A preliminary study about the apoptostic mechanism of RNA targeting basic fibroblast growth factor in glioma U251 cells / 中华外科杂志

<p><b>OBJECTIVE</b>To preliminarily investigate the mechanism of small interfering RNA (siRNA) induced apoptosis in glioma U251 cells by silencing basic fibroblast growth factor (bFGF).</p><p><b>METHODS</b>U251 cells were divided into the normal control group, the mock group and experiment group, the mock and experiment group were transfected with mock vector (Ad-null) and the recombinant adenovirus carrying bFGF-siRNA (Ad-bFGF-siRNA) respectively at a multiplicity of infection (MOI) of 100. After 72 hours, the expression of related proteins was revealed by the method of Western blot. Mitochondrial transmembrane potential (ΔΨm) was measured with flow cytometry and confocal microscopy, Groups were compared using single factor analysis of variance (One-way ANOVA).</p><p><b>RESULTS</b>After U251 cells were transfected with bFGF-siRNA, the results of Western blot showed that after 72 hours of transfection the bFGF protein in the experiment group decreased obviously, meanwhile Cytochrome C, Caspase-3 and Bax showed increased expression while in the Bcl-xl and Bcl-2 proteins decreased expression. The proportion of high mitochondrial membrane potential of cells by flow cytometry, the experimental group was 74.4% ± 4.7% decreased significantly compared with the control group 92.1% ± 2.5%, the mock group 90.9% ± 1.8% (F = 28.805, P < 0.05); laser scanning confocal microscopy results showed that the red fluorescence and green fluorescence ratio of the experimental group was 0.83 ± 0.12 decreased significantly compared with 1.36 ± 0.40 of the control group and 1.32 ± 0.35 of the mock group(F = 7.920, P < 0.05).</p><p><b>CONCLUSION</b>siRNA targeting bFGF induced U251 cell apoptosis may be achieved through the mitochondrial pathway.</p>

Establishment of iron overloaded bone marrow model in vitro and its impact on hematopoiesis / 中国实验血液学杂志

This study was to establish an iron overload bone marrow (BM) model by co-culturing the mononuclear cells from BM with iron, and investigate its hematopoiesis changes. The iron overload model was set up by adding different concentration of ferric citrate (FAC) into the mononuclear cells from BM and culturing for different time, and the model was confirmed by detecting labile iron pool (LIP). Then the apoptosis of hematopoietic cells, ability of hematopoietic colony forming (CFU-E, BFU-E, CFU-GM and CFU-mix) and percentage of the CD34(+) cells of the BM cells all were determined. The changes of these indexes were tested after the iron-overloaded BM was treated with deferasirox (DFO). The results showed that after BM cells were cultured with FAC at different concentrations for different time, the LIP increased in time-and concentration-dependent manners. The intracellular LIP reached maximum level when cultured at 400 µmol/L of FAC for 24 hours. The detection of BM cell hematopoietic function found that the apoptotic rate of the FAC-treated cells (24.8 ± 2.99%) increased significantly, as compared with normal control (8.9 ± 0.96%)(p < 0.01). The ability of hematopoietic colony forming in FAC-treated cells decreased markedly, as compared with normal control (p < 0.05). The percentage of CD34(+) cells of FAC-treated cells (0.39 ± 0.07%) also decreased significantly, as compared with normal control (0.91 ± 0.12%)(p < 0.01). And these changes could be alleviated by adding DFO. It is concluded that the iron-overloaded model has been set by adding iron into the mononuclear cells from BM in vitro, and the hematopoietic function of iron-overloaded BM is deficient. These changes can be alleviated by removing the excess iron from the BM cells through treating with DFO. These findings would be helpful to further study the mechanism of iron-overload on the hematopoiesis of BM and also useful to find the way to treat iron-overload patients with hematopoietic disorders.

Clinical significance of leukemia stem/progenitor cell related gene expression in acute leukemia / 中国实验血液学杂志

