中文摘要：

目的探讨低氧条件下HIF-1α和FTEN在胎鼠成纤维（MEFs）细胞增殖、分化中可能的调控作用，以及低氧对细胞周期的影响。方法低氧条件（5％O295％N2）下培养MEFs不同时间（0、2、4、6、8h）后，应用免疫细胞化学、RT-PCR检测方法，观察MEFs中HIF-1α和PTEN的表达并检测其细胞周期。结果免疫组化结果表明，HIF-1仅及PTEN蛋白的表达均随低氧时间增长而逐渐增强。RT-PCR结果显示，HIF-1αmRNA吸光度值常氧组为（0．93±0．06），低氧2。4h组达高峰分别为（1．46±0．05）和（2．30±0．05），随后开始下降；PTENmRNA吸光度值常氧组为（0．78±0．08），低氧2～6h组逐渐达到高峰分别（1．10±0．11）和（1．61±0．23），8h开始呈现下降趋势（P〈O．05）。流式细胞仪分析显示，随着低氧时间延长，GO／G1期细胞从（86．72±0．41）％上升至（92．41±1.10）％，低氧使MEFs细胞周期阻滞于G1／G0期。结论低氧微环境阻滞MEFs细胞周期于GO／G1期可能与PTEN和HIF-1α过表达相关。

英文摘要：

Objective To study the effect of hypoxia on PTEN and HIF-1α expressions and cell cycle in mouse embryo fibroblasts（MEFs）. Methods MEFs were cultured at different times（0, 2, 4, 6, 8 h）under hypoxic conditions （5% 02 95% N2）. the expressions of HIF-1 α and PTEN in MEFs were observed using immunoeytochemistry and RT-PCR, and the cell cycle was monitored simultaneously. Results Immunohistoehemistry showed that the expression levels of HIF- 1 α and PTEN protein increased gradually with the increased hypoxic time. RT-PCR showed that absorbanee values of HIF-lα mRNA and PTEN mRNA products were much lower in normoxia group than in hypoxia, reached the peak in hypoxia 2-4h group （P〈0.05）, then decreased gradually. Flow cytometry analysis showed that the number of G0/G1 phase cells increased from （86.72 ± 0.41 ）% to （92.41 ± 1.10）% with prolonged hypoxia, cell cycle of MEFs stoped at G1/G0 phase. Conclusion The inhibition of hypoxia cell micro-environment on MEFs cells in G0/G1 phase might be related to the overexpression of HIF-1 α and PTEN.