中文摘要：

目的：建立体外低氧模型，探讨低氧对人喉鳞癌细胞Hep2细胞周期以及顺铂对其诱导的凋亡的影响．方法：将体外培养的人喉鳞癌细胞分为4组：A组（对照组）、B组（低氧培养组）、C组（常氧培养加顺铂组）、D组（低氧培养加顺铂组）。流式细胞仪检测HIF-1α蛋白表达、细胞凋亡及细胞周期变化：MTT法检测C、D两组在不同浓度顺铂作用24h后的细胞抑制率；RT—PCR检测各组细胞HIF1αmRNA的表达水平。结果：低氧能明显增加Hep2细胞HIF-1α蛋白表达，而对HIF-1αmRNA的表达无明显影响。B、D组的Hep2细胞发生G0／G1期细胞周期阻滞，顺铂5μg／ml作用24h后C组细胞凋亡及抑制率（％）显著高于D组（P〈0．05）．结论：低氧使Hep2细胞产生化疗抵抗．其中HIF-1α蛋白表达水平升高以及低氧造成的G0／G1期细胞周期阻滞可能在顺铂诱导的人喉鳞癌细胞凋亡中发挥重要的抗凋亡作用.

英文摘要：

Objective： To establish a hypoxic model of Hep2 laryngeal cancer cell line, and to investigate the impact of hypoxia on cell cycle and Cisplatin （DDP）-induced apoptosis in Hep2 cells. Methods： Human laryngeal cancer cell line Hep2 was diviced into 4 groups： group A （contral）, group B （hypoxia）, group C （normoxia plus DDP） and group D （hypoxia plus DDP）. Flow cytometry （FCM） was used to measure the distribution of cell cycles and the protein levels of HIF-1α and to detect cell apoptosis. The rate of inhibition （IR） by DDP on Hep2 was determined using MTT. HIF-1α mRNA level was determined by RT-PCR. Results： Hypoxia evidently increased the protein level of HIF-1α in Hep2 cell, but had no effect on mRNA level of HIF-1α. Hypoxia could cause G0/G1 cell cycle arrest in human Hep2 cell. The apoptosis and inhibition rate in group C were significantly higher than that in group D after treatment of DDP （P〈0.05）. Conclutions： Hypoxia could induce G0/G1 cell cycle arrest and weaken the effect of DDP on inducing apoptosis of Hep2 cells.