mice were euthanasia on day 24 after radiotherapy. The expressions of VEGF were detected by immuno-histochemical, Q-PCR and Western blotting. Results Both the protein and mRNA levels of VEGF in VEGF knockdown and radiotherapy group were significantly decreased compared with the control group(P<0.05). The volume of tumor was decreased and the necrotic area of tumor were increased distinctly in siVEGF transfected and radiotherapy group compared with control group(P<0.05). Conclusion Knock down of VEGF and radiotherapy can inhibit tumor growth, and increase the radiosensitivity of lung cancer radiotherapy.