Analysis of isoenzyme patterns of acid phosphatase in acute leukemias

Induction of differentiation in the human leukemia cell line SPI-802: morphological, immunological, and isoenzymatic changes

The phorbolester 12-0-tetradecanoylphorbol 13-acetate (TPA) was used for the induction of differentiation in cells of the human leukemia cell line SPI-802. The cellular morphology, surface marker antigen expression, and isoenzyme profiles of four enzymes (carboxylic esterase, acid phosphatase, hexosaminidase, and lactate dehydrogenase) served as parameters for monitoring the induced phenotypical changes. TPA led to distinct alterations of the morphology and significantly affected the growth rate with cessation of cell proliferation. No major increase in the number of nitro blue tetrazolium-positive cells or aggregation of cells, phagocytosis of latex beads, adherence to plastic surface, or development of pseudopodia were observed. As TPA-treated SPI-802 cells remained negative for these markers of the monocyte-macrophage complex, it can be concluded that the cells did not differentiate into monocytes and macrophages. The immunological marker profile based on testing of 55 monoclonal antibodies, terminal deoxynucleotidyl transferase and two erythrocyte rosette tests indicated a differentiation of SPI-802 cells along the granulocytic cell lineage. This was confirmed by isoenzyme analysis, especially that of carboxylic esterase. An isoenzyme specific for monocytes and macrophages was not detected. In earlier studies it was found that SPI-802 cells produce hemoglobin upon exposure to TPA or hemin. This latter observation and the present results suggested a comparison with the two erythroleukemia cell lines K-562 and HEL. SPI-802 cells appear to have the potential to differentiate along several cell lineages.

Erythroleukemia cell lines HEL and K-562: changes in isoenzyme profiles and morphology during induction of differentiation

The effects of the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) and of hemin on the human erythroleukemia cell lines HEL and K-562 were studied using the parameters cellular morphology, cell proliferation, positivity in the nitro-blue tetrazolium (NBT)-reduction test, adherence to surface, development of pseudopodia, and isoenzyme profiles of carboxylic esterase, acid phosphatase, hexosaminidase and lactate dehydrogenase (LDH) separated by isoelectric focusing on horizontal polyacrylamide gels. TPA and hemin induced similar morphological changes in HEL and K-562, erythrocyte-like cells were seen to be the predominant population after exposure to hemin. Both TPA and hemin led to cessation of cell proliferation and to a dose-dependent decrease in the number of viable nucleated cells. Whereas HEL cells treated with TPA became positive in the NBT-reduction test, adhered to plastic surface and showed pseudopodia, HEL cells exposed to hemin and K-562 cells cultured with TPA or hemin did not show these markers indicative of the macrophage-cell lineage. TPA-treated HEL cells exhibited isoenzyme patterns which were characteristically seen in cells of the monocyte-macrophage complex. 'Myeloid isoenzyme profiles' were found in TPA-treated K-562 cells. As evidenced by the above described phenotypical changes, HEL cells appeared to differentiate along the macrophage and erythroid cell lineages. Induced K-562 cells displayed myeloid and erythrocytic markers.

Hodgkin's disease derived cell lines HDLM-2 and L-428: comparison of morphology, immunological and isoenzyme profiles

The cell lines HDLM-2 and L-428 were established from the pleural effusions of two patients with Hodgkin's disease. We studied and compared phenotypic characteristics of HDLM-2 and L-428 cells before and during induction of differentiation with 12-O-tetradecanoylphorbol 13-acetate (TPA) using a number of parameters. TPA-treated HDLM-2 and L-428 cultures did not show adhesion to plastic surface or aggregation of cells; the cells did not develop pseudopodia and were not phagocytic. Only a slight increase in the percentage of NBT-positive cells was observed for L-428 cells. TPA led to a cessation of cell proliferation and to a dose-dependent decrease in the number of viable cells in both cell lines. In HDLM-2 and L-428, treatment with TPA induced distinct morphological changes indicative of a partial differentiation along the myeloid cell lineage. In addition, the production and expellation of benzidine-positive, unnucleated particles were observed in HDLM-2 and L-428 cells. The induced isoenzyme profiles of carboxylic esterase and acid phosphatase resembled those found in myelomonocytic leukemia cell lines. Both cell lines were negative for immunological markers of the T- and B-cell lineages, but reacted with several markers associated with the myelomonocytic cell lineages. HDLM-2 cells produced a factor which could induce differentiation in 12 leukemia cell lines. The overall results suggest that Hodgkin and Sternberg-Reed cells constitute a unique cell type and might be derived from cells of the myelomonocytic cell lineage.

