两种慢性髓系白血病细胞株对干扰素-α的敏感性

背景和目的：临床研究表明干扰素-α(interferon-alpha,IFN-α)是造血系统恶性肿瘤和淋巴瘤的有效治疗剂之一。然而,IFN-α仅可使约70％～80％的慢性髓系白血病(chronic myeloid leukemia,CML)患者获得血液学缓解。不同的CML患者对IFN-α反应性不同的机制尚未阐明。本研究旨在比较两种CML细胞株KA-1／A3、K562对IFN-α的不同敏感性。方法：(1)采用MTT、半固体集落形成和台盼蓝染色液体培养细胞检测,不同浓度IFN-α(100、500、1000、5000和10000u／ml)对KT-1／A3及K562细胞生长的影响;(2)IFN-α(1000u／ml)诱导KT-1／A3、K562细胞48h后,采用流式细胞分析(flow cytometry,FCM)、荧光染色和DNA片段检测细胞凋亡;(3)加入IFN-α(1000u／m1)培养KT-1／A3、K562细胞48h后采用相对定量RT-PCR分析细胞bcr／abl基因表达水平。结果：(1)IFN-α呈剂量依赖性(从100u／ml到10000u／ml)抑制KT-1／A3细胞生长;(2)IFN-α(1000u／m1)诱导48h后使KT-1／A3细胞凋亡率从3．3％升到11．8％,并使KT-1／A3细胞中bcr／abl嵌合基因的表达水平降至对照组的66．7％;(3)IFN-α对K562细胞的生长、凋亡及bcr／abl嵌合基因表达无明显调节效应。结论：不同类型的CML细胞对IFN-α的反应性不同。

Different sensitivity of two chronic myeloid leukemia cell lines to interferon-alpha

BACKGROUND & OBJECTIVE: The clinical observation has shown that interferon-alpha(IFN-alpha) is one of the most effective therapeutic agents for the malignancies of hemopoietic system and lymphoma. However, IFN-alpha can only induce about 70-80% of the patients with chronic myeloid leukemia (CML) to get hematological remission. The mechanism by which various CML cases respond differently to IFN-alpha is still unclear. METHODS: (1)The effects of IFN-alpha in different concentrations (100, 500, 1,000, 5,000, and 10,000 U/ml) on growth of the two CML cell lines were detected by MTT assay,semisolid colony formation and trypan-blue staining for the cells in liquid culture. (2)The cell apoptosis was examined by flow cytometry(FCM),fluorescence microscopy and gel electrophoresis analysis for DNA fragmentation in 48 hours after IFN-alpha (1,000 U/ml) induction of both KT-1/A3 and K562 cells. (3)The expression levels of bcr/abl chimeric genes were analyzed by relative quantitative RT-PCR at 48 hours after cultivation of both KT-1/A3 and K562 cells with IFN-alpha in 1,000 U/ml. RESULTS: (1)The growth inhibition of KT-1/A3 cells was dose-dependent in IFN-alpha from the concentration of 100 U/ml to 10,000 U/ml. (2)Having been induced with IFN-alpha in 1000 U/ml for 48 hours, the apoptosis rate of KT-1/A3 cells raised from 3.29% to 11.8% and the expression level of bcr/abl chimeric gene in this cell line declined to 66.7% as compared with those of the control. (3)The growth and apoptosis rate as well as bcr/abl gene expression level of K562 cells were not significantly affected by IFN-alpha. CONCLUSION: Different populations of CML cells shows different sensitivity to IFN-alpha.