microRNA (miRNA) are about 22 nucleotide (nt) endogenous small non-coding RNA that play an important role in regulation of gene expression at the post-transcriptional level. miRNA control the expression of genes involved in several biologic processes, including apoptosis, proliferation, differentiation and metabolism of cells. miRNA can also act as oncogenes or antioncogenes. Abnormal expression of miRNA is associated with chronic myelogenous leukemia (CML) and contributes to the pathogenesis, disease progression, and response to therapy of CML. They may also serve as the potential therapy targets in the disease. In this review, the most important findings about the biogenesis pathway and function of miRNA as well as the role of miRNA in the pathogenesis, drug-resistance and therapy of CML are discussed.
Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; MicroRNAs

Fusion Proteins, bcr-abl ; genetics ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Mutation

OBJECTIVE: To analyze the immunological phenotype of chronic myeloid leukemia (CML), and explore its characteristics and significance. METHODS: The immunophenotypes of 40 CML children and 40 controls were analyzed by multicolor flow cytometry. CD45/SSC, as the basic gate, was used to delineate neutrophils. Then, the distribution of cluster differentiation (CD) molecules on the surface of granulocytes was analyzed in three ranges (≥1%, ≥5%, and ≥20%), and the expression rates of CD molecules (≥1% included in the statistical analysis) and the mean fluorescence intensity (MFI) were compared between the two groups. RESULTS: The proportion of granulocytes in the CML group was (82.1±6.4)%, which was significantly higher than (57.8±11.8)% in the control group (P <0.001). The expression rates of CD15/CD11b/CD33/CD13 in CML and control groups were high, and both distributed in the range of ≥20%. The differentiation trajectory of CD33/CD13 was normal and there were no significant differences in the expression rate and MFI between the two groups. However, both the expression rate of CD11b and CD15 MFI in the CML group were significantly lower than those in the control group (P <0.001). There were no significant differences in the expression rate and MFI of CD10 between the two groups, and the expression levels of CD10 between the two groups were consistent in different distributions. In the CML group, there was a large number of cases with abnormal high expression of CD56, 52.5% of the cases had a CD56 expression rate of ≥5%, and 42.5% had a CD56 expression rate of ≥20%, while the control group did not express CD56 (<1%). The expression distribution of CD117 was different between the two groups. In the range of expression rate ≥5%, there were 35.0% cases in the CML group, while only 2.5% in the control group. The expression rate of CD117 in the CML group was higher than that in the control group (P <0.001), though there was no significant difference in MFI. CONCLUSION The immunophenotyping of CML is characterized by increased proportion of mature neutrophils, decreased CD15 MFI, decreased proportion of CD11b and abnormal high expression of CD56 and CD117. Flow cytometric analysis of immunophenotype can effectively distinguish normal granulocytes from chronic granulocytes, and help in the diagnosis of CML.
Child ; Humans ; Flow Cytometry ; Leukemia, Myeloid ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics* ; Granulocytes ; Neutrophils ; Immunophenotyping

The key molecular events in the pathogenesis of myeloproliferative disorders (MPD) have been poorly defined to date, except the case of chronic myeloid leukaemia with the associated rearranged gene bcr/abl. In recent years, a number of different studies described the detection of JAK2 V617F mutation in haematopoietic cells from polycythemia vera patients and other MPDs, which indicates that it plays an important role in the pathogenesis of MPDs. In this review, the JAK2 V617F point mutation and its detection methods, its clinical correlations with MPDs and other malignant hepatopathies were summarized.
Humans ; Janus Kinase 2 ; genetics ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Myeloproliferative Disorders ; genetics

OBJECTIVETo revalidate the conversion factor（CF）for the conversion of BCR-ABL （P210）transcript levels to the international scale（BCR- ABLIS）in chronic myeloid leukemia（CML） which validated before.

METHODSPeking University People's Hospital（PKUPH）prepared the exchange samples for revalidation of CFs of 15 laboratories which validated nine or eighteen months ago. The fresh BCR-ABL（P210）（+）bone morrow or peripheral blood nucleated cells were diluted with BCR-ABL （P210）（-）cells to achieve different BCR- ABL levels, totally 16 sets and 24 samples per set were prepared. TRIzol reagent was added in each tube. Each laboratory tested BCR-ABL transcript levels of one set of samples. Agreement between BCR-ABLIS of each laboratory and PKUPH was assessed by the Bland- Altman method. For laboratories which did not meet the criteria of revalidation, linear regression equation was derived after the samples with maximum BCR-ABL deviation were removed until R²>0.98, then new CF was calculated.

RESULTS10 laboratories met the revalidation criteria with both bias within ±1.4 fold and 95% limits of agreement within ±6 folds, and their CFs still could be used for accurately conversion of BCR-ABLIS. New CFs were recalculated as of 1.8-6.3 folds of their previous CFs in 5 laboratories not met the criteria.

CONCLUSIONRevalidation of CF by sample exchange among laboratories was necessary for accurate and continuous application of BCR-ABLIS, which not only tested the validity of CF acquired before but also calculated new available CFs for those with invalid CFs.

