Efficacy of Micro-Transplantation Consolidation Therapy for Patients with Acute Myeloid Leukemia after Complete Remission / 中国实验血液学杂志

OBJECTIVE@#To investigate the efficacy and safety of micro-transplantation in acute myeloid leukemia (AML).@*METHODS@#The clinical data of 13 adult AML patients who received micro-transplantation as consolidation therapy from July 2014 to October 2019 was retrospectively analyzed, and the adverse reactions and efficacy of micro-transplantation were followed up.@*RESULTS@#Eight patients received micro-transpantation were still in complete remission, 5 patients relapsed after micro-transplantation, 1 of them received umbilical cord blood micro-transplantation after remission by reinduction, and all of the 13 patients have survived till now. The median overall survival time was 13 months, and the median relapse-free survival time was 12 months. All 13 patients developed grade 2-4 hematological adverse reactions. The median recovery time of neutrophils and platesets was 13 (11-15) and 15 (13-17) days, respectively. None of the 13 patients developed acute or chronic graft versus host disease. Twelve patients suffered from different infections, however, there were no serious organ function injury complications happened.@*CONCLUSION@#The micro-transplomtation of HLA-incompatible stem cells derived from peripheral blood or umbilical and blood is an effective regimen for the consolidation therapy of AML, especially for the patients suffered from low and moderate risk of AML or the aged AML patients.

Significance of Targeted Sequencing Assay for Patients with Suspected Myeloid Malignancies / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical significance of the targeted next-generation sequencing assay for patients with suspected myeloid malignancies.@*METHODS@#A total of 39 hematopenia patients with suspected myeloid malignamies in Department of Hematology of The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University from January 2018 to April 2019 were treated, 20 hot spot genes of myelodysplastic syndrome (MDS) were detected.@*RESULTS@#Regarding the diagnostic type, there were 7 cases of idiopathic cytopenia of undetermined significance (ICUS), 8 cases of clonal cytopenias of undetermined significance (CCUS) and 24 cases of myeloid myeloid malignancies which included 18 cases of MDS, 4 cases of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) and 2 cases of acute myeloid leukemia. Positive mutation was detected in 70.8% (17/24) of myeloid malignancy patients , and 72.7% (16/22) in MDS and MDS/MPN patients. The main mutation types were ASXL1, TET2 and RUNX1. Compared with gene negative group, there were no significant differences in sex, age (＜60 years old or ≥60 years old), proportion of bone marrow blast cells (＜5% or≥5%) and cytogenetics (good, medium and poor) (P＞0.05). Furthermore, all 8 CCUS patients showed positive mutation, and the incidence of double or multiple mutation in CCUS group was significantly lower than that of the MDS and MDS/MPN group (37.5% vs 54.5%) (P=0.002). The mutation types between the two groups were similar, and there was no significant difference in variant allele frequency (P＞0.05).@*CONCLUSION@#Our results suggest that there are high rates of double or multiple mutations in myeloid malignancies, especially in patients with MDS and MDS/MPN. Targeted sequencing assay can improve the diagnosis of myeloid malignancies, and guide clinical treatment.

Effects of Ubiquitination on the Expression of BCL6 Protein，Cell Proliferation and Apoptosis in K562/G01 Cells / 中国实验血液学杂志

OBJECTIVE@#To explore the the effects of ubiquitin-proteasome system (UPS) on BCL6 protein level，proliferation and apoptosis of cell imatinib（IM）-resistant K562/G01 cells.@*METHODS@#Western blot was used to detect the expression of BCL6 in K562/G01 cells before and after treatment with protease inhibitor MG-132.The RT-PCR and Western blot respectively were used to detect the mRNA and protein expression levels of BCL6 and USP2 in K562/G01 cells treated with or without ML364 (a ubiquitin-specific protease USP2 inhibitor). The effects of IM alone or in combination with ML364 on proliferation and apoptosis of K562/G01 were analysed by CCK-8 method and flow cytometry.@*RESULTS@#After treatment with protease inhibitor MG132, the BCL6 protein level of K562/G01 significantly increased (P<0.05). The mRNA and protein expression level of ubiquitin-specific protease USP2 in K562/G01 cell line was higher than that in K562 cell line (P<0.05). After treatment of K562/G01 with USP2 protease inhibitor ML364, the expression levels of USP2 and BCL6 proteins were down-regulated simultaneously (P<0.05) . After combination of ML364 and IM, both the proliferation inhibitory rate and the apoptosis rate of K562/G01 cells significantly increased(P<0.05).@*CONCLUSION@#ML364 decreases the BCL6 protein stability in K562/G01 by inhibiting the USP2-mediated deubiquitination, and down-regulate the BCL6 protein experssion, thereby increases the sensitivity of drug-resistant cells to IM.

