OBJECTIVETo analyze the association of different types of ABL tyrosine point mutations and imatinib resistance to probe the relation between ABL tyrosine point mutations and the prognosis of patients with chronic myeloid leukemia (CML).

METHODSNested reverse transcriptasepolym erase chain reaction was performed on samples from 70 patients to amplify the ABL kinase domain. Then, the amplified product was purified and sequenced in both direction. The homologous analysis was performed in combination of clinical data.

RESULTSThe ABL domain point mutations were detected in 32 patients (45.7%) including 16 patients in chronic phase (CP), 6 patients in accelerated phase(AP)and 10 patients in blast phase (BP), which were detected as T315I, E255K, C475Y, Y253H, G321W, G250E, F317L, E258K, F359V, E459K and F311I, respectively. Sokal score with intermediate and high risk and Ph+ chromosome with complex karyotype were important risk factors for ABL domain point mutations. The 5-year overall survival (OS) was not significantly different between the patients with or without ABL domain point mutations (78.1% vs 84.2%, P=0.985), while the 5-year cumulative event-free survival (EFS) of two groups were 34.4% and 68.4% (P=0.034), respectively. The rate of complete cytogenetic response was higher in patients treated with allogenic hematopetic stem cell transplantation (allo-HSCT) compared with patients merely treated with second-generation tyrosine kinase inhibitors or chemotherapeutics (P=0.001).

CONCLUSIONPatients with ABL domain point mutations had poor efficacy and prognosis compared to those without ABL domain point mutations. Detection of ABL domain point mutations in CML-CP was helpful for the adjustment of therapeutic options and improvement of prognosis. And allo-HSCT was a more effective therapy for patients with advanced phase.

Adolescent ; Adult ; Aged ; Benzamides ; therapeutic use ; Child ; Drug Resistance, Neoplasm ; Female ; Humans ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; drug therapy ; genetics ; Male ; Middle Aged ; Piperazines ; therapeutic use ; Point Mutation ; Prognosis ; Proto-Oncogene Proteins c-abl ; genetics ; Pyrimidines ; therapeutic use ; Young Adult

This study was aimed to investigate the effect of SU11248 on proliferation and apoptosis of leukemia cell line K562 in vitro and its mechanism. The inhibitory effect of 3.2 µg/ml SU11248 on K562 proliferation was tested by MTT assay. The ability of SU11248 to induce apoptosis of K562 cells was examined by TUNEL and DNA ladder. The expression of C-MYC, hTERT and BCR-ABL mRNA in K562 cells was detected by RT-PCR. The protein expression of Akt and p-Akt in K562 cells was detected by Western blot. The results showed that the proliferation of K562 cells was obviously inhibited by 3.2 µg/ml SU11248 in a time-dependent manner. SU11248 could induce K562 cells apoptosis in dose-and time-dependent manner. The mRNA expression of C-MYC, hTERT and BCR-ABL was reduced significantly by SU11248 in a time-dependent manner (P < 0.05). Western blot detection showed that the expression of p-Akt protein in K562 cells decreased in dose-and time-dependent manner after SU11248 treatment, but the expression of Akt was not significantly changed. It is concluded that SU11248 can inhibit the growth of K562 cells efficiently through inducing apoptosis, its mechanism may be closely relate with the expression down-regulation of C-MYC, hTERT, BCR-ABL and the inhibition of Akt phosphorylation.
Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Indoles ; pharmacology ; K562 Cells ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; Pyrroles ; pharmacology ; RNA, Messenger ; genetics ; Telomerase ; metabolism

OBJECTIVETo identify the distribution and differentiation of ABL kinase domain mutation in the Chinese Han nationality imatinib resistant chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+)ALL).

METHODSBone marrow or peripheral blood samples of 112 imatinib resistant CML patients and 21 Ph(+)ALL patients were obtained from the first affiliated hospital of Soochow university according to local law. Total RNA was extracted from the mononuclear cells using a TRIzol reagent. ABL kinase domain (KD) mutation was detected by direct sequencing.

RESULTSOf the 112 imatinib resistant CML patients, 54.46%(61 cases) had ABL KD mutation. Twenty-three mutants were identified in 20 amino acid sites and 23.21% (26 cases) ABL KD mutations were in P-loop region. ABL KD mutations were also detected in 71.43% (15 cases) imatinib resistant Ph(+)ALL patients, with 10 mutations in 8 amino acid sites. The most frequent mutation was T315I (28.57%), followed by E255K/V (19.05%) and Y253F/H (14.29%). The frequency of T315I was much higher in imatinib resistant Ph(+) ALL than that in imatinib resistant CML (P = 0.001). Ph(+)ALL with additional chromosomal aberrations also had a higher rate of ABL KD mutation than that of CML (P = 0.010). Ph(+)ALL gained ABL KD mutation faster than CML (P < 0.010).

