Efficacy Analysis of Unrelated Umbilical Cord Blood Transplantation for the Treatment of Wiskott-Aldrich Syndrome / 中国实验血液学杂志

OBJECTIVE@#To explore the clinical efficacy and safety of unrelated umbilical cord blood transplantation (UCBT) for the treatment of Wiskott-Aldrich syndrome(WAS).@*METHODS@#Five pediatric patients with WAS received single UCBT were retrospectively analyzed. The median age of these male patients was 268 days (range, 3 days -695 days). Among them, 2 patients were transplanted with a 6/6 matched cord blood graft，the other 3 patients received a 5/6 matched cord blood graft. Myeloablative conditioning regimen was applied, and all patients received a combination of cyclosporine and mycophenolate mofetil for the prophylaxis of graft versus host disease (GVHD). The recovery time of neutrophils and platelets as well as chimerism after transplantation were taken as the evidence of hematopoietic reconstruction.@*RESULTS@#All the five pediatric patients had hematopoietic recovery. A median time of neutrophil cells after transplantation was at 15.8 days (range,11 days -25 days), and platelet recovery was at a median of 20.4 days(range,12 days-30 days). Chimerism data were available for 5 patients at 30 days after UCBT, 4 out of the 5 patients had full donor chimerism and only one patient had mixed chimerism. There were 2 cases with pre-engraftment syndrome, 3 cases with acute GVHD gradeⅠ-Ⅲ, 4 cases with pulmonary infection and cytomegalovirus infection, but chronic GVHD was not observed in 5 cases. Four patients were alive with a median follow-up of 12.3 months (range, 5 months-17 months), and one patient had died at 22 days after UCBT.@*CONCLUSION@#Unrelated umbilical cord blood transplantation is a safe and effective treatment method for Wiskott-Aldrich syndrome.

Risk factors and outcome of invasive fungal infection in 79 patients received allogeneic hematopoietic cell transplantation / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the incidence, risk factors and outcome of invasive fungal infection(IFI) in the recipients with allogeneic hematopoietic cell transplantation(HSCT).</p><p><b>METHODS</b>79 cases received HSCT in our hospital from January 2005 to November 2014 with complete data were analyzed retrospectively according to the diagnostic criteria of IFI. the clinical features, risk factors and outcome of IFI were investigated and analysed.</p><p><b>RESULTS</b>17 cases of IFI were diagnosed, among them 13 cases were defined in clinic and 4 cases were possible. The median time of IFI occurence was 112 days(9-1931 d). The recurrence-free survival rate in non-infection and infection groups were 61.2% and 35.2% respectively. By single-factor analysis, the matching, II and IV degree of aGVHD were the risk factors of IFI, and the sex, protopathy, glucocorticoid used before infection were the risk factors of the death outcome. Multivariate analysis may indicated that the matching, II-IV degree of aGVHD and glucocorticoid used before infection were associated with IFI and outcome.</p><p><b>CONCLUSION</b>The patients received HSCT and having many risk factors are more likely predisposed to IFI. A greater dose of glucocorticoid used before infection is more likely to results in death, morever avoiding the risk factors may reduce the incidence of IFI, and the retrospecion of immunosupperssor dose used within 30 days before infection may improve prognosis.</p>

Clinical study of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation / 中国实验血液学杂志

This study was purposed to investigate the cytomegalovirus (CMV) infection and its related factors after allogenic hematopoietic stem cell transplantation (allo-HSCT). A total of 108 patients who received allo-HSCT in zhongda hospital from January 1, 2004 to March 31, 2014 were enrolled in this study. The CMV infection rate and the median time when the CMV-DNA was positive for the first time, and the risk factors related with CMV infection, CMV disease distribution and mortality after allo-HSCT were analyzed. The results showed that the infection rate of CMV was 52.78% (57/108), the median time of CMV infection was 44 d, especially during 30 d-100 d after transplantation. The univariate analysis showed that CMV infection rate was related with the HLA-identical situation between the donor and the recipient, and whether the use of anti-human thymus globulin(ATG) in conditioning regimen, neutropenic period after transplantation exceeded 10 d and graft-versus-host disease (GVHD). Multivariate analysis showed that CMV infection rate was related with neutropenic period longer than 10 d after transplantation and graft-versus-host disease (GVHD). The mortality of the patients with CMV disease was 58.82% (10/17), in which the mortality of CMV interstitial pneumonia was highest. The CMV infection was one of the most commonly happened infection after allo-HSCT. It is concluded that to reduce the incidence of CMV disease and mortality, the best choice of allo-HSCT is HLA-identical donor, ATG should be used during the conditioning process, and neutropenic period should be reduced less than 10 days. Moreover, it is necessary to strengthen the preemptive therapy of CMV infection actively.

