MiR-199a-5p Affects Sensitivity of Acute Myeloid Leukemia to Adriamycin by Targeting DRAM1 / 中国实验血液学杂志

OBJECTIVE@#To compare the expression of miR-199a-5p between ADM-resistant AML cell (K562/ADM)and ADM-sensitive AML cell (K562), and to investigate the effect of miR-199a-5p on regulating AML drug resistance as well as its molecular mechanism.@*METHODS@#MTT method was used to detect the proliferation inhibition effect of ADM on K562 and K562/ADM cells, the IC was calculated. miR-199a-5p expression in cell lines (K562 and K562/ADM) and bone marrow sample (refractory/relapsed AML patients and complete remission AML patients) was detected by RT-qPCR. K562/ADM and K562 cells were transfected by miR-199a-5p mimic and miR-199a-5p inhibitor respectively to ensure that miR-199a-5p expression in K562/ADM cells was increased and that in K562 cells was decreased. Then proliferation inhibition effect of ADM on both cells was detected by CCK-8 and mRNA and protein DRAM1 expression in both cells was measured by real time RT-PCR and Western blot respectively. Dual luciferase reporter assay was used to detect wether there were direct binding sites between miR-199a-5p and DRAM1 3' UTR. CCK-8 was used to measure the proliferation inhibition effect of ADM on K562/ADM cells when DRAM1 was downregulated by siRNA.@*RESULTS@#The IC of ADM for K562/ADM and K562 cells was 146.14±0.079 and 3.08±0.056 μg/ml respectively. As compared with patients in complete remission group, MiR-199a-5p expression in refractory/ relapsed AML patients significantly decreased, and the MiR-199a-5p expression in K562/ADM cells was also dramatically downregulated, compared with K562 cells (P＜0.05). When the expression of miR-199a-5p was upregulated in K562/ADM cells, the proliferation inhibition effect of ADM on cells elevated and both DRAM1 mRNA and protein expressions decreased. Conversely, when miR-199a-5p expression was downregulated in K562 cells, the proliferation inhibition effect of ADM on cells obviously reduced and both DRAM1 mRNA and protein expression increased (P＜0.05). Dual luciferase reporter Assay showed a direct interaction between miR-199a-5p and its binding site within DRAM1 mRNA. Both DRAM1 mRNA and protein expression in K562/ADM were markedly higher than those in K562 cells (P＜0.05). The ADM chemosensitivity of K562/ADM cells was improved significantly when DRAM1 expression was downregulated (P＜0.05).@*CONCLUSION@#miR-199a-5p is downregulated in chemoresistant AML cells. miR-199a-5p expression plays an important role in regulating the sensitivity of AML cells to ADM treatment. DRAM1 is a functional target gene for miR-199a-5p modulating AML chemoresistance.

Abnormal coagulation function in myeloproliferative neoplasms / 中国实用内科杂志

Myeloproliferative neoplasm is a clonal hematopoietic stem cell disease, which is often complicated by coagulation dysfunction, manifested as thrombosis and bleeding tendency. The mechanism of coagulation dysfunction in myeloproliferative neoplasm is unclear, which may be the result of multiple factors, such as proliferation and activation of leukocyte, abnormality of platelet and its receptors, JAK2V617 F mutation, vWF consumption and drugs. High-risk patients should be assessed to prevent and reduce adverse events.

Research Progress on Multiple Myeloma-Related Cardiovascular Events--Review / 中国实验血液学杂志

Abstract　　The patients with multiple myeloma are often accompanied by cardiovascular injuries, that not only related with age, but also with the disease itself and treatment. Timely detection and proper supervision of cardiovascular injuries in patients will reduce the mortality of patients with multiple myeloma. In this review, the pathophysiology, diagnosis and treatment of cardiovascular damages in patients with multiple myeloma are summarized briefly, so as to provide some references for clinical treatment and research.

