中文摘要：

目的：通过HIF-1α反义寡核苷酸转染hep-2细胞株，观察细胞凋亡及对放疗的反应情况。方法：体外培养人喉鳞状细胞癌hep-2细胞株，脂质体介导反义寡核苷酸转染，6h后4Gy7射线照射。低氧培养24h后RT—PCR检测HIF-1α mRNA表达，流式细胞仪检测HIF-1α蛋白水平及细胞凋亡率，MTT检测细胞存活情况。结果：低氧使人喉鳞状细胞癌hep-2细胞株对放射的敏感性下降；低氧并未影响HIF-1αmRNA的表达，HIF-1α蛋白在低氧6h时表达已开始升高，低氧36h时达高峰，之后表达逐渐下降；放射刺激对HIF-1α蛋白表达差异无统计学意义（P〉0．05）；各浓度的反义寡核苷酸转染组降低HIF-1α的转录及蛋白水平；MTT结果显示随反义核苷酸浓度增高，其增殖抑制效应越强（P〈0．05），正义对照核苷酸及脂质体对照没有显著的抑制效应（P〉0、05），但转染浓度在400nmol／L以上时，正义对照也表现出一定的增殖抑制作用（P〈0．05）；放疗后反义寡核苷酸转染组蛋白表达下降明显，较对照组及单纯放射组细胞凋亡率增加（P〈0．01）。结论：低氧环境下人喉鳞状细胞癌hep-2细胞株对放射有抵抗作用，这种抵抗作用与低氧时HIF-1α蛋白表达上调有关，而放射本身并未上调HF-1α蛋白的表达；HIF-1α反义寡核苷酸转染hep-2细胞株能够降低HIF-1α蛋白表达，提高低氧环境下人喉鳞状细胞癌hep-2细胞株对放疗的敏感性。

英文摘要：

Objective：To investigate the effect of HIF-1α down- regulation by antisense oligonucleotides （AS ODNs） on hep-2 cells apoptosis and radiotherapy sensitivity in vitro. Method： AS ODN was transfected into cultured hep-2 cells which received radiation under hypoxic condition. Twenty-four hours after hypoxic treatment cells were observed under the fluorescence inverse phase microscope. Apoptosis rate, expression of HIF-1αmRNA and protein were measured. Result： In cultured hep-2 cells, AS ODN down-regulated HIF-1αmRNA expression. The protein levels were lowered down and the cell viability were decreased. In contrast, the scrambled control ODN caused minimal HIF-1α loss and less cell inhibition. In addition, AS ODN sensitized Hep-2 cells to the radiation effects of 4Gy ^60Co ray. Conclusion： HIF-1α is a viable target for cancer therapy in human laryngeneal neoplasms. In cultured Hep-2 cells HIF-1α AS ODN can down-regulate HIF-1αprotein expression, induce apoptosis and enhance the radiotherapy sensitivity.