DLK1在急性白血病中的表达及其在K562细胞红系分化中的作用

目的:探讨急性白血病(acute leukemia,AL)患者骨髓单个核细胞DLK1基因的表达水平及其在K562细胞红系分化中的作用.方法:采用RT-PCR对65例AL患者及34例正常骨髓对照进行DLK1mRNA水平的检测,对其中20例AL患者及13例正常骨髓用Western 印迹法检测DLK1蛋白表达水平.培养K562细胞,用氯化高铁血红素(hemin)诱导其分化,观察DLK1在红系分化中的变化.结果:在AL患者和正常骨髓对照的骨髓单个核细胞中DLK1基因均存在明确表达.DLK1mRNA的表达水平AL组高于对照组,差异有统计学意义(P=0.018),但在ALL和ANLL之间DLK1mRNA的表达差异无统计学意义(P>0.05),且DLK1mRNA的表达水平与患者初诊时骨髓原始细胞数、外周血白细胞数及血小板数无关.对部分样品检测DLK1蛋白的表达,发现AL患者DLK1蛋白阳性表达率高于对照组,与mRNA表达趋势一致.在hemin诱导K562细胞向红系分化过程中,DLK1mRNA的表达水平逐渐下降.结论:DLK1基因可能参与了AL的发病过程,但DLK1mRNA的表达水平与AL患者某些临床特征无相关性.DLK1基因可能抑制K562细胞向红系分化.

Expression of DLK1 gene in acute leukemias and its function in erythroid differentiation of K562 cell line

ObjectiveTo determine the expression of DLK1 gene in acute leukemias (AL) and its function in erythroid differentiation of K562 cells. MethodsWe detected the expression of DLK1 gene in 65 different acute leukemia categories (a test group) and 34 normal bone marrow controls (a control group) with RT-PCR. DLK1 protein in 20 out of the 65 AL patients and 13 of the 34 controls was assayed by Western blot. The K562 cell line was induced to erythroid differentiation by hemin. We observed the relationship between its expression and erythroid differentiation.ResultsBoth leukemia cells and normal marrow cells expressed DLK1. The expression of DLK1mRNA in patients in the test group was higher than that in the control group (P=0.018), while there was no significance between acute lymphoblastic leukemia and acute myelogenous leukemia （P&;gt;0.05).The expression of DLK1 mRNA in the test group at onset had no relation with the WBC and platelet count in the total peripheral blood, and the same was true for blast cell rates in bone marrow cells.The level of DLK1 protein in the test group was higher than that in the control group, which was consistent with the mRNA expression (P=0.042). The expression of DLK1 mRNA decreased gradually with K562 cells towards hemin-induced erythroid differentiation.ConclusionDLK1 gene may be involved in leukemia,but the mRNA level of DLK1 has no relation with some clinical characteristics of AL patients at onset. DLK1 may inhibit the erythroid differentiation of K562 cells.