Role of Reactive Oxygen Species in GDC-0152-Induced Apoptosis and Autophagy of NB4 cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of reactive oxygen species (ROS) on GDC-0152-induced apoptosis and autophagy of acute promyelocytic leukemia cell line NB4.@*METHODS@#Different concentrations of GDC-0152 combined with Z-VAD-FMK was applied to NB4 cells. Cell proliferation was detected by CCK8 method. Apoptosis rate, autophagy and ROS level were detected by flow cytometry. The autophagy was observed by Cyto-ID staining fluorescence microscopy, and flow cytometry were used to detect the fluorescence expression. The expression of autophagy-related protein LC3B was detected by Western blot.@*RESULTS@#GDC-0152 increased proliferation inhibition rate and apoptosis rate in NB4 cells (P＜0.05); GDC-0152 induced increase of ROS level of NB4 cells; GDC-0152 increased autophagy of NB4 cells that was found by Cyto-ID staining fluorescence microscopy and flow cytometry (P＜0.05). Western blot showed that GDC-0152 increased LC3B expression in NB4 cells and promoted the conversion of LC3BI to LC3BII; as compared with GDC-0152 (100 ng/ml), GDC-0152 (100 ng/ml) combined with ROS inhibitor YCG063 (10 μmol/L) decreased apoptosis and autophagy (P＜0.05).@*CONCLUSION@#GDC-0152 inhibits cell proliferation by inducing apoptosis and autophagy of NB4 cells. ROS can promote GDC-0152-induced apoptosis and autophagy of NB4 cells.

Embelin Reverses the Multi-drug Resistance of K562/D to Daunorubicin Independently of P-gp and MDR1 mRNA / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of reversing drug resistance of K562/D cells to daunorubicin by Embelin and its relationship with P-gp and MDR1 mRNA.</p><p><b>METHODS</b>MTT assay was used to detect and compare the cell proliferation rate of treating with DNR alone and DNR combined with Embelin. Flow cytometry with Annexin V-FITC/PI double staining was used to detect cell apoptosis rate, Western blot was used to detect the expression of XIAP,Caspase-3,BCL-2,BAX and P-gp of K562/D cells after using DNR alone and combining with Embelin. Quantitative real-time PCR was used to detect XIAP,BCL-2,BAX and MDR1 mRNA.</p><p><b>RESULTS</b>The ICof K562 and K562/D cells treated with DNR for 24 h were 2.177 µg/ml and 69.43 µg/ml, respectively. The drug-resistance index was 31.89; The proliferation inhibition rates of K562/D cells treated with Embelin of 3, 10, 30, 100 and 300 µg/ml for 24 h were 2.70%±1.08%, 10.92%±4.89%, 28.13%±2.09%, 36.56%±3.24% and 43.59%±1.16%; The proliferation inhibition rates of K562/D cells treated with DNR of 0.1, 1, 10 and 100 µg/ml combined with 10 µg/ml Embelin for 24 h were 31.92%±3.29%, 49.57%±6.87%, 55.16%±0.78% and 71.94%±3.89%. The ICwas 2.11 µg/ml respectively. The reverse index was 32.91. The apoptosis rates of K562/D cells treated with 0.1 µg/ml DNR alone or combined with Embelin of 10 µg/ml and 30 µg/ml for 24 h were 12.06%±0.95%, 27.54%±0.59% and 39.59%±1.57%, respectively. The results of Western blot showed that after combination of DNR with Embelin, the expression of Caspase-3 was significantly down-regulated (P<0.05), moreover, the prolifiration inhibition effect of drug combination on cells could be countreacted by Z-VAD-FMK, at the same time the expression of XIAP and BCL-2 protein was significantly down-regulated(P<0.05), the expression of BAX protein was significantly up-regulated(P<0.05), while there was no change of P-gp expression later (P<0.05). The results of RT-PCR showed that after combination of DNR with Embelin, expression of XIAP and BCL-2 mRNA was significantly down-regulated(P<0.05), expression of BAX mRNA was significantly up-regulated(P<0.05), while there was no obvious change of MDR1 mRNA expression(P>0.05).</p><p><b>CONCLUSION</b>The down-regulation of XIAP contributes to enhance the effect of DNR on K562/D cells, the mechanism of Embelin-reversing the drug-resistence of K562/D cells to DNR does not relate with P-gp and MDR1 mRNA.</p>

