Establishment of a human myeloid cell line with trisomy 8 derived from overt leukemia following myelodysplastic syndrome

A human myeloid cell line with trisomy 8 was newly established from overt myelogenous leukemia arising in myelodysplastic syndrome. The cells of this cell line showed immature myelocyte characteristics. The karyotype retained trisomy 8. This cell line could improve understanding of the pathophysiology of myelogenous leukemia with trisomy 8.     

Establishment and characterization of a novel myeloid cell line from the bone marrow of a patient with the myelodysplastic syndrome

SUMMARY. A novel long-term cultured myeloid cell line was established from the bone marrow of a patient with myelodysplastic syndrome (MDS). This cell line, designated MDS92. proliferated in the presence of interleukin-3 or granulocyte-macrophage colony-stimulating factor and transiently in the presence of Steel factor, with a tendency for gradual maturation, and formed myeloid colonies in the semi-solid culture condition.
In addition, the MDS92 cell line represented rather complicated karyotypic abnormalities including the deletion of fifth and seventh chromosomes and a point mutation at codon 12 of the N-ras oncogene.
These characteristics of the MDS92 cell line are exclusively compatible with the property of preleukaemia.     

Simultaneous expression of lymphoid and myeloid phenotypes in acute leukemia arising from myelodysplastic syndrome

A 57-year-old female developed myelodysplastic syndrome (MDS) that terminated as a biphenotypic leukemia after exposure to chemoradiotherapy. Double staining of blast cells, using monoclonal antibodies specific for myeloid and lymphoid lineage, demonstrated that one-third of the leukemic cells simultaneously expressed the E rosette-associated antigen (OKT11) and myeloid-associated antigen (MY7). This finding suggests the possibility that some cases of MDS are clonal disorders that arise in a pluripotent stem cell that can also differentiate to T cell lineage.     

Establishment and characterization of a new human eosinophilic leukemia cell line

A human eosinophilic leukemia cell line, designated as EoL, was established from the peripheral blood of a patient with Philadelphia chromosome-negative eosinophilic leukemia (EL). The EoL cell line grows in single cell suspension with a doubling time of 48 hours for about one year. The reactivity of these cells was tested with a panel of monoclonal antibodies; they were found to express surface IA antigen, myeloid antigen (IF10, MY9) and membrane receptors for interleukin 2 (IL-2, Tac antigen). Under standard culture conditions, a small percentage of cells having more typical eosinophilic characteristics was present. These cells had cytoplasmic granules and were positive for Luxol-fast-blue and eosinophil peroxidase. Under culture conditions to induce the maturation of myeloid cells, such as alkaline medium or addition of dimethyl sulfoxide (DMSO), the frequency of cells with typical eosinophilic features increased to about 40%. In addition, cytogenetic studies showed that cultured cells and original leukemic blasts presented similar chromosome abnormalities. EoL seems to be a unique leukemic line committed to the eosinophilic lineage and can provide a useful in vitro model for the study of malignant eosinophilic properties.     

Prognostic implications of CD14 positivity in acute myeloid leukemia arising from myelodysplastic syndrome

Secondary acute myeloid leukemia (s-AML) arising from myelodysplastic syndrome (MDS) shows different clinical features from de novo AML. We assessed the prognostic significance of immunophenotypic markers in patients with s-AML arising from MDS. Sixty-five adults diagnosed with AML arising from MDS between 1996 and 2010 were retrospectively analyzed. Immunophenotyping was performed for markers including CD3, CD7, CD10, CD13, CD14, CD19, CD33, CD34, CD41, CD45, CD56, CD65, CD117, HLA-DR, and TdT. Of these immunophenotypic markers, only CD14 positivity was significantly associated with lower complete remission rate (P = 0.034) and significantly shorter overall survival (OS, P < 0.001) and event-free survival (EFS, P < 0.001) on univariate analysis. On multivariate analysis, these differences remained significant in terms of OS [hazard ratio (HR) 4.49; P < 0.001] and EFS (HR 4.06; P < 0.001). Other significant prognostic variables included age ≥60 years [shorter OS (P = 0.003) and EFS (P = 0.020)], higher WBC count (>60,000/μL) [shorter OS (P < 0.001) and EFS (P = 0.001)], and poor cytogenetic risk group [shorter OS (P = 0.005)]. CD14 expression on leukemic blasts is an independent prognostic factor for survival outcomes in patients with AML arising from MDS.     

