Effect of Magnolol on Proliferation and Apoptosis of HL-60 Cells and Its Molecular Mechanism / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of magnolol on proliferation and apoptosis of HL-60 cells and its mechanism.</p><p><b>METHODS</b>MTT assay was used to measure the proliferation of HL-60 cells after treatment with different concentration of magnolol (5, 10, 20, 40, 80 and 160 µg/ml). The morphological changes of HL-60 cells were examined by light microscopy, and DAPI staining was performed to observe the nuclear morphology of HL-60 cells. The early cell apoptosis was detected by flow cytometry with Annexin V-FITC/PI double-staining. RT-PCR was carried out to examine the mRNA expression of BAX and BCL-2. Western blot was performed to detect the protein expression of caspase family.</p><p><b>RESULTS</b>The magnolol inhibited HL-60 cell proliferation, and the inhibitory rate of cell proliferation increased significantly in a dose- and time- dependent manner (P < 0.05). HL-60 cells became small, even apoptotic bodies appeared after treatment with magnolol. In addition, nuclear condensation or fragmentation could be observed, which is the typical morphological features of apoptosis. When HL-60 cells were treated with 40 µg/ml of magnolol for 24 h, the ratio of early apoptotic cells reached to (11.7 ± 2.4) %, which was significant different from control (1.4 ± 1.1) % (P < 0.05). RT-PCR results showed that treatment of HL-60 cells with magnolol up-regulated the expression of BAX, whereas down-regulated the expression of BCL-2. Western blot results showed that the cleavages of caspase-3, -8 and -9 were significantly enhanced by magnolol.</p><p><b>CONCLUSION</b>The magnolol can significantly inhibit the proliferation of HL-60 cells and induce the apoptosis of HL-60 cells, which may occur through up-regulation of BAX, down-regulation of BCL-2 and the activation of caspases.</p>

Role of Autophagy in Acute Lymphoblastic Leukemia -Review / 中国实验血液学杂志

Autophagy is an evolutionarily highly conservative lysosomal degradative process and closely associates with pathogenesis, process, treatment, drug resistance and relapse of acute lymphoblastic leukemia (ALL). Whether the autophagy displays resistance to chemotherapy or a tumor suppressor in ALL, it mainly depends on the context of autophagy in the cells. Understanding the different role of autophagy in different conditions for ALL, determing the autophagy signaling pathways and targeting combination with autophagy revulsants or inhibitors were significant for the therapy of ALL, particularly for the treatment of refractory/relapsed ALL patients. This review summarizes the role of autophagy in pathogenesis, developmant, drug resistance and treatment of ALL, providing some theoretical guidance of new drugs targeting autophagy for ALL therapy.

Effect of modified zuoguiwan on Th17/Treg subpopulation of estrogen deficiency induced bone loss mice / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Modified Zuoguiwan (MZ) on the balance between helper T cell subsets 17 (Th17) and regulatory T cell subsets (Treg) in estrogen deficiency induced bone loss mice and to explore its mechanism.</p><p><b>METHODS</b>Totally 50 BALB/c mice were divided into the sham-operation group, the ovariectomy model group, the low dose MZ group, the middle dose MZ group, and the high dose MZ group by random digit table, 10 in each group. Mice in the low, middle, and high dose MZ groups were respectively administered with MZ at the daily dose of 7.25, 14.50, and 29.00 g/kg by gastrogavage, 0.5 mL each time for 12 successive weeks. Meanwhile, mice in the sham-operation group and the ovariectomy model group were administered with equal volume by gastrogavage, 0.50 mL each time. The serum estradiol (E2) level was assessed by enzyme linked immunosorbent assay (ELISA). Bone mineral density (BMD) of thigh bone was measured with dual energy X ray absorptiometry. In addition, the population of Th17/Treg subsets in spleen mononuclear cells was analyzed by extracellular and intracellular staining method using flow cytometry. Moreover, the mRNA expression of IL-17A and TGF-β in the spleen mononuclear cells was detected by reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Compared with the sham-operation group, both E2 and BMD significantly decreased, the percentage of Th17 subset and Th17/Treg ratio both increased, the percentage of Treg subset obviously decreased, the expression of IL-17A mRNA significantly increased, and the expression of TGF-β mRNA significantly decreased in the ovariectomy model group (all P < 0.05). Compared with the model group, BMD obviously increased, the percentage of Th17 subset and Th17/Treg ratio both decreased, the percentage of Treg subset obviously increased, the expression of IL-17A mRNA significantly decreased, and the expression of TGF-β mRNA significantly increased in the middle dose MZ group and the high dose MZ group (all P < 0. 05). Correlation analyses showed that BMD was positively related to both the serum E2 level and the percentage of Treg subset (P < 0.05), but negatively related to the percentage of Th17 subset (P < 0.05). In addition, the serum E2 level was positively related to the percentage of Treg subset, but obviously negatively related to that of Th17 subset (P < 0.05).</p><p><b>CONCLUSIONS</b>There was correlation between Th17/Treg imbalance and E2 deficient bone loss. MZ could decrease the proportion of Th17 subset, but elevate the proportion of Treg subset in E2 deficient bone loss mice. It could achieve therapeutic effect through adjusting the balance of Th17/Treg in E2 deficient bone loss mice.</p>