CAR Technology and Its Application in Treatment of Multiple Myeloma--Review / 中国实验血液学杂志

Multiple myeloma (MM) is a hematologic malignancy resulted from genetic mutations in the process of B lymphocyte differentiating into plasma cells, the chemotherapy is the main treatment method, especially with the development of proteasome inhibitors and other drugs, the overall survival rate of MM patients has improved greatly, but the chemoresistance is still an important reason for treatment failure. Chimeric antigen receptor (CAR)-modified T lymphocyte therapy is a new method for tumor adoptive immunotherapy. By means of genetic modification, T cells are able to identify the target antigen specifically, and to kill target cells without major histocompatibility complex (MHC) restriction, therefore the specific killing activity is conspicuous, which has got considerable attention by the public, and has made remarkable achievements particularly in the treatment of B-lineage leukemia and lymphoma, but no systematic literatures were reported in the field of multiple myeloma using CAR therapy. Therefore, this review summarizes the research results of different CAR target in vivo and in vitro experiments for multiple myeloma.

Dual role of autophagy in chronic myeloid leukemia / 中国实验血液学杂志

Autophagy is a lysosome-mediated self-degradation process that mediates degradation and recycling of all major components of eukaryotic cells to maintain intracellular homeostasis. Autophagy is associated with leukemo-genesis, treatment, drug-resistance and recurrence of chronic myeloid leukemia (CML). Autophagy is a double-edged sword which has dual characteristics to promote survival and death of CML cells. Thus exploring different roles of autophagy under different conditions, finding out different autophagy pathways and combination with autophagy inducer or inhibitor of autophagy is of great importance to improve therapeutic effect, overcome drug-resistance and recurrence and finally come to a cure. This article makes a summary on the dual role of autophagy in CML.

Mechanisms of Apoptosis Induced by FTY720 in Multiple Myeloma Cell Line U266 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of FTY720 on apoptosis in multiple myeloma cell line U266 and to clarify the molecular mechanism of apoptosis induced by FTY720.</p><p><b>METHODS</b>U266 cells were treated with 2.5, 5, 10 and 20 µmol/L of FTY720 for 24 hours, the apoptotic rates were tested by flow cytometry with Annexin-V-FITC/PI staining. Then U266 cells were treated with 20 µmol/L FTY720 for 0, 6, 16 and 24 hours, the apoptotic rates were tested. U266 cells were treated with DMSO and FTY720 separately and then were stained with DAPI for 5 min. Drop the cells to the slides and cover the slide with the glass. The cells were observed by fluorescence microscopy. U266 cells were treated with 5 µmol/L FTY720 or together with different doses of Z-VAD-fmk (12.5, 25, 50 µmol/L), a pancaspase inhibitor, for 24 hours, then the cell viability was tested by CCK-8. U266 cells were treated with 2.5, 5, 10 and 20 µmol/L of FTY720 for 24 hours, the expression of cleaved caspase-3 was tested by Western blot. U266 cells were treated with 0, 5, 10 and 20 µmol/L of FTY720 for 24 hours, the expressions of MCL-1, survivin, BCL-2, BID, BAX, BAK, P-ERK were tested by Western blot.</p><p><b>RESULTS</b>The apoptotic rate increased in U266 cells treated with FTY720 and showed the characteristic of time-dependent and dose-dependent manner. Karyopyknosis and nuclearfragmentation could be observed in U266 cells treated with FTY720 after being stained with DAPI under fluorescent microscope. The same effect was not observed in the cells treated with DMSO. Z-VAD-fmk could rescue the apoptosis in U266 cells treated with FTY720 in dose-dependent manner. The expression of MCL-1, survivin and BCL-2 decreased in U266 cells treated with FTY720. The cleavage of BID could be observed in U266 cells treated with FTY720. FTY720 had no effect on the expression of BAX, BAK and P-ERK.</p><p><b>CONCLUSION</b>FTY720 can induce the apoptosis in U266 cells, the apoptosis was Caspase-3-depended. The apoptosis induced by FTY720 is due to the decrease of MCL-1, survivin and BCL-2, which are the inhibitors of apoptosis. Meanwhile, the apoptosis was also due to the activation of BID, which is pro-apoptotic protein.</p>