This study was aimed to detect the expression of leukemia stem/progenitor cell (LSPC) related genes (ABCB1, BMI-1, HOXB4) in the patients with acute leukemia, and to explore its clinical significance in acute leukemia. Bone marrow samples were collected from de novo acute leukemia patients (41 cases), patients with complete remission (CR, 16 cases) and the patients with non-malignant hematologic diseases (10 cases) respectively. And the expressions of ABCB1, BMI-1, HOXB4 genes were detected by comparative real-time quantitative PCR (RQ-PCR) with SYBR Green assay. The results showed that the expressions of ABCB1, BMI-1, HOXB4 were not detected in the patients with non-malignant hematologic diseases, but were higher (relative expressive level: 4.26 ± 2.26, 3.72 ± 1.91, 3.74 ± 2.38) in de novo acute leukemia patients and lower (relative expressive level: 2.14 ± 1.47, 2.07 ± 0.99, 1.47 ± 0.89) in the acute leukemia patients with CR (p < 0.05). The expressions of LSPC related genes were lower (relative expressive level: 1.77 ± 1.29, 2.09 ± 1.26, 1.78 ± 1.49) in the patients acquired CR/partial remission (PR) than those in the patients not acquired CR/PR (relative expressive level: 7.23 ± 1.78, 3.96 ± 0.92, 4.48 ± 2.57) (p < 0.01). Univariate analysis revealed that there were more cases with the expression of LSPC immunophenotype (CD34(+)CD38(-)CD96(+) and CD34(+)CD38(-)CD123(+)) and more hyperleukocytosis cases in patients with any higher expression of LSPC related gene (p < 0.05). Analysis of multiple parameters discovered larger significance (p < 0.01). It is concluded that there is a good relationship between LSPC related genes (ABCB1, BMI-1, HOXB4) and LSPC immunophenotype. The expression of LSPC-related genes is higher in de novo acute leukemia patients, and lower in patients acquired CR/PR. The patients with higher expressed LSPC-related genes display worse response to chemotherapy, lower CR/PR rate and higher leukocytosis, the analysis of multiple parameters may be a good method for assessing the therapeutic efficacy/prognosis of acute leukemia.

In vitro effect of iron overload on bone marrow cell function by inducing the reactive oxygen species / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the in vitro effect of iron overload on the generation of reactive oxygen species (ROS) and of bone marrow (BM) cell function.</p><p><b>METHODS</b>BM mononuclear cells (BMMNCs) were cultured with ferric citrate (FAC) at different concentrations and for different time to create iron overload and confirmed by the detection of cellular labile iron pool (LIP). The changes of ROS, apoptosis, hematopoietic colony formation (CFU-E, BFU-E, CFU-GM and CFU-mix) and the percentage of the CD34 + cells percentage were analyzed. The differences of these index were tested after the iron overload treated with deferasirox (DFO) or antioxidants (N-acetyl-L-cysteine, NAC).</p><p><b>RESULTS</b>1) When BMMNCs were cultured with FAC, the LIP was found to increase in a time and concentration dependent manner. The intracellular LIP reached maximum at 400 micromol/L of FAC for 24 hours. 2) The ROS of total cells, leukocytes and erythrocytes increased to 1.77, 1.75 and 2.12 fold respectively compared with that of normal control when cells were cultured at 400 micromol/L of FAC for 24 hours . DFO and NAC could reduce the ROS efficiently (P<0.05). 3) The apoptotic rates of the FAC treated cells [(24.80 +/- 2.99)%] increased significantly compared with that of normal control [(8.90 +/- 0.96)%]. The capacity of hematopoietic colony formation in FAC treated cells decreased markedly compared with that of normal control (P<0.05). The percentage of CD34+ cells of FAC treated cells [(0.39 +/- 0.07)%] also decreased significantly compared with that of normal control [(0.91 +/- 0.12)%]. And these changes could be recovered by addition of NAC or DFO.</p><p><b>CONCLUSION</b>Iron overload can affect the hematopoiesis by inducing the generation of ROS and this damage could be corrected by removing the excess iron and ROS of the BM cells. These findings might improve the treatment of dyshematopoiesis in patients with iron overload.</p>

Anti-glioma effect of combination of bFGF-siRNA and Vpr in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the anti-glioma effect of recombinant adenovirus mediated combined gene therapy of bFGF-siRNA and HIV1-Vpr in vivo.</p><p><b>METHODS</b>Mouse glioma model was established by injecting 5 × 10(6) LN229 cells into BALB/c-nu nude mice. 30 nude mice were randomly divided into 5 groups: the negative control group, mock group, bFGF-siRNA group, Vpr group and combined therapy group, which at regular intervals were injected with PBS, rAd5-null, rAd5-bFGF-siRNA, rAd5-Vpr, rAd5-bFGF-siRNA plus rAd5-Vpr, respectively. The tumor volume was recorded every third day to draw a growth curve. After four weeks treatment, the mice were killed and specimens were taken. HE, immunohistochemical and TUNEL staining were performed to observe the cell morphology, detect the changes of relevant target proteins and cell apoptosis, respectively. Also the ultrastructural changes were observed by electron microscopy.</p><p><b>RESULTS</b>The tumor growth inhibition rates were 36.9%, 37.2% and 58.6% in the bFGF-siRNA group, Vpr group and combined therapy group, respectively, and the combined therapy group showed the most significant effect (P < 0.05). Also the results of HE, immunohistochemical and TUNEL staining revealed that the combined therapy group had the best effects on proliferation inhibition and apoptosis induced in glioma cells (P < 0.05). The most significant ultrastructural changes were observed in the combined therapy group.</p><p><b>CONCLUSION</b>The combined gene therapy of bFGF-siRNA with Vpr shows a prominent and synergistic anti-glioma effect compared with that of mono-gene therapy in nude mice.</p>