Inactive normal X in a female leukaemic patient with an acquired X/autosome translocation

Summary An X;9;22 translocation was detected in bone marrow cells of a female patient with blastic crisis of CML. A dynamic study following 5-BrdU treatment showed that the inactive late-replicating X chromosome was the normal one. This pattern of X-chromosome replication appears to be superimposable on the most usual model found in congenital X/autosome translocations.It is suggested that preferential autosome translocation onto the active X chromosome could be the general rule in acquired X/autosome translocations associated with long survival.     

Prognostic significance of the histomorphometric features of bone marrow trephine biopsies in patients with chronic myeloid leukemia

OBJECTIVE: To study the correlation of histomorphometric data of bone marrow trephine biopsies at the time of initial diagnosis in chronic myeloid leukemia (CML) patients with the patient prognosis. STUDY DESIGN: A total of 40 CML patients were divided equally in group I (developed accelerated phase or blast crisis within 18 months of initial diagnosis of chronic phase of CML) and group II (developed accelerated phase or blast crisis > 30 months after initial diagnosis of chronic phase of CML). The clinical, hematologic and histomorphometric data were compared in the 2 groups of CML patients. RESULTS: The percentage of bone marrow promyelocytes was significantly increased in group I. On morphometry, the number of blasts per square millimeter, the area of reticulin fibers per square millimeter and the percentage area occupied by reticulin fibers were statistically significant. CONCLUSION: There seems to be grounds for hope for predicting prognosis of CML patients at initial diagnosis based on histomorphometric findings. The percentage area of reticulin fibers and the number of blasts per square millimeter are important prognostic predictors in histomorphometry data.     

Blast crisis of Philadelphia chromosome-positive chronic myelocytic leukemia (CML). Treatment results of 69 patients

We have studied the clinical courses of 69 patients with blastic crises of Philadelphia chromosome positive CML to identify parameters that were associated with an increased response rate or survival. Cytogenetic analysis at the time of blastic transformation revealed additional chromosome changes in 70% of the patients tested. Bone marrow fibrosis was detected in 58% of evaluable patients. Lymphoblastic transformation was seen in 28% of the patients tested with cell surface marker analysis. The value of 5'-nucleotidase as a marker for distinguishing lymphoid from non-lymphoid blast crisis was confirmed. Of 57 evaluable patients, 23 (40%) responded to therapy (CR/PR longer than 14 days). Median survival was 75 days. Longer survival was related to the following factors: Ph1-chromosome as the only detectable cytogenetic abnormality; lymphoblastic transformation; no bone marrow fibrosis; high percentage of blasts and promyelocytes in the bone marrow, and response to therapy. No prognostic significance was associated with age, sex, Tdt, LDH, spleen size, duration of the chronic phase of the disease, white blood cell count, Hb, platelet count and percentages of basophils, eosinophils, erythroblasts and blasts and promyelocytes in the peripheral blood. These data confirm the poor prognosis of patients with blastic crisis of CML treated by conventional chemotherapy.     

Chromosomal rearrangements with a common breakpoint at 6p23 in five cases of myeloid leukemia

Rearrangement of the short arm of chromosome 6 with a breakpoint at 6p23 was found in five patients with myeloid leukemia. Three of them had different morphological variants of AML (M2, M3, M4) and two blastic crisis of Ph1 negative and Ph1 positive CML. Identical translocation, t(6;9)(p23;q34), was revealed in two patients. One of them had AML (M2), the other blastic crisis of Ph1 negative CML. The blast cells of the last patient were morphologically similar to those in the M2 variant of AML. Translocation (6;9)(p23;q34) was also detected in two AML patients of Rowley and Potter (1976). The role of the breakpoint at 6p23 in myeloid malignancies needs further investigation.     