Latest advances of research on autophagy and leukemia treatment / 中国实验血液学杂志

Autophagy, as a conservative self-degradative approach of eukaryotic cells, plays an important role in cellular growth, proliferation,differentiation, death and keeping intracellular steady state. On one hand, autophagy can protect tumor cells to keep survival; on the other hand, autophagy can lead to apoptosis of leukemia cells. The double-edged impacts of autophagy make it to be the hotspot for research on mechanism and treatment of leukemia. This article reviews the diverse effects of autophagy in different leukemia cell lines, as well as its corresponding mechanism resulting in drug resistance, so as to provide theoretic guide for direct rational application of drugs according to their various mechnisms.

Inducing effects of ursolic acid on Jurkat cell apoptosis and its mechanisms / 中国实验血液学杂志

The study was aimed to investigate the inducing effect of ursolic acid (UA) on the apoptosis of human T-cell leukemia/lymphoma (Jurkat), and whether the regulation of PTEN involved in the effect of UA on Jurkat cells. The Jurkat cells were treated with different concentrations of UA for different time. The cell proliferation was analyzed with cytotoxicity test (CCK8 method). Cell apoptosis was detected by fluorescence microscopy and flow cytometry. The expression of PTEN mRNA was detected by real-time quantitative PCR. The results indicated that UA could significantly inhibited the viability of Jurkat cells treated with 10-80 µmol/L and in dose- and time-dependent manner. UA could induce Jurkat cell apoptosis in a dose-dependent manner, which was statistical different from the control at the same time (P < 0.05). PTEN mRNA expression was up-regulated by UA, which was statistical different from the control (P < 0.05). It is concluded that UA may induce Jurkat cell apoptosis by up-regulating the PTEN mRNA expression.

Effects of TIEG1 on K562 cell apoptosis and expression of BCL-2/BAX, PTEN / 中国实验血液学杂志

The aim of this study was to investigate the effect of TIEG1 on K562 cell apoptosis and expression of BCL-2/BAX, PTEN. The different concentration(0, 1, 5, 10, 20 ng/ml) of TIEG1 were used to treat K562 cells, the cell growth inhibition rate was detected by using MTT method. After treating K562 cells with 10.00 ng/ml TIEG1, the cell apoptosis was detected with flow cytometry. The RT-PCR was used to detected the expression levels of BCL-2 /BAX and PTEN. The results showed that TIEG1 displays inhibitory effect on proliferation of K562 cells in time-and dose-dependent manner (r = 0.52, P < 0.05) ; after K562 cells were treated for 6, 12, 24 and 48 h, the IC50 of TIEG1 were 48.19, 18.72, 9.5 and 3.85 ng/ml respectively. After treating K562 cells with 10.00 ng/ml TIEG1 for 0, 6, 12, 24, 48 h, the apoptosis rate were (2.13 ± 0.42)%, (7.79 ± 0.71)%, (11.17 ± 1.37)%, (24.66 ± 0.29)% and (48.60 ± 1.38)% respectively, and there was significant difference between groups(P < 0.05). In process of K562 cell apoptosis, the expression level of BCL-2 gradually decreased (r = 0.48, P < 0.05), meanwhile the expression levels of BAX (r = 0.69, P < 0.05) and PTEN (r = 0.57, P < 0.05) gradually increased. It is concluded that TIEG1 can indue apoptosis of K562 cells and inhibit K562 cell proliferation in time-and dose-dependent manner. In apoptosis process of K562 cells induced by TIEG1, the expression changes of BCL-2/BAX and PTEN associate with the K562 cell apoptosis.

