scholarly journals BCR-ABL, ABL-BCR, BCR, and ABL genes are all expressed in individual granulocyte-macrophage colony-forming unit colonies derived from blood of patients with chronic myeloid leukemia

Blood ◽  
1995 ◽  
Vol 85 (8) ◽  
pp. 2171-2175 ◽  
Author(s):  
J Diamond ◽  
JM Goldman ◽  
JV Melo
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Peripheral Blood ◽  
Myeloid Leukemia ◽  
Pcr Amplification ◽  
Pcr Screening ◽  
Colony Forming Unit ◽  
Ph Chromosome ◽  
Polymerase Chain ◽  
Macrophage Colony ◽  
Positive Results

It has been suggested that the BCR-ABL gene of chronic myeloid leukemia (CML) is not uniformly expressed in Philadelphia (Ph)-positive cells, and that BCR-ABL gene expression precludes transcription of the normal BCR or ABL genes. Therefore, we have analyzed granulocyte-macrophage colony-forming unit (CFU-GM) colonies derived from peripheral blood of 11 CML patients by cytogenetic and by reverse transcriptase-polymerase chain reaction (PCR) amplification of BCR-ABL, ABL-BCR, BCR, and ABL. All CFU-GM colonies with analyzable metaphases were found to contain a Ph chromosome. In 2 patients, the initial PCR screening failed to detect BCR-ABL transcripts in 2 of 11 and 1 of 7 Ph-positive colonies. However, when amplification for BCR-ABL was repeated in quintuplicate, all but 1 colony from a single patient showed one or more positive results. Amplifications of the four genes in each colony showed that BCR-ABL, ABL-BCR, and the normal BCR and ABL were simultaneously expressed in the majority of CFU-GM colonies. Replicate PCR tests for BCR and for ABL in colonies initially scored as negative also uncovered previously undetected positive amplifications. We conclude that BCR-ABL expression does not suppress transcription from the normal BCR and ABL genes, and that Ph-positive, BCR-ABL-negative colonies derived from peripheral blood CFU-GM are rare or nonexistent.

Variant Philadelphia Translocation with BCR/ABL Fusion Gene Site In 10q24 In a Case of Chronic Myeloid Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4839-4839
Author(s):  
Rossana Bonomi ◽  
Pablo Lopez ◽  
Daniela Infante ◽  
Isabel Moro ◽  
Victoria Elizondo ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Peripheral Blood ◽  
Myeloid Leukemia ◽  
Fusion Gene ◽  
Chromosome 9 ◽  
Chromosome 22 ◽  
Fish Analysis ◽  
Signal Pattern ◽  
Ph Chromosome ◽  
Fusion Signal