Establishment and characterization of a granulocyte-macrophage colony-stimulating factor-dependent human myeloid cell line

A new human myeloid cell line has been established recently from the bone marrow cells of a patient with chronic myelogenous leukemia in blast crisis. The active proliferation and survival of the cells in RPMI 1640 medium containing fetal calf serum are clearly dependent on the presence of either natural or recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). Despite permanent culturing in rhGM-CSF (100 U/mL), the cells do not differentiate and bear the myelomonocytic surface markers CD34, CD13, CD36, as well as HLA-DR, but not CD3, CD7, CD10, CD11b, CD14, CD20, or CD42b. The predominant karyotype, apart from tetraploidy in several cells, is 45, XX, -9, -17, -19, -22, 7p-, 9q+ (der t[9;22]), der (13q), with three additional marker chromosomes, from which one was observed in the patient's leukemic cells. On BglII-digested DNA, Southern blot analysis with bcr 5' as the probe detected two additional hybridizing restriction fragments of 8.6 and 11.0 kilobase pairs.     

Establishment and characterization of a B-cell line derived from a patient with a myelodysplastic syndrome which expresses myelomonocytic and lymphoid markers

We describe a novel continuous B-cell line (PV-90) derived from a patient with myelodysplastic syndrome (MDS) and originating from spontaneous infection with the Epstein-Barr virus (EBV). The patient progressed to acute myeloblastic leukaemia (AML) 5 months after clinical onset of MDS. PV-90 is of clonal origin as indicated by the presence of immunoglobulin (Ig) gene rearrangements, monoclonal surface immunoglobulins, and a single DNA restriction fragment corresponding to the EBV genomic termini. PV-90 cells also express a number of myelomonocytic markers, including alpha-naphthyl acetate esterase (ANAE), coagulation factor XIII, and CD68 antigen. Moreover, PV-90 cells constitutively express the c-fms proto-oncogene mRNA as the patient's blast cells did. Whereas a trisomy 11 (+11) was found in the patient's bone marrow cells, PV-90 cells had a normal karyotype initially, but at 4 months showed two different and independent chromosomal abnormalities: 90, XX, -Y, -Y, t(9;16) (q11;p13), and 90, XX, -Y, -Y, t(17;18) (p13;q21), the latter possibly involving the p53 (17,p13) and bcl-2 (18, q21) proto-oncogenes. The early development of these chromosomal aberrations is consistent with a genetic instability of PV-90 cells. Expression of bi-lineage markers and genetic instability may suggest that PV-90 cells originated from transformation of a myelodysplastic progenitor cell capable of both myeloid and B-cell differentiation. The PV-90 cell line might be useful in a number of studies, including the possible role of c-fms in cell differentiation, pathogenetic mechanisms of human preleukaemia and lineage promiscuity in acute leukaemia.     

