肺癌膜蛋白识别分子诱导肺癌细胞凋亡的机制

目的:探讨肺癌患者血清中癌抗原识别分子及其抗肿瘤机制。方法:免疫亲合层析法分离纯化肺癌患者外周血中肺癌膜蛋白识别分子,SDS-PAGE电泳法分析其相对分子质量。MTT法测定细胞增殖情况;Annexin V/PI双标法检测细胞凋亡率,并通过流式细胞仪检测p53、Bcl-2蛋白表达水平。结果:肺癌患者外周血中存在肺癌膜蛋白识别分子,相对分子质量分别约为70×103、66×103和15.2×103。不同浓度膜蛋白识别分子(10、20和40mg/L)具有抑制肺癌细胞株(GLC-82)生长和促进细胞凋亡作用。肺癌细胞株与肺癌膜蛋白识别分子共培养6h后,Bcl-2蛋白表达水平明显降低,P=0.008;而p53水平明显增加,P=0.000。结论:肺癌患者外周血中存在肺癌膜蛋白识别分子,并具有抑制肺癌细胞增殖和促进凋亡作用,其机制与p53和Bcl-2表达改变有关。

Study of mechanisms on a kind of molecules recognizing lung cancer membrane in inducing GLC-82 cells apoptosis

OBJECTIVE:To study the mechanism of molecules recognizing tumor-antigen against cancer in the serum of lung cancer patients. METHODS: The molecules, which could recognize membrane proteins of lung cancer tissues, were separated by immune affinity chromatography, and then purified and analyzed by SDS-PAGE. The proliferation changes in GLC-82 cells were analyzed by MTT chronometry. The flow cytometry was used to detect apoptosis, and analyze the changes of expressions of p53 and Bcl-2 proteins in GLC-82 cells. RESULTS: The molecules, which could recognize membrane proteins of lung cancer tissues, were separated and purified with the molecular weight of 70 000, 66 000 and 15 200. Those markedly inhibited cell proliferation and viability, and prompted apoptosis in GLC-82 cells at 10, 20 and 40 mg/L. The mean fluorescent intensity of expression of Bcl-2 protein (P=0.008) in GLC-82 cells significantly decreased, however, of p53 proteins significantly increased at 6 h after co-cultured with drug decreased, P=0.000. CONCLUSIONS: There are molecules, recognizing the membrane proteins of lung cancer tissues in the sera of lung cancer patients, which could inhibit GLC-82 cells proliferation and induce apoptosis. Its mechanism is related to the changes of expressions of p53 and Bcl-2.