Meta-analysis of imatinib mesylate with or without interferon for chronic-phase chronic myeloid leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>Meta-analysis of the efficiencies of imatinib mesylate (IM) with or without interferon for chronic myeloid leukemia-chronic phase (CML-CP) patients.</p><p><b>METHODS</b>Published studies of IM with or without interferon for CML-CP patients as first-line therapy were collected from PubMed, Cochrane Central Register of Controlled Trials (CENTRAL) of the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), VIP information and WANFANG database. References of retrieved articles were also identified. The quality of each randomized controlled trial (RCT) was evaluated by the Cochrane collaboration's tool for assessing the risk of bias. Data analysis was performed with RevMan 5.1.</p><p><b>RESULTS</b>A total of 5 articles involving 1754 patients were included. Meta-analysis results showed that there were no statistical differences between IM with interferon and IM monotherapy for the complete cytogenetic response (CCyR) rate at 12 months,but IM with interferon could improve major molecular response (MMR) rate at 12 months (OR=1.57, 95% CI: 1.26-1.96, P=0.02). Furthermore, IM combined with pegylated-interferon demonstrated superiority for MMR at 12 months (OR=2.43, 95% CI: 1.78-3.33, P<0.01).</p><p><b>CONCLUSION</b>Combination of IM and interferon does not increase CCyR rate, but improve MMR rate at 12 months.</p>

Effect of valproic acid sodium on proliferation and apoptosis of acute T-lymphoblastic leukemia Jurkat cells / 中国实验血液学杂志

This study was aimed to investigate the effects of valproic acid sodium (VPA) on the proliferation and apoptosis of acute T-lymphoblastic leukemia Jurkat cells. Jurkat cells were treated with different concentration of VPA. Proliferation-inhibition curve was assayed and plotted by CCK-8 method and the cell apoptosis was detected by flow cytometry with Annexin V/PI double staining. The expression level of anti-apoptotic gene BCL-2 and pro-apoptosis gene Bak1 were detected by semi-quantitative RT-PCR. The results showed that the VPA inhibited the proliferation of Jurkat cells in concentration-dependent manner. As compared with the control group, the apoptosis of cells increased along with adding concentration of VPA; VPA could decrease the expression of BCL-2 gene, but did not show obvious effect on the expression of Bak1. It is concluded that the VPA can inhibit proliferation of Jurkat cells which possibly associates with the decrease of BCL-2 expression.

Influence of TIEG1 on apoptosis of HL-60 cells and expression of Bcl-2/Bax / 中国实验血液学杂志

This study was aimed to investigate the influence of TIEG1 on apoptosis of HL-60 cells and the expression of Bcl-2/Bax. Different concentration of TIEG1 were used to treat HL-60 cells, the cell growth inhibition rate was detected by MTT method. After treating HL-60 cells with 12.03 ng/ml TIEG1, cell apoptosis was detected with flow cytometry. Bcl-2 and Bax was detected with RT-PCR. The results showed that TIEG1 had inhibitory effect on HL-60 cell proliferation, and in time-and dose-dependent manners. The more obvious inhibitory effect was observed in HL-60 cells treated with TIEG1 of 12.03 ng/ml. During the course of cell apoptosis, Bax expression increased, but Bcl-2 expression decreased (P < 0.05). It is concluded that TIEG1 inhibits HL-60 cell proliferation and induces apoptosis in time and dose-dependent manners. During the course of HL-60 cells apoptosis induced by TIEG1, Bcl-2/Bax are associated with HL-60 cell apoptosis induced by TIEG1.

Mechanisms of ROS in U266 cell death induced by FTY720 / 中国实验血液学杂志

This study was purpose to investigate the role of reactive oxygen species (ROS) in apoptosis and autophagy induced by FTY720 in multiple myeloma cell line U266. U266 cells were treated by different concentrations of FTY720 for 24 h, the apoptotic rates were detected by flow cytometry, and the expression of LC3B was detected by Western blot. The results indicated that apoptosis and autophagy were induced by FTY720 in U266 cells. Autophagy induced by FTY720 could lead to cell death. Bafilomycin A1, the inhibitor of autophagy, could enhance the cell viability in U266 cells treated with FTY720. NAC or Tiron, ROS scavenger, could decrease the FTY720 induced apoptosis and the expression of LC3B-II was reduced in combination of FTY720 with NAC or Tiron as compared with treatment with FTY720 only. It is concluded that FTY720 can induce U266 cell apoptosis and autophagy. ROS is the mediator that regulates both the apoptosis and autophagy in multiple myeloma cells.

