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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the origin of leukemic progenitors in a case of the simultaneous occurrence of myelomonocytic leukemia and multiple myeloma (IgG-kappa). At presentation, myeloperoxidase and nonspecific esterase-positive myelomonocytic cells had proliferated up to 12.2 x 10(9)/liter in the peripheral blood. Bone marrow cell differentials revealed the coexistence of myelomonocytic cells (30%) and atypical plasmacytoid cells (26%). Myelomonocytic cells in peripheral blood expressed both myeloid antigens (CD11b, CD13, CD14, CD15, CD33) and T/B-lymphoid antigens (CD2, CD4, CD5, CD7, CD10, PCA-1). Bone marrow mononuclear cells (BMMC) could be divided into PCA-1 strongly positive and PCA-1 weakly positive populations, which were considered to represent myeloma cells and myelomonocytic cells, respectively; the former were CD2-positive (CD2+), CD14-, and CD15-, whereas the latter were CD2+, CD14+, and CD15+. Immunohistochemical analysis revealed that, in addition to plasmacytoid cells, a minority of myelomonocytic cells showed a positive reaction for IgG staining, and production of IgG was observed in the culture supernatant of CD14+ myelomonocytic cells in peripheral blood. Southern blot analysis revealed the presence of two identical rearrangement bands of immunoglobulin heavy chain gene in both BMMC containing myeloma cells and myelomonocytic cells and CD14+ myelomonocytic cells in peripheral blood. In a long-term methylcellulose assay, peripheral blood mononuclear cells produced large compact colonies consisting of macrophages and IgG+ plasmacytoid cells (M phi/P colonies), while BMMC produced a different type of colonies consisting of CD14+ myelomonoblasts, macrophages, and IgG+ plasma cells (Mb/M phi/P colonies) in addition to M phi/P colonies. Recloning experiments showed that primary Mb/M phi/P colonies gave rise to both secondary M phi/P and Mb/M phi/P colonies. These observations strongly suggest that common leukemic progenitors provide both myeloma and myelomonocytic leukemia cells, and the mechanism of "lineage infidelity" is probably involved in the development of their "bilineal" differentiation.
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PMID:Simultaneous occurrence of myelomonocytic leukemia and multiple myeloma: involvement of common leukemic progenitors and their developmental abnormality of "lineage infidelity". 165 17

Blast cells from 26 cases of acute myeloid leukaemia (AML) were examined, by single and "two-colour" flow cytometry, for relationships between membrane CD11b (monoclonal antibody OKM1), CD11c (KB90) and CD14 (Leu-M3). Increased expression of all three determinants was associated with myelomonocytic leukaemias, with their relative diagnostic value in discriminating monocytic (M4 and M5) from non-monocytic (M1, M2 and M3) subtypes being CD14 greater than CD11c greater than CD11b. However, the results also indicated, because of the heterogenous expression of CD11c in particular, and to a lesser extent CD11b, that the patterns or histograms of fluorescent staining were potentially more informative than an empirical subdivision of blasts into positive and negative subpopulations. In addition, analysis of phenotypic correlations by simultaneous two-colour fluorescence showed that the expression of CD11b and CD11c determinants by leukaemic myeloid blasts was highly correlated, in contrast to the expression of CD14 and CD11c which were relatively independent. Consequently, CD11c+ myeloid blasts almost always coexpressed CD11b whereas CD14+ cases of AML often comprised CD14+ CD11c+ and CD14+ CD11c- subpopulations. It is concluded from these observations that CD11c immunophenotyping is a useful supplementary investigation, particularly in CD14- cases of myelomonocytic leukaemia. However, it is also apparent that the presence of membrane CD11c per se is not lineage-specific and that the level of expression is perhaps a more discriminatory factor.
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PMID:Flow cytometric analysis of membrane CD11b, CD11c and CD14 expression in acute myeloid leukaemia: relationships with monocytic subtypes and the concept of relative antigen expression. 168 68

An increasing number of acute leukemias coexpressed markers normally believed to be restricted to a single lineage have been found recently. This special subgroup of leukemias have drawn a lot of attention because of their biologic and clinical significance. In a study of 100 consecutive de novo ANLL patients diagnosed by FAB criteria, T-cell antigen CD7 was identified on the leukemic blasts of 13 patients, ten of whom had M1 subtype of leukemia, myeloblastic leukemia without maturation. All the patients showed positive staining with myeloperoxidase and expressed myeloid markers CD13 and/or CD33, but lacked CD11b, a marker of more mature myeloid cells. Combined staining with myeloperoxidase and CD7 of the cells from four patients revealed coexpression of both markers on the same cells. None of the patients expressed the two other T-cell antigens CD2 or CD5. All ten patients who had DNA analysis showed germline configuration of TCR beta and gamma chain genes. One patient had chromosomal translocation involving 11q23, t(11; 19) (q23; p13), which is the site frequently associated with both myeloid and lymphoid malignancies. The clinical implications of this subgroup of patients need further study on more patients, and need longer follow-up.
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PMID:A subset of acute nonlymphocytic leukemia with expression of surface antigen CD7--morphologic, cytochemical, immunocytochemical and T cell receptor gene analysis on 13 patients. 169 99

