β-胡萝卜素对食管癌细胞凋亡与 Cav-1表达的影响

摘要

Aim:To observe the effect of β-carotene on cell apoptosis in esophageal cancer cells , and analyze the rela-tionship between the sensitivity of esophageal cancer cells to β-carotene and the expression of caveolin-1(Cav-1).Methods:The expressions of Cav-1 protein in normal esophageal epithelial cell line Het-1A and three esophageal cancer cell lines ( TE1, EC1,Eca109) were detected by Western blot; after treatment with different concentrations (0,1, 5, 10, 20, 30 and 50μmol/L) of β-carotene for 12, 24, 36, 48, 60 and 72 h, the proliferation rate of esophageal cancer cells was tested by CCK 8 assay, and the optimal time and concentration of β-carotene were determined; then the cell apoptosis of esophageal cancer cells were detected by Annexin V-FITC/PI staining;the mRNA level of Cav-1 was determined by qRT-PCR, the expression level of Cav-1 protein was detected by Western blot .Results:Cav-1 was over-expressed in esophageal cancer cells ( TE1>Eca109>EC1), and was undetectable in Het-1A.CCK-8 assay showed that β-carotene has no effect on Het -1A cells, but in-hibited the proliferation of three esophageal cancer cell lines in a dose-and time-dependent manner .In addition, there were relation between the expression of Cav-1 and the sensitivity of esophageal cancer cells to β-carotene.The dose and treatment time ofβ-carotene when the cell proliferations were decreased nearly 50%were used in the following experiments .After treat-ment with β-carotene, TE1,EC1 and Eca109 cells had higher apoptosis rate than that of negative control group (P<0.05), especially TE1.In addition, the mRNA and protein level of Cav-1 were both significantly downr-egulated.Conclusion :β-carotene can effectively induce apoptosis in esophageal cancer cells , which is nont-oxic to the normal esophageal epithelial cell.Moreover , the sensitivity of esophageal cancer cells to the β-carotene may be regulated by Cav1-.%目的：观察β-胡萝卜素对食管癌细胞凋亡的影响，并分析食管癌细胞对β-胡萝卜素的敏感性与小窝蛋白-1（Cav-1）表达的关系。方法：采用Western blot法检测正常食管上皮细胞株Het-1A及食管癌细胞（TE1、EC1和Eca109）中Cav-1蛋白的表达；CCK-8法检测不同浓度（0、1、5、10、20、30、50μmol／L）β-胡萝卜素处理食管癌细胞12、24、36、48、60、72 h后，对食管癌细胞增殖抑制的影响，筛选出β-胡萝卜素的最佳处理时间及浓度；在筛选条件下处理食管癌细胞，采用Annexin V-FITC／PI双染法检测细胞凋亡率；qRT-PCR检测Cav-1 mRNA表达水平的变化；Western blot检测Cav-1蛋白表达水平的变化。结果：Cav-1蛋白在食管癌细胞中呈过表达（ TE1＞Eca109＞EC1），而Het-1A细胞中无Cav-1表达。β-胡萝卜素对正常食管上皮细胞的增殖无抑制作用，而对食管癌细胞（ TE1、EC1和Eca109）的增殖抑制作用具有时间和剂量依赖性，且食管癌细胞对β-胡萝卜素的敏感性与Cav-1的表达有关。分别采用30、50、50μmol／Lβ-胡萝卜素处理48 h后，TE1、Eca109和EC1细胞凋亡率显著提高（P＜0．05），Cav-1 mRNA和蛋白质表达水平均明显下降。结论：β-胡萝卜素能够有效促进食管癌细胞凋亡，而对正常食管上皮细胞无毒性作用，且食管癌细胞对β-胡萝卜素的敏感性可能受到Cav-1的调节。