Study on mechanism of bortezomib inducing peripheral neuropathy and the reversing effect of reduced glutathione / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the mechanism of bortezomib inducing peripheral neuropathy and the reversing affection of reduced glutathione.</p><p><b>METHODS</b>Female Wistar rats were randomly divided into three groups. Group 1, treatment with bortezomib; Group 2, treatment with bortezomib and reduced glutathione; Group 3, saline control group. Drugs were administrated on the 1st, 4th, 7th and 11th day for the three groups. The amorphous of sciatic nerve and dorsal root ganglion (DRG) were observed by electron microscope on 14th and 42nd day. On 14th day, laser confocal microscopy was used to detect reactive oxygen species (ROS) of DRG neuron obtained from the rats by treated with DCFH-DA after primary culture.</p><p><b>RESULTS</b>On 14th day, morphology of sciatic nerve and DRG changed in both group 1 and 2. On 42nd day, the amorphous became normally in group 1. On 14th day, ROS releasing from DRG neuron was increased obviously in group 1 (P < 0.01), while decreased in both group 2 and 3, and the difference between the latter two groups had no statistical significance (P = 0.210).</p><p><b>CONCLUSION</b>Releasing ROS to injure mitochondrion and endoplasmic reticulum maybe involved in bortezomib induced peripheral neuropathy. Although reduced glutathione can inhibit ROS release, it has no obviously reversal effect for peripheral neuropathy.</p>

Different dose combinations of bortezomib and dexamethasone in the treatment of relapsed or refractory myeloma: an open-label, observational, multi-center study in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although previous clinical study revealed that bortezomib combined with dexamethasone had improved the outcomes of relapsed or refractory multiple myeloma (RRMM), the optimal dose combinations of bortezomib and dexamethasone remain unknown. This trial aimed to observe the efficacy and safety of different dose combinations of bortezomib and dexamethasone in the treatment of RRMM patients in China.</p><p><b>METHODS</b>A total of 168 patients with relapsed multiple myeloma (MM) who were refractory to at lest two prior treatments were enrolled in this multicenter, open-label, non-randomized, prospective clinical trial. Twenty patients received 1.3 mg/m(2) of bortezomib twice weekly for 2 weeks of a 3-week cycle for up to 8 cycles and oral or intravenous dexamethasone 20 mg on the day of and after each bortezomib dose (group 1); 66 patients received less than 1.3 mg/m(2) (0.7 - 1.0 mg/m(2)) of bortezomib and dexamethasone 20 mg on the same schedule (group 2); 37 patients received 1.3 mg/m(2)2 of bortezomib and dexamethasone 40 mg (group 3) and 45 patients received less than 1.3 mg/m(2) (0.7 - 1.0 mg/m(2)) of bortezomib and dexamethasone 40 mg (group 4). The response was evaluated according to the criteria of the European Group for Blood and Marrow Transplantation and confirmed by an independent review committee. Adverse events were graded according to the National Cancer Institute Common Toxicity Criteria, version 3.0.</p><p><b>RESULTS</b>The median age of groups 1 to 4 was 61, 62, 56, and 60 years, respectively. Most patients were in stages II/III of MM and the most common subtype was IgG. The rate of overall response to bortezomib and dexamethasone of group 1 to 4 was 72.2% (13/18), 73.8% (48/65), 78.8% (26/33) and 78.0% (32/41) (P = 0.91), including a complete response rate of 22.2% (4/18), 20.0% (13/65), 33.3% (11/33) and 29.3% (12/41) (P = 0.67), respectively. There was no statistical significance in time to progression and overall survival among these 4 groups (P > 0.05). The most commonly adverse events of any grade in the entire 4 groups were fatigue, gastrointestinal effects, peripheral neuropathy and thrombocytopenia, and there was no significance in the number of adverse events among the 4 groups (P > 0.05) except that peripheral neuropathy was reported more frequently in group 3 (36.3%) than in group 2 (13.8%, P < 0.05) and group 4 (14.6%, P < 0.05).</p><p><b>CONCLUSIONS</b>The combination of bortezomib and dexamethasone was associated with high responses in Chinese RRMM patients. No significant differences of efficacy were detected in different dose combinations of bortezomib and dexamethasone. Moreover, low dose of bortezomib reduced the incidence of peripheral neuropathy without affecting outcome in the treatment of patients with RRMM in China.</p>