The expression of adhesion molecules on blasts from 14 patients with acute myeloid leukemia (AML) was investigated by immunofluorescence and flow cytofluorometry. All tested blast populations expressed CD18/CD11a complex [leukocyte function antigen-1 (LFA-1)] and CD29 (very-late antigen (VLA)) and the majority were positive for CD54 [intercellular adhesion molecule-1 (ICAM-1), 78.6%] and CD56 [neural cell adhesion molecule (NCAM), 64.3%]. The expression of two other alpha chains of CD18/CD11b and CD11c varied considerably (64.3% and 42.8% of positive cases, respectively). Only one case (AML-M4) showed a weak expression of the activated platelet antigen CD41b. None of the tested blasts expressed the vitronectin receptor (CD61/CD51). No significant correlation between the expression of adhesion molecules and the FAB type of leukemia could be found. All tested blast populations were completely resistant to NK-mediated cytotoxicity and relatively resistant to LAK-mediated cytotoxicity in the standard 51Cr release assay. While no statistically significant correlation of the results in cytotoxicity assays with the expression of adhesion molecules or the expression of HLA-DR antigen could be observed, 2 out of 3 completely resistant cases lacked ICAM-1. These results show that even leukemic blasts which express all of the tested adhesion molecules can still be resistant to LAK-mediated cytotoxicity.
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PMID:Resistance of leukemic blasts to lymphokine activated killer (LAK)-mediated cytotoxicity is not related to their adhesion properties. 171 15

We have studied the effect of the DNA topoisomerase I inhibitor camptothecin on growth, differentiation, and gene expression in U-937 human promonocytic leukemia cells. At a concentration of 20 nM, camptothecin caused significant DNA strand breakage and decreased the growth activity by accumulating cells preferentially at the G2 phase of the cycle. The growth arrest occurred concomitantly with an increase in cell size. Under those conditions, camptothecin induced differentiation, as demonstrated by (a) the capacity of the cells to generate reactive oxygen species, (b) the increase in the surface expression of the leukocyte integrins CD11b/CD18 and CD11c/CD18, (c) the increase in the cellular content of the intermediate filament protein vimentin, and (d) the decrease in the surface expression of the transferrin receptor. Camptothecin also induced the expression of differentiation markers in other human myeloid cells, namely, the promonocytic THP-1 and the myelomonocytic HL-60 cell lines. Northern blot assays revealed that camptothecin stimulated the expression of CD11b, CD11c, and vimentin at the mRNA level. Moreover, the drug increased the transcription rate of the vimentin gene, as shown by "run-on" transcription assays.
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PMID:Camptothecin induces differentiation and stimulates the expression of differentiation-related genes in U-937 human promonocytic leukemia cells. 173 86

The administration of the DNA topoisomerase II inhibitors 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) (10(-7) M), VP-16 (2 x 10(-7) M), or novobiocin (1.5 x 10(-4) M) reduces the growth activity of human promonocytic leukemia U-937 cells, by arresting them preferentially at the G2 (m-AMSA and VP-16) or at the G1 and G2 (novobiocin) phases of the cell cycle. Under these conditions, m-AMSA and VP-16 induce the differentiation of the cells efficiently, as proved both by an increase in the production of reactive oxygen species and by the activation of the surface expression of CD11b and CD11c, two differentiation-specific antigens. Novobiocin also induces the expression of those differentiation markers, but to a lesser extent. Analyses by Northern blot indicate that the topoisomerase II inhibitors reduce the levels of c-myc and beta-actin mRNA and increase the levels of vimentin mRNA. The expression of vimentin is also stimulated at the protein level, as indicated by immunofluorescence assays. This represents one of the few known instances in which topoisomerase inhibitors stimulate gene expression in eukaryotic cells.
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PMID:Differentiation of human promonocytic leukemia U-937 cells with DNA topoisomerase II inhibitors: induction of vimentin gene expression. 185 89

An increasing number of papers document cases of acute leukemia in which individual blast cells co-express markers normally restricted to a single cell lineage. Numerous terms are used to refer to cases with unscheduled expression of lineage-foreign proteins; the best defined categories were hybrid acute leukemia and acute mixed-lineage leukemia. The incidence of phenotypically variant acute leukemia varies with the quality and quantity of parameters used and the stringency of the criteria employed for its definition. Considerable interest has focused on acute lymphoblastic leukemia (ALL) cells expressing one or several myeloid lineage-associated antigens (My+ ALL), CD13, CD14, CD15, CD33, and CDw65. Owing to legitimate and cryptic expression on lymphoid cells, CD11b and CD15 reagents may not be considered as specific indicators of myeloid differentiation. The reported incidence ranged from 5 to 46% in 14 studies on My+ ALL, totalling 3817 patients. Several detailed reports documented a higher incidence of My+ ALL in adults (realistically in the range 10-20%) than in children (5-10%) and in B-lineage ALL as opposed to T-lineage ALL. My+ ALL cases are more likely to display unique cytogenetic [t(9;22), 11q23, 14q32] features than My-neg ALL. There appears to be no predominant expression of a single myeloid-associated antigen among those analyzed. As the morphological diagnosis of a leukemia subtype is often imprecise, some T-neg B-neg My+ ALL cases might actually contain FAB AML-M0 populations. While the expression of myeloid-associated antigens has no apparent prognostic significance in the majority of childhood ALL subtypes, in adults myeloid antigens seem to identify a high risk group of ALL patients with a poorer response to standard ALL therapy.
Leukemia 1991 Aug
PMID:Review of the incidence and clinical relevance of myeloid antigen-positive acute lymphoblastic leukemia. 188 19