Effect of gambogic acid on proliferation of SKM-1 cells and its mechanism / 中国实验血液学杂志

The aim of this study was to explore the effect of gambogic acid (GA) on MDS SKM-1 cell proliferation, apoptosis and their possible mechanism. Cell proliferation was determined by MTT method. The apoptosis percentage and cell cycle regulation of SKM-1 cells were analyzed by flow cytometry. Morphological features were observed by light microscopy. The mRNA expression of bcl-2 and bax were detected by RT-PCR. The results showed that GA could inhibit the proliferation of SKM-1 cells in a dose- and time-dependent manner (IC50 was 0.37 µg/ml at 48 h), increase the apoptotic percentage of SKM-1 cells, and arrest cell cycle at the G0/G1. The expression of bax mRNA was up-regulated while that of bcl-2 mRNA was down-regulated in SKM-1 cells treated with GA for 48 h. It is concluded that GA can induce apoptosis, which may be related to its effect of arresting cells at phase of G0/G1 and down-regulating bcl-2/bax ratio.

Clinical application of BCR/ABL probes in myeloproliferative disorders / 中国实验血液学杂志

This study was purposed to explore the application value of fluorescence in situ hybridization (FISH) detection in differential diagnosis of chronic myeloproliferative disorders (CMPD) and Ph(+) acute lymphoblastic leukemia (Ph(+) ALL), as well as in dynamic monitoring of minimal residual disease (MRD) after treatment. The BCR/ABL fusion gene of newly diagnosed and treated cases was detected by using BCR/ABL (ES) probe and BCR/ABL (DF) probe respectively. The results showed that among 49 newly diagnosed cases considered as CMPD, 28 cases met the criterion of CML morphologically, out of them 23 cases were eventually diagnosed to be CML and with morphological consistent rate 82.1% (23/28), the sensitivity and specificity all were 100% (23/23). The BCR/ABL positive rate of eventually diagnosed cases was 81.3% ± 17.7%. Among 13 cases received allogeneic haemopoietic stem cell transplantation (allo-HSCT), 9 cases achieved long-term disease-free survival and 4 cases relapsed, the several monitoring for whom after donor lymphocyte infusion (DLI) and imatinib treatment or allo-HSCT showed BCR/ABL negative. Among 16 cases treated with imatinib, 11 cases remained BCR/ABL negative after 1 year; 5 cases showed BCR/ABL positive during 6, 7 and 10 years after treatment, respectively, but out of them BCR/ABL positive in 1 case turned negative after allo-HSCT. It is concluded that the FISH is sensitive and specific diagnostic technique, the detection of BCR/ABL fusion gene in newly diagnosed and treated cases by using 2 different probes can help to fast and accurately determine the differential diagnosis for CML and Ph(+) ALL, and dynamically monitor the MRD after treatment with imatinib and allo-HSCT.

Effects of advanced glycosylation end products and tetrandrine on proliferation of K562 and K562/A02 cells / 中国实验血液学杂志