Establishment of a leukaemic cell line from a patient with acquisition of chromosomal abnormalities during disease progression in myelodysplastic syndrome

Summary. A cell line designated SKM-1 was newly established from leukaemic cells of a 76-year-old Japanese male patient with monoblastic leukaemia following myelodysplastic syndrome (MDS). The cells were obtained from peripheral blood of the patient when he lost multiple point mutations of ras genes with acquisition of chromosomal abnormalities during disease progression in MDS. The cells grew as a single floating cell, and have been continuously growing with the morphological characteristics of immature monoblasts by serial passages during the past 42 months with a doubling time of about 48 h. By cytochemical analysis. the cloned cells were positive for butyrate esterase, but negative for the Epstein-Barr virus associated nuclear antigen. Phenotypic analysis revealed the expression of myelomonocyte specific antigens such as CD4, CD13, CD33 and HLA-DR. Cells from the primary peripheral blood and those from SO passages of the SKM-1 cell line both possessed no activated ras genes but showed karyotype abnormalities with 46.XY, del(9)(q13;q22), der(17) t(17:?)(p13:?). The SKM-1 cells have two mutations in p53 gene and overexpress the pS3 products. This cell line may contribute to a better understanding of molecular mechanisms in the progression from MDS to myelogenous leukaemia.     

Abrupt evolution of Philadelphia chromosome‐positive acute myeloid leukemia in myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a clonal disorder arising from an alteration in multipotent stem cells, which lose the ability of normal proliferation and differentiation. Disease progression occurs in approximately 30% MDS cases. Specific chromosomal alterations seem responsible for each step in the evolution of acute myeloid leukemia (AML). Multiple genetic aberrations occur during the clonal evolution of MDS; however, few studies report the presence of the Philadelphia (Ph) chromosome. We report a rare case of Ph‐positive AML, which evolved during the course of low‐risk MDS. The patient, a 76‐year‐old man with mild leukocytopenia, was diagnosed with MDS, refractory neutropenia (RN). After 1.5 yr, his peripheral blood and bone marrow were suddenly occupied by immature basophils and myeloblasts, indicating the onset of AML. A bone marrow smear showed multilineage dysplasia, consistent with MDS evolution. Chromosomal analysis showed an additional t(9;22)(q34;q11) translocation. Because progression occurred concurrently with emergence of the Ph chromosome, we diagnosed this case as Ph‐positive AML with basophilia arising from the clonal evolution of MDS. The patient was initially treated with nilotinib. A hematological response was soon achieved with disappearance of the Ph chromosome in the bone marrow. Emergence of Ph‐positive AML in the course of low‐risk MDS has rarely been reported. We report this case as a rare clinical course of MDS.     

Establishment of a novel human megakaryoblastic leukemia cell line, MEG- 01, with positive Philadelphia chromosome

A megakaryoblastic cell line, designated MEG-01, was established from the bone marrow of a patient with blast crisis of Philadelphia (Ph1) chromosome-positive chronic myelogenous leukemia. MEG-01 cells grew in single-cell suspension with a doubling time of 36 to 48 hours. Under the usual culture conditions, approximately half of the cells adhered to the culture flask with extention of pseudopods. MEG-01 cells were positive for the periodic acid-Schiff reaction, alpha-naphthyl acetate esterase, and acid phosphatase, and negative for myeloperoxidase, alpha- naphthyl butyrate esterase, naphthol AS-D chloroacetate esterase, and alkaline phosphatase. Ultrastructural platelet peroxidase was positive in MEG-01 cells. Cytoplasmic factor VIII (FVIII)-related antigen was weakly positive in larger MEG-01 cells by both an indirect immunofluorescent technique with monoclonal antibodies and a direct immunoperoxidase technique using horseradish peroxidase-conjugated conventional rabbit anti-human FVIII antibody. Platelet glycoprotein (GP) IIb/IIIa antigen was uniformly demonstrated on the surface of MEG- 01 cells by both indirect immunofluorescent and immunoperoxidase techniques using antiplatelet GP IIb/IIIa monoclonal antibodies; platelet GP lb antigen was demonstrated only in the cytoplasm of larger MEG-01 cells. MEG-01 cells possessed no markers for B or T lymphocytes or for myeloid cells. Chromosome analysis of this cell line revealed a human male hyperdiploid karyotype with a modal chromosome number of 56 to 58. The Ph1 chromosome was observed in all karyotypes analyzed. This novel human megakaryoblastic cell line may provide a useful model for the study of human megakaryopoiesis and of the biosynthetic mechanisms of proteins unique to megakaryocytic lineage.     

