X线照射对大肠癌细胞株Lovo细胞TNFR-p55表达及释放的影响

X-ray irradiation enhances tumor necrosis factor receptor p55 expression in human colorectal cancer cells and inhibits the release of its soluble form in vitro

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-p55表达及释放sTNFR-p55情况。方法免疫细胞化学检测细胞膜TNFR-p55蛋白的表达,ELISA法检测培养上清中sTNFR-p55水平,流式细胞仪分析细胞凋亡率,光镜观察细胞形态变化。结果X线照射后的细胞膜TNFR-p55蛋白表达显著增强(P<0.01);照射后大肠癌Lovo细胞上清sTNFRR-p55水平显著低于照射前sTNFRR-p55水平(P<0.01);光镜发现细胞体积缩小、变圆、胞浆浓缩、核固缩深染;流式细胞仪分析细胞凋亡率显著增高(P<0.05)。结论X线可通过上调细胞膜TNFR-p55蛋白的表达,抑制其脱落释放sTNFRR-p55到上清中,诱导细胞凋亡增强照射肿瘤的杀伤作用。

Objective To investigate the effects of X ray on human colorectal cancer cells for their tumor necrosis factor receptor-p55 （TNFR-p55） expression and release of soluble soluble TNFR-p55 （sTNFR-p55） in vitro. Methods The protein expression of TNFR-p55 in Lovo cells exposed to X ray was detected using immunohistochemistry, and enzyme-linked immunosorbent assay was used to examine the levels ofsTNFR-p55 in the supematants of the cell culture. The cell apoptosis of the exposed cells was analyzed with flow cytometry, and the changes in cell morphology were observed microscopically. Results X-ray exposure of cells resulted in a strong increase in TNFR-p55 expression of（P〈0.01） and LoVo cell apoptosis （P〈0.05）. The levels of sTNFR-p55 in the supematant of cells with X-ray exposure was significantly lowered in comparison with the levels before exposure （P〈0.01）. Optical microscopy showed that the exposed LoVo cells shrank and became spherical with cytoplasmic condensation and nuclear pyknosis. Conclusion X ray exposure can induce LoVo cell apoptosis by increasing TNFR-p55 expression on the cell membrane and inhibiting the release of sTNFR-p55 in the supematants.