Objective: To explore the role of receptors of the Wnt signaling pathway ( Frizzled/LRP and ROR2 ) in the pathogenesis of leukemia.Methods: Subgrouping of the experiment groups were as follows: Experiment Group 1, bone marrow with acute lymphocyte leukemia ( ALL ); Control Group 1, bone marrow with idiopathic thrombocytopenic purpura ( ITP ); Experiment Group 2: Jurkat, K562, and HL-60 cell lines treated with LiCl; and Control Group 2: Jurkat, K562, and HL-60 cell lines.The expression of the Frizzled-5 and ROR2 receptors in the leukemia cells were detected by reverse transcriptase polymerase chain reaction and Western blot analysis.An MTT assay was used to determine cell proliferation, whereas flow cytometry was used to measure the cell cycle.Results: Fz-2, LRP-6, and ROR2 were expressed in all of the leukemia cells.ROR2 expression was lower in the HL-60 cells than in other leukemia cells.There were no differences in expression with the receptors in other groups.For the 11 ITP bone marrow preparations, ROR2 expression was only seen in 2 of the preparations.No significant differences were found in Fz receptor expression between the ITP and leukemia cells.After the LiCl treatment of the cells, ROR2 expression was obviously lower in the Jurkat cells than in the untreated leukemia cells, whereas no significant differences were found in the expression of the other receptors.The results of the repeated MTT assay showed that LiCl inhibited the proliferation of the three leukemia cell lines in a dose-dependent manner.Comparison of the cell cycles of the Jurkat and HL-60 cells with the normal controls after treatment with LiCl revealed that the proportion of Dip G1 and Dip Sdecreased and that of G2 increased, with a G2/M block.There were statistically significant differences between the groups ( P ＜ 0.05 ).There were no significant differences in the cell cycle of the K562 cells between the groups treated with varying concentrations.Conclusion: ROR2 expression is higher in ALL cells than in ITP cells.LiCl might affect ROR2 expression in Jurkat cells, and inhibit cell proliferation of leukemic cells, which may suggest that ROR2 is related to the pathogenesis of ALL.%目的:探讨WNT信号通路中卷曲蛋白-低密度脂蛋白相关蛋白复合受体(Frizzled/LRP)、酪氨酸激酶样孤独受体-2(ROR2)在淋巴细胞白血病发生发展中的作用.方法:实验分组:1)实验组1:急性淋巴细胞白血病骨髓(ALL);2)对照组1:特发性血小板减少性紫癜骨髓(ITP);3)实验组2:氯化锂作用后的Jurkat、K562和HL-60细胞株;4)对照组2:Jurkat、K562和HL-60细胞株.以RT-PCR方法从mRNA水平检测Frizzled/LRP(FZD/LRP)受体、ROR2受体的表达;以Western blot方法从蛋白水平检测FZD-5和ROR2的表达;通过MTT法检测细胞增殖情况;通过流式细胞仪检测细胞周期.结果:所有白血病细胞中均可见FZD-2、LRP-6和ROR2的表达,ROR2在HL-60细胞中的表达明显低于其他白血病细胞,其他各组受体表达水平未见差异;11例ITP骨髓标本中2例标本可见ROR2表达,FZD受体的表达与白血病细胞无显著性差异.氯化锂处理后,ROR2在Jurkat细胞中的表达明显减少,其他受体的表达未见显著性差异.重复MTT试验结果显示:不同浓度(5、10、20 mmol/L)氯化锂(LiCl)对各组细胞均有增殖抑制作用,在一定范围内呈剂量依赖性.氯化锂处理后,Jurkat和HL-60细胞周期与正常组相比G1期和S期比例减少,G2期增高,发生G2/M期阻滞,差异有统计学意义(P＜0.05).不同浓度组K562的细胞周期未见明显差异.结论:ROR2在急性淋巴细胞白血病骨髓中的表达较其在ITP骨髓中的表达高,在Jurkat细胞株中有高表达,氯化锂作用后的Jurkat细胞中ROR2的表达明显减低,细胞增殖受抑制,提示ROR2可能与淋巴细胞白血病的发生有关.
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