Mechanism of mTOR Pathway in K562 cell Apoptosis Induced by Homoharringtonine / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of homoharringtonine (HHT) on proliferation and apoptosis of CML cell line K562 cells and to explore its possible mechanism through mTOR pathway.</p><p><b>METHODS</b>K562 cells were cultured with different concentrations of HHT or in its combination with mTOR inhibitor rapamycin (RAPA) for 24 hours. The cell viability was analyzed by CCK-8 assay, the cell apoptosis was detected by flow cytometry, the expressions of BCL-6, Caspase-3 and mTOR signal pathway related proteins was assayed by Western blot, the expression of BCL-6 mRNA was determined by RT-PCR.</p><p><b>RESULTS</b>The HHT inhibited proliferation and induced apoptosis of K562 cells in a concentration-dependent manner(r=0.970). With the increasing of HHT concentration, the expression level mTOR signal pathway related proteins increased(r=0.908), while the mRNA and protein expression levels of BCL-6 decreased(r=-0.961, r=-0.981), as compared with the HHT alone, the combination of HHT with RAPA could down-regulate the expression of mTOR signal pathway related protein and caspase-3, and up-regulated expression of BCL-6.</p><p><b>CONCLUSION</b>HHT induces apoptosis of K562 cells by inhibiting BCL-6 expression through mTOR signal pathway.</p>

Effect of Homoharringtonine Combined with Imatinib on the K562/G01 Cells and Its Mechanism / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of homoharringtonine(HHT) combined with imatinib(IM) on proliferation and apoptosis of K562/G01 cells and its potential mechanism.</p><p><b>METHODS</b>K562/G01 cells were cultured with HHT and/or IM. CCK-8 assay was used to detect cell proliferation. Cell apoptosis and phosphorylated tyrosine levels were analyzed by flow cytometry. The expression levels of p210, PI3K, p-Akt and Akt protein were determined by Western blot.</p><p><b>RESULTS</b>Compared with HHT or IM alone, drug combination significantly inhibited cell proliferation and induced apoptosis of K562/G01 cells (both P< 0.05). HHT combined with IM could inhibit the levels of phosphorylated tyrosine and phosphorylated Crkl and downregulate the expressions of p210, PI3K and p-Akt in K562/G01 cells.</p><p><b>CONCLUSION</b>HHT combined with IM can synergistically inhibit proliferation and induce apoptosis of K562/G01 cells by suppressing the p210 expression and its kinase activity.</p>

Progress of Researches on Prediction of Tyrosine Kinase Inhibitor Efficacy for Treatment of Chronic Myelocid Leukemia -Review / 中国实验血液学杂志

Tyrosine kinase inhibitors (TKI) have made a dramatic improvement in the clinical efficacy of chronic myelogenous leukemia, but the occurrence of TKL resistance and intolerance does not enable some patients to acquire the satisfactory efficacy. Screening the proper TKL for patients with high risk before the treatment and conversing drug timely based on early detection of TKL resistance are helpful to accurately use TKI and enhance therapeutic efficacy. In this article, the function of some indicators, such as baseline clinical, biochemical and molecular biological characteristics and influence of early treatment response law of imatinib on long-term prognosis of newly diagnosed patients are summarized.

Effect of Autophagy on Homoharringtonine-treated K562 Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the effect of homoharringtonine (HHT) alone or combined with 3-methyladenine (3-MA) , an autophagy inhibitor, on the apoptosis and autophagy of K562 cells.</p><p><b>METHODS</b>K562 cells were treated with HHT(10 ng/ml) or HHT(10 ng/ml) combined with 3-MA (1.5 mmol/L) for 1 to 8 days. The apoptosis of treated cells was tested by means of flow cytometry(FCM), and the autophagy levels were tested with RT-PCR, Western blot and electron microscopy.</p><p><b>RESULTS</b>In the early stage of HHT-treated group, the apoptosis rate increased and decreased later. Beclin1 mRNA expression level and the LC3II/I ratio were declined firstly and increased later in HHT group. While combining with autophagy inhibitor 3-MA, both the Beclin1 mRNA expression level and the LC3II/I ratio were declined continually during the treated period. The activated caspase-3 protein expression level was also raised sustainability during both HHT and 3-MA cultured period.</p><p><b>CONCLUSIONS</b>HHT can induce apoptosis of K562 cells, but the sustaining effect of HHT can induc autophagy of K562 cells, the combination of HHT with 3-MA may enhance the cytotoxicitic effect of HHT on K562 cells.</p>