Glycyrrhetinic acid induces apoptosis and alters survivin gene expression in human myeloma cell line U266 / 中国实验血液学杂志

This study was aimed to investigate the effects of glycyrrhetinic acid (GA) on proliferation, apoptosis and survivin mRNA expression in human myeloma cell line U266 in vitro. Cell proliferation was assayed by MTT method. Both cell apoptosis and cell distribution in cell cycle were analyzed by using flow cytometry. Scanning electron microscopy was used to observe the morphological changes in U266 cells induced by GA. Expression of survivin mRNA was detected by quantitative real-time reverse transcription-polymerase chain reaction. The results showed that GA inhibited proliferation of U266 cells in a time- and dose-dependent manners in vitro. GA presented apoptosis induction potency to U266 cells, obvious changes in morphology of U266 cells was observed under scanning electron microscope. The cells were arrested at the G(0)/G(1) phase, showing the accumulation in G(0)/G(1) phase, reduction of cells in G(2)/M phase and S phase. GA could down-regulate the expression of survivin gene in U266 cells in a dose-dependent manner. It is concluded that GA can inhibit proliferation of U266 cells in a time- and dose-dependent manners and induce apoptosis of this cell line in vitro through arresting G(0)/G(1) phase and down-regulating expression of survivin.

Effect of different concentrations of bortezomib on the expression of ERK, JNK and P38 in daunorubicin-resistant K562 cells / 中国实验血液学杂志

The aim of this study was to investigate the effect of proteasome inhibitor bortezomib on the expression of ERK, JNK, and P38 in daunorubicin (DNR)-resistant K562 cells and its mechanism. MTT method was used to determine the drug-resistant K562 cells and the cellular toxicity of bortezomib; Western blot was used to detect the expression of protein ERK, JNK and P38 in K562 cells after treatment with 100 nmol/L DNR alone or combined with 1 nmol/L and 10 nmol/L bortezomib for 36 hours. Flow cytometry assay was used to detect the apoptosis rate in each group cells. The results indicated that the expression of ERK and P38 were significantly suppressed (p < 0.05) and the expression of JNK was significantly enhanced (p < 0.05) in the cells treated by DNR combined with bortezomib. It is concluded that bortezomib can decrease the expressions of protein ERK and P38 and enhance the expression of JNK, the bortezomib reverses the cellular drug-resistance and promote cell apoptosis through MAPK pathway.

Immunophenotypes in 207 pediatric patients with ALL and theirs correlation with cytogenetics and clinical features / 中国实验血液学杂志

The objective of this study was to investigate the immunophenotypic subtype profiles of 207 pediatric patients with acute lymphoblastic leukemia (ALL) and its correlation with cytogenetics and clinical features. 207 children with ALL were immunophenotyped by four color flow cytometry using a panel of monoclonal antibodies. 207 patients were enrolled in this study, out of which 146 cases were subjected to karyotype analysis by R-banding technology. The results showed that 11.6% out of 207 children with ALL were identified as T-ALL, 88.4% as B-ALL. Myeloid antigen (MyAg) expression was documented in 42.5% out of 207 cases analyzed and CD13 was the most commonly expressed MyAg (31.4%). No difference was observed in the expression of MyAg between the groups of patients with T-ALL (41.7%) and B-ALL (42.6%). Abnormal karyotypes were detected in 84 out of 146 (57.5%) children. The clinical and biological characteristics of ALL patients between MyAg(+) and MyAg(-) groups showed that higher percentage of patients with high WBC count (> 50 × 10(9)/L) and higher CD34 positivity were found to be correlated with MyAg(+) ALL. It is concluded that immunophenotype analysis is useful for ALL diagnosis and classification, and the immunophenotypes are in relevance to the abnormal cytogenetic changes as well as clinical features in childhood ALL.