Establishment and characterization of a new human leukemia cell line derived from M4E0

A new human leukemia cell line, designated as ME-1, was established from the peripheral blood leukemia cells of a patient with acute myelomonocytic leukemia with eosinophilia (M4E0). This cell line has the characteristic chromosome abnormality of M4E0, inv(16) (p13q22). When cultured in RPMI 1640 medium containing 10% fetal calf serum, ME-1 cells were monoblastoid, but with the addition of cytokines such as interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-4, or medium conditioned by phytohemagglutinin-stimulated human peripheral leukocytes (PHA-LCM), the cells exhibited differentiation to macrophage-like cells. PHA-LCM also promoted eosinophilic-lineage differentiation of this cell line, although IL-5 did not do so. To elucidate the mechanism of proliferation and differentiation of ME-1 cells, we studied the effect of a potent inhibitor of protein kinase C, 1-(5-isoquinolinyl-sulfonyl)-2- methylpiperazine (H-7), on colony formation of ME-1 cells. H-7 inhibited colony formation of ME-1 cells by IL-3 or GM-CSF dose dependently, but had little inhibitory effect on colony formation by IL- 4. These results indicate that the proliferation and differentiation of ME-1 cells by IL-3 or GM-CSF were related to the activation of protein kinase C, while those by IL-4 involved other regulatory systems. ME-1 cells should be useful for studying the pathogenesis of M4E0 and the mechanisms of proliferation and differentiation of leukemic and normal progenitors by cytokines.     

Philadelphia chromosome-negative chronic myelogenous leukemia without breakpoint cluster region rearrangement: a chronic myeloid leukemia with a distinct clinical course

The hallmarks of chronic myelogenous leukemia (CML) include the Philadelphia chromosome (Ph) translocation [t (9;22)(q34;q11)] and consistent molecular genetic aberrations: a break within a restricted 5.8 kb DNA segment, bcr, on chromosome 22q11; transposition of the c-abl protooncogene from chromosome 9q34 to 22q11; and formation of a hybrid bar-abl gene encoding an abnormal 210 Kd bcr-abl protein with augmented tyrosine kinase enzymatic activity. These molecular phenomena may occur even in the absence of cytogenetic evidence of the Ph translocation. They are highly specific and sensitive markers for CML, and are presumed to play a significant role in the pathogenesis of this malignancy. Surprisingly, we have encountered 11 patients who lacked the Ph translocation, bcr rearrangement, and (in the four patients with available mRNA) a bcr-abl message, and yet had a disease phenotype at diagnosis that was a morphologic facsimile of classic chronic phase CML. These patients presented with high white blood cell counts, neutrophilia, occasional basophilia, splenomegaly, and a hypercellular bone marrow with granulocytic hyperplasia and a left shift in myeloid maturation. Despite the striking resemblance between the early stages of bcr-negative and bcr-positive CML, disease progression manifests distinctly in these two disorders. In contrast to the blastic transformation that inevitably complicates bcr-positive CML, the natural history of our 11 Ph-negative, bcr-negative CML patients was characterized by increasing leukemia burden with leukocytosis, pronounced organomegaly, extramedullary infiltrates, and eventual bone marrow failure (anemia and thrombocytopenia) without marked increases in blast cells. Our current observations suggest that a chronic myeloid leukemia process can develop without associated changes in the bcr or c-abl genes. Although the initial phase of this disease is indistinguishable from CML, the presence or absence of molecular markers may aid in the prediction of the clinical course of Ph-negative CML.     

