[Expression of 5 genes in CD7 positive acute myeloid leukemia stem/progenitor cells from bone marrow]

This study was aimed to investigate abca5, mdr-1, kdr, dapk and irf-1 expressions in leukemia stem/progenitor cells (LSC) from CD7 positive acute myeloid leukemia, the expression of these 5 genes in mononuclear cells (MNC) from 15 normal bone marrow (NBM) and 16 AML patients bone marrow (AML BM) specimen were detected by real-time quantitative PCR (RQ-PCR). CD34(+)CD38(+) progenitor cells and CD34(+)CD38(-)Lin(-) stem cells were sorted by flow cytometry (FCM) from the MNCs of 10 NBM and 21 AML BM specimen. These 5 gene expressions in the sorted cells were detected by small amount cell RQ-PCR. The results showed that these 5 genes above mentioned all expressed in NBM-MNC, in which the expression levels of irf-1 and dapk were highest with the relative expression levels 4.08 and 3.86, the expression levels of abca 5 and mdr-1 were in the middle with the relative expression 0.49 and 0.84 respectively, the kdr expression was lowest with the relative expression level 0.02. In CD34(+)CD38(+) progenitor cells, the expression level of kdr increased dramatically (p < 0.05) while irf-1 and dapk dramatically decreased (p < 0.05). There was no obvious change of expression in the rest 2 genes. In CD34(+)CD38(-) stem cells the expression level of these 5 genes all increased nearly 2 times as much as that in CD34(+)CD38(+) progenitor cells, but kdr increased 3 times as much, and the increase of kdr and irf-1 expressions was of statistical significance (p < 0.05). Compared with the NBM, expression levels of 5 genes in AML-MNC decreased, and out of them abca 5, mdr-1, kdr and dapk were decreased most remarkably (p < 0.05). Comparison between AML CD34(+)CD38(+) cells and AML MNC showed that the expression level of irf-1 and dapk were decreased dramatically (p < 0.05) while the rest 3 genes increased their expression with statistical significance (p < 0.05). The expression levels of these 5 genes were higher in CD34(+)CD38(-) cells than those in CD34(+)CD38(+) stem cells, and the increase of kdr and irf-1 expressions showed statistical difference (p < 0.05). These 5 genes expression levels were all higher than those in CD34(+)CD38(+) cells whether in AML CD34(+)CD38(-)CD7(+) cells or CD34(+)CD38(-)CD7(-) cells. The increase of kdr expression in CD34(+)CD38(-)CD7(+) cells as well as kdr and irf-1 expressions in CD34(+)CD38(-)CD7(-) cells were all of statistical significance (p < 0.05). In conclusion the expression level of kdr in NBM was highest in stem cells while dapk and irf-1 were highest in differentiated cells. The expression levels of these 5 genes in CD34(+)CD38(-)Lin(-) stem cells were higher than those in CD34(+)CD38(+) progenitor cells. The gene expressions in AML CD34(+)CD38(-)CD7(+) cells and CD34(+)CD38(-)CD7(-) cells are in accordance with the characteristics of stem cells.