Co-expression of myeloid antigens on the leukaemic blast cells was evaluated in 532 children with a diagnosis of acute lymphoblastic leukaemia (ALL). Using a panel of monoclonal antibodies belonging to CD11b, CD13, CD14, CD15 and CD33 an overall incidence of 4.3% was found, with values ranging between 1.8% for CD14 and 6.1% for CD15. When the data were further dissected, a significantly higher incidence of co-expression was noted in null-ALL (15/70 cases = 21.4%), compared to cases expressing a more mature immunophenotype, i.e. common-ALL (7/394 cases = 1.7%) and T-ALL (1/68 cases = 1.4%) (P less than 0.001). In null-ALL, 9/15 patients were infants, five of whom with the t(4;11); two further children also had a t(4;11). The clinical outcome of the 23 cases which co-expressed myeloid antigens was unfavourable. Only two of the 15 null-ALL, two of the seven common-ALL and the unique case with T-ALL are in fact in persistent first remission between 19 and 93 months from diagnosis. Though the overall incidence of childhood ALL expressing myeloid antigens is low, the evidence that this co-expression may be related to an unfavourable clinical course and that it more frequently occurs in null-ALL, particularly in the first year of life, suggests that the routine assessment of myeloid antigens may allow to identify a subgroup of childhood ALL with a poor clinical outcome.
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PMID:Co-expression of myeloid antigens in childhood acute lymphoblastic leukaemia: relationship with the stage of differentiation and clinical significance. 158 Dec 45

A five-year-old boy initially diagnosed common ALL was developed to acute myelomonocytic leukemia. At onset, the bone marrow was hypercellular and 77% of the cells were blasts, mainly lymphoblast-like cells and cytogenetic study demonstrated 45, XY, -7 in all blasts. Cytochemically most of those blasts were negative for peroxidase, sudan black B, alpha-NB esterase staining. The immunological phenotype was J5 (CD10)+, I2 (HLA-DR)+, SmIg-, CyIgmu-, Leu1 (CD5)-, OKT11 (CD2)-, MY7 (CD13)-, suggesting common ALL. Eight months later, the bone marrow cells were occupied with large sized blasts which were almost positive for peroxidase stain and the cells showed coexpression of Mo1 (CD11b)+, MY4 (CD14)+, MY7+, MY9 (CD33)+, MCS2 (CD13)+, I2+, J5-, B4 (CD19)-, Mo2 (CDw14)-, at relapse. He died 2 years and 6 months after his initial diagnosis. An autopsy was performed which revealed generalized infiltration of leukemic cells and aspergillosis of the lung. In general, monosomy 7 is associated with myelodysplastic syndrome in childhood, and is terminated to acute myeloblastic leukemia. In this case, bone marrow blasts demonstrated monosomy 7 cytogenetically, and this case was considered as an acute mixed lineage leukemia of bilineal type. And this case proved that a monosomy 7 can also be terminated to acute mixed lineage leukemia with both lymphoid and myeloid phenotypes.
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PMID:[An autopsy case of acute mixed lineage leukemia with monosomy 7 in a child]. 194 26

In this work we have mapped by double-label immunofluorescence the cellular distribution of integrins and their relationship with cytoskeletal proteins in normal and malignant monocytes. In normal monocytes, CD18 and CD11c are concentrated at specific adhesion sites, named podosomes, together with actin, vinculin, and talin, while CD11a, CD11b, CD29/beta 1, CDw49d/alpha 4 and CD54/ICAM-1 retain a diffuse distribution on the cell surface without a selective pattern of localization. U-937 and fresh leukemic monoblasts under standard culture conditions do not adhere and do not form podosomes, but, when treated with TPA, they promptly adhere to substrate, form podosomes and focal adhesions in different cells and display the same integrin/cytoskeleton relationship as normal mature monocytes. Further, in these cells CD18, CD11a, CD11c, ICAM-1, and talin, but not vinculin, co-localize in homotypic cell junctions, thus showing a close relationship between integrins and talin. These observations provide morphological evidence that, in cells of the monocytic lineage, podosome formation is acquired upon differentiation and different integrins are selectively localized at different adhesion sites.
Leukemia 1990 Oct
PMID:Integrin distribution and cytoskeleton organization in normal and malignant monocytes. 197 70


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