A New Conditioning Regimen Can Significantly Promote Post-Transplant Immune Reconstitution and Improve the Outcome of Umbilical Cord Blood Transplantation for Patients.

This study included data from 81 consecutively enrolled patients with hematological diseases who had been treated with unrelated umbilical cord blood transplantation (UCBT) between September 2014 and April 2019. All patients received intense conditioning regimens with combined fludarabine and high-dose cyclophosphamide (FC) before undergoing UCBT. Sixty-seven patients received a single UCBT, and 14 patients received a double UCBT. Fifty patients were pretreated with the fludarabine, busulfan, and cyclophosphamide (FBC) protocol, while 31 patients were treated with FC before transplantation. Graft-versus-host disease (GVHD) was prevented with cyclosporine A and mycophenolate mofetil administration. According to low-resolution, human leukocyte antigen (HLA) donor-recipient matching at six sites, 53 patients had 5-6 matches, while 28 patients had 4 matches. Seventy-eight patients (96.3%) achieved complete engraftment in this study. Thirty-six patients developed acute GVHD (aGVHD). The cumulative incidence of grade I-II aGVHD at day 100 posthematopoietic stem cell transplantation was 29.6%, and the cumulative incidence of grade III-IV aGVHD was 14.8%. At the end of the follow-up, 12 patients died due to treatment-related complications, and 4 died of disease relapse after transplantation. The transplant-related deaths were due to transplant-related infection (8 of 81), GVHD (2 of 81), and organ toxicity (2 of 81). The probability of overall survival (OS) was 80.2%. A higher dose of cyclophosphamide combined with fludarabine conditioning in UCBT was an effective curative method for treatment of hematologic disorders and could enhance the engraftment of umbilical cord blood stem cells, promote post-transplant immune reconstitution, and improve OS.

A randomized phase II, open-label and multicenter study of combination regimens of bortezomib at two doses by subcutaneous injection for newly diagnosed multiple myeloma patients.

PURPOSE: Combinations of bortezomib (Velcade), cyclophosphamide and dexamethasone have shown significant efficacy and safety for patients of newly diagnosed multiple myeloma (NDMM). In this study, we compared the efficacy and safety of modified VCD regimens with novel changes in bortezomib dose and schedule for NDMM. METHODS: Eighty-five NDMM patients from multiple centers were randomly assigned to a high-dose (1.6 mg/m2) (group A) or a low-dose (1.3 mg/m2) (group B) bortezomib, administrated on days 1, 6, 11, and 16 subcutaneously in a 4-week cycle for nine cycles, combined with 40 mg dexamethasone on bortezomib days and cyclophosphamide 300 mg/m2 on days 1-3 intravenously. RESULTS: After four cycles, complete response (CR) or better in group A (43.6%) was higher than that in group B (12.8%) (P = 0.002). During induction, for patients with R-ISS stage III, the CR or better rate in group A was superior to that in group B (P = 0.01). Of patients < 65, the CR or better rate of group A was superior to that of group B (P = 0.004). Rapid onset of CR occurred in group A (P < 0.01). Meanwhile, rate of 3-4 diarrhea was higher in group A (P = 0.03), which caused higher rate of dose reduction for patients ≥ 65 (P = 0.041). No significant difference between the two groups in PFS and OS. CONCLUSIONS: The studied high-dose VCD as induction regimen had an improved CR rate, especially in patients < 65 or with R-ISS stage III, and is feasible for young and high-risk patients. Trial registration ClinicalTrials.gov: NCT02086942.

[Efficacy Analysis of Unrelated Umbilical Cord Blood Transplantation for the Treatment of Wiskott-Aldrich Syndrome].

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.

A Randomized Study Comparing Stem Cell Transplantation Versus Conventional Therapy for Low- and Intermediate-Risk Myelodysplastic Syndromes Patients.

The treatment of myelodysplastic syndromes (MDS) involves improving patient survival and quality of life (QoL) and decreasing the likelihood of progression to AML. Although the treatment outcomes of MDS remain unsatisfactory, few comparative studies have been performed while comparing the outcomes of low-risk and intermediate-risk patients treated with supportive care and chemotherapeutics to those of patients treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Therefore, we designed a clinical control study to compare the outcomes of supportive care and chemotherapeutics versus allo-HSCT treatment in MDS patients. A total of 182 patients with MDS were enrolled in the study, including 91 in the no-HSCT (control) group and 91 in the allo-HSCT group. The complete remission (CR) rate in the allo-HSCT group was significantly higher than that in the control group (53.8% vs. 33.0%; P < 0.05). The QoL of patients in the HSCT group was much higher than that in the control group (53.8% vs. 37.4%; P < 0.05). The overall survival (OS) rates were 79.0% and 56.0% (P < 0.05) in the HSCT group and the control group, respectively. In conclusion, a high-dose fludarabine (Flu), busulfan (Bu), cyclophosphamide (CTX)-based conditioning regimen was well tolerated and significantly speeded hematopoietic recovery. In addition, this regimen increased procedure-related toxicity and improved QoL and OS.

[Risk factors and outcome of invasive fungal infection in 79 patients received allogeneic hematopoietic cell transplantation].

OBJECTIVE: To study the incidence, risk factors and outcome of invasive fungal infection(IFI) in the recipients with allogeneic hematopoietic cell transplantation(HSCT). METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Superselective arterial embolization of the superior mesenteric artery for the treatment of gastrointestinal hemorrhage following allogeneic hematopoietic stem cell transplantation.