This study was aimed to investigate the effect of advanced glycosylation end products (AGE) on the proliferation of K562 and K562/A02 cells, the effect of tetrandrine (Tet) on proliferation of K562 and K562/A02 cells induced by AGE, and their mechanisms. The effects of AGE on proliferation of K562 and K562/A02 cells and Tet on the proliferation of AGE-induced K562 and K562/A02 cells were assayed by CCK8 kit, the apoptosis rate and the expression of receptor of advanced glycosylation end products (RAGE) in K562 and K562/A02 cells were determined by flow cytometry, the expression of RAGE mRNA was detected by semi-quantitative RT-PCR. The results showed that AGE could promote the proliferation of K562 and K562/A02 cells in a concentration-dependent manner, the cell proliferation was enhanced with time increasing in 0 - 48 h, and was higher than control group after 72 h. AGE up-regulated the RAGE mRNA and protein expressions of K562 and K562/A02 cells in a concentration-dependent manner. Treatment of Tet combined with AGE for 48 h could inhibit the proliferation of K562 and K562/A02 cells promoted by AGE in a concentration-dependent manner, which probably by inducing cell apoptosis, however, there was no obvious effect in the up-regulating expression of RAGE mRNA and protein induced by AGE. It is concluded that AGE can promote the proliferation of K562 and K562/A02 cells, which is probably induced by up-regulating the expression of RAGE mRNA and protein. Tet can inhibit the proliferation of K562 and K562/A02 cells induced by AGE, and the mechanism may be not closely associated with changes of the up-regulating expression of RAGE mRNA and protein induced by AGE.

Reversal effect of gambogic acid on multidrug resistance of K562/A02 cell line / 中国实验血液学杂志

This study was purposed to investigate the reversal effect of gambogic acid (GA) on multidrug resistance of K562/A02 cells and its mechanism. The IC(50) (half maximal inhibitory concentration) of adriamycin (ADM) was evaluated by MTT. Cell apoptosis was detected by flow cytometry. Morphological changes of K562/A02 cells were observed by fluorescent microscopy with DAPI staining. The expressions of Survivin and P-gp were determined by Western blot. The results showed that the IC(50) of ADM on K562 and K562/A02 cell proliferation were (1.42 ± 0.07) µg/ml and (28.42 ± 1.40) µg/ml respectively. GA ≤ 0.0625 µmol/L had no inhibitory effect on proliferation of K562 and K562/A02. 0.0625 µmol/L GA could enhance the sensitivity of K562/A02 cells to ADM (P < 0.05) and the reversal multiples was 1.53. The apoptotic rate was raised after treating with ADM combined with 0.0625 µmol/L GA for 48 h (P < 0.05). Morphological differences were typical and obvious between cells of control and treated groups under fluorescence microscopy using DAPI staining. After treating K562/A02 cells with ADM combined with 0.0625 µmol/L GA for 48 h, the expressions of Survivin and P-gp were down-regulated at protein levels. It is concluded that GA can enhance the sensitivity of K562/A02 cells to ADM, which may be related to increasing cell apoptosis and down-regulating expressions of Survivin and P-gp.

Association of polymorphisms of cytosine arabinoside-metabolizing enzyme gene with therapeutic efficacy for acute myeloid leukemia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The cytosine arabinoside (Ara-C)-based chemotherapy is the major remedial measure for acute myeloid leukemia (AML). Deoxycytidine kinase (DCK) and cytidine deaminase (CDA) are the key enzymes in the metabolism of Ara-C. Many single nucleotide polymorphisms (SNPs) and haplotypes of DCK and CDA, which contribute to susceptibility to Ara-C, have been identified in Africans and Europeans. However, there has been no report about the relation among three SNPs in DCK (rs115543896, rs72552079, and rs111454937) and two SNPs in CDA (rs2072671 and rs60369023), and their clinical response to Ara-C for a Chinese population. In this study, we aimed to investigate whether these five SNPs are associated with the therapeutic outcomes of Ara-C-based chemotherapy regimens in patients with AML.</p><p><b>METHODS</b>A total of 151 Chinese patients with AML were enrolled in our study. SNPs genotyping were performed using the MassARRAY system by means of the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) method.</p><p><b>RESULTS</b>The results illustrated that DCKrs111454937 AA genotype was more frequent in patients with higher platelet count, and A allele frequency was significantly higher in the group £40 years, lower white blood cell (WBC) count patients group and the group with platelet counts > 60'10(9)/L. Meanwhile, both DCKrs72552079 TC (OR = 1.225, 95%CI = 1.225 - 9.851, P = 0.0192) and CDArs60369023 GA (OR = 9.851, 95%CI = 1.31 - 77.93, P = 0.0263) significantly improved Ara-C-based chemotherapy response. While DCKrs11554389 AA (OR = 0.147, 95%CI = 0.027 - 0.801, P = 0.0267) was associated with the decrease of Ara-C-based chemotherapy response.</p><p><b>CONCLUSION</b>It is evident that the DCK and CDA polymorphisms might be the important markers for the AML patients' therapy outcomes in a Chinese population.</p>

