In vitro activation of bone marrow natural killer T cells of aplastic anemia patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the quantitative and qualitative changes of TCRVα24(+)Vβ11(+) natural killer T (NKT) cells from bone marrow (BM) of aplastic anemia (AA) after in vitro stimulation of α-galactosylceramide (α-Galcer).</p><p><b>METHODS</b>NKT cells in the bone marrow mononuclear cells (BMMNCs) from either AA patients or healthy controls were enumerated with flow cytometry. BMMNCs were cultured in RPMI1640 medium supplemented with either α-Galcer and rhIL-2 or α-Galcer, rhIL-2 and rhG-CSF. The proliferative capacity of NKT cells was determined by NKT cell numbers before and after in vitro culture. Expression of intracellular IFNγ and IL-4 in activated NKT cells was analyzed with flow cytometry.</p><p><b>RESULTS</b>In AA group, the percentage of NKT cells in BMMNCs was (0.19 ± 0.09)%. Addition of rhG-CSF into the α-Galcer/rhIL-2 culture medium resulted in significantly reduced expansion of NKT cells (67.45 ± 29.42-fold vs 79.91 ± 40.56 fold, P < 0.05). Meanwhile, addition of rhG-CSF reduced IFNγ positive NKT cells \[(37.45 ± 7.89)% vs (62.31 ± 14.67)%, P < 0.01\] and increased IL-4 positive NKT cells \[(55.11 ± 12.13)% vs (27.03 ± 9.88)%, P < 0.01\]. In healthy control group, the percentage of NKT cells in BMMNCs was (0.25 ± 0.12)%. Addition of rhG-CSF into the α-Galcer/rhIL-2 culture medium also significantly reduced expansion of NKT cells (97.91 ± 53.22-fold vs 119.58 ± 60.49-fold, P < 0.05), reduced IFNγ positive NKT cells \[(28.65 ± 10.63)% vs (50.87 ± 12.66)%, P < 0.01\], and increased IL-4 positive NKT cells \[(66.53 ± 14.96)% vs (31.11 ± 10.07)%, P < 0.01\].</p><p><b>CONCLUSION</b>Compared to those from healthy controls, BMMNCs from AA patiants have a reduced fraction of NKT cells, which possesses a decreased potential to expand in vitro in response to α-Galcer stimulation, and produce more IFNγ(+) NKT1 cells. rhG-CSF, in combination with α-Galcer, confers polarization of NKT cells towards IL-4(+) NKT2 subpopulation.</p>

Changes of gene expression profile in homoharringtonine-induced leukemia multi-drug resistant cell line K562/HHT / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the resistant related molecules of human leukemia drug resistant K562 cells (K562/HHT) induced by homoharringtonine (HHT).</p><p><b>METHODS</b>Gene expression profiles on K562/HHT, K562 and K562/HHT/RU486 (K562/HHT reversed by RU486) cells were detected by DNA microarray. The bone marrow tyrosine kinase gene in chromosome X (BMX) which changed dynamically among the three cells was confirmed by RT-PCR and Western blot. Then, BMX was transfected into K562 and K562/HHT cells, and the changes of daunorubicin (DNR) concentrations in these two cells were observed for BMX overexpression.</p><p><b>RESULTS</b>As compared with K562, there were changes in 117 gene expressions in K562/HHT, 57 of which were up-regulated and 60 down-regulated. The mdrl gene was significantly up-regulated. When compared with K562/HHT, 50 significantly differently expressed genes were screened out in the K562/HHT/RU486 cells, of which up- and down-regulated genes were 13 and 37 respectively. These genes involved in drug resistance, cell signaling, cell differentiation, cell proliferation, transcription regulator, ion transport and so on. Four genes [NM-001721 (BMX), NM-031459 (SESN2), NM-033642 (FGF13) and AL-049309 (SFRS12)] expressed significantly differently in the two group cells, BMX gene expression was higher in K562/HHT, than in K562, but lower than in K562/HHT/RU486 as confirmed by RT-PCR and Western blot. After the plasmid pCI-neo-BMX was transfected into K562 and K562/HHT cells, DNR concentration was significantly lower (79.28 +/- 4.04, 29.84 +/- 2.67) than those before transfection (158.52 +/- 8.08, 58.58 +/- 6.53).</p><p><b>CONCLUSION</b>BMX is associated with multi-drug resistance of K562/HHT cell line.</p>

