OBJECTIVE: To explore the combined pro-apoptosis effect of HSP90 inhibitor BIIB021 and chloroquine (CQ) in chronic myeloid leukemia (CML) cells bearing T315I mutation and its mechanism. METHODS: The p210-T315I cells were divided into 4 groups by different treatment: control, BIIB021, CQ, and BIIB021 + CQ. After treated with BIIB021 or/and CQ for 24 hours, Annexin V/PI binding assay was used to detect apoptosis rates of CML cells. DAPI staining was used to observe nuclear fragmentation, and Western blot was used to detect the expression of caspase 3, PARP (apoptosis related proteins) and p62, LC3-I/II (autophagy related proteins). P210-T315I cells were inoculated subcutaneously into mice and CML mouse models were established. The mice in treatment groups were injected with BIIB021 and/or CQ while mice in control group were treated with PBS and normal saline. The tumor volume of mice was measured every 4 days, and protein level of cleaved-caspase 3 and LC3-II in tumor tissue were detected by immunohistochemistry. RESULTS: The results showed that BIIB021 induced apoptosis of CML cells in a dose-dependent manner ( r=0.91). CQ could enhance the apoptosis-inducing effect of BIIB021. Flow cytometry analysis results showed that the apoptosis rate of p210-T315I cells in combination group was higher than that in BIIB021 or CQ only group (P<0.05). DAPI staining showed nuclear fragmentation in combination group could be observed more obviously. Western blot analysis showed that BIIB021 could induce LC3-I to convert to LC3-II and decrease p62 protein levels (P<0.05). Moreover, the combination group had higher expression of LC3-II, p62 (P<0.05), activated PARP and activated caspase 3 than BIIB021 only group (P<0.05). Besides, experiment in vivo showed the mean tumor volume in co-treatment group was lower than that in single drug group (P<0.01). Immunohistochemistry of tumor tissue also showed the protein level of cleaved-caspase 3 and LC3-II in combined group was higher than that in BIIB021 only group. CONCLUSION HSP90 inhibitor BIIB021 induced significant apoptosis of CML cells bearing T315I both in vivo and in vitro. CQ can enhance this effect probably by autophagy inhibition.
Adenine/analogs & derivatives* ; Animals ; Apoptosis ; Autophagy ; Caspase 3/metabolism* ; Cell Line, Tumor ; Chloroquine/therapeutic use* ; Fusion Proteins, bcr-abl/pharmacology* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Mice ; Mutation ; Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use* ; Pyridines

OBJECTIVETo investigate the effect of steadily down-regulating the expression of VE-cadherin on the chemotheraputic sensitivity of K562 cells, and explore its possible mechanism.

METHODSSpecifically targeting interference sequences carrying human VE-cadherin were designed, the recombinant lentiviral vector containing the IRES-GFP and NEO segment was constructed; recombinant lentivirus was generated by three-plasmids packing system, and transfected into K562 cells, then the cells steadily down-regulated were sorted. CCK-8 assay was performed to evaluate the VE-cadherin of chemotherapeutic (Imatinib) sensitivity of K562 cells. The apoptosis was analyzed by flow cytometry with Annexin V/7-AAD double labeling. The expressions of CD133 and ALDH1 mRNA were determined by real time PCR. The protein expressions of VE-cadherin, BCR-ABL and β-catenin were analyzed by Western blot.

RESULTSThe recombinant lentiviral vector pLB-shVEC-NEO-IRES-GFP was successfully constructed, packed into the lentivirus, then the K562 cells steadily down-regulating VE-cadherin expression was obtained. When VE-cadherin was down-rengulated in K562 cells, the proliferation rate was reduced while the the apoptosis rate was increased; the mRNA levels of CD133 and ALDH1 also were reduced; BCR-ABL fusion protein was not obviously changed; the total β-catenin protein, as well as the nuclear β-catenin protein were decreased in the K562/shVEC cells. Conclution: K562 cells are more susceptible to chemotherapy when VE-cadherin is down-regulated, that may be realized via reducing the stability and the nuclear transfer of β-catenin protein.

Antigens, CD ; metabolism ; Apoptosis ; Cadherins ; metabolism ; Cell Proliferation ; Fusion Proteins, bcr-abl ; Humans ; K562 Cells

Adenocarcinoma ; complications ; drug therapy ; metabolism ; Aged ; Antineoplastic Agents ; therapeutic use ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; etiology ; metabolism ; Male ; Organoplatinum Compounds ; therapeutic use ; Stomach Neoplasms ; drug therapy ; metabolism

INTRODUCTIONThe prognosis of patients with chronic myeloid leukaemia (CML) has improved since the introduction of imatinib. However, patients who do not achieve complete cytogenetic response (CCyR) and major molecular response (MMR) have poorer prognosis. Recent clinical trials have demonstrated that early and deeper cytogenetic and molecular responses predict a better long-term outcome. This study aimed to analyse the relationship between early molecular response and clinical outcome in a real-life setting.