Establishment and characterization of a novel CD34-positive human myeloid leukemia cell line: MHH225 growing in serum-free culture

A new human multilineage myeloid leukemia cell line, MHH225, has been established in our laboratory from the bone marrow of a 60-year-old patient suffering from acute megakaryoblastic leukemia (M7); it provides a unique model for studying the effect of biologic and chemical agents on the lineage specificity of a multipotent myeloid leukemia clone containing a mixed population of megakaryoblast, erythroblast, and myeloblast cells in a serum-free culture. Morphologically, all 225 cells are large blast cells with basophilic cytoplasm containing no granules, large round nucleus containing 2–3 prominent nucleoli, and fine chromatin structure and a large nuclear/cytoplasm ratio. The MHH225 cells are CD34⁺HLA-DR⁺CD33⁺CD13⁺ with 57.6%, 28.3%, and 7.8% of them being CD41⁺, glycophorin A⁺, and CD15⁺, respectively, and all lymphoid-specific antigens are negative. The karyotype analysis of MHH225 cells revealed a deletion of the short arm of chromosome 7: del(7)(p13)-, a whole-arm translocation between the long arms of chromosomes 9 and 21: t(9;21)(q10;q10), and a chromosome 11 with an elongated long arm due to duplication of chromosome 11 material as well as to translocation of part of chromosome 9 onto 11q+. Also, chromosome 21 was deleted in some metaphases or showed a ring formation in other metaphases. Utrastructurally, MHH25 cells display a strong platelet peroxidase activity in the nuclear envelope and the endoplasmic reticulum. The MHH25 cells have been grown exponentially without growth factors or conditioned media or serum only in RPMI1640 culture medium. None of the myelopoietic growth factors, i.e., interleukin-3, GM-CSF, G-CSF, erythropoietin, or interleukin-6, has any effect on the proliferation and differentiation of MHH25 cells. The two, hematopoietic inhibitory cytokines, interferon-alpha and tumor necrosis factor-alpha, have only minimal growth inhibitory effect. Stem cell factor showed only weak growth-stimulatory effect on MHH225 cells but significantly inhibited chemotherapy-induced apoptosis in these cells. The new cell line MHH225 should constitute a useful model for studying stem cell antigen (CD34)-positive human multilineage myeloid leukemia cells carrying a deletion in the short arm of chromosome 7 and an aberration in chromosome 11 and provide a unique tool for investigating human hematopoietic stem cell biology and its cytokine regulation in serum-free cultures. To our knowledge, the MHH225 cell line is the first human CD34-positive leukemia cell line growing in serum-free cultures to be established.     

Angiogenesis in acute myeloid leukemia and myelodysplastic syndrome

Increased angiogenesis is important in the pathophysiology of solid tumors. Recent studies show that angiogenesis and angiogenic factors play an important role in hematological malignancies. Both acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are associated with a substantial increase in vascularity in the bone marrow as well as increased levels of various angiogenic factors including vascular endothelial growth factor (VEGF), basic fibroblast growth factor, angiogenin, angiopoietin-1, platelet-derived growth factor, hepatocyte growth factor, epidermal growth factor, tumor necrosis factor-alpha, and transforming growth factor-alpha and transforming growth factor-beta. Most of these angiogenic factors appear to be secreted by the neoplastic hematopoietic cells and appear to promote the growth and proliferation of the leukemic cells in an autocrine fashion. More importantly, angiogenic factors play a role in the clinical behavior and outcome of both AML and MDS. Despite significant overlap between MDS and AML in many aspects, higher levels of cellular VEGF and lower levels KDR are seen in MDS than in AML. Antiangiogenic therapy may play a role in AML and MDS and some differences in response may exist between MDS and AML.     

