Inhibitory effects of parthenolide on the activity of NF-κB in multiple myeloma via targeting TRAF6 / 华中科技大学学报（医学）（英德文版）

This study examined the mechanism of the inhibitory effect of parthenolide (PTL) on the activity of NF-κB in multiple myeloma (MM). Human multiple myeloma cell line RPMI 8226 cells were treated with or without different concentrations of PTL for various time periods, and then MTT assay was used to detect cell proliferation. Cell cycle and apoptosis were flow cytometrically detected. The level of protein ubiquitination was determined by using immunoprecipitation. Western blotting was employed to measure the level of total protein ubiquitination, the expression of IκB-α in cell plasma and the content of p65 in nucleus. The content of p65 in nucleus before and after PTL treatment was also examined with immunofluorescence. Exposure of RPMI 8226 cells to PTL attenuated the level of ubiquitinated Nemo, increased the expression of IκB-α and reduced the level of p65 in nucleus, finally leading to the decrease of the activity of NF-κB. PTL inhibited cell proliferation, induced apoptosis and blocked cell cycle. Furthermore, the levels of ubiquitinated tumor necrosis factor receptor-associated factor 6 (TRAF6) and total proteins were decreased after PTL treatment. By using Autodock software package, we predicted that PTL could bind to TRAF6 directly and tightly. Taken together, our findings suggest that PTL inhibits the activation of NF-κB signaling pathway via directly binding with TRAF6, thereby suppressing MM cell proliferation and inducing apoptosis.

Inhibitory effects of parthenolide on the activity of NF-κB in multiple myeloma via targeting TRAF6 / 华中科技大学学报（医学）（英德文版）

This study examined the mechanism of the inhibitory effect of parthenolide (PTL) on the activity of NF-κB in multiple myeloma (MM). Human multiple myeloma cell line RPMI 8226 cells were treated with or without different concentrations of PTL for various time periods, and then MTT assay was used to detect cell proliferation. Cell cycle and apoptosis were flow cytometrically detected. The level of protein ubiquitination was determined by using immunoprecipitation. Western blotting was employed to measure the level of total protein ubiquitination, the expression of IκB-α in cell plasma and the content of p65 in nucleus. The content of p65 in nucleus before and after PTL treatment was also examined with immunofluorescence. Exposure of RPMI 8226 cells to PTL attenuated the level of ubiquitinated Nemo, increased the expression of IκB-α and reduced the level of p65 in nucleus, finally leading to the decrease of the activity of NF-κB. PTL inhibited cell proliferation, induced apoptosis and blocked cell cycle. Furthermore, the levels of ubiquitinated tumor necrosis factor receptor-associated factor 6 (TRAF6) and total proteins were decreased after PTL treatment. By using Autodock software package, we predicted that PTL could bind to TRAF6 directly and tightly. Taken together, our findings suggest that PTL inhibits the activation of NF-κB signaling pathway via directly binding with TRAF6, thereby suppressing MM cell proliferation and inducing apoptosis.

siRNA-induced down-regulation of Livin expression increases spontaneous apoptosis in K562 cell line / 中国实验血液学杂志

This study was aimed to observe the effects of siRNA on Livin expression and function in K562 cells. Livin siRNA were designed and synthesized, then were transfected into K562 cells by using AMAXA nucle transfactor. Expressions of Livin mRNA and protein in transfected K562 cells was detected by RT-PCR and Western blot respectively. Non-transfected cells were used as control. The enhanced green fluorescent protein plasmid was used as positive control and the transfection efficiency was detected by flow cytometry. Cell apoptosis was measured by flow cytometry with Annexin V-FITC/PI double staining. The results showed that the transfection efficiency of electroporation method was about 50. The synthesized siRNA inhibited livin expression at both mRNA and protein levels. The rate of K562 cell apoptosis increased from (9.63 ± 0.89) in control group to (12.07 ± 1.39) and (27.41 ± 2.30) at 24 h and 48 h after transfection, respectively (P < 0.05). It is concluded that the siRNA can inhibit anti-apoptosis of livin gene via down-regulating livin gene expression, which may provide the new method for anti-leukemia study.