METHODSThis retrospective study included all patients with CML, in chronic or accelerated phase, who were treated with imatinib at University of Malaya Medical Centre, Malaysia.

RESULTSA total of 70 patients were analysed. The median follow-up duration was 74 months, and the cumulative percentages of patients with CCyR and MMR were 80.0% and 65.7%, respectively. Overall survival (OS) and event-free survival (EFS) at ten years were 94.3% and 92.9%, respectively. Patients who achieved CCyR and MMR had significantly better OS and EFS than those who did not. At six months, patients who had a BCR-ABL level ≤ 10% had significantly better OS and EFS than those who had a BCR-ABL level > 10%. The target milestone of CCyR at 12 months and MMR at 18 months showed no survival advantage in our patients.

CONCLUSIONOur data showed that imatinib is still useful as first-line therapy. However, vigilant monitoring of patients who have a BCR-ABL level > 10% at six months of treatment should be implemented so that prompt action can be taken to provide the best outcome for these patients.

Academic Medical Centers ; Adult ; Antineoplastic Agents ; therapeutic use ; Cytogenetics ; Disease-Free Survival ; Female ; Follow-Up Studies ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Imatinib Mesylate ; therapeutic use ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; drug therapy ; genetics ; Malaysia ; Male ; Middle Aged ; Predictive Value of Tests ; Prognosis ; Retrospective Studies ; Treatment Outcome ; Universities

No abstract available.
Aged ; Cytidine Deaminase/*genetics/metabolism ; Dasatinib/therapeutic use ; Disease Progression ; Drug Resistance, Neoplasm ; Fusion Proteins, bcr-abl/genetics/metabolism ; Humans ; Imatinib Mesylate/*therapeutic use ; In Situ Hybridization, Fluorescence ; Karyotype ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/*drug therapy ; Male ; Microfilament Proteins/*genetics/metabolism ; Oncogene Proteins/*genetics/metabolism ; Protein Kinase Inhibitors/*therapeutic use

No abstract available.
Bone Marrow/pathology ; Chromosomes, Human, Pair 12 ; Chromosomes, Human, Pair 9 ; Core Binding Factor Alpha 2 Subunit/*genetics ; DNA/metabolism ; Gene Rearrangement ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis/*genetics ; Male ; Middle Aged ; Oncogene Proteins, Fusion/*genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Translocation, Genetic

No abstract available.
Aged, 80 and over ; Base Sequence ; Bone Marrow/pathology ; DNA/chemistry/metabolism ; Female ; Fusion Proteins, bcr-abl/*genetics ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis/*genetics ; Multiplex Polymerase Chain Reaction ; Protein Isoforms/genetics ; Sequence Analysis, DNA

OBJECTIVETo evaluate the efficiency of dasatinib as the second- or third-line tyrosine kinase inhibitor (TKI)in imatinib-resistant patients with chronic myeloid leukemia (CML)based on BCR-ABL mutation detection.

METHODS122 CML patients received dasatinib treatment, including 83 with imatinib-resistance and 39 with both imatinib- and nilotinib-resistance, 55 in the chronic-phase (CP), 21 in the accelerated- phase (AP)and 46 in the blast- phase (BP). Those harboring dasatinib highly- resistant mutations (T315I/A, F317L/V/C and V299L)were excluded based on BCR-ABL kinase domain mutation screening by Sanger sequencing at baseline. Hematologic, cytogenetic and molecular responses were evaluated regularly, and rates of progression-free-survival (PFS)and overall survival (OS)were analyzed. BCR- ABL mutation detection was performed once the patients failed on dasatinib.