Effects of 5-bromotetrandrine and daunorubicin on apoptosis and expression of survivin in K562/A02 cells / 中国实验血液学杂志

The aim of this study was to investigate the potential benefit of combination therapy with 5-bromotetrandrine (5-BrTet) and daunorubicin (DNR) on chronic leukemia. The apoptosis of K562/A02 cells treated by DNA, BrTet and BrTet combined with DNR for 48 hours was detected by flow cytometry; the expressions levels of survivin mRNA and protein K562/A02 cells treated by DNR, BrTet and BrTet combined with DNR and in untreated K562 cells for 48 hours were measured by RT-PCR and Western blot respectively. The results showed that the combination of BrTet with DNR increased apoptotic rate of K562/A02, down-regulated the expression levels of survivin mRNA and protein in K562/A02 cells as compared with blank control and cells treated by BrTet or DNR alone, the survivin expression in K562/A02 cells was higher than that in K562 cells. It is concluded that the combination of BrTet with DNR can effectively reverse the multidrug resistance of K562/A02 cells, promote the apoptosis of K562/A02 cells, the mechanism of which may be related with down-regulation of survivin expression. Survivin may be a target for the treatment of MDR in hematopoietic malignancies.

Analysis of prognostic risk factors in patients with diffuse large B-cell lymphoma / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the relationship of clinical features, therapeutic measures, laboratory findings, the origin of tumor cells as well as prognosis in Chinese patients with diffuse large B-cell lymphoma (DLBCL).</p><p><b>METHODS</b>One hundred and six patients with DLBCL were retrospectively assayed and followed up, the international prognostic index (IPI) score, Ann Arbor staging, ECOG score, the origin of tumor cells and different therapeutic methods were analyzed.</p><p><b>RESULTS</b>According to the IPI, there were 61 cases (57.5%) with low-intermediate risk and 45 (42.5%) with intermediate-high risk. According to Ann Arbor staging, there were 8 phase I cases (7.5%), 16 phase II (15.0%), 54 phase III (51.0%) and 28 phase IV (26.5%). Twenty-five cases (23.6%) were accompanied with bone marrow invasion, 16 of them were diagnosed as lymphosarcoma cell leukemia; 38 cases with ECOG score ≥ 2; 67 cases (63.2%) had an increased LDH level; 59 cases (55.7%) had B symptom. The response rate (RR) for the whole group was 71.7%, the complete remission (CR) rate was 59.4% (63 cases), the partial remission (PR) rate was 12.3% (13 cases), the stable disease rate was 2.8% (3 cases) and the death rate was 27.4% (29 cases). The 4-year survival rate was 72.6%. Univariate analysis indicated that eight factors were related with prognosis (P < 0.05), including IPI score, Ann Arbor staging, ECOG score, the origin of tumor cells, LDH level, bone marrow invasion, different therapeutic methods and whether or not CR. Multivariate analysis showed that the origin of non-germinal center (HR = 4.24, P = 0.001), bone marrow invasion (HR = 2.08, P = 0.012), whether or not CR (HR = 2.72, P = 0.006) and therapy modality (HR = 2.58, P = 0.009) were significant factors for prognosis.</p><p><b>CONCLUSION</b>The bone marrow invasion and the origin of tumor cells are independent risk factors for prognosis. The rituximab combined with chemotherapy can significantly improve the therapeutic effect of the DLBCL, and hematopoietic stem cell transplantation is the best choice for treating patients with DLBCL.</p>

