Genotyping of chimerical BCR-ABL1 RNA in chronic myeloid leukemia by integrated DNA chip.

Chronic myelogenous leukemia (CML) and Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL) are associated with fusion of the BCR and ABL1 genes by chromosome translocation. The chimerical BCR-ABL1 gene encodes different fusion proteins that vary in size, depending on the breakpoint in the BCR region. Different types of fusion genes in CML and Ph(+) ALL are thought to be related to the clinical course and outcome of each patient.

Comprehensive therapeutic outcomes of frontline imatinib mesylate in newly diagnosed chronic phase chronic myeloid leukemia patients in Korea: feasibility assessment of current ELN recommendation.

Optimal responses during imatinib therapy are commonly defined following the European LeukemiaNet (ELN) recommendations. Achievements of these optimal responses have not, however, been comprehensively tested as response-related prognostic factors using single center data sets. We evaluated the parameters using long-term (median 63 months) outcomes from 363 chronic phase chronic myeloid leukemia patients treated with imatinib as frontline therapy at our center.

Long-term pattern of pleural effusion from chronic myeloid leukemia patients in second-line dasatinib therapy.

Dasatinib is a potent second-generation tyrosine kinase inhibitor approved for the treatment of chronic myeloid leukemia after imatinib failure. However, some patients treated with dasatinib experience pleural effusions (PEs). The determinants of pleural effusion in long-term dasatinib treatment (median 35 months, range 1-55) were investigated in single-center data of 65 patients enrolled in global phase 2 and phase 3 trials.

Sensitive quantitation of minimal residual disease in chronic myeloid leukemia using nanofluidic digital polymerase chain reaction assay.

Undetectable BCR-ABL transcripts in patients with chronic myeloid leukemia (CML) should not be regarded as indicative of a cure, due to the sensitivity limit of current real-time quantitative polymerase chain reaction (RQ-PCR) technology. To demonstrate the feasibility of more sensitive approaches, 62 samples from 43 patients with CML were screened by conventional RQ-PCR, replicate RQ-PCR (rRQ-PCR), and/or nanofluidic digital PCR (dPCR). First, we confirmed the correlation of dPCR to conventional RQ-PCR using 30 patient samples with various minimal residual disease (MRD) levels.

Establishment of the first World Health Organization International Genetic Reference Panel for quantitation of BCR-ABL mRNA.

Serial quantitation of BCR-ABL mRNA levels is an important indicator of therapeutic response for patients with chronic myelogenous leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia, but there is substantial variation in the real-time quantitative polymerase chain reaction methodologies used by different testing laboratories. To help improve the comparability of results between centers we sought to develop accredited reference reagents that are directly linked to the BCR-ABL international scale. After assessment of candidate cell lines, a reference material panel comprising 4 different dilution levels of freeze-dried preparations of K562 cells diluted in HL60 cells was prepared.

Chronic myeloid leukemia in the Asia-Pacific region: current practice, challenges and opportunities in the targeted therapy era.

Chronic myeloid leukemia (CML) management varies across Asia due to disparities in affluence and healthcare provision. We surveyed CML management practice at 33 hospitals in 14 countries/regions to identify treatment challenges and opportunities for harmonization. Patients were generally treated according to international guidelines; however, tyrosine kinase inhibitors (TKIs) and molecular monitoring are inaccessible to many patients not covered by national insurance or eligible for subsidized treatment.

Dynamic change of T315I BCR-ABL kinase domain mutation in Korean chronic myeloid leukaemia patients during treatment with Abl tyrosine kinase inhibitors.

We analysed the dynamic change of imatinib-resistant mutations in BCR-ABL kinase domain focusing on T315I mutation during dasatinib or nilotinib therapy. Fifty-five imatinib-resistant chronic myeloid leukaemia patients (32 patients with imatinib-resistant mutations and 23 patients without mutation) in different disease phases were treated with dasatinib (median 17.3 months) or nilotinib (median 6.

Previous best responses can be re-achieved by resumption after imatinib discontinuation in patients with chronic myeloid leukemia: implication for intermittent imatinib therapy.

Although imatinib is considered as a front line therapy in patients with chronic myeloid leukemia (CML), it is still unclear whether transient imatinib discontinuation may adversely affect the outcome. This study was conducted to investigate long-term outcome after discontinuation and resumption of imatinib, and to determine whether intermittent imatinib therapy can be employed in patients with CML. Twenty six Philadelphia chromosome positive (Ph+) patients with CML discontinued imatinib when they achieved complete cytogenetic response (CCyR) or complete molecular response (CMR), and they were retreated with imatinib in case of hematologic, cytogenetic or molecular relapse.