RESULTSIn the CP patients, the rates of complete hematological response (CHR), complete cytogenetic response (CCyR), major molecular response (MMR)and molecular response 4.5 (MR4.5)were 92.7%, 53.7%, 29.6% and 14.8%, respectively. 4-year PFS and OS rates were 84.4% and 89.5%, respectively. In the AP patients, HR and CCyR rates were 81.0% and 35.0%; and 3-year PFS and OS rates were 56.1% and 59.3%, respectively. In the BP patients, HR and CCyR rates were 63.0% and 21.4%; and 1-year PFS and OS rates were 43.6% and 61.8%, respectively. Outcomes were similar when dasatinib was used as the second- line TKI or the third-line TKI. Of the 75 patients who were resistant to dasatinib, 37 (48.7%)developed new mutation(s), and T315I (59.5%)was the most common mutation type. The patients who already harbored mutation(s)before dasatinib therapy achieved similar responses and outcomes to those with no mutation at baseline. However, they had higher likelihood of developing additional mutations associated with resistance to dasatinib (65.7%vs 34.1%,P=0.006).

CONCLUSIONSDasatinib was proved to be effective in the treatment of imatinib- or/and nilotinib-resistant CML patients, especially in both CP and AP cohorts. The significance of BCR-ABL mutation screening and monitoring should be highlighted before and during dasatinib therapy.

Blast Crisis ; Cytogenetics ; Dasatinib ; therapeutic use ; Disease-Free Survival ; Drug Resistance, Neoplasm ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; drug therapy ; Mutation ; Protein Kinase Inhibitors ; therapeutic use ; Pyrimidines

OBJECTIVETo explore the effect of a novel emodin derivative E19 on proliferation inhibition and apoptosis induction of human chronic myelogenous leukemia (CML) cell line K562 and imatinib-resistant CML cell line (K562/G01), and to clarify the involved mechanisms.

METHODSMTT and colony formation test were used to detect the cell proliferation. Apoptotic induction effects were examined by DAPI staining method and DNA ladder assay. Western blot was performed to detect the changes of P210(Bcr-Abl) protein.

RESULTSThe emodin derivative E19 could efficiently inhibit proliferation and induce apoptosis in K562 and K562/G01 cells. IC50 of K562 cells and IC50 of K562/G01 cells were (1.20 ± 0.19) µmol/L and (1.22 ± 0.16) µmol/L, respectively. DNA fragmentation in K562 cells and K562/G01 cells confirmed that the E19 induced apoptosis in dose-dependent manner. Western blot showed that emodin derivative inhibited phosphorylation of P210 protein in K562 cells and K562/G01 cells and down-regulated the expression level of P210 in dose- and time-dependent manners.

CONCLUSIONThe emodin derivative E19 can efficiently inhibit growth and induce apoptosis of K562 cells and K562/G01 cells, while the inhibition of phosphorylation of P210 protein and down-regulation of P210 protein expression may be involved in these processes.

Apoptosis ; drug effects ; Cell Proliferation ; Down-Regulation ; Drug Resistance, Neoplasm ; Emodin ; analogs & derivatives ; pharmacology ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Imatinib Mesylate ; pharmacology ; K562 Cells ; drug effects ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; pathology ; Phosphorylation

OBJECTIVETo investigate the effects of Sinopodophyllum hexundrum on apoptosis in K562 cells.

METHODSK562 cells were treated with Sinopodophyllum hexundrum at different concentrations and for different lengths of time to determine the optimal conditions of SinoPodophyllum hexandrum treatment for K562 cells using CCK8 assay. The cell apoptotic rate was detected by flow cytometry, and the cell morphology and nuclear morphology of K562 cells were observed with Wright staining and DPAI staining, respectively. The protein expressions of BCR/ABL, p-BCR/ABL, STAT5, p-STAT5 and the apoptosis-related proteins PARP, caspase-3 and cleaved-caspase-3 were determined with Western blotting.

RESULTSThe cell proliferation was inhibited in a concentration-and time-dependent manner by 1, 2, and 3 µg/mL Sinopodophyllum hexundrum. The treatment was optimal with a Sinopodophyllum hexundrum concentration of 2 µg/mL a treatment time of 48 h, and the cell apoptotic rate increased in a time-dependent manner and significantly increased at 48 h (P<0.001). The expression of apoptosis-related proteins PARP, caspase-3 and cleaved-caspase-3 were also activated in a time-dependent manner. The cells showed typical apoptotic changes after treatment with 2 µg/mL Sinopodophyllum hexundrum for 48 h with significantly reduced expressions of BCR/ABL, p-BCR/ABL, STAT5, AND p-STAT5.

CONCLUSIONSinopodophyllum hexundrum promotes K562 cell apoptosis possibly by inhibiting BCR/ABL-STAT5 survival signal pathways and activating the mitochondrion-associated apoptotic pathways.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Proliferation ; Drugs, Chinese Herbal ; pharmacology ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; K562 Cells ; Mitochondria ; metabolism ; STAT5 Transcription Factor ; metabolism ; Signal Transduction