两种慢性髓系白血病细胞株对干扰素-α的敏感性

Different Sensitivity of Two Chronic Myeloid Leukemia Cell Lines to Interferon-Alpha

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(chronicmyeloidleukemia,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(flowcytometry,FCM)、荧光染色和DNA片段检测细胞凋亡;(3)加入IFN-α(1000u/ml)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/ml)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。

BACKGROUND &OBJECTIVE: The clinical observation has shown that interferon alpha(IFN α) is one of the most effective therapeutic agents for the malignancies of hemopoietic system and lymphoma. However, IFN αcan 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 αis still unclear. METHODS:(1)The effects of IFN αin 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 electropho resis analysis for DNA fragmentation in 48 hours after IFN α(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 αin 1 000 U/ml. RESULTS:(1)The growth inhibition of KT 1/A3 cells was dose dependent in IFN αfrom the concentration of 100 U/ml to 10 000 U/ml. (2)Having been induced with IFN αin 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 α. CONCLUSION: Different populations of CML cells shows different sensitivity to IFN α.