Effect of EBV immediate-early protein Zta on the cell cycle of Daudi cells and its mechanisms / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of EBV immediate-early protein Zta on cell cycle of Daudi cells and the involved mechanisms.</p><p><b>METHODS</b>The expression vector encoding Zta was constructed and electroporated into Daudi cells. Flow cytometric analysis was used to detect the cell cycle, Western blot to the protein levels of p21, Rb and E2F-1.</p><p><b>RESULTS</b>The vector was constructed successfully, the expression of Zta protein inhibited the proliferation of Daudi cells and promoted cell cycle from G(0)/G(1) phase \[(30.0 ± 3.4)%\] to S phase \[(47.7 ± 1.1)%\]. Meanwhile, Rb expression was significantly downregulated, E2F-1 and p21 expression upregulated by Zta.</p><p><b>CONCLUSION</b>Zta could promote G(0)/G(1) phase to S phase transition in Daudi cells, which might be associated with the reduced expression of Rb and increased expression of E2F-1 and p21 protein.</p>

Molecular mechanism of HL-60 cell apoptosis induced by baicalin / 中国实验血液学杂志

This study was aimed to investigate the effect of baicalin on proliferation and apoptosis of HL-60 cells and its mechanism. Cell proliferation was assayed by using Cell Counting Kit-8. The morphological changes of HL-60 cells were examined by light microscopy and nucleolus morphological changes were observed by fluorescent microscopy after Hoechst 33342 staining. The early cell apoptosis was detected by using flow cytometry with Annexin V-FITC/PI double staining. The expression of caspase-3, caspase-9, Bcl-2 and Bax mRNA was detected by RT-PCR and Western blot assay was carried out to examine Bax, Bcl-2, caspase-8 and cleaved caspase-3 expression. The results showed that Baicalin inhibited the proliferation of HL-60 cells in a time- and concentration-dependent manner. HL-60 cells exhibited typical morphological features (for example, cell shrinkage, membrane blebbing and formation of apoptotic bodies). Cell apoptosis in early stage could be detected, the expression of caspase-3, caspase-9 and Bax mRNA was obviously up-regulated, while the Bcl-2 expression down-regulated, and accordingly Bcl-2/Bax ratio decreased. Such results were consistent with the expression of these proteins. In addition, the expression of cleaved caspase-8 protein was induced significantly after treated with baicalin. It is concluded that baicalin can significantly inhibit the proliferation of HL-60 cells and induce the apoptosis of HL-60 cells, which may occur through decreasing Bcl-2/Bax ratio by intrinsic pathway and through extrinsic pathway. It suggests that baicalin may be a promising drug for the therapy of acute myeloid leukemia.

The molecular mechanisms of As_2O_3- induced un-terminal differentiation of HL-60 cells / 国外医学(肿瘤学分册)

To approach the effect of CCAAT/enhancer binding proteins (C/EBPs) on un-terminal differentiation of HL-60 cells after treatment with Arsenic Trioxide ( As_2O_3) . Methods The changes of cell morphology were observed by Wright staining, the alteration in the cell proliferation was determined by WST1 experiment and the NBT reduction assay was used to detect the differentiation condition of cells, determination and analysis cell cycle. The expressions of C/EBP? and C/EBP? mRNA in HL-60 cells exposed to ATRA and As_2O_3 were assayed by semi-quantitative RT-PCR. Results It was found that ATRA could up- regulate the mRNA expression of C/EBP? obviously, but down-regulate the mRNA expression of C/EBP?. As_2O_3 could up-regulate the mRNA expression of C/EBP? lightly, down-regulate the expression of C/EBP?. Conclusion Both of ATRA and As_2O_3 can down-regulate the mRNA expression of C/EBP?,but there is no significant difference between these two groups,ATRA and As2O3 can up- regulate the mRNA expression of C/EBP?, with significant differences (P