Abstract Abstract 4839 Introduction. Chronic myeloid leukemia (CML) is characterized by the Philadelphia chromosome (Ph) observed in more than 90% of patients with CML as a result of t(9;22)(q34;q11), leading to the formation of chimeric gene BCR/ABL encoding for proteins with abnormal tyrosine kinase activity. Cytogenetic variants of Ph chromosome can be identifed in 5 to 10% of CML patients, involving additional chromosomes other than 9 and 22. To explain the formation of variant translocations one-step, two-step and multi-step mechanisms have been proposed. Rarely, the variant Ph chromosome results from a BCR insertion on the ABL region and form a BCR/ABL fusion gene, generally mapping to 9q34, instead of the usual location at 22q11. In very few variant Ph cases, the insertion of the BCR/ABL product in a third chromosome was demonstrated. Case Report 28 year-old man, with bilateral central scotoma and gingivorragia. Physical examination: Grade 4 splenomegaly. Peripheral blood count showed hemoglobin concentration 11.5 g/dl, platelet count: 300.000/mm3, and white blood cell count 590.000/mm3. Blood smear: myelemia exhibiting 30% of myeloid blasts. Bone marrow biopsy: panmyelosis showing 20% of myeloid blasts. Cytogenetic analysis by G-banding performed in peripheral blood verified the following karyotype: 46, XY, t(9;22;10)(q34;q11;q24)[20] The analysis of the BCR-ABL fusion gene according to standard protocols detected the presence of the b3a2 isoform. Fluorescence in situ hybridization (FISH) studies using dual color dual fusion probes in metaphases showed a signal pattern 1F2G1R. The fusion signal mapped to 10q24, the red signal to 9q34, and the normal green signal to chromosome 22, while a second low intensity green signal mapped to the Ph chromosome. No signal was observed in der(9). Interphase FISH analysis in nuclei (n=200) presented the same signal pattern. Instead of using whole chromosome probes for 9 and 22, we hybridised probes used to detect DiGiorge syndrome. These probes detect gene control ARSA (spectrum green) localized at 22q13 and Tuple1 at 22q11 (spectrum orange). Two signals, green and orange were identified in normal chromosome 22. Ph chromosome showed the orange signal, whereas the green signal mapped to der(10). Discussion. The localization of the hybrid BCR/ABL gene on chromosomes other than 22q is a rare event wich can only be detected by FISH techniques. When these unusual translocation occurs, the hypothesis most often put forward is that several consecutive chromosome rearrangements have taken place. In the present case the interpretation of karyotypes, FISH data and molecular evidence lead to the following hypothesis: Insertion of the BCR sequence from chromosome 22 to chromosome 9 may have ocurred, producing a BCR/ABL fusion in der(9). The Ph chromosome detected by G-banding showed a different green fluorescence intensity in the metaphase FISH signal pattern with BCR/ABL dual color dual fusion probes, as a result of an insertion on chromosome 9. This first event was followed by the translocation between the derivative 9 and chromosome 10, being the final localization of the BCR/ABL gene in 10q24. FISH analysis using a DiGeorge syndrome probe, supports the hypothesis of a multistep mechanism underlying insertion and translocations events in the present case. The relocation of BCR/ABL fusion sequence on sites other than chromosme 22q11 represent a rare type of variant Ph translocation. At least 21 cases described in the literature, showed fusion gene BCR/ABL located at 9q24. Only 12 patients with variant Ph were reported bearing BCR/ABL on a third chromosome. All of them involved a masked Ph chromosome. To our best knowledge this is the first report showing a variant Ph chromosome detected by G-banding in a CML patient due to a BCR insertion on ABL sequences and exhibiting the fusion signal in a third chromosome. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Philadelphia-negative (Ph-) chronic myeloid leukemia (CML): comparison with Ph+ CML and chronic myelomonocytic leukemia. The Groupe Francais de Cytogenetique Hematologique

Blood ◽  
1991 ◽  
Vol 78 (1) ◽  
pp. 205-211 ◽  
Author(s):  
P Martiat ◽  
JL Michaux ◽  
J Rodhain
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Chronic Myelomonocytic Leukemia ◽  
Ras Mutation ◽  
Ph Chromosome ◽  
Polymerase Chain ◽  
Atypical Cml ◽  
Myelomonocytic Leukemia ◽  
Monocytic Lineage