Superselective arterial embolization is a common therapeutic procedure for cases of visceral hemorrhage. However, until now, it has not been applied in the treatment of gastrointestinal (GI) hemorrhage caused by acute graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation. We describe a case presenting with persistent GI bleeding associated with acute GVHD successfully treated by superselective arterial embolization of the superior mesenteric artery with gelatin sponge after noneffective conventional management. This case will help guide hematologists to deal with a similar situation in the future.

[Clinical study of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation].

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.

[Clinical application of BCR/ABL probes in myeloproliferative disorders].

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.

An anti-human thymocyte globulin-based reduced-intensity conditioning regimen is associated with a higher quality of life and lower organ toxicity without affecting lymphocyte reconstitution.

Reduced-intensity (RIT) conditioning regimens are gaining increased attention as a result of their advantages and efficacy. However, no data are available regarding whether these regimens improve patient quality of life (QoL). In our study, health-related QoL (HRQoL) was retrospectively assessed in 111 patients with hematological malignancies. Analysis of the Quality of Life Questionnaire indicated that 35 of the RIT patients were able to perform their normal work and returned to their baseline levels of function 2 to 3 months after transplantation. In the myeloablative (MA) group, only 24 patients were able to resume work, and these patients returned to their baseline levels of function 6 to 8 months after transplantation (68.6% vs. 40.0%, P = 0.004). Grade III-IV organ toxicity occurred in 20% of the RIT patients and in 52% of the MA patients (P = 0.001), and the cumulative incidences of grades III-IV acute graft-versus-host disease (GVHD) were 13.7% and 35.0% in RIT and MA patients, respectively (P = 0.015). In conclusion, the RIT conditioning regimens were well tolerated by the patients, with a low incidence of transplant-related mortality (TRM) and serious acute GVHD. In addition, these regimens minimized procedure-related toxicity, improved QoL and did not influence lymphocyte reconstitution; however, OS was similar for both regimens because the relapse rate was relatively increased in the RIT groups.

[Effect of gambogic acid on proliferation of SKM-1 cells and its mechanism].

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.

The role of Tα1 on the infective patients after hematopoietic stem cell transplantation.

The present study was designed to investigate the effect of thymosin α1 (Tα1) administration in infective recipients of hematopoietic stem cell transplantation (HSCT) for hematologic malignancies. Eight patients were enrolled in our study, including seven allo-HSCT patients and one auto-HSCT patient. These patients were allocated randomly into the treatment group (four cases) and control group (four cases). Tα1 was used in the treatment group to test its effectiveness in infection control. The concentrations of cytokines IFN-γ, IL-2, IL-4, IL-10, and IL-12 were observed, and the levels of CD3(+), CD4(+), and CD8(+) T cells, as well as of CD4(+)/CD8(+) and CD4(+)/CD25(+) regulatory T cell (Treg) were measured. When Tα1 was administered for 2 weeks, the concentrations of these cytokines were increased after 1 month in the treatment group. Interestingly, the levels of IFN-γ, IL-2, IL-10, and IL-12 were increased in the treatment group more than those in the control group, whereas there were no significant differences between the treatment and control group in the levels of CD3(+), CD4(+), and CD8(+) T cells, or in CD4(+)/CD8(+) or CD4(+)/CD25(+) Treg cells. Notably, Tα1 administration did not cause acute or chronic graft versus host disease (GVHD). We conclude that Tα1 administration is safe and may impact favorably on immune function, and that it may improve resistance to infection and induce immunotolerance without GVHD.

Association of polymorphisms of cytosine arabinoside-metabolizing enzyme gene with therapeutic efficacy for acute myeloid leukemia.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: It is evident that the DCK and CDA polymorphisms might be the important markers for the AML patients' therapy outcomes in a Chinese population.

[Effects of advanced glycosylation end products and tetrandrine on proliferation of K562 and K562/A02 cells].

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].

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.

Quality of life of patients after allogeneic hematopoietic stem cell transplantation with antihuman thymocyte globulin.

The utility of graft-versus-host disease (GVHD) prophylaxis with cyclosporine (CSA), methotrexate (MTX), and antihuman thymocyte globulin (ATG) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) exists in the literature; however, up to now, it has not yet been fully described. This study was to observe the influence of adding ATG on GVHD prophylaxis and the quality of life (QoL) of 96 hemopathic patients after allo-HSCT. We retrospectively analyzed the outcomes of 96 consecutive patients undergoing allo-HSCT, including 54 patients who received ATG regimen without in vitro T cell depletion (TCD) (ATG group) and 42 patients who received neither ATG regimen nor TCD (control group). All patients were followed up, and the factors, including age, sex, HLA and ABO compatibility, related and unrelated donors, and disease status, were undertaken to analysis. All patients in the study achieved trilineage engraftment with full-donor chimerism. The cumulative incidence of acute GVHD (aGVHD) was lower in the ATG group than that in the control group (29.6% versus 57.1%, P = .006), and the cumulative incidence of chronic GVHD (cGVHD) was 35.2% for patients with ATG and 66.7% for patients without ATG (P < .01). Notably, the proportion of patients with Karnofsky scores of >90 was 70.4% in the patients with ATG, and 28.6% in the patients without ATG (P < .001). Furthermore, the cumulative incidence of patients with opportunistic infection was significantly different in both groups posttransplantation, with 44.4% and 19.1% in recipient patients with or without ATG respectively (P < .05). Additional usage of ATG not only decreases the occurrence of aGVHD and cGVHD, but also improves QoL of patients after allo-HSCT without affecting stem cell engraftment or overall survival.

[Analysis of risk factors for relapse of 82 patients with hematologic malignancies after allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To explore the risk factors for relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and the measures of prophylaxis and treatment. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Effect of desferrioxamine on K562/A02 cell line and its mechanism].

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 5-bromotetrandrine and daunorubicin on apoptosis and expression of survivin in K562/A02 cells].

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.