血管内皮生长因子反义核酸对宫颈癌Hela细胞的放射增敏作用

Effects of Antisense Oligonucleotides Targeting VEGF on Radiosensitivity of HeLa Cervical Cancer Cells

目的:血管内皮生长因子(Vascular endothelial growth factor,VEGF)在人类多数实体肿瘤中均有表达,射线可诱导其表达增加,产生放射抗拒。本实验目的在于探讨血管内皮生长因子反义寡核苷酸干涉对高转移宫颈腺癌Hela细胞株的放射增敏作用。方法:实验组通过脂质体介导将VEGF基因反义寡核苷酸瞬时转染入Hela细胞,设VEGF正义寡核苷酸组和空白对照组作比较,各组均予6MV-X线照射,剂量为0Gy、2Gy、4Gy和6Gy,用RT-PCR检测照射前后Hela细胞中VEGF mRNA表达;用流式细胞术检测细胞凋亡;平板克隆形成试验检测克隆形成率的变化。结果:与对照组比较,VEGF反义寡核苷酸不仅可抑制Hela细胞中内源性VEGF mRNA的表达(P<0.01),亦可显著抑制辐射诱导的VEGF表达的增加(P<0.01);VEGF表达下调使射线诱导的细胞凋亡率明显升高(P<0.01),细胞克隆数量明显降低(P<0.01)。结论:针对人VEGF基因反义寡核苷酸干涉可抑制射线诱导的VEGF的高表达,增强射线对肿瘤细胞的杀伤作用,提高细胞的放射敏感性。

Objective： Vascular endothelial growth factor （VEGF） is expressed in most solid tumors. Overexpression of VEGF induced by radiation is involved in resistance to irradiation. This study was performed to determine the impact of antisense oligonucleotides targeting VEGF on radiosensitivity of HeLa cervical cancer cells. Methods： VEGF ASODN was transfected into HeLa cells using liposomes. Cells transfected with the same oligodeoxynucleotide and saline were used as the control. Cells were irradiated by 6 MV X-rays at doses of 0 Gy, 2 Gy, 4 Gy and 6 Gy. The expression of VEGF mRNA was determined by RT-PCR. Apoptosis was evaluat- ed with flow cytometry, and cloning efficiency was determined by colony formation assay. Results： The expres- sion of VEGF mRNA was inhibited by ASODN （P〈0.01）in HeLa cells. The ASODN-induced inhibition coupled with radiation resulted in increased apoptosis （P〈0.01） and decreased plating efficiency （P〈0.01）. Conclusion： VEGF ASODN can block the expression of VEGF induced by X-ray irradiation in HeLa cells and thus increase apoptosis and enhance radiosensitivity.