To better understand the Philadelphia-negative (Ph-) chronic myeloid leukemia (CML) and its relationships with Philadelphia-positive (Ph+) CML and chronic myelomonocytic leukemia (CMML), a study was undertaken by the Groupe Francais de Cytogenetique Hematologique. Thirty-five Ph- CML patients were investigated and compared with 55 chronic phase Ph+ CML and 100 CMML patients. There were 12 M-BCR positive (M-BCR+) and 23 M-BCR negative (MBCR+) patients. No clinical or biologic differences were found between Ph+ and Ph-, M-BCR+ patients. In the Ph- group, M- BCR+ and M-BCR- patients differed significantly in age (47.7 +/- 6.6 v 67.0 +/- 6.1 years, respectively; P = .001), leukocytosis (153.4 +/- 135.1 v 58.5 +/- 37.7 10(9)/L, P = .002), relative monocytosis (1.8% +/- 1.2% v 5.6% +/- 1.4%, P = .048), absolute basophilia (8.5 +/- 9.7 v 0.9 +/- 1.5 10(9)/L, P = .001), percentage of immature myeloid precursors (IMP) in peripheral blood (29.0% +/- 9.5% v 15.3% +/- 8.1%, P = .001), and percentage of erythroblasts in bone marrow (BM) (6.5% +/- 3.5% v 14.6% +/- 3.6%, P = .001). Karyotypic abnormalities other than the Ph chromosome occurred in 0 of 12 M-BCR- at diagnosis and 7 of 23 M-BCR- Ph- CML (P = .033). None of the 13 investigated BCR- patients had detectable BCR/ABL transcripts using polymerase chain reaction (PCR) and none had an N-RAS mutation. Cytologic findings showed a marked morphologic difference between M-BCR+ and M-BCR- patients, especially in the monocytic lineage. Dysmyelopoietic features in CMML and M-BCR- patients were very similar, and the differences were of quantitative order only. Using four criteria (monocytosis, percentage of IMP, basophilia, and percentage of erythroblasts in BM), patients could be divided into typical and atypical CML and this classification correlated well with molecular findings. We conclude that, while Ph-, M- BCR+, and Ph+ CML are identical diseases, Ph-, M-BCR- CML, and CMML have many similarities and might be only different aspects of a same entity.

BCR/ABL Fusion Gene On Constitutional Der(14;22) Roberstsonian Translocation in a Case of Chronic Myeloid Leukemia with Masked Philadelphia Chromosome

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4822-4822
Author(s):  
Pablo Lopez ◽  
Daniela Infante ◽  
Isabel Moro ◽  
Victoria Elizondo ◽  
Gerardo Romanelli ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Peripheral Blood ◽  
Cytogenetic Analysis ◽  
Myeloid Leukemia ◽  
Robertsonian Translocation ◽  
Philadelphia Chromosome ◽  
Chromosome 9 ◽  
Ph Chromosome ◽  
One Step

Abstract Abstract 4822 Chronic myeloid leukemia (CML) is characterized by the Philadelphia chromosome (Ph) observed in more than 90% of patients with CML as a result of t(9;22)(q34;q11), leading to the formation of the BCR/ABL chimeric gene. The remaining 5–10% of CML cases exhibit a variant Ph translocation generally involving a third or even a fourth chromosome in addition to chromosome 9 and 22, potentially leading to masked Ph chromosome or reveal cryptic translocations that remains undetected under conventional cytogenetic analysis. These chromosome rearrangements can be disclosed by means of fluorescence in situhybridization (FISH) or polymerase chain reaction (PCR) procedures. A very few Ph positive CML cases were reported with constitutional robertsonian translocations, i.e. translocation between two acrocentric chromomosomes (13–15, 21–22), with breakpoints in the short arms, leading to a dicentric chromosome and thus to 45 instead of 46 chromosomes Case Report. 42 year-old woman presenting with asthenia. Physical examination: Grade 1 splenomegaly. Peripheral blood count showed: hemoglobin concentration 117g/L, platelet count: 329×109/L and white blood cell count (WBC): 199×109/L. Peripheral blood smear: myelemia exhibiting 3% of myeloid blasts. Cytogenetic analysis by G-banding performed on bone marrow metaphase cells afforded the following karyotype: 45, XX, der(14;22)(q10;q10)c?, t(9;22;11)(q34;q11;q13) [20]. The analysis of the BCR-ABLfusion gene according to standard protocols detected the presence of the b3a2 isoform. FISH studies using dual color dual fusion probes in metaphases showed a 1F2G2R signal pattern. We detect a normal ABL signal on chromosome 9 and BCR signal on chromosome 22; the fusion signal was present on the der(14;22);extra-signals BCR and ABL with reduced intensities were present on der(11) and der(9) respectively: ish der(9)(ABLdim+), der(11)(BCRdim+), der(14;22)(BCR+,ABL+) [10]. FISH analysis on interphase nuclei (n=200) presented the same signal pattern. Nuc ish (ABL, BCRx3)(BCR con ABL x1) [200]. Chromosome analysis of bone marrow cells after six months of Imatinib therapy showed the following karyotype: 45, XX, der(14;22)(q10;q10)c [20] thus demonstrating complete cytogenetic remission and that der(14;22) is a robertsonian constitutional abnormality that could be inherited and thus necessitate a familial genetic councelling to inform about the familial risk of congenital malformations and miscarriage. Discussion. To explain the formation of variant chromosome Ph translocations one-step, two-step and multi-step mechanisms have been proposed. In our case complex translocations involving four chromosomes and the participation of two acrocentric chromosomes, led to the hypothesis of the presence of a constitutional or acquired Robertsonian translocation. Karyotype analysis six months after treatment confirmed the presence of a constitutional Robertsonian translocation. According to the FISH pattern, this variant Ph chromosome was formed in one step. The occurrence of Philadelphia positive CML in a patient with a constitutional Robertsonian translocation is probably coincidental. The role of constitutional chromosomes abnormalities in hematologic malignancies is well known in Down syndrome patients and in chromosome breakage syndromes such as Fanconi anemia. In the literature, only one case of CML patients with Robertsonian t(14;22) have been described. To our knowledge this is the first report showing a Robertsonian t(14;22) in a variant Ph involving four chromosomes and exhibiting the fusion FISH signal in a derivative chromosome 14, with masked Ph. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Philadelphia-negative (Ph-) chronic myeloid leukemia (CML): comparison with Ph+ CML and chronic myelomonocytic leukemia. The Groupe Francais de Cytogenetique Hematologique