ATM-dependent DNA damage-response pathway as a determinant in chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) begins with an indolent chronic phase, and subsequently progresses to an accelerated or blastic phase. Although several genes are known to be involved in the progression to blastic phase, molecular mechanisms for the evolution toward blast crisis have not been fully identified. Oncogenic stimuli enforce cell proliferation, which requires DNA replication. Unscheduled DNA replication enforced by oncogenic stimuli leads to double strand breaks on DNA. We found the DNA damage-response pathway is activated in bone marrow of chronic-phase CML patients possibly due to an enforced proliferation signal by BCR-ABL expression. Since ataxia telangiectasia mutated (ATM) is a central player of the DNA damage-response pathway, we studied whether loss of this pathway accelerates blast crisis. We crossed Atm-knockout mice with BCR-ABL transgenic mice to test this hypothesis. Interestingly, the loss of one of the Atm alleles was shown to be enough for the acceleration of the blast crisis, which is supported by the finding of increased genomic instability as assayed by breakage–fusion–bridge (BFB) cycle formation. In light of these findings, the DNA damage-response pathway plays a vital role for determination of susceptibility to blast crisis in CML.     

An unusual case of a basophilic variant of chronic myelogenous leukemia

The described basophilic variant of CML in blastic crisis was characterized by a distinct hyperhistaminemia, a moderate hypocoagulation and an insufficiently effective cytostatic therapy. Cell kinetic was characterized by a marked diminution of the whole marketing index (with H3-thymidine) of blasts and immature basophils with simultaneous prolongation of the generation time in comparison to myeloblasts at the chronic stage of the CML. Aneuploid cell clones prevailed in the bone-marrow.     

A new case of chronic myelogenous leukemia with 14q+ marker and review of the literature

We report a new case of Ph 1 positive chronic myelogenous leukemia (CML) with 14q+ marker shown during chronic phase (CP) and subsequently in blastic crisis (BC). After a review of the literature, we discuss the biological significance of 14q+ marker in developing lymphoid cellular differentiation, during evolution of CML, that remains still unclear. Besides, we also discuss the prognostic value of this change, concluding that a larger number of cases may clarify this question, as also the unresponsivity to chemotherapy of the patient studies so far, may not be related to 14q+ marker.     

Detection of B-cell antigen on the blast cells in chronic myeloid leukemia]

The presence of the common antigen on B lymphocytes of healthy donors and myeloblasts of patients with chronic myeloid leukemia in blastic crisis was observed with antimyeloblastic serum in the indirect surface immunofluorescence test. The cytotoxic test showed this antigen in the blastic cells in 27 out of 57 patients with CML BC, in 3 of 11 patients with acute lymphoid leukemia, in 1 of 8 patients with chronic lymphoid leukemia and in 2 of 2 patients with undifferentiated leukemia. The antigen was not found in the peripheral blood cells of healthy donors.     

Effects of the tyrosine kinase inhibitor imatinib mesylate (STI571) on bone marrow features in patients with chronic myelogenous leukemia

Preliminary data are available about bone marrow (BM) changes in patients with chronic myeloid leukemia (CML) who received the molecularly targeted and highly effective tyrosine kinase inhibitor Imatinib mesylate (STI571). This review is focused on a systematic assessment of BM features detectable at different stages of CML (stable, accelerated, blastic) following long-term (more than 10 months) treatment. By applying enzyme- and immunohistochemistry including monoclonal antibodies visualizing proliferating cell nuclear antigen (PCNA) and apoptosis (anti-apostatin), a more elaborate insight into alterations affecting hematopoiesis and the stroma compartment was gained. In patients with stable-phase CML therapy resulted in a significant reduction in cellularity, neutrophil granulopoiesis and number of megakaryocytes, accompanied by a retrieval of erythroid precursors. In patients with Imatinib as the only treatment morphometric analysis of CD61+ megakaryopoiesis was in keeping with a significant decrease in maturation defects implying a lesser amount of atypical micromegakaryocytes almost consistent with normalization. Moreover, a reduction of the initially enhanced (CD34+) microvessel density was detectable associated with a decrease in luminal distension. Regression of marked to moderate myelofibrosis was recognizable in about 70% of patients especially in the accelerated and blastic phases. The amount of myeloblasts, CD34+ progenitor cells and lysozyme-expressing immature myelomonocytic cells declined with treatment, but recurred in about 19% of patients that developed a leukemic relapse after 21+/-6 months of therapy. Data on proliferative activity and apoptosis in general supported in vitro findings concerning the inhibitory effect of this agent on growth associated with a tendency for stimulated apoptosis, at least in responding patients.     

