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

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

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

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

BACKGROUND/AIMS: The treatment of chronic myeloid leukemia (CML) has achieved impressive success since the development of the Bcr-Abl tyrosine kinase inhibitor, imatinib mesylate. Nevertheless, resistance to imatinib has been observed, and a substantial number of patients need alternative treatment strategies. METHODS: We have evaluated the effects of deferasirox, an orally active iron chelator, and imatinib on K562 and KU812 human CML cell lines. Imatinib-resistant CML cell lines were created by exposing cells to gradually increasing concentrations of imatinib. RESULTS: Co-treatment of cells with deferasirox and imatinib induced a synergistic dose-dependent inhibition of proliferation of both CML cell lines. Cell cycle analysis showed an accumulation of cells in the subG1 phase. Western blot analysis of apoptotic proteins showed that co-treatment with deferasirox and imatinib induced an increased expression of apoptotic proteins. These tendencies were clearly identified in imatinib-resistant CML cell lines. The results also showed that co-treatment with deferasirox and imatinib reduced the expression of BcrAbl, phosphorylated Bcr-Abl, nuclear factor-kappaB (NF-kappaB) and beta-catenin. CONCLUSIONS: We observed synergistic effects of deferasirox and imatinib on both imatinib-resistant and imatinib-sensitive cell lines. These effects were due to induction of apoptosis and cell cycle arrest by down-regulated expression of NF-kappaB and beta-catenin levels. Based on these results, we suggest that a combination treatment of deferasirox and imatinib could be considered as an alternative treatment option for imatinib-resistant CML.
Antineoplastic Agents/*pharmacology ; Apoptosis/drug effects ; Apoptosis Regulatory Proteins/metabolism ; Benzoates/*pharmacology ; Cell Proliferation/drug effects ; Dose-Response Relationship, Drug ; Drug Resistance, Neoplasm/*drug effects ; G1 Phase Cell Cycle Checkpoints/drug effects ; Humans ; Imatinib Mesylate/*pharmacology ; Iron Chelating Agents/*pharmacology ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/*drug therapy/metabolism ; Protein Kinase Inhibitors/*pharmacology ; Signal Transduction/drug effects ; Triazoles/*pharmacology

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 understand the prognostic value of early monitoring BCR-ABL transcripts in patients with chronic myeloid leukemia (CML) after treatment with imatinib, and to provide the information for early assessment of prognosis and treatment options.

METHODSThe clinical data of 251 patients with CML in chronic phase (CML-CP) who received imatinib as first-line therapy were retrospectively analyzed, the progression-free survival (PFS)and overall survival (OS) between different BCR-ABL transcriptional level at 3 and 6 month after imatinib treatment were compared. Meanwhile, Chi-square test and logistic regression were used to analyze the risk factors for disease progression.

RESULTSAt 3 months after imatinib treatment BCR-ABL transcriptional levels>10%, >1%-≤ 10% and ≤ 1% were found in 92, 94 and 64 patients, their PFS were 53.3%, 71.3% and 86.2%, respectively. The results showed that the PFS of patients with low BCR-ABL transcriptional levels was significantly superior to that with high BCR-ABL transcriptional levels for CML at 3 months treatment (P<0.05). The OS of three group did not reach statistical significance (92.4% vs 96.8% vs 93.8%, P> 0.05). When 182 patients received imatinib treatment at 6 months, 22 patients with BCR-ABL transcriptional levels>10%, 50>1% -≤ 10% and 110 ≤ 1%, their PFS were 27.3% vs 66.0% vs 82.7% (P<0.05), the OS of three groups were 86.4% vs 94.0% vs 100%. There were significant differences among the three groups (P<0.05). Logistic regression confirmed that the level of BCR-ABL transcriptional level at 3 and 6 months after imatinib treatment was independent factor to influence the progress of disease.

CONCLUSIONIt is important for the prognosis evaluation of CML patients to monitor BCR-ABL transcriptional level at 3 and 6 months after imatinib treatment.

Antineoplastic Agents ; therapeutic use ; Disease-Free Survival ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Imatinib Mesylate ; therapeutic use ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; drug therapy ; Prognosis ; Retrospective Studies ; Risk Factors

No abstract available.
Aged ; Antineoplastic Agents/therapeutic use ; Bone Marrow/pathology ; Fusion Proteins, bcr-abl/genetics/metabolism ; Humans ; Imatinib Mesylate/therapeutic use ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/complications/*diagnosis/drug therapy ; Leukocyte Count ; Male ; Multiple Myeloma/complications/*diagnosis/drug therapy ; Platelet Count ; Polymerase Chain Reaction ; Thrombocytosis/etiology

Cryptotanshinone (CPT), a lipid soluble active compound in Salvia miltiorrhiza, has a significant inhibitory effect on multiple malignant tumors, e. g. chronic myeloid leukemia (CML) cells and can effectively enhance imatinib's chemotherapeutic effect. However, its functional molecular mechanism remained unclear. In this experiment, the authors conducted a systematic study on the effect of CPT on the imatinib sensitivity and P-glycoprotein (P-gp) expression in CML cells by using CML cells K562 and imatinib persister K562-R. The MTT assays were performed to determine CPT's impact on the inhibitory effect of imatinib. Annexin V-FITC/PI staining analysis was used to detect the changes in the cell apoptosis rate. The active changes in apoptosis regulatory proteins Caspase-3, Caspase-9 and PARP were determined by Western blot. After the cells were pretreated with the gradient concentration of CPT, the expression of P-gp was analyzed by Western blot and flow cytometry. The changes in intracellular concentrations of imatinib were determined by HPLC analysis. The results indicated that the pretreatment with CPT significantly increased the proliferation inhibiting and apoptosis inducing effects of imatinib on K562 and K562-R cells as well as the degradation product expression of pro-apoptotic proteins Caspase-3, Caspase-9 and PARP, with a significant difference with the control group (P < 0.01). However, CPT showed no impact on the P-gp expression in CML cells and the intracellular concentrations of imatinib. In summary, the findings suggested that CPT enhanced the sensitivity of CML cells to imatinib. Its mechanism is not dependent on the inhibition in P-gp expression and the increase in intracellular drug concentration.
ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; genetics ; metabolism ; Caspase 9 ; genetics ; metabolism ; Drug Resistance, Neoplasm ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Imatinib Mesylate ; pharmacology ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; drug therapy ; genetics ; metabolism ; physiopathology ; Phenanthrenes ; pharmacology

No abstract available.
Adult ; Antineoplastic Agents/therapeutic use ; *Chromosome Deletion ; *Chromosomes, Human, Pair 9 ; Cytogenetic Analysis ; DNA Mutational Analysis ; Fusion Proteins, bcr-abl/*antagonists & inhibitors/genetics/metabolism ; Gene Expression Regulation ; Humans ; Incidental Findings ; Klinefelter Syndrome/complications/diagnosis/*genetics ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/complications/diagnosis/*drug therapy/enzymology/genetics ; Male ; Molecular Targeted Therapy ; Protein Kinase Inhibitors/*therapeutic use ; Remission Induction ; Time Factors ; Treatment Outcome