CONCLUSIONChinese imatinib resistant CML and Ph(+)ALL patients had different characteristics in ABL KD mutation. The rate of ABL KD mutation in Ph(+)ALL with additional chromosomal aberrations was much higher than that of CML with additional chromosomal aberrations.

Adolescent ; Adult ; Aged ; Asian Continental Ancestry Group ; genetics ; Benzamides ; pharmacology ; Chromosome Aberrations ; Drug Resistance, Neoplasm ; genetics ; Female ; Humans ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Middle Aged ; Mutation ; Philadelphia Chromosome ; Piperazines ; pharmacology ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; Protein-Tyrosine Kinases ; genetics ; Proto-Oncogene Proteins c-abl ; genetics ; Pyrimidines ; pharmacology ; Young Adult

Studies on chronic myeloid leukemia (CML) have served as a paradigm for cancer research and therapy. These studies involve the identification of the first cancer-associated chromosomal abnormality and the subsequent development of tyrosine kinase inhibitors (TKIs) that inhibit BCR-ABL kinase activity in CML. It becomes clear that leukemia stem cells (LSCs) in CML which are resistant to TKIs, and eradication of LSCs appears to be extremely difficult. Therefore, one of the major issues in current CML biology is to understand the biology of LSCs and to investigate why LSCs are insensitive to TKI monotherapy for developing curative therapeutic strategies. Studies from our group and others have revealed that CML LSCs form a hierarchy similar to that seen in normal hematopoiesis, in which a rare stem cell population with limitless self-renewal potential gives rise to progenies that lack such potential. LSCs also possess biological features that are different from those of normal hematopoietic stem cells (HSCs) and are critical for their malignant characteristics. In this review, we summarize the latest progress in CML field, and attempt to understand the molecular mechanisms of survival regulation of LSCs.
Animals ; DNA-Binding Proteins ; genetics ; metabolism ; Fusion Proteins, bcr-abl ; antagonists & inhibitors ; metabolism ; Humans ; Hypoxia-Inducible Factor 1 ; metabolism ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; drug therapy ; metabolism ; pathology ; Lipid Metabolism ; Neoplastic Stem Cells ; drug effects ; metabolism ; Protein Kinase Inhibitors ; pharmacology ; therapeutic use ; Proto-Oncogene Proteins c-bcl-6 ; src-Family Kinases ; metabolism

Imatinib mesylate has been commonly used in the treatment of patients with chronic myeloid leukemia (CML). However, a significant number of CML patients treated with imatinib developed thrombocytopenia. Platelet-derived growth factor (PDGF)/platelet-derived growth factor receptor (PDGFR) plays a significant role in the regulation of thrombopoiesis. It is suggested that imatinib may block the PDGF/PDGFR and PI3-K/Akt pathway, then inducing the apoptosis of megakaryocytes and developing thrombocytopenia in these patients. In this review, the potential molecular mechanism of imatinib-induced thrombocytopenia in the treatment of CML patients is discussed, including imatinib and thrombocytopenia, PDGF/PDGFR and thrombopoiesis, potential mechanism of imatinib-induced thrombocytopenia in treatment of patients with CML and so on.
Antineoplastic Agents ; adverse effects ; therapeutic use ; Benzamides ; Caspase 3 ; metabolism ; Humans ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; drug therapy ; genetics ; metabolism ; Piperazines ; adverse effects ; therapeutic use ; Platelet-Derived Growth Factor ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Pyrimidines ; adverse effects ; therapeutic use ; Signal Transduction ; Thrombocytopenia ; chemically induced ; Thrombopoiesis

OBJECTIVETo compare the signal patterns of dual color extra-signal BCR/ABL probe (ES-FISH) and dual color dual fusion BCR/ABL probe (D-FISH) in the fluorescence in situ hybridization (FISH) detection of Ph-positive leukemia, and to explore their diagnostic value.

METHODSES-FISH probe and D-FISH probe were used, respectively, to detect the BCR/ABL fusion gene in 74 cases with typical t(9;22)(q34;q11) and 37 cases with variant t(9;22)(q34;q11) translocation or complex karyotypic abnormalities containing Ph translocation.

RESULTSThe BCR/ABL fusion gene in all cases with typical t(9;22)(q34;q11) could be detected by both FISH probes. D-FISH had a signal pattern of 1O1G2F, while ES-FISH showed a signal pattern of 2O1G1F. ES-FISH enables the minor breakpoint cluster region to be identified in 9 cases (12.2% ) of Ph-positive leukemia, whereas D-FISH could not differentiate the minor breakpoint cluster region from major breakpoint cluster region. D-FISH could distinguish simple ABL gene deletion from simultaneous deletion of the ABL and BCR genes in 8 cases (10.8%) of Ph-positive leukemia patients, but ES-FISH could not. For variant Ph translocation or complex karyotypic abnormalities containing Ph translocation, each FISH probe showed four or six types of signal pattern, most of which were atypical. The exact interpretation was dependent on conventional karyotypic analysis and FISH on metaphases.