Acadesine Inhibits the Proliferation of K562 Cells and Enhances their Sensitivity to Imatinib / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of AMPK agonist Acadesine (AICAR) on growth inhibition of K562 cells and their sensitivity to imatinib (IM).</p><p><b>METHODS</b>K562 cells were cultured with different concentrations of AICAR alone or its combination with IM for 48 hours, the CCK-8 assay was used to detect cell proliferation, the cell cycle distribution and apoptosis were analyzed by flow cytometry. The expression levels of Cyclin D1, Cyclin E1 and Caspase 3 protein were determined by Western blot.</p><p><b>RESULTS</b>AICAR inhibited the proliferation of K562 cells in dose-dependent manner, and their IC50 value was 0.45 mmol/L at 48 hours. AICAR could induce arrest of K562 cells in G1 phase and down-regulated the protein expression levels of Cyclin D1 and Cyclin E1; whereas it didn't influence the cell apoptosis. Additionally, the growth inhibition of cells induced by IM was enhanced by AICAR.</p><p><b>CONCLUSION</b>AICAR can inhibit the proliferation of K562 cells by arresting the cell cycle and enhancing the sensitivity of K562 cells to IM.</p>

Effects of Homoharringtonine Combined with Imatinib on K562 Cell Apoptosis and BCL6 expression / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the effects of homoharringtonine (HHT) alone or combined with imatinib (IM) on K562 cell proliferation and apoptosis, as well as the mRNA and protein expression of BCL6.</p><p><b>METHODS</b>The CCK-8 was used to detect the inhibitory effect of drugs on cell growth, the flow cytometry was used to detect the cell apoptosis. The expression of BCL6 protein was assayed by Western blot, and BCL6 mRNA expression was detected by RT-PCR.</p><p><b>RESULTS</b>HHT alone displayed a proliferation inhibition effect with dose- dependent manner, and induced apotosis; after combination of HHT and IM drugs, both the inhibitory rate and the apoptosis rate were significantly increased compared with the drug alone(P<0.05). Western blot showed that the expression of BCL6 protein was down-regulated after being treated with HHT, however, the BCL6 protein was up-regulated after being treated with IM . The effect of drug combination showed that BCL6 protein significantly down-regulated(P<0.05 ). The expression of BCL6 mRNA was decreased both in the treatment of HHT or IM alone when compared with control. And the effect of drug combination showed that BCL6 mRNA expression was more significantly down-regulated(P<0.05 ).</p><p><b>CONCLUSION</b>HHT can inhibit the K562 cell proliferation and induce apoptosis of K562 cells. Combination of IM with HHT shows a significant synergistic effect, the mechanism may be associated with down-regulation of BCL6.</p>

Effect of YM155 on Apoptosis and Autophagy of K562 Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was purposed to investigate the effect of YM155, a survivin inhibitor, on the apoptosis and autophagy of K562 cells.</p><p><b>METHODS</b>K562 cells were treated with YM155 at different concentration. Cell survival was analyzed by CCK-8 assay, the cell apoptosis was detected by flow cytometry. Survivin, BCL-2 and beclin1 mRNA expressions were determined by RT-PCR. Survivin, BCL-2, caspase-3, PARP and LC-3 protein expressions were assayed by Western blot.</p><p><b>RESULTS</b>YM155 inhibited the proliferation of K562 cells in a time- and dose-dependent manners. With the increasing of YM155 concentration and prolonging of action time, the expression levels of mRNA and protein of survivin and BCL-2 decreased, while the expression levels of caspase-3, PARP, beclin1 and LC-3 increased. Compared with the YM155 group, the protein levels of LC-3 and caspase-3 were lower in YM155 combined with 3-MA group.</p><p><b>CONCLUSION</b>YM155 can inhibit K562 cell proliferation by inducing apoptosis and autophagy, while autophagy induction effect can enhance its cytotoxic effect.</p>