γ射线诱导人肿瘤细胞B7.1分子表达的研究(英文)

STUDY OF B7.1 MOLECULE EXPRESSION IN HUMAN TUMOR CELLS AFTER γ RAYS IRRADIATION INDUCED

为研究电离辐射与人肿瘤细胞B7.1分子表达之间的关系 ,探讨肿瘤细胞在照射后免疫原性增强的机理。采用间接免疫荧光 流式细胞仪测定技术 ,用 30、4 0、5 0、6 0Gyγ射线照射 5种肿瘤细胞和一种非肿瘤细胞后 ,观察不同培养时间 (2 4、4 8、72、96h)内这些细胞B7.1分子的表达水平。用3H TdR释放试验测定肿瘤细胞和淋巴细胞共反应后细胞毒活性。结果表明 ,未经照射的肿瘤细胞不表达B7.1分子。经 4 0Gy照射后 ,SMMC 772 1肝癌细胞、PC 12嗜铬神经瘤细胞、A 5 49肺癌细胞表达B7.1共刺激分子 ,与对照组相比有非常显著性差异 ,但SHG胶质瘤细胞和HOS骨肉瘤细胞经 6 0Gy照射后仍未B7.1分子的表达。淋巴细胞与表达B7.1分子的肿瘤细胞共反应后细毒胞活性明显高于未照射组 p <0 .0 1)。实际提示 ,γ射线能诱导人肿瘤细胞表达B7.1分子 。

The relationships between irradiation and B7.1 costimulatory molecule expression of human tumor cells were studied to explore reason of tumor cell's immunogenicity enhanced.The effect of γ rays irradiation on B7.1 molecule expression in human tumor cells which was irradiated with 30,40,50,60Gy γ rays was investigated. At 24,48,72,96h after irradiation the change of B7.1 molecule was measured by flow cytometry (FCM) with immunofluorescence technique.B7.1m RNA was determined by reverse transcription polymerase chain reaction (RT PCR).The cytotoxicity of lymphocyte upon tumor target cell after exposure was measured by 3H thymidine( 3H TdR) release assay.The results showed that after γ rays irradiation SMMC 7721 hepatoma, PC 12 pheochromacytoma,A 459 lung cancer cell lines express B7.1 costimulatory molecule.RT PCR showed that expression of B7.1 molecule in SMMC 7721 is resulted from B7.1mRNA expression.Furthermore,B7.1 molecule membrane expression after γ rays irradiation is shown to enhance the cytotoxicity of lymphocyte.The data could explain the enhanced immunogenicity of tumor cells after irradiation, and could lead to new immunotherapy protocols. The experiments suggested that γ rays irradiation could selectively induce human tumor cells to express B7.1 costimulatory molecules and enhance immunogenicity of tumor cell.