CONCLUSIONES-FISH and D-FISH probes displayed different signal patterns in Ph-positive leukemia due to their differences in size and covered regions. ES-FISH and D-FISH probes may be selected as better probe for Ph-positive acute lymphocytic leukemia and Ph-positive chronic myeloid leukemia, respectively. When imatinib was used for treatment, there was no preference between ES-FISH and D-FISH probe, because major breakpoint cluster region, minor breakpoint cluster region and partial sequence deletion of derivative chromosome 9, would not affect the prognosis of Ph-positive leukemia. However, considering that ES-FISH probe has a better cost-performance than D-FISH probe does, it is recommended as first choice.

Case-Control Studies ; Chromosomes, Human, Pair 9 ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Karyotyping ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics ; Proto-Oncogene Proteins c-bcr ; genetics

The aim of this study was to investigate the apoptosis-inducing effect of anti-CD44 monoclonal antibody IM7 on chronic myeloid leukemia (CML) stem/progenitor cells in vitro and to explore its possible mechanism. Leukemic stem/progenitor cells (LSPCs) expressing CD34(+), CD38(-) and CD123(+) were isolated from bone marrow (BM) cells of 20 patients with newly-diagnosed chronic myeloid leukemia by using EasySep(TM) magnetic beads. The percentage of apoptotic CML-LSPCs was assayed by Annexin-V/PI staining; the expression changes of c-myc and NF-kappaB mRNA were detected by real-time quantitative PCR (RQ-PCR) and RT-PCR; the NF-kappaB activity was detected by NF-kappaB Activation Nuclear Translocation Assay Kit; the BCL-2 protein expression was determined in the Western blot method. The results showed that the IM7 effectively induced apoptosis of CML-LSPCs; the mean percentage of early apoptotic cells significantly increased, as compared with the untreated control CML-LSPCs cells 12.58 +/- 2.84% vs 5.42 +/- 1.84% (p < 0.05). The c-myc, NF-kappaB mRNA expressions were down-regulated as compared with the control group (0.65 +/- 0.10 vs 1.00, 0.42 +/- 0.21 vs 1.00, respectively) (p < 0.01) by RQ-PCR and (0.49 +/- 0.09 vs 0.60 +/- 0.12, 0.47 +/- 0.11 vs 0.67 +/- 0.08, respectively)(p < 0.01) by RT-PCR. The BCL-2 protein level in CML-LSPCs treated with IM7 also decreased as compared with the control group (p < 0.01). In addition, the depression of NF-kappaB activity was observed through fluorescence microscope. It is concluded that the anti-CD44 monoclonal antibody IM7 effectively induces apoptosis of CML-LSPCs through down-regulating c-myc and bcl-2 mRNA expression, and decreasing NF-kappaB activity in CML-LSPCs.
Antibodies, Monoclonal ; pharmacology ; Apoptosis ; drug effects ; genetics ; Humans ; Hyaluronan Receptors ; immunology ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; metabolism ; NF-kappa B ; metabolism ; Neoplastic Stem Cells ; drug effects ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; Tumor Cells, Cultured

This study was purposed to investigate the expression of c-fes gene in leukemia patients and its clinical significance. The expression of c-fes mRNA in bone marrow cells from 121 cases of acute and chronic leukemia patients, and the expression of c-fes mRNA in peripheral blood mononuclear cells of 20 normal persons were detected by real time-quantitative reverse transcription polymerase chain reaction (RQ-PCR). The results showed that the level of c-fes mRNA in AML patients was higher than that in normal controls [(48.017 +/- 57.170) x 10(-3) vs (0.152 +/- 0.398) x 10(-3)] (p < 0.0001); but there was no significant differences of level of c-fes mRNA between samples of ALL and normal controls(0.047 +/- 0.068) x 10(-3) vs(0.152 +/- 0.398) x 10(-3) (p>0.05); the level of c-fes mRNA in CML patients was higher than that in normal persons (21.605 +/- 24.818) x 10(-3) vs (0.152 +/- 0.398) x 10(-3) (p < 0.0001). The positive expression rate of c-fes gene in CML-CP patients (80%) was higher than that in CML-AP patients (66.7%) and CML-BP (28.6%) patients. In AML patients, c-fes gene was expressed higher in M(2) (80.77%) and M(3) (92.86%) patients. The remission rate of AML (except M(3))patients who had expression of c-fes gene was 81.08%, which was higher than that of patients with no expression of c-fes gene (40.00%). It is concluded that c-fes gene expression was found in myeloid leukemias, whereas low or no expression in lymphocytic leukemias. The differentiation of myelocytic cells may be related to c-fes gene. All AML (except M(3))patients with high level of c-fes mRNA may get good prognosis.
Adult ; Case-Control Studies ; Female ; Gene Expression ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Leukemia, Myeloid ; genetics ; Leukemia, Myeloid, Acute ; genetics ; Male ; Prognosis ; Proto-Oncogene Proteins c-fes ; genetics ; RNA, Messenger ; genetics

Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disease of transformed hematopoietic progenitor cells. The expressions of JunB and CDH13 (cadherin-13) gene as tumor suppressor gene were inactivated by promoter methylation in CML patients. This study was purposed to investigate the methylation difference of JunB and CDH13 gene promoter and the expression levels of JunB and CDH13 gene in CD34(+)CD38(-) cells in CML patients vs normal individuals. CD34(+)CD38(-) cells from 8 cases of CML and 5 normal individuals were selected by flow cytometry. The methylation status of JunB and CDH13 genes were detected by MS-PCR in selected CD34(+)CD38(-) cells. The expression levels of JunB and CDH13 gene was detected with real time polymerase chain reaction (RT-PCR). The results showed that no methylation of JunB and CDH13 gene was detected in CD34(+)CD38(-) cells of 5 normal individuals. Methylations of JunB and CDH13 promoter were found in 87.5% (7/8) and 50% (4/8) CML CD34(+)CD38(-) cells, percentages of which were significantly higher than those in normal individuals. The difference was statistically significant (p < 0.05). The relative expression levels of JunB and CDH13 mRNA in CD34(+)CD38(-) cells of CML patients were significantly lower than those in normal individuals (2(-DeltaDeltaCT) were 1/5.21 and 1/10.63 respectively). It is concluded that the high methylation of JunB and CDH13 gene promoter occurs in CD34(+)CD38(-) cells of CML patients, their mRNA expression level is significantly lower, thus the methylation of JunB and CDH13 gene promoter probably plays a role in the pathogenesis of CML and may have clinical significance in predicting prognosis of CML.
ADP-ribosyl Cyclase 1 ; immunology ; Adult ; Aged ; Antigens, CD34 ; immunology ; Cadherins ; genetics ; DNA Methylation ; Female ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Male ; Middle Aged ; Promoter Regions, Genetic ; Proto-Oncogene Proteins c-jun ; genetics

BACKGROUND: Cytogenetic abnormalities are one of the most reliable prognostic factors in acute leukemia. Combination of conventional chromosome analysis (CCA) and FISH provides higher sensitivity in detecting these genetic abnormalities, and it is effective to apply several FISH probes as a profile test. The objective of this study was to investigate the utility of FISH profile analyses in the initial diagnosis of acute leukemia. METHODS: Two hundred and forty one de novo acute leukemia patients diagnosed from January, 2002 to November, 2007 were included. For acute lymphoblastic leukemia profile test, FISH probes for BCR/ABL, TEL/AML1, MLL gene rearrangement and CDKN2A deletion were used. For acute myeloid leukemia profile test, probes for AML1/ETO, MLL and CBFbeta gene rearrangement were used. The results of CCA and FISH profile tests were collected, and the positive rates were compared. RESULTS: ALL FISH profile tests revealed additional genetic aberrations not detected by chromosome analysis in 48.6% (67/138) of cases, including those with normal karyotypes or no mitotic cells (37%, 51/138). Among these 51 cases, TEL/AML1 abnormalities were detected in 44.3%, followed by the abnormal CDKN2A signal (24.6%) and hyperdiploidy (18.0%). AML FISH profile tests revealed additional genetic abnormalities in 7.8% (8/103) of cases. CONCLUSIONS: FISH analysis as a profile test detected additional genetic aberrations in a significant proportion of acute leukemia, and was effective especially in detecting cryptic translocations, submicroscopic deletions and complex karyotypes. Our study supports the need to incorporate FISH profile test at initial work up in acute leukemia.
Adolescent ; Adult ; Child ; Child, Preschool ; *Chromosome Aberrations ; Core Binding Factor Alpha 2 Subunit/genetics ; Core Binding Factor beta Subunit/genetics ; Cyclin-Dependent Kinase Inhibitor p16/genetics ; Female ; Humans ; In Situ Hybridization, Fluorescence/*methods ; Infant ; Infant, Newborn ; Karyotyping ; Leukemia, Myeloid, Acute/*diagnosis/genetics ; Male ; Middle Aged ; Myeloid-Lymphoid Leukemia Protein/genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/*diagnosis/genetics ; Proto-Oncogene Proteins c-bcr/genetics