Analysis of risk factors for relapse of 82 patients with hematologic malignancies after allogeneic hematopoietic stem cell transplantation / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the risk factors for relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and the measures of prophylaxis and treatment.</p><p><b>METHODS</b>We summarized the clinical data of 82 patients with hematologic malignancies who were treated in our hospital from August 2003 to December 2008. Factors including age, sex, ABO blood group disparity of donor and recipient as well as the type of donor, status of disease, HLA-match, conditioning regimen, whether or not having developed acute GVHD and chronic GVHD, infusion number of CD34(+) cells, relationship between CMV infection and relapse post-transplantation were considered and analyzed.</p><p><b>RESULTS</b>Single factor analysis indicated that there were five independent risk factors related with the disease relapse (P < 0.05), including status of disease, time of diagnosis to transplantation, acute graft versus host disease (aGVHD), conditioning regimen, and chronic graft versus host disease (cGVHD). Simultaneously, the type of donor was a substantial factor (P < 0.01), determined by multi-factor Cox regression analysis. Cox regression analysis determined that disease status (OR = 2.58, 95%CI 1.26 - 5.01, P = 0.01), time from diagnosis to treatment (OR = 1.98, 95%CI 1.11 - 3.63, P = 0.025) and cGVHD (OR = 3.74, 95%CI 1.96 - 7.97, P < 0.001) were major factors for relapse of the patients who had undergone transplantation.</p><p><b>CONCLUSIONS</b>Relapse remains the primary cause of failure after allo-HSCT. Status of disease, time from diagnosis to treatment and not cGVHD are the major risk factors. Effective prevention and treatment of relapse after engraftment can improve the efficacy of HSCT.</p>

Inducing apoptosis and reversal effect of nilotinib in combination with tetrandrine on multidrug resistance of K562/A02 cell line / 中国实验血液学杂志

This study was aimed to investigate the relevance of nilotinib in combination with tetrandrine (Tet) on reversing multidrug resistance and inducing apoptosis of K562/A02 cell line and its mechanism. Methyl-thiazol tetrazolium (MTT) assay was employed to examine the pharmacological effect of nilotinib or Tet alone on K562/A02 cell line, the IC(50) of daunorubicin (DNR) on K562/A02 cell line treated with nilotinib and Tet was calculated; the flow cytometry (FCM) was employed to detect the apoptosis rate of K562/A02. The expression of bax/survivin mRNA was determined by RT-PCR, and the expression of bax/survivin protein was assayed by Western blot. The results showed that after being treated by 5 nmol/L nilotinib or 1.0 µml/L Tet for 48 hours, IC(50) of DNR to K562/A02 was 5.71 ± 0.72 mg/L or 6.52 ± 0.43 mg/L, respectively, while in their combined treatment, IC(50) decreased to 3.12 ± 0.13 mg/L. Nilotinib or Tet alone could increase DNR-inducing apoptosis rate of K562/A02 cell, while the apoptosis rate of K562/A02 increased remarkably in combination treatment of nilotinib with Tet. After being treated with 5 nmol/L nilotinib or 1.0 µml/L Tet alone for 48 hours, the expressions of bax mRNA and BAX protein was up-regulated, while both effects were more obvious in combination treatment of nilotinib with Tet. Treatment with 5 nmol/L nilotinib or 1.0 µmol/L Tet alone for 48 hours down-regulated the expression of survivin mRNA and its protein, while treatment of nilotinib in combination with Tet had more significant effect on down-regulation of their expression. It is concluded that the K562/A02 cells are resistant to DNR, nilotinib or Tet alone both can partially reverse resistance of K562/A02 cells to DNR, increase the apoptosis rate of K562/A02 cells. Combination of nilotinib with Tet shows obvious synergistic action, mechanism of which may associate with up-regulation of bax mRNA and BAX protein expressions and down-regulation of survivin mRNA and its protein expressions.

Detection of bcr-abl fusion gene mRNA level in K562/A02 cell line by real-time quantitative RT-PCR / 中国实验血液学杂志

This study was aimed to quantitatively analyze the mRNA level of bcr-abl fusion gene in K562/A02 cell line by real-time quantitative reverse transcriptase polymerase chain reaction (RQ-RT-PCR) technique. After being cultured for a period of time, the K562/A02 cell line was collected and RNA was extracted using TRIzoL kit. The real-time quantitative reverse transcriptase polymerase chain reaction technology was used to detect the level of bcr-abl fusion gene and internal reference abl gene. The results showed that a fine reproducibility was obtained between 10(7) and 10(3) copies/ml, reproducible sensitivity of RQ-RT-PCR was 10(-5). The expression of bcr-abl fusion gene in K562/A02 cells was higher and the level of bcr-abl mRNA was more than 100% in K562/A02 cells. It is concluded that RQ-RT-PCR is a reliable, sensitive and reproducible method for detecting mRNA level of bcr-abl fusion gene, which may be useful in monitoring the chronic myeloid leukemia.