Blood ◽  
1991 ◽  
Vol 78 (1) ◽  
pp. 205-211 ◽  
Author(s):  
P Martiat ◽  
JL Michaux ◽  
J Rodhain
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Chronic Myelomonocytic Leukemia ◽  
Ras Mutation ◽  
Ph Chromosome ◽  
Polymerase Chain ◽  
Atypical Cml ◽  
Myelomonocytic Leukemia ◽  
Monocytic Lineage

Abstract To better understand the Philadelphia-negative (Ph-) chronic myeloid leukemia (CML) and its relationships with Philadelphia-positive (Ph+) CML and chronic myelomonocytic leukemia (CMML), a study was undertaken by the Groupe Francais de Cytogenetique Hematologique. Thirty-five Ph- CML patients were investigated and compared with 55 chronic phase Ph+ CML and 100 CMML patients. There were 12 M-BCR positive (M-BCR+) and 23 M-BCR negative (MBCR+) patients. No clinical or biologic differences were found between Ph+ and Ph-, M-BCR+ patients. In the Ph- group, M- BCR+ and M-BCR- patients differed significantly in age (47.7 +/- 6.6 v 67.0 +/- 6.1 years, respectively; P = .001), leukocytosis (153.4 +/- 135.1 v 58.5 +/- 37.7 10(9)/L, P = .002), relative monocytosis (1.8% +/- 1.2% v 5.6% +/- 1.4%, P = .048), absolute basophilia (8.5 +/- 9.7 v 0.9 +/- 1.5 10(9)/L, P = .001), percentage of immature myeloid precursors (IMP) in peripheral blood (29.0% +/- 9.5% v 15.3% +/- 8.1%, P = .001), and percentage of erythroblasts in bone marrow (BM) (6.5% +/- 3.5% v 14.6% +/- 3.6%, P = .001). Karyotypic abnormalities other than the Ph chromosome occurred in 0 of 12 M-BCR- at diagnosis and 7 of 23 M-BCR- Ph- CML (P = .033). None of the 13 investigated BCR- patients had detectable BCR/ABL transcripts using polymerase chain reaction (PCR) and none had an N-RAS mutation. Cytologic findings showed a marked morphologic difference between M-BCR+ and M-BCR- patients, especially in the monocytic lineage. Dysmyelopoietic features in CMML and M-BCR- patients were very similar, and the differences were of quantitative order only. Using four criteria (monocytosis, percentage of IMP, basophilia, and percentage of erythroblasts in BM), patients could be divided into typical and atypical CML and this classification correlated well with molecular findings. We conclude that, while Ph-, M- BCR+, and Ph+ CML are identical diseases, Ph-, M-BCR- CML, and CMML have many similarities and might be only different aspects of a same entity.