Study of mifepristone on reversing multidrug resistance of leukemic cell line K562/A02 / 中华血液学杂志

<p><b>OBJECTIVE</b>To study whether progestogen antagonist mifepristone could reverse multidrug resistance of K562/A02 cells and its mechanisms.</p><p><b>METHODS</b>MTT was used to study the proliferation of K562/A02 cells and sensitivity of K562/A02 cells to ADM after 72 hours treatment with mifepristone. Flow cytometry was used to assay the expression of P-glycoprotein and the mean fluorescent intensity of intracellular daunorubicin. The expressions of apoptosis related proteins (bcl-2, Bax and caspase-3) were assayed by immunohistochemistry and the glucosylceramide synthase mRNA expression by RT-PCR before and after mifepristone treatment.</p><p><b>RESULTS</b>MTT assay revealed that 2.5, 5.0 and 10 micromol/L mifepristone did not affect the proliferation of K562/A02 cells, but enhanced the sensitivity of K562/A02 cells to ADM, by 1. 68-, 4.17- and 10.71- fold increase, respectively. Expression of P-gp in K562/A02 cells was (49.03 +/- 5.32)%, and was decreased to (28.60 +/- 2.13)% (P < 0.01) after 10 micromol/L mifepristone treatment for 72 hours. and intracellular DNR accumulation in K562/A02 was (61.07 +/- 8.61)%, and was increased to (92.72 +/- 3.48)% (P < 0.01). After 10 micromol/L mifepristone treatment, the expression of bcl-2 protein was decreased from (56 +/- 9)% to (37 +/- 6)% (P < 0.05), Bax and caspase-3 proteins was increased from (40 +/- 5)% to (87 +/- 10)% (P < 0.01), and from (36 +/- 7)% to (89 +/- 6)% (P < 0.01) respectively. RT-PCR analysis revealed that expression of glucosylceramide synthase mRNA was higher in K562/A02 than in K562 cells, whereas 10 micromol/L mifepristone significantly down-regulated its expression in K562/A02 cells.</p><p><b>CONCLUSION</b>Mifepristone at 10 micromol/L could dose-dependently reverse the multidrug resistance of K562/A02 cells. The possible mechanisms are related with decreasing the expression of P-gp, regulating the expression of apoptosis related proteins and decreasing the expression of glucosylceramide synthase.</p>

Improvement effect of bacterium derived oligonucleotides on maturation of K562/A02 cells derived dendritic cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the maturation effect of CpG2006 and phosphodiester oligonucleotides on leukemia-derived dendritic cells.</p><p><b>METHODS</b>Leukemia cells K562/A02 were induced into dendritic cells by rhGM-CSF and rhIL-4. After 7 days induction, the cell-morphology was observed, the immunophenotype of cells was detected by flow cytometry and the cell function was evaluated by allogeneic mixed lymphocyte reactions, CTL responses and secretion of IL-12 and IL-6. Then a CpG oligonucleotide CpG2006, two synthetic bacterial phosphodiester oligonucleotides A-ODN and T-ODN were added to these leukemia-derived DCs. Three days later, the DCs were re-detected by the above-mentioned methods.</p><p><b>RESULTS</b>After induced by CpG2006, A-ODN or T-ODN, the leukemia-derived DCs with typical dendritic morphology were increased. The expressions of CD83, HLA-DR and CD86 were (65.5 +/- 8.4)%, (32.0 +/- 4.3)% and (18.6 +/- 3.2)% respectively in day 7 leukemia-derived DCs, raised to (88.9 +/- 3.6)%, (53.9 +/- 3.2)% and (39.9 +/- 7.3)% respectively after exposing CpG2006 for 3 days; increased to (97.0 +/- 5.3)%, (63.9 +/- 7.3)% and (40.2 +/- 7.4)% respectively after treated by A-ODN; and further increased to (93.26 +/- 4.65)%, (58.3 +/- 5.6)% and (36.2 +/- 6.8)% respectively after treated by T-ODN. These results was markedly different than unaffected cells did. These DCs induced by the above-mentioned three oligonucleotides could upregulate significantly the capacity for stimulating allogeneic T cells. They could also induce CTL to generate specific cytotoxic activity against K562/A02 cells. The secretion of IL-6 and IL-12 was increased remarkably.</p><p><b>CONCLUSION</b>CpG2006, as well as two phosphodiester oligonucleotides can induce leukemia-derived DCs maturation.</p>