Effect of desferrioxamine on K562/A02 cell line and its mechanism / 中国实验血液学杂志

Iron is an essential element for cell growing including tumor cells. This study was purposed to explore the effect of desferrioxamine (DFO) on cell line K562/A02 and its mechanism. K562/A02 cells were cultured with different concentrations of DFO. The inhibitory effects of adriamycin (ADM) used alone or combined with DFO on the proliferation of K562/A02 was evaluated by MTT assay. The apoptosis rate of K562/A02 cells after treatment with 0, 12.5, 25 and 50 µmol/L DFO alone or in combination with 1 mg/L ADM were analyzed by flow cytometry. ADM accumulation in K562/A02 cells after treatment with different concentrations of 0, 12.5, 25 and 50 µmol/L DFO were also analyzed by flow cytometry. The levels of BAX/BCL-2 and MDR1 mRNA were determined by RT-PCR, and then the protein level of P-glycoprotein (P-gp) was detected by Western blot. The results showed that the IC(50) of ADM for K562 and K562/A02 cells were (1.46 ± 0.07) mg/L and (40.98 ± 3.05) mg/L respectively. The resistance of K562/A02 cells to ADM was 28.06 times as that of K562 cells. After treatment of K562/A02 cell with DFO of 12.5, 25 and 50 µmol/L for 48 hours, the resistance of K562/A02 cells to ADM were increased by 24.95, 16.11 and 9.99 times respectively. When K562/A02 cells were incubated with different concentrations of DFO of 12.5, 25, 50 µmol/L for 48 hours, the apoptosis rat were (3.50 ± 0.30)%, (7.27 ± 0.32)% and (12.53 ± 1.21)% respectively. After co-culture with DFO and ADM for 48 hours, apoptosis rate were (6.13 ± 0.29)%, (9.57 ± 0.40)% and (18.97 ± 1.10)% respectively. The above apoptosis rates was much higher than that of control group (p < 0.05) and they were dose-dependent. In comparison between DFO + ADM group and DFO group, there was no significant difference (p > 0.05). Expression rate of BAX/BCL-2 increased. The levels of MDR1 mRNA reduced. Furthermore, expression of P-gp also decreased in K562/A02 cells. It is concluded that iron increase can promote K562/A02 cells growth and inhibit their apoptosis. Otherwise, iron-deprivation can induce K562/A02 cells apoptosis. DFO disturbs the iron metabolism and inhibits DNA synthesis of K562/A02 cells. This action of DFO may enhance the susceptibility of K562/A02 cells to apoptosis induced by chemotherapeutic drugs. The iron-deprivation may play a role in the treatment of leukemia with combination of DFO with other anticancer agents.

Effects of magnetic nanoparticle of Fe3O4 on apoptosis induced by Gambogic acid in U937 leukemia cells / 中国实验血液学杂志

This study was aimed to explore the potential therapy of Gambogic acid (GA) combined with magnetic nanoparticle of Fe3O4 (Fe3O4-MNP) on leukemia. The proliferation of U937 cells and the cytotoxicity were evaluated by MTT assay. Cell apoptosis was observed and analyzed by microscopy and flow cytometry respectively. The expressions of gene and protein were detected by quantitative real-time polymerase chain reaction and Western blot respectively. The results showed that GA enhanced the cytotoxicity for U937 cells in dose- and time-dependent manners. The Fe3O4-MNP itself had not cytotoxicity, but could enhance the inhibitory effect of GA on proliferation of U937 cells. The apoptotic rate of U937 cells induced by combination of GA with Fe3O4-MNP was higher than that by GA alone. The typical apoptotic features of cells treated with GA and Fe3O4-MNP were observed. The expression levels of caspase-3 and bax after co-treatment of GA and Fe3O4-MNP were higher than that exposed to GA or Fe3O4-MNP alone, but the expressions of bcl-2, NF-kappaB and survivin were down-regulated. It is concluded that Fe3O4-MNP can promote GA-induced apoptosis in U937 cells, and the combination of GA with Fe3O4-MNP may be a safer and less toxic new therapy for leukemia.