Treatment of chronic myelogenous leukemia with interferons alpha and gamma

A 23-year-old male patient with Philadelphia chromosome (Ph) positive chronic myelogenous leukemia (CML) was treated with both IFN alpha and IFN gamma. Normalization of leukocyte counts was reached after 3 months of treatment. Southern blot analysis failed to detect the neoplastic cell clone after 19 months of therapy. Cytogenetically, complete suppression of Ph positive cells in the patient's bone marrow and blood was observed after 20 months and 25 months, respectively. This response was achieved with doses of IFN alpha and IFN gamma which were considerably lower than the dosage of IFN used in single agent therapy of CML.     

Megakaryoblastic micromegakaryocytic crisis in chronic myeloid leukemia

Atypical megakaryoblasts (MKB) or megakaryocytes (MK) are occasionally present in the peripheral blood during the terminal development of chronic myeloid leukemia (CML). We report on a 49-year-old female suffering from Ph1 chromosome-positive CML with typical megakaryoblastic transformation in the peripheral blood and in the bone marrow. The small "blasts" were at the most only slightly larger and were occasionally even smaller than lymphocytes but showed megakaryoblastic or atypical megakaryocytic differentiation. The cytoplasmic cytochemical pattern of the atypical megakaryocytic cells was identical to that of large atypical thrombocytes. Platelet peroxidase was detected upon electron-microscopic (EM) examination. Immunologic characterization disclosed the presence of MK-specific antigens. When cultured in vitro on agar, the blasts transformed spontaneously into large mature MK, exhibiting characteristic cytochemical and immunological patterns. Cytogenetic examination of peripheral blood showed severe abnormalities. The patient did not respond to therapy and died 3 months after manifestation of the blast crisis.     

MYC in chronic myeloid leukemia: induction of aberrant DNA synthesis and association with poor response to imatinib

Untreated chronic myeloid leukemia (CML) progresses from chronic phase to blastic crisis (BC). Increased genomic instability, deregulated proliferation, and loss of differentiation appear associated to BC, but the molecular alterations underlying the progression of CML are poorly characterized. MYC oncogene is frequently deregulated in human cancer, often associated with tumor progression. Genomic instability and induction of aberrant DNA replication are described as effects of MYC. In this report, we studied MYC activities in CML cell lines with conditional MYC expression with and without exposure to imatinib, the front-line drug in CML therapy. In cells with conditional MYC expression, MYC did not rescue the proliferation arrest mediated by imatinib but provoked aberrant DNA synthesis and accumulation of cells with 4C content. We studied MYC mRNA expression in 66 CML patients at different phases of the disease, and we found that MYC expression was higher in CML patients at diagnosis than control bone marrows or in patients responding to imatinib. Further, high MYC levels at diagnosis correlated with a poor response to imatinib. MYC expression did not directly correlate with BCR-ABL levels in patients treated with imatinib. Overall our study suggests that, as in other tumor models, MYC-induced aberrant DNA synthesis in CML cells is consistent with MYC overexpression in untreated CML patients and nonresponding patients and supports a role for MYC in CML progression, possibly through promotion of genomic instability.     

Non-blastic meningeal leukemia during the myelofibrotic phase of chronic myeloid leukemia

Myeloblastic involvement of the central nervous system has been noted in the course of chronic myeloid leukemia in the blastic phase; meningeal leukemia in the chronic phase of CML is almost unknown. We report on a case of CML in which meningeal infiltration by cells of the granulocytes series in all stage of cellular maturation developed 15 years after initial diagnosis and seven months after a myelofibrotic transformation of the systemic disease.     

Identification of a melanoma antigen, PRAME, as a BCR/ABL-inducible gene

In order to elucidate molecular events in BCR/ABL-induced transformation, we adopted a polymerase chain reaction (PCR)-based technique of differential display and compared mRNA expression in human factor-dependent cells, TF-1, with that in factor-independent cells, ID-1, which were established from TF-1 cells by transfection of BCR/ABL. Cloning and sequencing of a gene which was upregulated in ID-1 cells revealed that the gene was identical to a melanoma antigen, PRAME. Our present study demonstrated that PRAME was markedly expressed in primary leukemic cells with chronic myeloid leukemia (CML) in blastic crisis and Philadelphia (Ph)+-acute lymphoblastic leukemia (ALL), in which BCR/ABL played an important role as a pathogenic gene. Moreover, comparison of PRAME expression among CD34+ cells with CML in blastic, accelerated, and chronic phases revealed a higher expression in CML in advanced phases. Thus PRAME was considered to be a good candidate for a marker of Ph+-leukemic blast cells as well as a new target antigen of leukemic blast cells that cytotoxic T cells can recognize.     

