TPA诱导K562细胞分化过程中线粒体铁蛋白表达情况研究  

Expression of Mitochondrial Ferritin in K562 Leukemic Cell du-ring TPA-Induced Cell Differentiation

作　　者：孙蕾[1] 高举[1] 袁粒星[2] 陈婷婷[1] 潘玲丽[1] 周晨燕[1] 朱易萍[1] 

机构地区：[1]四川大学华西第二医院儿童血液科 [2]四川大学华西第二医院妇幼医学实验中心,成都610041

出　　处：《中国实验血液学杂志》2007年第2期272-277,共6页Journal of Experimental Hematology

基　　金：国家自然科学基金资助;编号30370601

摘　　要：为了研究K562白血病细胞在十四烷酰佛波醇-乙酯(TPA)诱导分化过程中线粒体铁蛋白(MtF)、运铁蛋白受体Ⅰ(TfR1)和铁蛋白(Fn)mRNA表达水平的变化情况,并探讨MtF在白血病细胞增殖和细胞铁代谢方面的作用,采用TPA(终浓度16nmol/L)诱导K562白血病细胞向单核细胞定向分化,并于诱导分化后第1、3和5天收集细胞,用瑞氏染色法观察各时点细胞形态,流式细胞术检测细胞表面分化抗原CD64的表达水平,使用半定量RT-PCR方法检测各时点细胞MtF、TfR1和Fn mRNA表达水平,管家基因β-actin用作对照。结果表明,TPA(16nmol/L)可诱导K562细胞向单核细胞分化,细胞呈现单核细胞典型的形态学特征,在诱导培养第5天诱导分化率可达95%,细胞表面CD64表达水平显著增加。诱导分化前K562细胞具有一定水平MtF表达,但随着TPA诱导细胞分化的增强,MtF和TfR1 mRNA表达水平进行性下调,诱导分化第5天的表达水平分别为诱导分化前的50.3%和68.2%,而Fn mRNA表达水平则逐渐上调,诱导分化第5天表达水平为诱导分化前的1.97倍。结论:TPA诱导K562细胞向单核细胞分化过程中MtF和TfR1 mRNA表达下调,而Fn mRNA表达上调;这种协调变化有助于降低细胞通过TfR1介导的铁摄取,从而抑制或影响细胞增殖能力。Mitochondrial ferritin （MtF）, a new player in iron metabolism, first identified in 2001, is highly homologous to ferritin both structurally and functionally. Preliminary studies have suggested that MtF might play very important roles in the regulation of mitochondrial iron homeostasis. Leukemic cells, just like other malignant cells, demand more iron for their greater proliferation potential. However, little is known about what roles MtF might play in leukemic cell iron metabolism and cell proliferation. The aim of this study was to investigate the expression of MtF, transferrin receptor 1 （TfR1） and ferritin （Fn） mRNAs in K562 leukemic cells during TPA-induced cell differentiation and to explore the interrelationship between the expression levels of these iron metabolism-related molecules. K562 cells cultured with or without TPA （16 nmol/L） were collected at 24, 72 and 120 hours respectively. Cell differentiation toward monocyte lineage was confirmed by microscopic study （Wright＇s staining） and flow cytometry. Semiquantitative RT-PCR was performed to determine mRNA expression, with house-keeping gene β-actin as control reference. This study revealed that over 95% of K562 cells showed morphological features of monocyte/macrophage, and the expression of CD64 on cell surface increased significantly at day 5 with TPA treatment. K562 cells could express a certain level of MtF before TPA-induced differentiation. With increase of TPA-induced cell differentiation, MtF mRNA expressions were downregulated progressively. After 5 days of induced cell differentiation, expression levels of MtF and TfR1 mRNA were just 50.3% and 68.2% of that before TPA treatment. While Fn mRNA expression increased to 1.97 folds of that before TPA treatment. It is concluded that MtF expression is downregulated during TPA-induced K562 cell differentiation, with concomitant downregulation of TfR1 and upregulation of Fn. The coordinated expression regulation of these key iron metabolism-related molecules during cell differen

关 键 词：TPA K562细胞 线粒体铁蛋白 运铁蛋白受体Ⅰ 铁蛋白 

分 类 号：R733.7[医药卫生—肿瘤]