Effects of hypoxia-inducible factor inhibitor on expression of HIF-1alpha and VEGF and induction of apoptosis in leukemic cell lines / 中国实验血液学杂志

This study was purposed to investigate the effect of a hypoxia-inducible factor inhibitor (YC-1) on expression of hypoxia-inducible factor 1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) as well as induction of apoptosis in leukemic cell lines. RT-PCR was used to determine the levels of HIF-1alpha mRNA and VEGF mRNA in K562, U937 and Jurkat cells. After treatment of U937 cell with 4 micromol/L YC-1, cell apoptosis was assayed by DAPI staining under fluorescent microscope and flow cytometry with Annexin V-FITC/PI staining; the expression levels of HIF-1alpha mRNA and VEGF mRNA were measured with RT-PCR; the expression levels of HIF-1alpha, VEGF, BAX, BCL-2 and caspase-3 proteins were measured by Western blot. The results showed that HIF-1alpha mRNA and VEGF mRNA were expressed in all three leukemia cell lines. After treatment of U937 cell with 4 micromol/L YC-1 for 0, 8, 16 and 24 hours, the changes of morphologic features of U937 cells could be observed under fluorescent microscope and the apoptotic rates significantly increased in time-dependent manner, they were (4.87 +/- 0.70)%, (27.27 +/- 2.00)%, (51.53 +/- 2.81) and (60.5 +/- 3.20)% respectively, the expression levels of VEGF mRNA reduced, while the expression levels of HIF-1alpha mRNA had no obviously changes.Furthermore, the expression of HIF-1alpha, VEGF and BCL-2 decreased, while the expression of BAX and caspase-3 increased, the ratio of BAX/BCL-2 increased in time-dependent manner (r = 0.973, p < 0.01). It is concluded that HIF-1alpha mRNA and VEGF mRNA are all expressed in in K562, U937 and Jurkat cells, YC-1 has significant effect on down-regulating the protein expression of HIF-1alpha and VEGF, and induces the apoptosis in U937. The mechanism of apoptosis in leukemic cells may involve in up-regulating BAX/BCL-2 ratio and expression of protein caspase-3.

Effect of PDMP, a glucosylceramide synthase inhibitor, on reversion of daunorubicin resistance in human leukemia cell line K562/A02 / 中国实验血液学杂志

This study was purposed to investigate the reversal effect of glucosylceramide synthase (GCS) inhibitor D, L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) hydrochloride, on multidrug resistance in K562/A02 cells and its mechanism. The IC(50) (the half maximal inhibitory concentration) of PDMP was measured by MTT method. Cell apoptosis and intracellular daunorubicin (DNR) concentration were detected by flow cytometry. The expression of GCS and mdr1 genes were assayed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot. The results showed that the IC(50) of DNR in K562 and K562/A02 cells were 0.23 +/- 0.02 and 7.15 +/- 0.24 microg/ml respectively. When the concentration of PDMP was equal to or less than 20 micromol/L ( < / = 20 micromol/L), the obviously inhibitory effect on proliferation of K562 and K562/A02 cells was not observed, but both 20 micromol/L and 10 micromol/L PDMP could enhance the sensitivity of K562/A02 cells to DNR (p < 0.01) and the reversal multiples were 2.59 and 1.69 respectively. After treating with 20 micromol/L and 10 micromol/L PDMP for 48 hours, the concentration of DNR in K562/A02 cells increased (p < 0.05) and the apoptotic rate also was elevated (p < 0.01). The expressions of GCS and mdr1 genes were down-regulated at mRNA and protein levels after treating K562/A02 cells with 20 micromol/L PDMP for 48 hours. It is concluded that PDMP can enhance the sensitivity of K562/A02 cells to DNR by increasing cell apoptosis rate and accumulation concentration of DNR in cells, which may be related to down-regulated expressions of GCS and mdr1 genes.