Fludarabine and cytarabine combined chemotherapy followed by transfusion of donor blood stem cells for treating relapse of acute leukaemia after allogeneic haematopoietic stem cell transplantation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Relapse remains an obstacle to successful allogeneic haematopoietic stem cell transplantation (allo-HSCT) for patients with acute leukaemia and no standard treatment is available. We assessed fludarabine and cytarabine with transfusion of donor haematopoietic stem cell in treating the relapse of acute leukaemia after allo-HSCT.</p><p><b>METHODS</b>Seven patients, median age 34 years, with relapse of acute leukaemia after allo-HSCT received combination chemotherapy of fludarabine with cytarabine for 5 days. Five patients suffered from acute myeloid leukaemia (2 refractory) and 2 refractory acute lymphoblastic leukaemia. After the transplantation, the median relapse time was 110 days (range, 38 - 185 days). Two days after chemotherapy, 5 patients received infusion of donor's peripheral blood stem cells, mobilized by granulocyte colony stimulating factor. No prophylactic agents of graft versus host diseases were administered.</p><p><b>RESULTS</b>Six patients achieved haematopoietic reconstitution. DNA sequence analysis at day 30 after treatment identified all as full donor chimera type. The median observation time was 189 days. After the treatment, the median time for neutrophilic granulocyte value = 0.5 x 10(9)/L and for platelet value = 20 x 10(9)/L were 13 days (range, 10 - 18 days) and 15 days (range, 11 - 24 days), respectively. Graft versus host disease occurred in 2 patients (acute) and 3 (chronic). Five patients suffered from pulmonary fungal infection (2 died), 3 haemorrhagic cystitis and 2 cytomegalovirus viraemia. The other patients died of leukaemia related deaths. Three patients with chronic graft versus host disease who had received donor peripheral blood stem cells reinfusion have survived for 375 days, 232 days and 195 days, respectively.</p><p><b>CONCLUSIONS</b>Fludarabine with cytarabine plus the donor haematopoietic stem cell should be considered as an effective therapeutic regimen for relapse of acute leukaemia after allo-HSCT. The disease free state of patients may increase, though with high risk of secondary fungal infection.</p>

Inhibitory Effect of EGCG on angiogenesis induced by multiple myeloma cell line KM3 and its mechanism / 中国实验血液学杂志

The aim of this study was to investigate the effect of [(-)-epigallocatechin-3-gallate (EGCG)] on angiogenesis induced by multiple myeloma cell line KM3 and its mechanism. The effects of KM3 cell supernatant after being treated with EGCG in different concentrations on migration and vascular formation ability of endothelial cell line HUVEC were investigated through culture of MM cell line KM3 in vitro. The secretion level of vascular endothelial growth factor (VEGF) in KM3 cell supernatant and the expression level of VEGF mRNA in KM3 were detected by ELISA and RT-PCR respectively. The results indicated that the KM3 cell supernatant significantly induced endothelial cell migration and vascular formation in vitro. EGCG inhibited the effect of endothelial cell migration induced by KM3 cell supernatant, and the numbers of migrated cells were 414 +/- 27, 299 +/- 70, 202 +/- 42 and 116 +/- 13 at 5, 25, 50, 100 micromol/L respectively. The numbers of migrated cells showed negative correlation with the dose of EGCG (r = -0.952, p < 0.05). The areas of the capillary-like structures decreased while the concentrations of EGCG increased, 88343.9 +/- 3231.1 microm(2) at 25 micromol/L, 60897.5 +/- 914.1 microm2 at 50 micromol/L, which were significantly less than that in the control (p < 0.01) and showed negative correlation with the dose of EGCG (r = -0.888, p < 0.05). 48 hours after treatment with EGCG at concentrations of 5, 25, 50 and 100 micromol/L, the levels of VEGF in the culture supernatant were 1399.0 +/- 47.4, 660.1 +/- 5.7, 108.5 +/- 5.8 and 26.2 +/- 18.6 pg/ml respectively. Except 5 micromol/L, all the other groups showed significant changes while compared with the controls (p < 0.01). Furthermore, EGCG depressed the mRNA expression of VEGF in KM3 cells in a dose-dependent manner. It is concluded that the EGCG can significantly inhibit angiogenic ability of multiple myeloma KM3 cells, its pharmacological mechanism may be downregulation of VEGF mRNA expression and reduction of VEGF secretion.

Indoleamine 2, 3-dioxygenase activity in acute myeloid leukemia cells contributing to tumor immune escape / 中国实验血液学杂志

This study was aimed to investigate the mechanism of indoleamine 2, 3-dioxygenase (IDO) activity in acute myeloid leukemia cells contributing to tumor immune escape. Myeloid leukemia cells were isolated from bone marrow of 23 patients with acute myeloid leukemia (AML) and IDO expression was detected by immunochemistry and RT-PCR methods. Then mixed lymphocyte reaction (MLR) of one way was carried out, leukemia cells were used as stimulating cells and T-lymphocytes were used as reactive cells in culture with or without 1-MT. T-lymphocyte proliferation rate was determined by MTT assay and IDO activity in supernatant of MLR was detected by high-performance liquid chromatography (HPLC). The results showed that IDO expression was found in 17 out of 23 cases of acute myeloid leukemia cells; IDO enzyme activity in leukemia cells inhibited T-lymphocyte proliferation in MLR cultures. It is concluded that IDO activity expressing in leukemia cells can suppress T-lymphocyte proliferation responses, which may be contributing to tumor immune escape.