X线照射对大肠癌细胞株Lovo细胞膜TNFR—p75表达的研究

目的研究X线照射在体外培养人大肠癌细胞株Lovo后，其膜TNFR-p75表达情况。方法免疫细胞化学检测TNFR-p75蛋白的表达，流式细胞仪分析细胞凋亡率，光镜及透射电镜观察细胞形态变化。结果X线照射后的TNFR—p75蛋白表达显著增强（P〈0．01）；光镜及电镜发现细胞体积缩小，变圆，核缩小，染色质凝集，染色质呈颗粒、块状均质无结构样物质，细胞间散在膜包裹的凋亡小体；流式细胞仪分析细胞凋亡率显著增高（P〈0．05）。结论X线可通过上调TNFR—p75蛋白的表达抑制其脱落，诱导细胞凋亡增强照射肿瘤的杀伤作用。

Effect of X-ray Radiation on Expression and Shedding of Tumor Necrosis Factor Receptor-p75 in Human Colorectal Cancer Cell Lovo in Vitro

Objective To investigate the effects of X-ray on the expression of tumor necrosis factor receptor-p75 （TNFR-p75） in human colorectal cancer in vitro. Methods The protein expression of TNFR-p75 was detected by immunohistochemical technique. Distribution of apoptotic cell death was analysed by flow cytomctry. Morphological changes were studied by light or electron microscope. Results X-ray treatment of ceils resulted in strong increases in the expression of TNFR-p75 （P 〈0.01 ） and in the apoptotic cell death （P 〈 0.05）. The morphological changes of Lovo cells which treated with Silibinin were observed by light or electron microscope, i.e. the cells shrank and turned to round, cytoplasm condensed and nuclei pycnosed. Conclusion X-ray treatment induces Lovo cell apoptosis through increasing the expression of TNFR-p75 on it.