OBJECTIVE: To analyze the significance of various abnormal signal patterns appreared in CML and B-ALL patients by using BCR/ABL/ASS1 tricolor dual-fusion probe, and to explore its application value in detecting BCR/ABL fusion gene and ASS1 gene deletion. METHODS: 50 newly diagnosed CML patients and 50 newly diagnosed B-ALL patients were detected by fluorescence in situ hybridization (FISH) with BCR/ABL/ASS1 tricolor dual-fusion probe. Meanwhile, karyotype analysis was performed on all the patients using the 24 hours short-term culture and R-banding. RESULTS: Among the 50 CML patients, Ph was found in 49 cases, 5 normal interphase karyotype was observed in 1 case. FISH detection showed that BCR/ABL fusion gene existed in all patients (100%), while the positive signal pathway showed that 1R1G2B2F was observed in 39 cases (78%), 2R1G2B1F in 2 cases (4%) and 1R1G2B1F in 6 cases (12%), simultaneous existence of 1R1G1B1F and 1R1G2B3F in 1 case (2%), 2R1G1B1F in 1 case (2%) 1R1G3B3F in 1 case (2%). FISH detection also showed that the karyotype of 6 case at ASS1 gene deletion (1R1G1B1F) all were simple t (9; 22) translocation, and other abnormalities not were observed. Among 50 cases of B-ALL, Ph was found in 13 cases, the numerical aberration and structural aberration of non t (9; 22) in 16 cases, normal karyotype in 20 cases, absence of mitotic phase in 1 case. FISH detection showed that 16 cases (32%) had BCR/ABL fusion gene including 13 cases (26%) of 1R1G2B2F, 1 case (2%) of stimultaneous exitance of 1R1G2B2F and 1R1G3B3F 1 case (2%) of 2R1G1B1F, 1 case (2%) of 1R1G3B2F. FISH detection also showed that 3 cases had BCR/ABL fusion gene, including 1 case with ASS1 gene deletion (2R1G1B1F), 1 case with classical t (9; 22) translocation (1R1G2B2F) and 1 case with BCR/ABL fusion gene and increase of ASS1 gene copy (1R1G3B3F). CONCLUSION Tricolor dual-fusion FISH probe for detecting BCR/ABL fusion gene and ASS1 gene deletion is simple, rapid, sensitive and stable. It can detect various forms of molecular fusion and avoid the false positive results due to coincidental overlap of signals generated by D-FISH probe and ES-FISH probe. In addition, this detection method not only can directly observe the presence or absence of ASS1 gene deletion, but also improve the reliability of the positive results of newly diagnosed BCR/ABL fusion gene and accuracy of monitoring results of minimal residual disease for the subsequent visit.
Fusion Proteins, bcr-abl ; genetics ; Gene Deletion ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics ; Reproducibility of Results

Chronic myeloid leukemia is a myeloproliferative disorder characterized by excessive cloning of bone marrow multipotent stem cells. According to the disease course, the CML may be divided into chronic phase (CP), accelerated phase (AP) and blastic phase (BP). At present, the molecular mechanisms of acute transformation of CML has not been fully understood. The recent studies have shown that the epigenetics is one of mechanisms in blastic transformation of CML, including three molecular mechanisms such as DNA modification, histone modifications and RNA-related dysregulation. The molecular mechanisms for epigenetics leading to the transformation of CML are discussed in this review.
Blast Crisis ; genetics ; Disease Progression ; Epigenesis, Genetic ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; genetics

Transgenic animal model provide a good platform to research the pathogenesis and therapy of chronic myelogenous leukemia (CML). To date, a number of BCR/ABL transgenic animal models have been established using different promoter or tetracycline-controlling system. Some of them appear the characteristics of human CML, which have contributed greatly to research the pathogenesis and therapy of CML. In this article, the researching progress, advantage and drawback, application of BCR/ABL transgenic animal model are reviewed.
Animals ; Animals, Genetically Modified ; Disease Models, Animal ; Fusion Proteins, bcr-abl ; genetics ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive

OBJECTIVE: To investigate the pro-apoptotic effect and mechanism of miR-30a overexpression on chronic myeloid leukemia K562 cells. METHODS: The k562 cells were transfected with the recombinant plasmid pEGFP-pre-miR-30a, the real-time quantitative PCR was used to detect the level of miR-30a and BCR/ABL, and then the cell apoptosis was assessed by flow cytometry with AnnexinV-FITC/PI double staining. Western blot was used to detect the expression of BCR/ABL protein,apoptosis-related protein BCL-2 and BAX, PTEN, AKT and p-AKT. RESULTS: Sequencing and digestion map indicated that the recombinant plasmid was constructed successfully. Compared with 2 control groups, the miR-30a expression in k562 cells transfected with recombinant plasmid pEGFP-pre-miR-30a was obviously up-regulated. The expression of BCR/ABL mRNA and BCR/ABL protein was both significantly down-regulated. Apoptotic rate was significantly enhanced (both P<0.05),and the expression of anti-apoptotic protein BCL-2 was down-regulated while the expression of pro-apoptotic protein BAX was up-regulated. The level of PTEN was significantly up-regulated in omparison with control groups,no variation was found in total AKT, but the expression of p-AKT was down-regulated. CONCLUSION The overexpression of miR-30a is abled to down-regulate the level of BCR/ABL mRNA and BCR/ABL protein, and increase apoptotic rate, its mechanism may be related with inhibition of the activity of BCR/ABL-PTEN/AKT signaling pathway.
Apoptosis ; Cell Proliferation ; Fusion Proteins, bcr-abl ; Humans ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; MicroRNAs ; genetics

All kinds of tumors have their specific DNA methylation patterns. The study of DNA methylation changes in chronic myelogenous leukemia includes (1) the hypomethylation of carcinogenic gene, (2) the hypermethylation of tumor-suppressing gene, and (3) the hypermethylation of fusion gene. In this paper, DNA methylation change in chronic myeloid leukemia (CML) and its role in clinical stages and evaluation of prognosis were reviewed so as to illuminate the relationship between DNA methylation and CML.
DNA Methylation ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics ; pathology ; Prognosis