Wang X W, Xu Y H
Chongqing Medical University, Chongqing, China.
Department of Hematology, Children's Hospital of Chongqing Medical University, Chongqing, China
Genet Mol Res. 2015 Jul 14;14(3):7883-93. doi: 10.4238/2015.July.14.14.
We investigated the expression differences of the TEL-AML1 fusion gene in a leukemia glucocorticoid (GC)-sensitive cell line (CEM) and a GC-resistant cell line (Jurkat). Changes in TEL-AML1 expression before and after GC exposure were analyzed. Expression of GC-sensitive and GC-resistant leukemia cells following initial diagnosis and during treatment was simulated. Leukemia cells were divided into a GC-unexposed or a GC-exposed group. A methyl thiazolyl tetrazolium assay was used to detect cell proliferation inhibition, flow cytometry was used to observe cell apoptosis, reverse transcription-polymerase chain reaction was used to detect the mRNA expression of TEL-AML1 before and after exposure, and western blotting was used to analyze protein levels of TEL-AML1 before and after exposure. Inhibitory concentrations of 50% of cells in the Jurkat and CEM cells at 24 h were 382 and 9 mM, respectively, and at 48 h they were 216 and 2 mM. The proliferation inhibition effect of dexamethasone sodium phosphate on Jurkat cells was much lower than that on CEM cells. Jurkat cells showed obvious apoptosis after exposure to 100 mM dexamethasone sodium phosphate for 48 h. In the exposed group, Jurkat cells showed higher TEL-AML1 expression than did CEM cells (P < 0.05). In the unexposed group, TEL-AML1 gene expression in Jurkat cells was not affected by GC exposure (P > 0.05), while the CEM cells presented significant differences before and after exposure (P < 0.05). Sustained high expression of TEL-AML1 participated in and maintained the occurrence of GC resistance. Inhibition of TEL-AML1 may provide a new therapeutic approach to reverse GC resistance.
我们研究了TEL-AML1融合基因在白血病糖皮质激素（GC）敏感细胞系（CEM）和GC耐药细胞系（Jurkat）中的表达差异。分析了GC暴露前后TEL-AML1的表达变化。模拟了初诊和治疗期间GC敏感和GC耐药白血病细胞的表达情况。将白血病细胞分为未暴露于GC组和暴露于GC组。采用甲基噻唑基四氮唑蓝法检测细胞增殖抑制情况，流式细胞术观察细胞凋亡，逆转录-聚合酶链反应检测暴露前后TEL-AML1的mRNA表达，蛋白质印迹法分析暴露前后TEL-AML1的蛋白水平。Jurkat细胞和CEM细胞在24 h时50%细胞的抑制浓度分别为382和9 mM，48 h时分别为216和2 mM。地塞米松磷酸钠对Jurkat细胞的增殖抑制作用远低于对CEM细胞的作用。Jurkat细胞在暴露于100 mM地塞米松磷酸钠48 h后出现明显凋亡。在暴露组中，Jurkat细胞的TEL-AML1表达高于CEM细胞（P < 0.05）。在未暴露组中，Jurkat细胞的TEL-AML1基因表达不受GC暴露影响（P > 0.05），而CEM细胞在暴露前后存在显著差异（P < 0.05）。TEL-AML1的持续高表达参与并维持了GC耐药的发生。抑制TEL-AML1可能为逆转GC耐药提供一种新的治疗方法。