scholarly journals Variable transcription of BCR-ABL by Ph+ cells arising from hematopoietic progenitors in chronic myeloid leukemia [see comments]

Blood ◽  
1994 ◽  
Vol 83 (7) ◽  
pp. 1744-1749 ◽  
Author(s):  
A Keating ◽  
XH Wang ◽  
P Laraya
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Internal Control ◽  
Myeloid Leukemia ◽  
Critical Role ◽  
Pcr Amplification ◽  
Chronic Phase ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Polymerase Chain ◽  
Aberrant Gene

Recent studies suggest that the BCR-ABL gene plays a critical role in the pathogenesis of Ph+ chronic myeloid leukemia (CML). We investigated the hematopoietic colonies derived from the marrows of 12 patients with Ph+ CML in chronic phase by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification of BCR-ABL mRNA and by cytogenetics. Colonies were individually harvested and each colony divided into two portions, one for cytogenetics and the other for isolation of total RNA for PCR of BCR-ABL transcripts and for an RNA internal control. We found that 23% +/- 18% (mean +/- SD, range 0% to 60%) of Ph+ colonies did not transcribe the aberrant gene. In each case when BCR-ABL transcription was not detected, normal ABL mRNA was present. The data suggest that hitherto unknown mechanisms may regulate BCR-ABL expression in some Ph+ cells and indicate that caution should be exercised in the interpretation of results using RT-PCR analysis of hematopoietic colonies from clinical specimens and from experiments with antisense oligonucleotides directed at the BCR-ABL gene. These data also raise the notion of a transitional Ph+ precursor cell in which BCR-ABL may become upregulated and lead to a fully expressed phenotype. We conclude that further studies correlating the frequency of Ph+ PCR- progenitors with prognostic clinical variables are warranted.

scholarly journals Variable transcription of BCR-ABL by Ph+ cells arising from hematopoietic progenitors in chronic myeloid leukemia [see comments]

Blood ◽  
1994 ◽  
Vol 83 (7) ◽  
pp. 1744-1749 ◽  
Author(s):  
A Keating ◽  
XH Wang ◽  
P Laraya
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Internal Control ◽  
Myeloid Leukemia ◽  
Critical Role ◽  
Pcr Amplification ◽  
Chronic Phase ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Polymerase Chain ◽  
Aberrant Gene

Abstract Recent studies suggest that the BCR-ABL gene plays a critical role in the pathogenesis of Ph+ chronic myeloid leukemia (CML). We investigated the hematopoietic colonies derived from the marrows of 12 patients with Ph+ CML in chronic phase by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification of BCR-ABL mRNA and by cytogenetics. Colonies were individually harvested and each colony divided into two portions, one for cytogenetics and the other for isolation of total RNA for PCR of BCR-ABL transcripts and for an RNA internal control. We found that 23% +/- 18% (mean +/- SD, range 0% to 60%) of Ph+ colonies did not transcribe the aberrant gene. In each case when BCR-ABL transcription was not detected, normal ABL mRNA was present. The data suggest that hitherto unknown mechanisms may regulate BCR-ABL expression in some Ph+ cells and indicate that caution should be exercised in the interpretation of results using RT-PCR analysis of hematopoietic colonies from clinical specimens and from experiments with antisense oligonucleotides directed at the BCR-ABL gene. These data also raise the notion of a transitional Ph+ precursor cell in which BCR-ABL may become upregulated and lead to a fully expressed phenotype. We conclude that further studies correlating the frequency of Ph+ PCR- progenitors with prognostic clinical variables are warranted.

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