Reversal of multidrug-resistance in human leukemia cell line K562/A02 by tyrosine kinase inhibitors / 中国实验血液学杂志

This study was aimed to investigate the reversal effect of tyrosine kinase inhibitors (TKI) Imatinib and Nilotinib on multidrug-resistant cell line K562/A02. The expression levels of mdr-1 mRNA and bcr-abl mRNA were assayed by RT-PCR. The protein levels of P-glycoprotein (P-gp) and P210 were detected by Western blot. The daunorubicin (DNR) accumulation in K562/A02 cells were analyzed by flow cytometry (FCM). The results showed that the 0.0625 micromol/L Imatinib or 5 nmol/L Nilotinib alone had no cytotoxic effect on the inhibition of K562/A02 cells. When K562/A02 cells were treated with Imatinib or Nilotinib alone for 48 hours, the expressions of mdr-1 mRNA, der/abl mRNA, P-gp and P210 protein were all down-regulated, furthermore the effect of Nilotinib was stronger than that of Imatinib. The detection of fluorescence intensity revealed that the DNR concentration in K562/A02 cells treated with Imatinib or Nilotinib alone for 48 hours were 7.85% and 12.02% of K562 cells respectively. It is concluded that the tyrosine kinase inhibitors show great effect reversing drug resistance of cells, moreover, the effect of Nilotinib is stronger than that of Imatinib.

Construction and identification of Mdr-1-shRNA eukaryotic expression vector / 中国实验血液学杂志

This study was purposed to construct and identify the short hairpin RNA (shRNA) eukaryotic expression vector for targeting gene mdr-1 which may play an important role in K562/A02. Short hairpin RNA (shRNA) aiming at the target sequence was to synthesized, the 3491-3509, 1539-1557and 3103-3121 nucleotide of mdr-1 mRNA were selected as targets. The selected nucleotides were cloned in the plasmid pGCSilencer-U6-neo-GFP respectively, and the resultant recombinant plasmids were named as pGY1-1, pGY1-2 and pGY1-3. The sequences of the recombinant plasmids were identified by DNA sequencing and PCR electrophoresis. The recombinant plasmids were transfected into the cell line K562/A02 by lipofection. After being transfected for 48 hours, the inhibition of mdr-1 mRNA was detected by real time-PCR, and P-gp expression was detected by Western blot. The results showed that the specific oligonucleotide was cloned into the vector successfully, and the expression of mdr-1 mRNA and P-gp in K562/A02 cells was reduced after transfecting the recombinant plasmid, as compared to the control group. It is concluded that the shRNA eukaryotic expression vector has been successfully established which can inhibit the expression of mdr-1 mRNA, setting up the basis to futher explore the effects of mdr-1 on cell line of K562/A02.

Influence of magnetic Fe3O4 nanoparticle on functions of lymphocytes and macrophages in mice / 中国实验血液学杂志

This study was purposed to investigate the effects of magnetic nanoparticle of Fe3O4 (Fe3O4-MNPs) on murine immune system. ICR mice were assigned randomly into four groups which were treated with normal saline, low, middle and high dose of MNP-Fe3O4 respectively. The mice were killed after being exposed by intragastric administration for 2 weeks. The ratios of spleen weight to body weight, lymphocyte transformation rate in spleen suspension and phagocytic index of macrophage in abdominal cavity were detected. The results showed that the ratios of spleen weight to body weight in Fe3O4-MNP groups were not significantly different in comparison with the control (p > 0.05). The lymphocyte transformation rate in spleen suspension in Fe3O4-MNP groups were all higher than that in control group (-0.1775 +/- 0.0246), especially in the middle dose group (0.1833 +/- 0.0593) (p < 0.05), and the phagocytic index of macrophages in abdominal cavity of middle dose group (0.2051 +/- 0.0213) was higher than that of control group and other two Fe3O4-MNP group (low dose 0.1538 +/- 0.0100, high dose 0.1511 +/- 0.0184) (p < 0.05). It is concluded that suitable dose of Fe3O4-MNP can enhance the cellular immune activity and phagocytic function of macrophages of mice.