Biochemical enzyme analysis in acute leukaemia

This report summarises the current knowledge regarding the clinical utility of biochemical enzyme markers for both diagnostic and therapeutic purposes in acute leukaemia. The enzymes studied most extensively in this field are terminal deoxynucleotidyl transferase, adenosine deaminase, 5'-nucleotidase, purine nucleoside phosphorylase, and acid phosphatase, esterase, hexosaminidase isoenzymes. For each enzyme, the quantitative and qualitative characteristics in various immunologically defined subclasses of acute leukaemia are described. The quantitative evaluation of enzyme activities represents an adjunctive classification technique which should be incorporated into the multivariate analysis, the "multiple marker analysis." By qualitative characterisation pronounced heterogeneity of leukaemia subsets is uncovered. The application of 2'-deoxycoformycin, a specific inhibitor of adenosine deaminase, and the potential usefulness of two other enzymes as targets for treatment with selective agents is discussed. The concept that gene products expressed at certain developmental stages of normal cells can similarly be detected in leukaemic cells (which therefore seem to be "frozen" or "arrested" at this particular maturation/differentiation stage) is supported by the results obtained in enzyme studies. Besides their practical clinical importance for classification and treatment of acute leukaemias, biochemical enzyme markers constitute a valuable research tool to disclose biological properties of leukaemic cells.

Isoenzyme studies in human leukemia-lymphoma cells lines--II. Acid phosphatase

This report describes the qualitative acid phosphatase (acP) isoenzyme profiles detected in permanent human hematopoietic cell lines. The acP activity was separated into its isoenzymes by isoelectric focusing on horizontal thin-layer polyacrylamide gels. The pattern of acP isoenzyme was investigated in a total of 86 cell lines. These cell lines were classified into five groups on the basis of their phenotypes characterized in the multiple marker analysis: 74 leukemia-lymphoma cell lines (26 T-, 34 B-, 6 myelomonocytic, 8 Non-T, Non-B cell lines) and 12 so-called 'normal' Epstein-Barr virus transformed B-lymphoblastoid cell lines. Their immunological features had been analysed in detail by use of a large panel of poly- and monoclonal antibodies which led to a further subclassification into stages of differentiation. A progressive increase in number and staining intensity of the isoenzymes which paralleled the expression of surface markers at different stages of differentiation along their developmental pathway was seen in the T- and B-leukemia-lymphoma cell lines. Some cell lines whose isoenzyme profiles did not correspond to the stage of differentiation as evidenced by surface antigen analysis might represent good examples of deranged gene expression in otherwise normally programmed malignant cells, i.e. in our study a mismatch between the isoenzymatic and immunological phenotypes. The tartrate-resistant isoenzyme was detected in 9 out of 74 leukemia-lymphoma cell lines (4 T-, 2 B-, 1 myelomonocytic, 2 Non-T, Non-B cell lines) and in 10 out of 12 normal B-lymphoblastoid cell lines; the only one studied hairy cell leukemia cell line did not express this isoenzyme. The relative specificity of the tartrate-resistant acP is discussed in detail. No leukemia-lymphoma specific isoenzyme or an additional isoenzyme which was not seen in normal hematopoietic cells could be observed. Nor did we find an isoenzyme or isoenzyme pattern characteristic for a certain cell lineage. This underlines the necessity of a combined analysis using markers from different disciplines in the 'multiple marker analysis' in order to accurately characterize normal and malignant blood cells. Furthermore, our results support the concept of maturation arrest at particular stages of differentiation together with the theory of normal gene expression in leukemic cells equivalent to that in their normal counterparts.

Leukemic cell differentiation in childhood leukemias. Analysis by enzyme markers

Enzyme marker analysis has become a valuable tool in leukemia research, especially as a part of the so-called multiple marker analysis which combines several disciplines for characterization of leukemia cells. In this study the qualitative activities of three enzyme markers were determined in leukemic cells from pediatric patients with acute leukemias: acid phosphatase (E.C. 3.1.3.2), carboxylic esterase (E.C. 3.1.1.1) and hexosaminidase (E.C. 3.2.1.30). The leukemia subtypes displayed different types of isoenzyme patterns. No additional isoenzyme was found that was not observed in normal blood cells, nor a single isoenzyme specific for a leukemia subtype. The biochemical profiles illustrated the existence of subsets in cALL, T-ALL and AML. The enzymologic polymorphism and the immunologic heterogeneity seen in leukemia subclasses have led together to an extended classification scheme of leukemias as well as to model schemes of normal hematopoietic cell differentiation. Despite former and constantly published assumptions there are still no specific markers of leukemia cells.