RESUMO
<p><b>OBJECTIVE</b>To investigate the effects of human umbilical cord blood-derived mesenchymal stem cells(HUCMSC) on the leukemic cell line HL-60 and acute lymphoblastic leukemia cell line Jurkat as well as the role of CXCL12/CXCR4.</p><p><b>METHODS</b>HL-60 cells and Jurkat cells were co-cultured with human umbilical cord blood mesenchymal stem cell (HUCMSC), and the model was treated with G-CSF, AMD3100 and their combination. The cell viability and cell cycle were measured by Cell Counting Kit-8 (CCK-8), the apoptosis and the cell-cycle analysis were assessed by flow cytometry with the Annexin V/PI double staining. The expression of surface CXCR4 protein and total CXCR4 protein of leukemic cells were detected by flow cytometry and Western blot respectively.</p><p><b>RESULTS</b>HUCMSC could decrease the viability of HL-60 cells and Jurkat cells, as well as the percentage of apoptotic cells, they could also increase the number of G/Gcells, while G-CSF and AMD3100 could reduce the proliferation of HL-60 cells and Jurkat cells in HUCMSC co-culture model, destructed the anti-apoptotic effect of HUCMSC on HL-60 cells and Jurkat cells, and the combination of 2 drugs resulted in a synergistic effect. The G-CSF could reduce the expression of surface CXCR4 protein and total CXCR4 protein in leukemic cells, while AMD3100 could only decrease the expression of surface CXCR4 protein of leukemia cell membrane, having no effect on the expression of CXCR4 protein in cytoplasm.</p><p><b>CONCLUSION</b>Human umbilical cord blood mesenchymal stem cells can inhibit the proliferation and apoptosis of acute leukemia cells and increase the number of G/Gphase cells in leukemic cells. The AMD3100 can decrease the expression of surface CXCR4 protein in leukemia cells, G-CSF can decrease expression of total CXCR4 protein as well as membrane CXCR4 protein. Both of them can block the CXCL12/CXCR4 signal axis, weakening the relationship between leukemia cells and microenvironment. And on the basic of HUCMSC influenced leukemia cells' growth and proliferation, the cell viability will be weakened, its apoptosis will be promoted, and the percentage of G/Gphase cells in leukemia cells will be decreased.</p>
RESUMO
<p><b>OBJECTIVE</b>To investigate HOXB4, PRDM16 and HOXA9 gene expression in patients with acute myeloid leukemia (AML) and its clinical significance.</p><p><b>METHODS</b>Real-time quantitative PCR (RT-qPCR) with SYBR Green assay was used to detect the expression of HOXB4, PRDM16 and HOXA9 gene in AML patients (40 cases), the patients with complete remission (9 cases) and patients with non-malignant hematologic diseases as control (10 cases). The relationship between the expression levels of gene HOXB4, PRDM16, HOXA9 and clinical features was investigated by statistical analysis.</p><p><b>RESULTS</b>The gene expression levels of HOXB4, PRDM16, HOXA9 in newly diagnosed or relapsed AML patients were significantly higher than those in patients with non-malignant hematologic disease (P < 0.05). It was observed that the expression of HOXB4 gene in newly diagnosed or relapsed patients positively correlates with leukemic blasts in bone marrow (r = 0.39). The expression levels of HOXB4, PRDM16 and HOXA9 positively correlate with each other. There was statistical significance among gene expressions in different phases (newly diagnosed, relapse, remission). No correlation was observed between expression levels of HOXB4, PRDM16, HOXA9 and chromosome risk status. It was noticed that expression levels of HOXB4, PRDM16, HOXA9 genes were lower in the patients achieved remission after two courses of chemotherapy than those in the other. And high expression group of each gene had a lower remission rate than that in the low expression group.</p><p><b>CONCLUSION</b>The expression level of HOXB4, PRDM16, HOXA9 genes and leukemic blasts somewhat correlate with curative effect and prognosis. The expression of HOXB4, PRDM16, HOXA9 genes is higher in newly diagnosed and relapsed leukemia patients, and lower in the patients acquired CR/PR. High expression of HOXB4, PRDM16, HOXA9 genes predicts an adverse prognosis.</p>