Hypercalcemia associated with osteolytic lesions in the extramedullary blastic crisis of chronic myelogenous leukemia: report of a case

A 43-year-old male patient with hypercalcemia and osteolytic lesions complicating chronic myelogenous leukemia is presented. Extramedullary myeloid blastic crisis was diagnosed by the histological finding of the specimen biopsied from a osteolytic lesion in the right femur. As the serum levels of parathyroid hormone, 1,25 (OH)2 vitamin D, prostaglandin E2 and interleukin 1, and the urinary excretion of cyclic AMP were all normal, it was considered that the hypercalcemia was attributed to the bone destruction by the invasion of leukemic myeloblasts.     

Correlations between the clinical course,characteristics of blast cells,and karyotype patterns in chronic myeloid leukemia

Summary Results of chromosome studies of blood and bone marrow cells from 101 patients with Ph¹ positive chronic myeloid leukemia (CML) confirm the assumption that clinical and morphologic manifestations of the disease correlate with karyotype peculiarities of leukemic cells. Several variants of the clinical course of CML may be distinguished. One is the variant with a short chronic phase and a comparatively long terminal phase. In blastic crisis the blast cells are peroxidase negative and do not possess cytoplasmic inclusions. Acute transformation occurs without any additional chromosome damage. The second, more common form is less severe because of longer chronic phase but it has a short and grave acute stage. The blast cells present definite signs of myeloid differentiation, they have basophilic or neutrophilic cytoplasmic granules and are peroxidase positive. Marker i(17q) often combined with trisomy 8 is a characteristic chromosome abnormality in the terminal stage of this variant. The third type has an extremely long chronic phase but ends in a rapidly progressing severe and resistant to therapy lymphoid blastic crisis. Blast cells have typical lymphoid morphology, they are peroxidase negative and contain granular PAS positive substance. Various additional chromosome changes appear in the terminal stage. Future studies of a larger series of patients may possibly reveal more CML variants.     

Dual PPARα/γ Ligand TZD18 Either Alone or in Combination with Imatinib Inhibits Proliferation and Induces Apoptosis of Human CML Cell Lines

Despite progress in the treatment of early-stage chronic myeloid leukemia (CML), the accelerated and blastic phases of CML still remain a therapeutic challenge. Persistence of BCR-ABL-positive (bcr-abl+) cells or secondary resistance during imatinib therapy frequently occurs. In this study, we investigated the activity of a novel dual ligand specific for peroxisome proliferator-activated receptor α and γ (PPARα/γ) against CML blast crisis cell lines. Exposure of these cell lines (K562, KU812 and KCL22) to TZD18 resulted in a growth inhibition in a dose- and time-dependent manner. This effect may not be mediated through PPARγ and/or PPARα activation, since antagonists of PPARg and/or PPARa could not reverse this inhibition. Western blotting analysis showed that expression of the cyclin dependent kinase inhibitor (CDKI) p27kip1 was enhanced, whereas levels of cyclin E, cyclin D2 and cyclin dependent kinase 2 (CDK-2) were decreased when these cells were treated with TZD18. Most interestingly, TZD18 synergistically enhanced the antiproliferative and pro-apoptotic effects of imatinib. Overall, our findings strongly suggest that TZD18, either alone or in combination with imatinib may be beneficial for the treatment of CML in myeloid blast crisis.     

Single cilium in human leukemic cells heterotransplanted into hamsters

Single cilium formation was studied in two human hematopoietic cell lines, KCL-22 and MT-2, KCL-22, established from a patient with chronic myelogenous leukemia in blastic crisis, and MT-2, a human cord T cell line carrying human T-lymphotropic virus type I, were transplanted into hamsters. Ciliogenesis was observed in both cell lines, only after transplantation into hamsters.