血液系统肿瘤细胞系中CD34^+干细胞特性研究

IDENTIFICATION AND CHARACTERIZATION OF CD34^+ STEM CELLS OF HEMATOPOIETIC TUMOR CELL LINES

目的探讨造血系统多种肿瘤细胞系中CD34+干细胞是否存在,并对其性质进行研究。方法利用流式细胞检测技术,检测了急性单核细胞白血病细胞THP_1、红白血病细胞MEL、慢性粒细胞白血病细胞K562,急性淋巴细胞白血病细胞MOLT_4,恶性淋巴瘤细胞RAJI,多发性骨髓瘤细胞RPMI8226、SP2/0和树突状细胞肉瘤DCS肿瘤细胞中CD34+的肿瘤细胞所占的比例。选取了MOLT_4和K562细胞系,分选出CD34+细胞,继续培养,观察CD34+细胞比例变化;比较CD34+与CD34-肿瘤细胞在功能状态、细胞周期、分化状态、耐药性的差异。结果8种不同类型造血系统肿瘤细胞中CD34阳性率依次为2·5%、5·2%、3·1%、2·1%、1·4%、0、0和6·2%。从K562细胞中分选出CD34+细胞,继续培养后恢复为原来比例。MOLT_4和K562细胞系中分离出的CD34+细胞RNA含量低、细胞处于G0/G1期的比率较高(81·5%和77·9%)、分化抑制蛋白Id_1表达强阳性/阳性(分化程度低)、多耐药蛋白p_gp高表达(耐药性强)。结论血液系统肿瘤细胞系中有一小部分肿瘤细胞带正常造血干细胞的标记,并且带有这种标记的细胞表现出更为原始的细胞特性,其中包括血液肿瘤细胞干细胞。

Objective To identify and characterize the CD34^＋ stem cells of hematopoietic tumor cell lines. Methods Taking CD34 molecule as a marker to identify if there are CD34^＋ tumor cells in hematopoietic tumor cell lines（THP-1, MEL, K562, MOLT-4, RAJI, RPMI8226 ,SP2/0 and DCS） by fluorescence staining and FCM technology. We separated CD34^＋ cells from K562 and MOLT-4 for further study. CD34^＋ cells were cultured and observed their development. CD34^＋ and CD34^＋ cells were compared in their functional status（mRNA） ,cell cycles（G0/G1 ）, their degree of differentiation（Id-1 expression） and their multidrug resistance（gp expression）. Results The percentages of CD34^＋ cells were 6.2% （DCS）,5.2% （ MEL）, 1.4% （ RAJI）, 2.5 % （ THP- 1 ）, 2.1% （ MOLT-4 ）, 3.1% （ K562 ）, 0 （ SP2/0 ） , and 0 （RPMI8226） respectively. After culturing CD34^＋ cells isolated from K562 cells line could proliferate and the percentage of CD34^＋ reminded the same. CD34^＋ tumor cells contained much less RNA,more G0/G1 cells, expressed more Id-1 protein（less differentiated state） and possessed more P-gp（stronger multi-drug resistance） .Conclusion There exists a very small portion of CD34^＋ stem cells among hematopoletic tumor cells and these cells are in a more primitive state.