论文部分内容阅读
目的:探讨肺癌细胞中抑癌蛋白PTEN低表达的相关机制。方法:Western blot方法检测肺癌细胞和正常人肺上皮细胞BEAS-2BPTEN蛋白的表达;用放线菌酮(1μg/mL)处理人肺腺癌细胞A549和正常人肺上皮细胞BEAS-2B阻断细胞翻译后,Western blot方法检测不同时相PTEN蛋白的表达。RT-PCR检测肺癌细胞与正常肺上皮细胞PTEN mRNA水平;放线菌素D(1μg/mL)处理肺癌细胞与正常肺上皮细胞阻断新生RNA合成,RT-PCR检测不同时相PTEN mRNA的水平。结果:Western blot结果显示,肺癌细胞中PTEN蛋白表达与正常肺上皮细胞比较有不同程度的降低(0.38～1.32倍);使用放线菌酮处理A549和BEAS-2B后,24h内A549及BEAS-2B细胞PTEN蛋白表达无明显改变。RT-PCR结果显示肺癌细胞中PTEN mRNA与正常人肺上皮细胞相比明显降低(0.41～0.68倍);放线菌素D处理显示肺癌细胞PTEN mRNA降解速率比正常肺上皮细胞降解速率明显加快。结论:肺癌细胞中抑癌蛋白PTEN低表达的主要原因是其mRNA降解加速,这为进一步研究PTEN蛋白低表达的详细分子机制提供了线索。
Objective: To investigate the mechanism of low expression of tumor suppressor protein PTEN in lung cancer cells. METHODS: The expression of BEAS-2BPTEN protein in lung cancer cells and normal human lung epithelial cells was detected by Western blot. The cells of human lung adenocarcinoma A549 and normal human lung epithelial cells BEAS-2B were treated with cycloheximide (1μg / mL) After translation, the expression of PTEN protein in different phases was detected by Western blot. RT-PCR was used to detect PTEN mRNA expression in lung cancer cells and normal lung epithelial cells; Actinomycin D (1μg / mL) treated lung cancer cells with normal lung epithelial cells to block the nascent RNA synthesis, RT-PCR to detect PTEN mRNA levels . Results: Western blot results showed that the expression of PTEN protein in lung cancer cells was decreased to some extent (0.38-1.32 times) compared with that in normal lung epithelial cells. After treated with cycloheximide, A549 and BEAS- 2B cells PTEN protein expression no significant change. RT-PCR results showed that PTEN mRNA in lung cancer cells was significantly lower than that in normal human lung epithelial cells (0.41-0.68 fold). Actinomycin D treatment showed that the degradation rate of PTEN mRNA in lung cancer cells was significantly higher than that of normal lung epithelial cells. CONCLUSION: The main reason for the low expression of PTEN in lung cancer cells is the accelerated mRNA degradation, which provides a clue to further study the molecular mechanism of PTEN low expression.