Acute eosinophilic leukemia in a patient with preexistent myelodysplastic syndrome

A case of acute eosinophilic leukemia (EoL) that occurred in a patient with preexistent myelodysplastic syndrome is reported. The patient was initially diagnosed as having refractory anemia (RA) on the basis of pancytopenia with dysplasia and chromosomal abnormalities. Two years later, he was readmitted because of progression of pancytopenia, and bone marrow and peripheral blood showed immature dysplastic eosinophils. Clonal assay of peripheral blood mononuclear cells revealed autonomous growth of colony-forming unit eosinophils. Cytotoxic chemotherapy did not induce remission, and extensive myelofibrosis developed. Cytogenetic analysis in the RA state showed +1p- and -7 whereas complicated abnormalities including +1p-, 3q- and 7p- dominated in the EoL state.     

Hematopoietic cell transplantation in patients with myelodysplastic syndrome or acute myeloid leukemia arising from myelodysplastic syndrome: similar outcomes in patients with de novo disease and disease following prior therapy or antecedent hematologic disorders

We analyzed outcomes after hematopoietic cell transplantation (HCT) in 257 patients, 3 to 72.7 years old (median, 43 y), with secondary myelodysplastic syndrome (MDS) including those with transformation to acute myeloid leukemia (tAML). Conditioning regimens included high-dose total-body irradiation (TBI)/chemotherapy (n = 83); busulfan (BU)/cyclophosphamide (CY) (BUCY, n = 122; with BU targeting [tBUCY], n = 93); fludarabine (Flu) with tBU (FLUtBU; n = 12); Flu plus 200 cGy TBI (n = 26); and miscellaneous regimens (n = 14). Donors were HLA-identical or partially mismatched family members in 135 and unrelated individuals in 122 patients. Five-year relapse-free survival was highest (43%) and nonrelapse mortality lowest (28%) among tBUCY-conditioned patients. Outcomes were compared with results in 339 patients who received transplants for de novo MDS/tAML, and a multivariate analysis failed to show significant differences in outcome between the 2 cohorts. Relapse probability and relapse-free survival correlated significantly with disease stage (P < .001) and karyotype (P < .001). Relapse incidence was lower (P = .003) and relapse-free survival superior (P = .02) with unrelated donor transplants. The data suggest that overall inferior outcome in patients with secondary MDS/tAML was related to the frequency of high-risk cytogenetics. For both cohorts, transplantation outcomes improved over the time interval studied.     

Autologous stem cell transplantation for therapy-related acute myeloid leukemia and myelodysplastic syndrome

We report the results of 65 patients with treatment-related myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML) who were transplanted from an autograft and reported to the EBMT. The median age was 39 years (range, 3-69), and stem cell source was bone marrow (n = 31), or peripheral blood progenitor cells (n = 30), or the combination of both (n = 4). The primary disease was solid tumors (n = 37), Hodgkin's disease (n = 13), non-Hodgkin's lymphoma (n = 10), acute lymphoblastic leukemia (n = 2) or myeloproliferative syndromes (n = 3). The types of MDS were as follows: RAEB (n = 1; 2%), RAEB-t (n = 3; 5%), or AML (n = 56; 87%). The median time between diagnosis and transplantation was 5 months (range, 3-86). The Kaplan-Meier estimates of the probability of 3-year overall and disease-free survival were 35% (95% CI: 21-49%) and 32% (95% CI: 18-45%), respectively. The median leukocyte engraftment was faster after transplantation with peripheral blood stem cells than with bone marrow: 12 (range, 9-26) vs 29 (range, 11-67) days (P<0.001). The cumulative incidence of relapse was 58% (95% CI: 44-72%) and of treatment-related mortality 12% (95% CI: 6-38%). Lower relapse rate was seen in patients transplanted in first complete remission (CR1 vs non-CR1: 3 years: 48 vs 89%; P = 0.05). Furthermore, age beyond 40 years resulted in a higher treatment-related mortality (47 vs 7%; P = 0.01). In a multivariate analysis, transplantation in CR1 age as well as their interaction influenced overall survival significantly. Autologous transplantation may cure a substantial number of patients with treatment-related MDS/AML, especially if they are in CR1 and of younger age.