Analysis of Bcr-Abl kinase domain mutations in Korean chronic myeloid leukaemia patients: poor clinical outcome of P-loop and T315I mutation is disease phase dependent.

Despite durable responses to imatinib in chronic myeloid leukaemia (CML), mutations in Bcr-Abl kinase domain (KD) are known to induce imatinib resistance and cause poor clinical outcome. We characterized Bcr-Abl KD mutations in 137 Korean CML patients with imatinib resistance (n = 111) or intolerance (n = 26) using allele specific oligonucleotide polymerase chain reaction (PCR) and direct sequencing. Seventy (51%) patients harboured 81 mutations of 20 different types with increasing prevalence in advanced phase.

Structural modeling of V299L and E459K Bcr-Abl mutation, and sequential therapy of tyrosine kinase inhibitors for the compound mutations.

Sequential treatment with different tyrosine kinase inhibitors (TKIs) is one of the strategies for handling chronic myeloid leukemia (CML) in which dynamic change in Bcr-Abl kinase domain mutation is often an obstacle faced during TKI therapy. Here we report successful sequential therapy with different TKIs for the CML patient harboring V299L and E459K compound mutations. Molecular monitoring including quantitative analysis of BCR-ABL transcript level and mutation analysis were performed regularly for successful treatment.

Comparative analysis of cell surface proteins in chronic and acute leukemia cell lines.

This study was designed to identify the cell surface protein markers that can differentiate between chronic myeloid leukemia (CML) and acute promyelocytic leukemia cells (APL). The differentially expressed plasma membrane proteins were analyzed between CML cell line (K562) and APL cell line (NB4) using the comparative proteomic approach. The cell membrane proteins were enriched by labeling with a membrane-impermeable biotinylation reagent, sulfo-NHS-SS-Biotin, and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS).

Comprehensive analysis of BCR-ABL transcript types in Korean CML patients using a newly developed multiplex RT-PCR.

Diagnosis of chronic myeloid leukemia (CML) is based on the detection of BCR-ABL gene or Philadelphia chromosome (Ph chromosome), and fusion proteins with different sizes are encoded depending on the breakpoint in the BCR gene. In general, 3 breakpoint cluster regions in the BCR gene have been described: major (M-bcr), minor (m-bcr), and micro (mu-bcr). This study was designed to determine the frequency of BCR-ABL transcripts using one-step multiplex reverse transcription polymerase chain reaction (RT-PCR).

Comparison of allele specific oligonucleotide-polymerase chain reaction and direct sequencing for high throughput screening of ABL kinase domain mutations in chronic myeloid leukemia resistant to imatinib.

To identify a fast and sensitive method for screening for mutations in patients with imatinib- resistant chronic myeloid leukemia (CML), we compared allele specific oligonucleotide- polymerase chain reaction (ASO-PCR) assay with conventional direct sequencing. Among the 68 imatinib resistant CML patients studied, 18 amino acid substitutions were detected in 44 patients by two assays. The sensitivity of ASO-PCR was superior to that of direct sequencing as it could detect one mutant allele in 100 approximately 100,000 wild type sequences.

Early prediction of molecular remission by monitoring BCR-ABL transcript levels in patients achieving a complete cytogenetic response after imatinib therapy for posttransplantation chronic myelogenous leukemia relapse.

Imatinib induces a high complete cytogenetic response (CCR) rate in relapsed chronic myelogenous leukemia. By analyzing minimal residual disease (MRD) under the levels of CCR, we tried to assess the molecular response after imatinib therapy. By using real-time quantitative reverse transcriptase-polymerase chain reaction (Q-RT-PCR), MRD was evaluated in 23 patients (3 in cytogenetic relapse, 6 in chronic phase, 9 in accelerated phase, and 5 in blast crisis) who were treated with standard-dose imatinib for relapsed chronic myelogenous leukemia after allogeneic stem cell transplantation.

Allele frequencies of 15 STR loci using AmpF/STR Identifiler kit in a Korean population.

The genetic variations for 15 short tandem repeat (STR) loci D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA were performed on 231 unrelated Korean population using commercially available AmpF/STR Identifiler kit.