Shen Sylvie W, Dolnikov Alla, Passioura Toby, Millington Michelle, Wotherspoon Simon, Rice Alison, MacKenzie Karen L, Symonds Geoff
Children's Cancer Institute Australia for Medical Research, Randwick, NSW, Australia.
Exp Hematol. 2004 Sep;32(9):852-60. doi: 10.1016/j.exphem.2004.06.001.
Ras oncogene mutations are the most frequently observed genetic abnormality (20-40% of patients) in acute myeloid leukemia (AML), and in the preleukemic conditions myelodysplastic syndrome (MDS) and myeloproliferative disorder (MPD). We have previously shown that mutant N-ras (N-rasm) can induce myeloproliferative disorders and apoptosis in a murine reconstitution system. In the present study we investigated the effect of N-rasm in human primary hematopoietic progenitor cells (HPC).
Cord blood CD34+ hematopoietic progenitor cells (HPC) were transduced with retroviral vectors containing green fluorescence protein (GFP) alone, or in combination with N-rasm. Cells were then cultured in vitro with a cytokine supplement or cocultured with murine stroma MS-5 cells. The in vivo behavior of transduced cells was examined in the NOD/SCID mouse model.
N-rasm-transduced cells exhibited greater proliferative capacity; a higher frequency of granulocyte-macrophage colony-forming unit (CFU-GM); and an increase in myelomonocytic lineage cells with a concomitant decrease in lymphoid and erythroid cells. Analysis of transduced HPC in NOD/SCID mice revealed higher bone marrow engraftment by N-rasm HPC and increased numbers of myeloid lineage cells.
The results demonstrate that N-rasm in HPC induces myeloproliferation both in vitro and in the NOD/SCID mouse model as a primary event that does not appear to be dependent on cooperating transforming events.
Ras癌基因突变是急性髓系白血病（AML）以及白血病前期疾病骨髓增生异常综合征（MDS）和骨髓增殖性疾病（MPD）中最常见的基因异常（20%-40%的患者）。我们之前已经表明，突变型N-ras（N-rasm）可在小鼠重建系统中诱导骨髓增殖性疾病和细胞凋亡。在本研究中，我们调查了N-rasm对人原代造血祖细胞（HPC）的影响。
用单独含有绿色荧光蛋白（GFP）或与N-rasm组合的逆转录病毒载体转导脐血CD34+造血祖细胞（HPC）。然后将细胞在含有细胞因子补充剂的体外培养，或与小鼠基质MS-5细胞共培养。在NOD/SCID小鼠模型中检查转导细胞的体内行为。
转导N-rasm的细胞表现出更强的增殖能力；粒细胞-巨噬细胞集落形成单位（CFU-GM）频率更高；髓单核细胞系细胞增加，同时淋巴细胞和红细胞减少。对NOD/SCID小鼠中转导的HPC分析显示，N-rasm HPC的骨髓植入率更高，髓系细胞数量增加。
结果表明，HPC中的N-rasm在体外和NOD/SCID小鼠模型中均诱导骨髓增殖，这是一个似乎不依赖于协同转化事件的主要事件。
